Purpose: To evaluate the associations for vaginal dose points of vaginal stricture in image-guided brachytherapy. Materials and Methods: Twenty-six patients of locally advanced cervical cancer were treated with Image-...Purpose: To evaluate the associations for vaginal dose points of vaginal stricture in image-guided brachytherapy. Materials and Methods: Twenty-six patients of locally advanced cervical cancer were treated with Image-Guided Brachytherapy (IGBT) with the dose at least 7 Gy per fraction to the D90 of High-Risk Clinical Target Volume (HR-CTV). The vaginal dose points of recommendations of the American Brachytherapy Society (ABS) were added into the plan and cumulative dose to these points was evaluated in Equivalent Dose of 2 Gy (EQD2) concepts. Results: The mean doses to right vaginal dose point (VR), left vaginal dose point (VL) and average dose of VR/VL ((VR + VL)/2) were 101.5 Gy, 98.2 Gy and 99.8 Gy in EQD2 concepts, respectively. Volume-based planning significantly reduced the cumulative dose in EQD2 concepts at vaginal points. At the median follow-up time of 22 months, grade-2 vaginal stricture was observed in two patients. The incidences of vaginal stricture were not differed between the cumulative dose to vaginal dose points in EQD2 concepts of ≤90 Gy versus >90 Gy (P = 1.000) and ≤100 Gy versus >100 Gy (P = 0.815). Conclusion: No association for cumulative vaginal doses and events of vaginal stricture was found.展开更多
BACKGROUND Three-dimensional(3D)modelling technology translates the patient-specific anatomical information derived from two-dimensional radiological images into virtual or physical 3D models,which more closely resemb...BACKGROUND Three-dimensional(3D)modelling technology translates the patient-specific anatomical information derived from two-dimensional radiological images into virtual or physical 3D models,which more closely resemble the complex environment encountered during surgery.It has been successfully applied to surgical planning and navigation,as well as surgical training and patient education in several surgical specialties,but its uptake lags behind in colorectal surgery.Rectal cancer surgery poses specific challenges due to the complex anatomy of the pelvis,which is difficult to comprehend and visualise.AIM To review the current and emerging applications of the 3D models,both virtual and physical,in rectal cancer surgery。METHODS Medline/PubMed,Embase and Scopus databases were searched using the keywords“rectal surgery”,“colorectal surgery”,“three-dimensional”,“3D”,“modelling”,“3D printing”,“surgical planning”,“surgical navigation”,“surgical education”,“patient education”to identify the eligible full-text studies published in English between 2001 and 2020.Reference list from each article was manually reviewed to identify additional relevant papers.The conference abstracts,animal and cadaveric studies and studies describing 3D pelvimetry or radiotherapy planning were excluded.Data were extracted from the retrieved manuscripts and summarised in a descriptive way.The manuscript was prepared and revised in accordance with PRISMA 2009 checklist.RESULTS Sixteen studies,including 9 feasibility studies,were included in the systematic review.The studies were classified into four categories:feasibility of the use of 3D modelling technology in rectal cancer surgery,preoperative planning and intraoperative navigation,surgical education and surgical device design.Thirteen studies used virtual models,one 3D printed model and 2 both types of models.The construction of virtual and physical models depicting the normal pelvic anatomy and rectal cancer,was shown to be feasible.Within the clinical context,3D models were used to identify vascular anomalies,for surgical planning and navigation in lateral pelvic wall lymph node dissection and in management of recurrent rectal cancer.Both physical and virtual 3D models were found to be valuable in surgical education,with a preference for 3D printed models.The main limitations of the current technology identified in the studies were related to the restrictions of the segmentation process and the lack of 3D printing materials that could mimic the soft and deformable tissues.CONCLUSION 3D modelling technology has potential to be utilised in multiple aspects of rectal cancer surgery,however,it is still at the experimental stage of application in this setting.展开更多
