Artificial intelligence(AI)has seen tremendous growth over the past decade and stands to disrupts the medical industry.In medicine,this has been applied in medical imaging and other digitised medical disciplines,but i...Artificial intelligence(AI)has seen tremendous growth over the past decade and stands to disrupts the medical industry.In medicine,this has been applied in medical imaging and other digitised medical disciplines,but in more traditional fields like medical physics,the adoption of AI is still at an early stage.Though AI is anticipated to be better than human in certain tasks,with the rapid growth of AI,there is increasing concerns for its usage.The focus of this paper is on the current landscape and potential future applications of artificial intelligence in medical physics and radiotherapy.Topics on AI for image acquisition,image segmentation,treatment delivery,quality assurance and outcome prediction will be explored as well as the interaction between human and AI.This will give insights into how we should approach and use the technology for enhancing the quality of clinical practice.展开更多
High resolution (4 mm) tof PET-CT (positron emission tomography-computed tomography) from Philips of model Ingenuity TF is newly installed at Institute of Nuclear Medical Physics (INMP). 128 slice CT component incorpo...High resolution (4 mm) tof PET-CT (positron emission tomography-computed tomography) from Philips of model Ingenuity TF is newly installed at Institute of Nuclear Medical Physics (INMP). 128 slice CT component incorporated with PET provides comparatively lower dose than the 511 keV annihilation photons associated with positron decay from PET scan. So, for designing shielding in our PET-CT facility, only 511 keV annihilation photons energy has been considered. The main objective of this paper is to show what measures have been taken to protect patients, occupational workers as well as environment from PET-CT radiation hazard through a cost effective design that satisfy the national regulatory demand. In this paper, AAPM (American Associations of Physicists in Medicine) Task group 108 analysis for PET and PET-CT shielding requirements is followed for our PET-CT facility shielding design. From theoretical calculation as shielding requirement, 1.1 cm Pb thickness or, 13 cm concrete thicknesses are found. Practically, all walls and ceiling are of 30.48 cm (1 foot) thick made of concrete with density 2.35 gcm-3 for more safety. As x-ray from CT is not taken into account for shielding analysis, Bangladesh Atomic Energy Commission (BAEC) conducted an extensive radiation survey at controlled, supervised and public area for CT. The report that is found meets the national regulatory requirements.展开更多
The original online version of this article (Liu, Y.X., Saleh, Z., Song, Y.L., Chan, M., Li, X., Shi, C.Y., Qian, X. and Tang, X.L (2017) Novel Wavelet-Based Segmentation of Prostate CBCT Images with Implanted Calypso...The original online version of this article (Liu, Y.X., Saleh, Z., Song, Y.L., Chan, M., Li, X., Shi, C.Y., Qian, X. and Tang, X.L (2017) Novel Wavelet-Based Segmentation of Prostate CBCT Images with Implanted Calypso Transponders. International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, 6, 336-343. doi: 10.4236/ijmpcero.2017.63030) was published without acknowledging our support. The authors wish to add the acknowledgments.展开更多
The knowledge of interactions among functional proteins helps researchers understand disease mechanisms and design potential strategies for treatment.As a general approach,the fluorescent and affinity tags were employ...The knowledge of interactions among functional proteins helps researchers understand disease mechanisms and design potential strategies for treatment.As a general approach,the fluorescent and affinity tags were employed for exploring this field by labeling the Protein of Interest(POI).However,the autofluorescence and weak binding strength significantly reduce the accuracy and specificity of these tags.Conversely,HaloTag,a novel self-labeling enzyme(SLE)tag,could quickly form a covalent bond with its ligand,enabling fast and specific labeling of POI.These desirable features greatly increase the accuracy and specificity,making the HaloTag a valuable system for various applications ranging from imaging to immobilization of POI.Notably,the HaloTag technique has already been successfully employed in a series of studies with excellent efficiency.In this review,we summarize the development of HaloTag and recent advanced investigations associated with HaloTag,including in vitro imaging(e.g.,POI imaging,cellular condition monitoring,microorganism imaging,system development),in vivo imaging,biomolecule immobilization(e.g.,POI collection,protein/nuclear acid interaction and protein structure analysis),targeted degradation(e.g.,L-AdPROM),and more.We also present a systematic discussion regarding the future direction and challenges of the HaloTag technique.展开更多
Medical diagnostic X-rays are the largest manmade source of ionizing radiation received by the members of the general public. The aim of this study was to evaluate the radiographic reject/repeat rate and also to deter...Medical diagnostic X-rays are the largest manmade source of ionizing radiation received by the members of the general public. The aim of this study was to evaluate the radiographic reject/repeat rate and also to determine dose to the patients from radiographic rejects/repeats in radiology centers of Urmia University of Medical Sciences. During a 4 month period the most frequently examinations were chosen in three radiology centers. A form was designed as a reject/repeat analysis form for radiographers to complete each time a film was rejected by radiologists or repeated. The collected data were compiled at the end of each week and entered into a computer for analysis at the end of study. The results of this study showed that highest and lowest repetition rates were for pelvis, 14.01% and upper limb, 4.17%, respectively. The main reasons of repetition of radiographs were due to exposure (54%) and positioning (18%) errors. The average repeat rate in all three hospitals was 7.20%. It was found that human error has important role to repetition of radiographs. It is demonstrated that those patients having repeated radiographs received an average of 3.23 Gy·cm2. Based on the findings of this study it must be remembered that the highest repetition rate was for pelvis. Considering the radiosensitive organs related to pelvis especially in pediatric patients some special considerations must be applied for pelvis examinations.展开更多
Dosimetric characteristic is one of the essential parameters of a medical linear accelerator (LINAC), which must be obtained before clinical use. The dosimetric characteristics for 6 MV photon beam were measured and c...Dosimetric characteristic is one of the essential parameters of a medical linear accelerator (LINAC), which must be obtained before clinical use. The dosimetric characteristics for 6 MV photon beam were measured and compared with the corresponding published data. The study was done using a Varian linear accelerator (Model Clinac-iX) at the Institute of Nuclear Medical Physics (INMP), AERE, Savar, Dhaka, under the Bangladesh Atomic Energy Commission (BAEC). The data is taken for 10 field sizes (2 × 2, 3 × 3, 5 × 5, 7 × 7, 10 × 10, 15 × 15, 20 × 20, 25 × 25, 30 × 30 and 40 × 40 cm<sup>2</sup>) at same conditions. The measured Percent Depth Dose (PDD) curves were obtained for 6 MV photon beams with the field as mentioned above and compared with the calculated PDD curves. The measured depth dose (D<sub>max</sub>) for reference field size (FS) 10 × 10 cm<sup>2</sup> is 15.99 mm, and the PDD at 10 cm depth (D<sub>10</sub>) is 66.87% for 6 MV photon energies that are found to be compatible with the published report BJR supplement 25. The measured PDD curves for photon energies show a good agreement with the standard PDD curves. The photon beam dosimetry data found in the current study are compatible and all the tolerances are within the clinically acceptable tolerance limit.展开更多