In single photon emission computed tomography-based three-dimensional radiotherapy(SPECT-B-3DCRT), im-ages of Tc-99 m galactosyl human serum albumin(GSA), which bind to receptors on functional liver cells, are merged ...In single photon emission computed tomography-based three-dimensional radiotherapy(SPECT-B-3DCRT), im-ages of Tc-99 m galactosyl human serum albumin(GSA), which bind to receptors on functional liver cells, are merged with the computed tomography simulation im-ages. Functional liver is defined as the area of normal liver where GSA accumulation exceeds that of hepato-cellular carcinoma(HCC). In cirrhotic patients with a gigantic, proton-beam-untreatable HCC of ≥ 14 cm in diameter, the use of SPECT-B-3DCRT in combination with transcatheter arterial chemoembolization achieved a 2-year local tumor control rate of 78.6% and a 2-year survival rate of 33.3%. SPECT-B-3DCRT was applied to HCC to preserve as much functional liver as possible. Sixty-four patients with HCC, including 30 with Child B liver cirrhosis, received SPECT-B-3DCRT and none ex-perienced fatal radiation-induced liver disease(RILD). The Child-Pugh score deteriorated by 1 or 2 in > 20% of functional liver volume that was irradiated with ≥ 20 Gy. The deterioration in the Child-Pugh score decreased when the radiation plan was designed to irradiate ≤ 20% of the functional liver volume in patients givendoses of ≥ 20 Gy(FLV20Gy). Therefore, FLV20 Gy ≤ 20% may represent a safety index to prevent RILD during 3DCRT for HCC. To supplement FLV20 Gy as a qualitative index, we propose a quantitative indicator, F 20 Gy, which was calculated as F 20 Gy = 100% ×(the GSA count in the area irradiated with ≥ 20 Gy)/(the GSA count in the whole liver).展开更多
Objective:To study the correlation between tumor size,radiation source intensity,prescription dose,and source dwell time in afterloading treatment plan,and to establish a rapid quality control method for afterloading ...Objective:To study the correlation between tumor size,radiation source intensity,prescription dose,and source dwell time in afterloading treatment plan,and to establish a rapid quality control method for afterloading treatment plan.Methods:A total of 181 patients with gynecological tumor were enrolled in our hospital.A total of 84 patients were installed with three tubes of Fletcher'applicator,58 patients with single uterine tube and 39 patients with vaginal applicator.Each patient was scanned with CT before treatment,and the target area and organs were delineated by doctors.The treatment plan was optimized by IPSA.The planned source intensity,prescription dose,source residence time and tumor volume of each case were recorded and the CI,RV,and k value were calculated,The CI distribution characteristics and the relationship with RV value were analyzed.In addition,46 cases of gynecological tumor patients'afterloading plan used this method for quality control verification.Results:The CI of the three kinds of applicators was normal distribution.The average Ci of Fletcher applicator was 0.720±0.067,k=1394,r=0.894,the average CI of Fletcher applicator was 0.697±0.076,k=1428,r=0.940,the average CI of vaginal applicator was 0.742±0.067,k=1362,r=0.909.Conclusion:Using this method,we could quickly evaluate the target volume,radiation source intensity,prescription dose and treatment time,to determine the cause of deviation according to the feedback results,ensuring that the afterloading treatment plan can be implemented efficiently quickly,and accurately in accordance with the clinical requirements.展开更多
Brachytherapy(BT)is an excellent ablative treatment modality capable of delivering extremely high radiation doses precisely to the tumor.Nevertheless,despite its significant potential,the conventional two-dimensional ...Brachytherapy(BT)is an excellent ablative treatment modality capable of delivering extremely high radiation doses precisely to the tumor.Nevertheless,despite its significant potential,the conventional two-dimensional intracavitary BT often faces various challenges,such as inaccurate targeting of the tumor and excessive irradiation of adjacent organs,which can lead to reduced tumor control and increased radiotoxic toxicities,thereby limiting its widespread clinical adoption and implementation.The emergence of four-dimensional image-guided adaptive BT,complemented by interstitial intercalation as well as three-dimensional(3D)-printed patient-specific applicators and implant templates,has brought about a highly individualized,precise,conformal,and tissue-preserving approach to BT.These advanced techniques enhance the accuracy of BT,ensuring that the dose is concentrated within the tumor while rapidly decreasing outside the target.As a result,image-guided adaptive BT can be effectively utilized in multiple tumor types.Moreover,magnetic resonance imaging(MRI)is widely recognized as the most optimal guiding imaging modality for distinguishing between malignant and healthy tissues in BT.However,the clinical application of MRI in BT is currently hindered by challenges related to MRI-compatible applicators and interstitial needles,which require further innovation to enable more extensive utilization.Future developments in BT are expected to focus on personalized dose optimization strategies and dose-guided BT strategies.Additionally,achieving consensus among medical professionals and driving technological innovations to overcome the limitations of current imaging modalities will be crucial for the continuous evolution of BT.展开更多