The flexibility in radiotherapy can be improved if patients can be moved between any one of the department’s medical linear accelerators (LINACs) without the need to change anything in the patient’s treatment plan. ...The flexibility in radiotherapy can be improved if patients can be moved between any one of the department’s medical linear accelerators (LINACs) without the need to change anything in the patient’s treatment plan. For this to be possible, the dosimetric characteristics of the various accelerators must be the same, or nearly the same. The purpose of this work is to describe further and compare measurements and parameters after the initial vendor-recommended beam matching of the five LINACs. Deviations related to dose calculations and to beam matched accelerators may compromise treatment accuracy. The safest and most practical way to ensure that all accelerators are within clinical acceptable accuracy is to include TPS calculations in the LINACs matching evaluation. Treatment planning system (TPS) was used to create three photons plans with different field sizes 3 × 3 cm, 10 × 10 cm and 25 × 25 cm at a depth of 4.5 cm in Perspex. Calculated TPS plans were sent to Mosaiq to be delivered by five LINACs. TPS plans were compared with five LINACs measurements data using Gamma analyses of 2% and 2 mm. The results suggest that for four out of the five LINACs, there was generally good agreement, less than a 2% deviation between the planned dose distribution and the measured dose distribution. However, one specific LINAC named “Asterix” exhibited a deviation of 2.121% from the planned dose. The results show that all of the LINACs’ performance were within the acceptable deviation and delivering radiation dose consistently and accurately.展开更多
Calibration of medical imaging systems that provide quantitative measures relating to complex physiological flows is challenging. Physical test objects available for the purpose either offer a known simple flow far re...Calibration of medical imaging systems that provide quantitative measures relating to complex physiological flows is challenging. Physical test objects available for the purpose either offer a known simple flow far removed from the complexity of pathology (e.g. parabolic flow in a straight pipe) or complex relevant flows in which the details of the flow behaviour are unknown. This paper presents the ring vortex as a candidate for a complex flow phantom, since it is marked by inherently complex flow features that are controllable, predictable, reproducible and stable. These characteristics are demonstrated by a combination of analytical, numerical (CFD) and experimental methods. Together they provide a consistent perspective on ring vortex behaviour and highlight qualities relevant to phantom design. Discussion of the results indicates that a liquid phantom based on the ring vortex may have merit as a complex flow phantom for multimodal imaging. Furthermore, availability of such a flow reference may also serve as a benchmark for quality assurance of simulation methodologies.展开更多
Context: Medical imaging has a wide range of applications in today’s society. Basic projectional radiography, CT scans, mammograms and a range of other advanced technologies all use x-rays to create a large number of...Context: Medical imaging has a wide range of applications in today’s society. Basic projectional radiography, CT scans, mammograms and a range of other advanced technologies all use x-rays to create a large number of examinations every day across the world. The most essential component of such medical equipment is the x-ray tube, which creates and produces x-rays. Objective: We describe and investigate an abstract model-geometry of a simple x-ray tube utilizing the open-source software package of BEAMnrc of the EGSnrcmp family, which is well validated by several studies over the years, for high and low energy photons generation. Methodology: Our research focuses on two different electron beam energies: 120 keV and 30 keV. The 120 keV is the typical energy for simple projectional radiographic exams and CT examinations, whereas the 30 keV is the typical energy of mammography. Results: Two different anode materials are used for each case, Gold (Au) and Tungsten (W) for 120 keV because these are the most common in projectional radiography and CT;Molybdenum (Mo) and Rhodium (Rh) for 30 keV because with these targets most mammography exams are carried out. The aim of this work is to show how the BEAMnrc software package can simulate effectively x-ray generation of low-energy photons which are utilized in modern medical imaging procedures. We describe useful information on anode-target characteristics, such as anode angle, anode material, and metal filter materials, based on previous quality studies even by using software other than BEAMnrc. Conclusion: We demonstrate that BEAMnrc can be efficiently used for Monte Carlo modeling of low-energy photons.展开更多
Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is...Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is not able to observe the internal structure, and there is a risk of sacrificing animals to remove the suture and damaging the materials. Therefore, we introduced optical coherence tomography (OCT) to observe and evaluate four different kinds of surgical sutures in vivo (monofilament absorbable and nonabsorbable sutures and braided absorbable and nonabsorbable sutures). As a result, while the monofilament nonabsorbable sutures showed almost no change over time, the absorbable sutures had color fading and it was also confirmed that the internal structure became chaotic due to decomposition, which improved the OCT signal intensity. For the braided sutures, both absorbable and nonabsorbable, we found that the reflection signal improved from week 0 because blood got among the filaments of sutures and dried during recovery which increased OCT signal from week 0 to week 1. We also confirmed that the braided sutures untwisted over time. All four kinds of sutures were pulled due to the movement of rats during recovery. It is expected that OCT technology will be of great help in in vivo experiments on biomaterials such as sutures.展开更多
This study introduces a novel concept,biological in vivo three-dimensional(3D)dose distribution verification,aimed at investigating how respiratory motion affects the efficacy of lung cancer radiotherapy,representing ...This study introduces a novel concept,biological in vivo three-dimensional(3D)dose distribution verification,aimed at investigating how respiratory motion affects the efficacy of lung cancer radiotherapy,representing an evolution from the current standard of rigid-body dose distribution verification.A 3D ex vivo biological lung motion simulation device(3D-BioLungEx)was designed to replicate human respiration.A radiotherapy plan of the patient was copied to the porcine lung,which was driven by 3D-BioLungEx to simulate various respiratory patterns that occur during treatment.To ensure anatomical consistency with the patient’s lung structure,during transmission,skin,skeleton,and organs were adjusted according to CT images of the porcine lung.The patient’s radiotherapy plan was then adapted to the porcine lung using the Monaco treatment planning system(TPS).Next,an iterative optimization and scatter inversion-based dose distribution retro-analysis algorithm(IOSI-BLDose)was developed to calculate the dose distribution during treatment.Gamma passing rates were used to quantify discrepancies between this dose distribution and that of the radiotherapy plan.When respiratory conditions were replicated,the passing rate reached up to 93.61%,while irregular breathing dropped it to 70%-90%,primarily due to amplitude changes.However,cycle variations had minimal impact.Compared to conventional rigid-body dose distribution verification,our method provides real-time biological feedback and more effectively captures motion-induced deviations.Accordingly,our biological in vivo 3D dose distribution verification has potential for improving treatment precision and enabling adaptive radiotherapy in clinical practice.展开更多
In contrast to the conventional spermiogram, metabolomics approaches give insights into the molecular composition of semen and mayprovide more detailed information on the fertility status of the respective donor. Give...In contrast to the conventional spermiogram, metabolomics approaches give insights into the molecular composition of semen and mayprovide more detailed information on the fertility status of the respective donor. Given the intra-individual variability of spermiogramparameters between two donations, this study sought to elucidate the biological variability of the seminal plasma metabolome overan average period of 8 weeks. Two time-shifted semen samples from 15 healthy donors were compared by a targeted metabolomicsapproach utilizing the Biocrates AbsoluteIDQ p180 kit. Next to intraclass correlation coefficients (ICC), which represent a measureof reliability, coefficients of variation within individuals(CVW) and coefficients of variation between individuals (CVB) were calculatedfor each metabolite to demonstrate its stability. Furthermore, men were divided into two cohorts, a similar sperm concentration(SSC) and a differing sperm concentration (DSC) cohort, based on the observed variance in sperm concentration between the twosemen donations. The ICC was higher in the SSC compared to the DSC cohort. The levels of 18 metabolites, primarily acylcarnitines,varied between the initial and subsequent donations. After subdivision into subgroups, only ornithine and phosphatidylcholine 40:5exhibited differential levels between the two donations in the SSC group, compared to 14 metabolites in the DSCgroup.CVBwashigher than CVW but both differed between the metabolite subclasses. Biogenic amines were identified as the least reliable analytesover time, exhibiting the highest CVW,compared to sphingomyelins, which demonstrated the highest reliability with the lowestvariation.CVB was the highest for ether-bound glycerophosphatidylcholines and the lowest for amino acids.展开更多
Multi-resonance thermally ac-tivated delayed fluorescence(MR-TADF)emitters are one of the most excellent materi-als for high performance or-ganic light-emitting diodes(OLEDs)with high color puri-ty benefiting from the...Multi-resonance thermally ac-tivated delayed fluorescence(MR-TADF)emitters are one of the most excellent materi-als for high performance or-ganic light-emitting diodes(OLEDs)with high color puri-ty benefiting from their nar-row full width at half maxi-mum(FWHM)and great de-vice performance.However,small spin-orbit coupling(SOC)is one of drawbacks for MR-TADF emitters and introduction of heavy atoms may be one effective solution.In this work,four MR-TADF molecules with different atoms(O,S,Se)are carried out based on the first-principles calculation,and excited state dynamics in both toluene and solid phase is investi-gated.Our calculation results indicate that heavy atoms could induce smaller adiabatic ener-gy gap and larger SOC between the first singlet excited state and the first triplet excited state,which is advantageous for the conversion of singlet and triplet excitons,and thus the generation of thermally activated delayed fluorescence(TADF).Though the reorganization energy and full width at half maximum(FWHM)of emission are increased,the influence is quite limited.Besides,the fluorescent rates are also little influenced.Our calculation results indicate that heavy atom introduction is an efficient strategy to enhance the SOC values of MR-TADF emitters without influencing other properties significantly.展开更多
Dose estimation and quality control in computed tomography (CT) scanners are useful in controlling the dose of radiation given to patients while tests are carried out. The study was performed in a 16-slice Computed To...Dose estimation and quality control in computed tomography (CT) scanners are useful in controlling the dose of radiation given to patients while tests are carried out. The study was performed in a 16-slice Computed Tomography (CT) system of LightSpeed RT16 Xtra CT scanner. Quality control was done using a vendor-provided QA Phantom, and the six aspects of image quality were measured. For CT dosimetry, Computed Tomography Dose index volume (CTDIvol) was performed using Computed Tomography Dose Index (CTDI) Phantom. CTDI Phantom consists of three parts: Pediatric Head, Adult Head, and Adult Body Phantom. A 10 cm long pencil ion chamber DCT-10 was used to measure the dose at different positions inside the CTDI Phantom. Data were collected using MagicMax Universal software. For dose estimation of the CTDIvol Report of AAPM Task Group, 96 and 111 formalisms were used. For Pediatric Head, Adult Head, and Adult Body Phantom the measured CIDIvol was 61.04 mGy, 48.11 mGy, and 18.08 mGy respectively. The study has shown deviations of 7%, 15%, and 19% between estimated and console-displayed doses for Pediatric Head, Adult Head, and Adult Body scan techniques respectively. The six aspects of image quality measured by QA Phantom were found to be compatible with the specifications of the machine and CTDIvol measured by CTDI Phantom were found within a tolerance limit of ±20%. Hence, the QC and dosimetry of the mentioned machine are within the limit.展开更多
The forming processes of 4,40-dipyridyl-based single-molecule junctions and mechanically induced conductance switching as well as the side-group effects are systematically investigated by applying the ab initio-based ...The forming processes of 4,40-dipyridyl-based single-molecule junctions and mechanically induced conductance switching as well as the side-group effects are systematically investigated by applying the ab initio-based adiabatic geometric optimization method and the one-dimensional transmission combined with three-dimensional correction approximation(OTCTCA)method.The numerical results show that for the 4,40-dipyridyl with a p-conjugated phenyl-phosphoryl or diphenylsilyl side group,the pyridyl vertically anchors on the second atomic layer of the pyramid-shaped Au tip electrode at small inter-electrode distances by laterally pushing the apical Au atom aside,which induces stronger pyridyl-electrode coupling and high-conductance state of the formed junctions.As the inter-electrode distance increases,the pyridyl shifts to the apical Au atom of the tip electrode.This apical Au atom introduces additional scatterings to the tunneling electrons and significantly decreases the conductance of the junctions.Furthermore,for the 4,40-dipyridyl with a phenyl-phosphoryl side group,the probability of manifesting the high-conductance state is decreased due to the oxygen atom reducing the probability of the pyridyl adsorbing on the second layer of Au tip electrode.In contrast,for the 4,40-dipyridyl with a nonconjugated cyclohexyl-phosphoryl side group,the steric hindrance from the bulky cyclohexyl group leads the molecule to preferentially form the O-Au contact,which prevents both the high conductance and mechanically induced conductance switching of the junction.Our results provide a theoretical understanding of the side-group effects on electronic transport properties of single-molecule junctions,offering an alternative explanation for the experimental observations.展开更多
Objective:This review provides a comprehensive overview of the current research landscape on artificial intelligence(AI)in prostate cancer(PCa)management,highlighting its potential to enhance diagnosis,improve medical...Objective:This review provides a comprehensive overview of the current research landscape on artificial intelligence(AI)in prostate cancer(PCa)management,highlighting its potential to enhance diagnosis,improve medical image quality,facilitate risk stratification,and aid prognosis.The review also identifies opportunities and challenges associated with integrating AI into clinical practice.Methods:This review synthesizes findings from recent studies on AI applications in PCa management.It examines the use of machine learning and deep learning techniques in diagnostic imaging,surgical skill assessment,and outcome prediction.The analysis emphasizes empirical evidence demonstrating the efficacy and limitations of AI models in clinical settings.Results:AI,particularly machine learning and deep learning algorithms,is improving diagnostic accuracy by analyzing medical images with greater efficiency and precision compared to traditional methods.AI-based tools are also being developed for surgical skill assessment,offering objective evaluations and feedback to surgeons.Additionally,AI applications in predicting patient outcomes are facilitating the creation of personalized treatment plans.Empirical evidence shows that AI models exhibit higher sensitivity and specificity in detecting clinically significant PCa,outperforming conventional diagnostic techniques.Conclusion:AI holds significant promise for transforming PCa management by improving diagnostic accuracy,personalizing treatment plans,and enhancing patient outcomes.While the evidence underscores its potential,challenges such as the need for larger,more diverse datasets and addressing implementation barriers remain critical.Despite these hurdles,the benefits of AI in PCa management represent a compelling area for future research and clinical integration.展开更多
Nanomedicine has evolved significantly over the last decades and expanded its applications in pediatric oncology,which represents a special domain with unique patients and distinct requirements.The need for early canc...Nanomedicine has evolved significantly over the last decades and expanded its applications in pediatric oncology,which represents a special domain with unique patients and distinct requirements.The need for early cancer diagnosis andmore effective and targeted therapies aiming to increase the pediatric patients’survival rates andminimize the treatment-related side effects to survivors is profound.Nanoparticles(NPs)come as a beacon of hope to provide sensitive cancer diagnostic tools and assist contrast agents’transport to the malignant tumors.Besides,NPs could be designed to deliver targeted drugs and genes to tumors,minimizing the medicine-related toxicities.Metal and metal oxide NPs could be exploited as sensitizers to enhance chemotherapy and radiotherapy effects.Future research should emphasize pediatric models to gain secure results about NPs’safety and efficiency for pediatric cancer patients.This review presents the recent studies on the use of NPs in pediatric cancer management and highlights their impact on diagnosis,treatment outcomes,and the quality of life of the survivors.The purpose of this study is to investigate the benefits that may arise from the use of NPs in pediatric oncology,address the potential limitations and challenges,and discuss the needs for future research efforts.展开更多
With advancements in systemic therapy,the incidence of brain metastases(BMs)continues to rise,leading to severe neurological complications.Effective and precise treatment modalities are,therefore,critically important ...With advancements in systemic therapy,the incidence of brain metastases(BMs)continues to rise,leading to severe neurological complications.Effective and precise treatment modalities are,therefore,critically important for managing BMs.Radiation therapy(RT),including photon therapy,has been essential in managing BMs.Recent technological advances have significantly enhanced the precision,efficacy,and safety of these treatments.This comprehensive review provides an in-depth examination of the latest advancements in radiation and photon therapy technologies for treating BMs,focusing on innovations such as stereotactic radiosurgery(SRS),whole-brain radiation therapy(WBRT),laser interstitial thermal therapy(LITT),and other radiation-related treatment modalities.Additionally,we discuss clinical outcomes,challenges,and future directions in this rapidly evolving field.While a detailed comparison of techniques is beyond the scope of this paper,this paper provides up-to-date technical information for physicians,medical physicists,patients,and researchers in related fields,potentially enhancing clinical outcomes.Among the treatment modalities,SRS has become a cornerstone of RT for BMs,with its implementation spanning multiple modalities over the past few decades.Given its inherent minimally invasive nature and growing clinical acceptance,SRS is positioned to further evolve as a key therapeutic tool in both neurosurgery and radiotherapy.展开更多
The purpose of this study was to evaluate the clinical application of a rotating pod and assess its dosimetric considerations,positional accuracy,and anatomical structure stability.A pre-dosimetric study conducted on ...The purpose of this study was to evaluate the clinical application of a rotating pod and assess its dosimetric considerations,positional accuracy,and anatomical structure stability.A pre-dosimetric study conducted on 11 patients revealed the potential for lung dose reduction using the rotational pod.Subsequently,seven patients underwent treatment with the rotational pod,and the target coverage and organs at risk doses were compared with those of conventional methods.The positional accuracy of the rotational pod,in collaboration with the imaging guidance system,was analyzed.The Dice similarity coefficient(DSC)was used to assess the settlement of tumors,trachea,and thoracic vertebrae after rotation for 20 min.In the pre-dosimetric study,there was no statistically significant difference in the volume of the internal gross tumor volume receiving≥99%of the prescription dose between the pod and conventional couch plans.However,compared to conventional couch plans,pod plans demonstrated a significant reduction in the average lung dose by 5-53%(p<0.01).Patient accrual,comprising seven cases,revealed reduced lung doses(9-26%)in four patients.For the other three patients,although there was no significant reduction in the lung dose,the use of the 90°beamline contributed to a decrease in the patient admission waiting time.The positional errors between the beams for lateral,longitudinal,vertical,ISO,pitch,and roll directions were 0.0 mm±5.3 mm,-1.2 mm±2.3 mm,-1.1 mm±2.7 mm,0.0°±0.6°,-0.1°±0.5°,and 0.0°±0.8°,respectively.The DSC for the target region and thoracic vertebrae between CT images captured before and after a 20-min rotation was higher than 0.85,whereas the DSC for the trachea was approximately 0.8.The preliminary clinical application of the rotational pod for lung tumors in fixed ion beamlines shows promise for achieving target coverage,reducing lung dose,and maintaining position accuracy.展开更多
Background:Patients with unrepaired Ebstein’s anomaly experience exercise intolerance,heart failure and premature mortality.Volumetric assessment of right ventricular function is difffcult due to the complex anatomy ...Background:Patients with unrepaired Ebstein’s anomaly experience exercise intolerance,heart failure and premature mortality.Volumetric assessment of right ventricular function is difffcult due to the complex anatomy of the right ventricle and tricuspid valve.Myocardial deformation indices are an early marker in other cardiac pathologies of ventricular dysfunction.Objectives:1.Assess myocardial deformation in unrepaired Ebstein’s compared to healthy controls.2.Investigate the relationships between myocardial deformation and exercise capacity.Methods:Myocardial deformation parameters(strain)were calculated using feature tracking from standard cardiac magnetic resonance cine images.Cardiopulmonary exercise results were included where available.Results:36 patients with unrepaired Ebstein’s and 36 matched controls were included.Right ventricular,right atrial,and left ventricular global longitudinal,as well as left ventricular circumferential strain were impaired in Ebstein’s patients compared to controls(p<0.05).In Ebstein’s patients right atrial peak strain correlated with their percentage predicted VO_(2) max(r=−0.448,p=0.022)and VE/VCO_(2) slope(r=0.435,p=0.026).There were no correlations between right ventricular ejection fraction and exercise parameters.When Ebstein’s patients were divided by severity into mild or severe according to the median total right/left index,those with severe demonstrated signiffcantly impaired right ventricular global longitudinal strain compared to those in the mild category(−17.5±5.4%vs.−21.4±4.4%,p=0.0017).Conclusions:Myocardial deformation parameters for both the right and left ventricle are impaired in patients with unrepaired Ebstein’s compared to healthy controls.Right atrial peak strain is related to impaired exercise capacity and warrants further investigation as an early prognostic marker in this patient cohort.展开更多
文摘Artificial intelligence(AI)has seen tremendous growth over the past decade and stands to disrupts the medical industry.In medicine,this has been applied in medical imaging and other digitised medical disciplines,but in more traditional fields like medical physics,the adoption of AI is still at an early stage.Though AI is anticipated to be better than human in certain tasks,with the rapid growth of AI,there is increasing concerns for its usage.The focus of this paper is on the current landscape and potential future applications of artificial intelligence in medical physics and radiotherapy.Topics on AI for image acquisition,image segmentation,treatment delivery,quality assurance and outcome prediction will be explored as well as the interaction between human and AI.This will give insights into how we should approach and use the technology for enhancing the quality of clinical practice.
文摘High resolution (4 mm) tof PET-CT (positron emission tomography-computed tomography) from Philips of model Ingenuity TF is newly installed at Institute of Nuclear Medical Physics (INMP). 128 slice CT component incorporated with PET provides comparatively lower dose than the 511 keV annihilation photons associated with positron decay from PET scan. So, for designing shielding in our PET-CT facility, only 511 keV annihilation photons energy has been considered. The main objective of this paper is to show what measures have been taken to protect patients, occupational workers as well as environment from PET-CT radiation hazard through a cost effective design that satisfy the national regulatory demand. In this paper, AAPM (American Associations of Physicists in Medicine) Task group 108 analysis for PET and PET-CT shielding requirements is followed for our PET-CT facility shielding design. From theoretical calculation as shielding requirement, 1.1 cm Pb thickness or, 13 cm concrete thicknesses are found. Practically, all walls and ceiling are of 30.48 cm (1 foot) thick made of concrete with density 2.35 gcm-3 for more safety. As x-ray from CT is not taken into account for shielding analysis, Bangladesh Atomic Energy Commission (BAEC) conducted an extensive radiation survey at controlled, supervised and public area for CT. The report that is found meets the national regulatory requirements.
文摘The original online version of this article (Liu, Y.X., Saleh, Z., Song, Y.L., Chan, M., Li, X., Shi, C.Y., Qian, X. and Tang, X.L (2017) Novel Wavelet-Based Segmentation of Prostate CBCT Images with Implanted Calypso Transponders. International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, 6, 336-343. doi: 10.4236/ijmpcero.2017.63030) was published without acknowledging our support. The authors wish to add the acknowledgments.
基金The authors are grateful for financial support from the University of Wisconsin—Madison and National Institutes of Health(P30CA014520).
文摘The knowledge of interactions among functional proteins helps researchers understand disease mechanisms and design potential strategies for treatment.As a general approach,the fluorescent and affinity tags were employed for exploring this field by labeling the Protein of Interest(POI).However,the autofluorescence and weak binding strength significantly reduce the accuracy and specificity of these tags.Conversely,HaloTag,a novel self-labeling enzyme(SLE)tag,could quickly form a covalent bond with its ligand,enabling fast and specific labeling of POI.These desirable features greatly increase the accuracy and specificity,making the HaloTag a valuable system for various applications ranging from imaging to immobilization of POI.Notably,the HaloTag technique has already been successfully employed in a series of studies with excellent efficiency.In this review,we summarize the development of HaloTag and recent advanced investigations associated with HaloTag,including in vitro imaging(e.g.,POI imaging,cellular condition monitoring,microorganism imaging,system development),in vivo imaging,biomolecule immobilization(e.g.,POI collection,protein/nuclear acid interaction and protein structure analysis),targeted degradation(e.g.,L-AdPROM),and more.We also present a systematic discussion regarding the future direction and challenges of the HaloTag technique.
文摘Medical diagnostic X-rays are the largest manmade source of ionizing radiation received by the members of the general public. The aim of this study was to evaluate the radiographic reject/repeat rate and also to determine dose to the patients from radiographic rejects/repeats in radiology centers of Urmia University of Medical Sciences. During a 4 month period the most frequently examinations were chosen in three radiology centers. A form was designed as a reject/repeat analysis form for radiographers to complete each time a film was rejected by radiologists or repeated. The collected data were compiled at the end of each week and entered into a computer for analysis at the end of study. The results of this study showed that highest and lowest repetition rates were for pelvis, 14.01% and upper limb, 4.17%, respectively. The main reasons of repetition of radiographs were due to exposure (54%) and positioning (18%) errors. The average repeat rate in all three hospitals was 7.20%. It was found that human error has important role to repetition of radiographs. It is demonstrated that those patients having repeated radiographs received an average of 3.23 Gy·cm2. Based on the findings of this study it must be remembered that the highest repetition rate was for pelvis. Considering the radiosensitive organs related to pelvis especially in pediatric patients some special considerations must be applied for pelvis examinations.
文摘Dosimetric characteristic is one of the essential parameters of a medical linear accelerator (LINAC), which must be obtained before clinical use. The dosimetric characteristics for 6 MV photon beam were measured and compared with the corresponding published data. The study was done using a Varian linear accelerator (Model Clinac-iX) at the Institute of Nuclear Medical Physics (INMP), AERE, Savar, Dhaka, under the Bangladesh Atomic Energy Commission (BAEC). The data is taken for 10 field sizes (2 × 2, 3 × 3, 5 × 5, 7 × 7, 10 × 10, 15 × 15, 20 × 20, 25 × 25, 30 × 30 and 40 × 40 cm<sup>2</sup>) at same conditions. The measured Percent Depth Dose (PDD) curves were obtained for 6 MV photon beams with the field as mentioned above and compared with the calculated PDD curves. The measured depth dose (D<sub>max</sub>) for reference field size (FS) 10 × 10 cm<sup>2</sup> is 15.99 mm, and the PDD at 10 cm depth (D<sub>10</sub>) is 66.87% for 6 MV photon energies that are found to be compatible with the published report BJR supplement 25. The measured PDD curves for photon energies show a good agreement with the standard PDD curves. The photon beam dosimetry data found in the current study are compatible and all the tolerances are within the clinically acceptable tolerance limit.
文摘The flexibility in radiotherapy can be improved if patients can be moved between any one of the department’s medical linear accelerators (LINACs) without the need to change anything in the patient’s treatment plan. For this to be possible, the dosimetric characteristics of the various accelerators must be the same, or nearly the same. The purpose of this work is to describe further and compare measurements and parameters after the initial vendor-recommended beam matching of the five LINACs. Deviations related to dose calculations and to beam matched accelerators may compromise treatment accuracy. The safest and most practical way to ensure that all accelerators are within clinical acceptable accuracy is to include TPS calculations in the LINACs matching evaluation. Treatment planning system (TPS) was used to create three photons plans with different field sizes 3 × 3 cm, 10 × 10 cm and 25 × 25 cm at a depth of 4.5 cm in Perspex. Calculated TPS plans were sent to Mosaiq to be delivered by five LINACs. TPS plans were compared with five LINACs measurements data using Gamma analyses of 2% and 2 mm. The results suggest that for four out of the five LINACs, there was generally good agreement, less than a 2% deviation between the planned dose distribution and the measured dose distribution. However, one specific LINAC named “Asterix” exhibited a deviation of 2.121% from the planned dose. The results show that all of the LINACs’ performance were within the acceptable deviation and delivering radiation dose consistently and accurately.
文摘Calibration of medical imaging systems that provide quantitative measures relating to complex physiological flows is challenging. Physical test objects available for the purpose either offer a known simple flow far removed from the complexity of pathology (e.g. parabolic flow in a straight pipe) or complex relevant flows in which the details of the flow behaviour are unknown. This paper presents the ring vortex as a candidate for a complex flow phantom, since it is marked by inherently complex flow features that are controllable, predictable, reproducible and stable. These characteristics are demonstrated by a combination of analytical, numerical (CFD) and experimental methods. Together they provide a consistent perspective on ring vortex behaviour and highlight qualities relevant to phantom design. Discussion of the results indicates that a liquid phantom based on the ring vortex may have merit as a complex flow phantom for multimodal imaging. Furthermore, availability of such a flow reference may also serve as a benchmark for quality assurance of simulation methodologies.
文摘Context: Medical imaging has a wide range of applications in today’s society. Basic projectional radiography, CT scans, mammograms and a range of other advanced technologies all use x-rays to create a large number of examinations every day across the world. The most essential component of such medical equipment is the x-ray tube, which creates and produces x-rays. Objective: We describe and investigate an abstract model-geometry of a simple x-ray tube utilizing the open-source software package of BEAMnrc of the EGSnrcmp family, which is well validated by several studies over the years, for high and low energy photons generation. Methodology: Our research focuses on two different electron beam energies: 120 keV and 30 keV. The 120 keV is the typical energy for simple projectional radiographic exams and CT examinations, whereas the 30 keV is the typical energy of mammography. Results: Two different anode materials are used for each case, Gold (Au) and Tungsten (W) for 120 keV because these are the most common in projectional radiography and CT;Molybdenum (Mo) and Rhodium (Rh) for 30 keV because with these targets most mammography exams are carried out. The aim of this work is to show how the BEAMnrc software package can simulate effectively x-ray generation of low-energy photons which are utilized in modern medical imaging procedures. We describe useful information on anode-target characteristics, such as anode angle, anode material, and metal filter materials, based on previous quality studies even by using software other than BEAMnrc. Conclusion: We demonstrate that BEAMnrc can be efficiently used for Monte Carlo modeling of low-energy photons.
文摘Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is not able to observe the internal structure, and there is a risk of sacrificing animals to remove the suture and damaging the materials. Therefore, we introduced optical coherence tomography (OCT) to observe and evaluate four different kinds of surgical sutures in vivo (monofilament absorbable and nonabsorbable sutures and braided absorbable and nonabsorbable sutures). As a result, while the monofilament nonabsorbable sutures showed almost no change over time, the absorbable sutures had color fading and it was also confirmed that the internal structure became chaotic due to decomposition, which improved the OCT signal intensity. For the braided sutures, both absorbable and nonabsorbable, we found that the reflection signal improved from week 0 because blood got among the filaments of sutures and dried during recovery which increased OCT signal from week 0 to week 1. We also confirmed that the braided sutures untwisted over time. All four kinds of sutures were pulled due to the movement of rats during recovery. It is expected that OCT technology will be of great help in in vivo experiments on biomaterials such as sutures.
基金supported by the National Natural Science Foundation of China(No.62371243)National Key Research and Development Program of China(No.2025YFC2427600)+4 种基金the Jiangsu Provincial Key Research and Development Program Social Development Project(No.BE2022720)the Natural Science Foundation of Jiangsu Province(No.BK20231190)Jiangsu Provincial Medical Key Discipline Cultivation Unit of Oncology Therapeutics(Radiotherapy)(No.JSDW202237)Changzhou Social Development Program(Nos.CE20235063 and CJ20244020)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.JX13614239).
文摘This study introduces a novel concept,biological in vivo three-dimensional(3D)dose distribution verification,aimed at investigating how respiratory motion affects the efficacy of lung cancer radiotherapy,representing an evolution from the current standard of rigid-body dose distribution verification.A 3D ex vivo biological lung motion simulation device(3D-BioLungEx)was designed to replicate human respiration.A radiotherapy plan of the patient was copied to the porcine lung,which was driven by 3D-BioLungEx to simulate various respiratory patterns that occur during treatment.To ensure anatomical consistency with the patient’s lung structure,during transmission,skin,skeleton,and organs were adjusted according to CT images of the porcine lung.The patient’s radiotherapy plan was then adapted to the porcine lung using the Monaco treatment planning system(TPS).Next,an iterative optimization and scatter inversion-based dose distribution retro-analysis algorithm(IOSI-BLDose)was developed to calculate the dose distribution during treatment.Gamma passing rates were used to quantify discrepancies between this dose distribution and that of the radiotherapy plan.When respiratory conditions were replicated,the passing rate reached up to 93.61%,while irregular breathing dropped it to 70%-90%,primarily due to amplitude changes.However,cycle variations had minimal impact.Compared to conventional rigid-body dose distribution verification,our method provides real-time biological feedback and more effectively captures motion-induced deviations.Accordingly,our biological in vivo 3D dose distribution verification has potential for improving treatment precision and enabling adaptive radiotherapy in clinical practice.
文摘In contrast to the conventional spermiogram, metabolomics approaches give insights into the molecular composition of semen and mayprovide more detailed information on the fertility status of the respective donor. Given the intra-individual variability of spermiogramparameters between two donations, this study sought to elucidate the biological variability of the seminal plasma metabolome overan average period of 8 weeks. Two time-shifted semen samples from 15 healthy donors were compared by a targeted metabolomicsapproach utilizing the Biocrates AbsoluteIDQ p180 kit. Next to intraclass correlation coefficients (ICC), which represent a measureof reliability, coefficients of variation within individuals(CVW) and coefficients of variation between individuals (CVB) were calculatedfor each metabolite to demonstrate its stability. Furthermore, men were divided into two cohorts, a similar sperm concentration(SSC) and a differing sperm concentration (DSC) cohort, based on the observed variance in sperm concentration between the twosemen donations. The ICC was higher in the SSC compared to the DSC cohort. The levels of 18 metabolites, primarily acylcarnitines,varied between the initial and subsequent donations. After subdivision into subgroups, only ornithine and phosphatidylcholine 40:5exhibited differential levels between the two donations in the SSC group, compared to 14 metabolites in the DSCgroup.CVBwashigher than CVW but both differed between the metabolite subclasses. Biogenic amines were identified as the least reliable analytesover time, exhibiting the highest CVW,compared to sphingomyelins, which demonstrated the highest reliability with the lowestvariation.CVB was the highest for ether-bound glycerophosphatidylcholines and the lowest for amino acids.
基金supported by the National Natural Science Foundation of China(No.11974216,No.12374269)the support of the Taishan Scholar Project of Shandong Province。
文摘Multi-resonance thermally ac-tivated delayed fluorescence(MR-TADF)emitters are one of the most excellent materi-als for high performance or-ganic light-emitting diodes(OLEDs)with high color puri-ty benefiting from their nar-row full width at half maxi-mum(FWHM)and great de-vice performance.However,small spin-orbit coupling(SOC)is one of drawbacks for MR-TADF emitters and introduction of heavy atoms may be one effective solution.In this work,four MR-TADF molecules with different atoms(O,S,Se)are carried out based on the first-principles calculation,and excited state dynamics in both toluene and solid phase is investi-gated.Our calculation results indicate that heavy atoms could induce smaller adiabatic ener-gy gap and larger SOC between the first singlet excited state and the first triplet excited state,which is advantageous for the conversion of singlet and triplet excitons,and thus the generation of thermally activated delayed fluorescence(TADF).Though the reorganization energy and full width at half maximum(FWHM)of emission are increased,the influence is quite limited.Besides,the fluorescent rates are also little influenced.Our calculation results indicate that heavy atom introduction is an efficient strategy to enhance the SOC values of MR-TADF emitters without influencing other properties significantly.
文摘Dose estimation and quality control in computed tomography (CT) scanners are useful in controlling the dose of radiation given to patients while tests are carried out. The study was performed in a 16-slice Computed Tomography (CT) system of LightSpeed RT16 Xtra CT scanner. Quality control was done using a vendor-provided QA Phantom, and the six aspects of image quality were measured. For CT dosimetry, Computed Tomography Dose index volume (CTDIvol) was performed using Computed Tomography Dose Index (CTDI) Phantom. CTDI Phantom consists of three parts: Pediatric Head, Adult Head, and Adult Body Phantom. A 10 cm long pencil ion chamber DCT-10 was used to measure the dose at different positions inside the CTDI Phantom. Data were collected using MagicMax Universal software. For dose estimation of the CTDIvol Report of AAPM Task Group, 96 and 111 formalisms were used. For Pediatric Head, Adult Head, and Adult Body Phantom the measured CIDIvol was 61.04 mGy, 48.11 mGy, and 18.08 mGy respectively. The study has shown deviations of 7%, 15%, and 19% between estimated and console-displayed doses for Pediatric Head, Adult Head, and Adult Body scan techniques respectively. The six aspects of image quality measured by QA Phantom were found to be compatible with the specifications of the machine and CTDIvol measured by CTDI Phantom were found within a tolerance limit of ±20%. Hence, the QC and dosimetry of the mentioned machine are within the limit.
基金supported by the National Natural Science Foundation of China(Grant Nos.12474286,22173052,and 12204281).
文摘The forming processes of 4,40-dipyridyl-based single-molecule junctions and mechanically induced conductance switching as well as the side-group effects are systematically investigated by applying the ab initio-based adiabatic geometric optimization method and the one-dimensional transmission combined with three-dimensional correction approximation(OTCTCA)method.The numerical results show that for the 4,40-dipyridyl with a p-conjugated phenyl-phosphoryl or diphenylsilyl side group,the pyridyl vertically anchors on the second atomic layer of the pyramid-shaped Au tip electrode at small inter-electrode distances by laterally pushing the apical Au atom aside,which induces stronger pyridyl-electrode coupling and high-conductance state of the formed junctions.As the inter-electrode distance increases,the pyridyl shifts to the apical Au atom of the tip electrode.This apical Au atom introduces additional scatterings to the tunneling electrons and significantly decreases the conductance of the junctions.Furthermore,for the 4,40-dipyridyl with a phenyl-phosphoryl side group,the probability of manifesting the high-conductance state is decreased due to the oxygen atom reducing the probability of the pyridyl adsorbing on the second layer of Au tip electrode.In contrast,for the 4,40-dipyridyl with a nonconjugated cyclohexyl-phosphoryl side group,the steric hindrance from the bulky cyclohexyl group leads the molecule to preferentially form the O-Au contact,which prevents both the high conductance and mechanically induced conductance switching of the junction.Our results provide a theoretical understanding of the side-group effects on electronic transport properties of single-molecule junctions,offering an alternative explanation for the experimental observations.
基金partly funded by the NIH/NCI Cancer Center Support Grant under grant No.P30 CA008748(MSK).
文摘Objective:This review provides a comprehensive overview of the current research landscape on artificial intelligence(AI)in prostate cancer(PCa)management,highlighting its potential to enhance diagnosis,improve medical image quality,facilitate risk stratification,and aid prognosis.The review also identifies opportunities and challenges associated with integrating AI into clinical practice.Methods:This review synthesizes findings from recent studies on AI applications in PCa management.It examines the use of machine learning and deep learning techniques in diagnostic imaging,surgical skill assessment,and outcome prediction.The analysis emphasizes empirical evidence demonstrating the efficacy and limitations of AI models in clinical settings.Results:AI,particularly machine learning and deep learning algorithms,is improving diagnostic accuracy by analyzing medical images with greater efficiency and precision compared to traditional methods.AI-based tools are also being developed for surgical skill assessment,offering objective evaluations and feedback to surgeons.Additionally,AI applications in predicting patient outcomes are facilitating the creation of personalized treatment plans.Empirical evidence shows that AI models exhibit higher sensitivity and specificity in detecting clinically significant PCa,outperforming conventional diagnostic techniques.Conclusion:AI holds significant promise for transforming PCa management by improving diagnostic accuracy,personalizing treatment plans,and enhancing patient outcomes.While the evidence underscores its potential,challenges such as the need for larger,more diverse datasets and addressing implementation barriers remain critical.Despite these hurdles,the benefits of AI in PCa management represent a compelling area for future research and clinical integration.
文摘Nanomedicine has evolved significantly over the last decades and expanded its applications in pediatric oncology,which represents a special domain with unique patients and distinct requirements.The need for early cancer diagnosis andmore effective and targeted therapies aiming to increase the pediatric patients’survival rates andminimize the treatment-related side effects to survivors is profound.Nanoparticles(NPs)come as a beacon of hope to provide sensitive cancer diagnostic tools and assist contrast agents’transport to the malignant tumors.Besides,NPs could be designed to deliver targeted drugs and genes to tumors,minimizing the medicine-related toxicities.Metal and metal oxide NPs could be exploited as sensitizers to enhance chemotherapy and radiotherapy effects.Future research should emphasize pediatric models to gain secure results about NPs’safety and efficiency for pediatric cancer patients.This review presents the recent studies on the use of NPs in pediatric cancer management and highlights their impact on diagnosis,treatment outcomes,and the quality of life of the survivors.The purpose of this study is to investigate the benefits that may arise from the use of NPs in pediatric oncology,address the potential limitations and challenges,and discuss the needs for future research efforts.
基金supported by the Natural Science Foundation of Zhejiang Province,China(Grant No.LTGY23H220001).
文摘With advancements in systemic therapy,the incidence of brain metastases(BMs)continues to rise,leading to severe neurological complications.Effective and precise treatment modalities are,therefore,critically important for managing BMs.Radiation therapy(RT),including photon therapy,has been essential in managing BMs.Recent technological advances have significantly enhanced the precision,efficacy,and safety of these treatments.This comprehensive review provides an in-depth examination of the latest advancements in radiation and photon therapy technologies for treating BMs,focusing on innovations such as stereotactic radiosurgery(SRS),whole-brain radiation therapy(WBRT),laser interstitial thermal therapy(LITT),and other radiation-related treatment modalities.Additionally,we discuss clinical outcomes,challenges,and future directions in this rapidly evolving field.While a detailed comparison of techniques is beyond the scope of this paper,this paper provides up-to-date technical information for physicians,medical physicists,patients,and researchers in related fields,potentially enhancing clinical outcomes.Among the treatment modalities,SRS has become a cornerstone of RT for BMs,with its implementation spanning multiple modalities over the past few decades.Given its inherent minimally invasive nature and growing clinical acceptance,SRS is positioned to further evolve as a key therapeutic tool in both neurosurgery and radiotherapy.
基金supported by the Shanghai Municipal Health Commission Funds(No.20214Y0026).
文摘The purpose of this study was to evaluate the clinical application of a rotating pod and assess its dosimetric considerations,positional accuracy,and anatomical structure stability.A pre-dosimetric study conducted on 11 patients revealed the potential for lung dose reduction using the rotational pod.Subsequently,seven patients underwent treatment with the rotational pod,and the target coverage and organs at risk doses were compared with those of conventional methods.The positional accuracy of the rotational pod,in collaboration with the imaging guidance system,was analyzed.The Dice similarity coefficient(DSC)was used to assess the settlement of tumors,trachea,and thoracic vertebrae after rotation for 20 min.In the pre-dosimetric study,there was no statistically significant difference in the volume of the internal gross tumor volume receiving≥99%of the prescription dose between the pod and conventional couch plans.However,compared to conventional couch plans,pod plans demonstrated a significant reduction in the average lung dose by 5-53%(p<0.01).Patient accrual,comprising seven cases,revealed reduced lung doses(9-26%)in four patients.For the other three patients,although there was no significant reduction in the lung dose,the use of the 90°beamline contributed to a decrease in the patient admission waiting time.The positional errors between the beams for lateral,longitudinal,vertical,ISO,pitch,and roll directions were 0.0 mm±5.3 mm,-1.2 mm±2.3 mm,-1.1 mm±2.7 mm,0.0°±0.6°,-0.1°±0.5°,and 0.0°±0.8°,respectively.The DSC for the target region and thoracic vertebrae between CT images captured before and after a 20-min rotation was higher than 0.85,whereas the DSC for the trachea was approximately 0.8.The preliminary clinical application of the rotational pod for lung tumors in fixed ion beamlines shows promise for achieving target coverage,reducing lung dose,and maintaining position accuracy.
基金This observational retrospective study was approved by the local Clinical Governance Committee(RRK6237)conformed to the principles of Good Clinical Practice guidelines.Additionally,healthy controls were identiffed from a national ethics board approved observational CMR study(NCT01028703).
文摘Background:Patients with unrepaired Ebstein’s anomaly experience exercise intolerance,heart failure and premature mortality.Volumetric assessment of right ventricular function is difffcult due to the complex anatomy of the right ventricle and tricuspid valve.Myocardial deformation indices are an early marker in other cardiac pathologies of ventricular dysfunction.Objectives:1.Assess myocardial deformation in unrepaired Ebstein’s compared to healthy controls.2.Investigate the relationships between myocardial deformation and exercise capacity.Methods:Myocardial deformation parameters(strain)were calculated using feature tracking from standard cardiac magnetic resonance cine images.Cardiopulmonary exercise results were included where available.Results:36 patients with unrepaired Ebstein’s and 36 matched controls were included.Right ventricular,right atrial,and left ventricular global longitudinal,as well as left ventricular circumferential strain were impaired in Ebstein’s patients compared to controls(p<0.05).In Ebstein’s patients right atrial peak strain correlated with their percentage predicted VO_(2) max(r=−0.448,p=0.022)and VE/VCO_(2) slope(r=0.435,p=0.026).There were no correlations between right ventricular ejection fraction and exercise parameters.When Ebstein’s patients were divided by severity into mild or severe according to the median total right/left index,those with severe demonstrated signiffcantly impaired right ventricular global longitudinal strain compared to those in the mild category(−17.5±5.4%vs.−21.4±4.4%,p=0.0017).Conclusions:Myocardial deformation parameters for both the right and left ventricle are impaired in patients with unrepaired Ebstein’s compared to healthy controls.Right atrial peak strain is related to impaired exercise capacity and warrants further investigation as an early prognostic marker in this patient cohort.