Objective:To evaluate the physical properties of commonly used 3D-printed materials and the dose attenuation around a high-dose-rate ^(192)Ir source,in order to provide a reference for selecting appropriate 3D-printed...Objective:To evaluate the physical properties of commonly used 3D-printed materials and the dose attenuation around a high-dose-rate ^(192)Ir source,in order to provide a reference for selecting appropriate 3D-printed materials for brachytherapy.Methods:Fifteen 3D-printed materials(12 non-metallic material and 3 metallic material)were assessed.Each material was fabricated into a wafer with a diameter of 30 mm and thickness of 3 mm using 3D printing.The CT number of each material was measured,and attenuation measurements were conducted with a Valencia skin applicator and well-type ionization chamber.192Ir was used as the radioactive source,and the attenuated ionization charges were normalized against that obtained in the presence of a solid water phantom at the same depth.Results:The CT number of nylon was(-7.78±3.36)HU,closest to water among all materials.The CT numbers of the other 11 non-metallic materials were below 300 HU.Moreover,the CT number of the Al alloy was(1,350.89±374.55)HU,while the CT numbers of the Ti alloy and stainless steel exceeded 2,976 HU,reaching the upper limit of the CT number range.The results of the attenuation measurements were normalized with the solid water phantom.The average attenuation coefficients of a polyamide,epoxy resin,photosensitive resin,carbon fiber,silica gel,Al alloy,Ti alloy,and stainless steel were 1.003,0.994,0.992,0.995,0.995,0.967,0.939,and 0.866,respectively.Conclusions:Among the common 3D-printed materials with a density similar to that of water,nylon exhibited the best performance,while the metallic materials caused significant dose attenuation and exhibited CT number distortion.As a result,care should be taken when metallic materials are used as 3D-printed materials for brachytherapy.展开更多
文摘Purpose: To evaluate the associations for vaginal dose points of vaginal stricture in image-guided brachytherapy. Materials and Methods: Twenty-six patients of locally advanced cervical cancer were treated with Image-Guided Brachytherapy (IGBT) with the dose at least 7 Gy per fraction to the D90 of High-Risk Clinical Target Volume (HR-CTV). The vaginal dose points of recommendations of the American Brachytherapy Society (ABS) were added into the plan and cumulative dose to these points was evaluated in Equivalent Dose of 2 Gy (EQD2) concepts. Results: The mean doses to right vaginal dose point (VR), left vaginal dose point (VL) and average dose of VR/VL ((VR + VL)/2) were 101.5 Gy, 98.2 Gy and 99.8 Gy in EQD2 concepts, respectively. Volume-based planning significantly reduced the cumulative dose in EQD2 concepts at vaginal points. At the median follow-up time of 22 months, grade-2 vaginal stricture was observed in two patients. The incidences of vaginal stricture were not differed between the cumulative dose to vaginal dose points in EQD2 concepts of ≤90 Gy versus >90 Gy (P = 1.000) and ≤100 Gy versus >100 Gy (P = 0.815). Conclusion: No association for cumulative vaginal doses and events of vaginal stricture was found.
文摘BACKGROUND Three-dimensional(3D)modelling technology translates the patient-specific anatomical information derived from two-dimensional radiological images into virtual or physical 3D models,which more closely resemble the complex environment encountered during surgery.It has been successfully applied to surgical planning and navigation,as well as surgical training and patient education in several surgical specialties,but its uptake lags behind in colorectal surgery.Rectal cancer surgery poses specific challenges due to the complex anatomy of the pelvis,which is difficult to comprehend and visualise.AIM To review the current and emerging applications of the 3D models,both virtual and physical,in rectal cancer surgery。METHODS Medline/PubMed,Embase and Scopus databases were searched using the keywords“rectal surgery”,“colorectal surgery”,“three-dimensional”,“3D”,“modelling”,“3D printing”,“surgical planning”,“surgical navigation”,“surgical education”,“patient education”to identify the eligible full-text studies published in English between 2001 and 2020.Reference list from each article was manually reviewed to identify additional relevant papers.The conference abstracts,animal and cadaveric studies and studies describing 3D pelvimetry or radiotherapy planning were excluded.Data were extracted from the retrieved manuscripts and summarised in a descriptive way.The manuscript was prepared and revised in accordance with PRISMA 2009 checklist.RESULTS Sixteen studies,including 9 feasibility studies,were included in the systematic review.The studies were classified into four categories:feasibility of the use of 3D modelling technology in rectal cancer surgery,preoperative planning and intraoperative navigation,surgical education and surgical device design.Thirteen studies used virtual models,one 3D printed model and 2 both types of models.The construction of virtual and physical models depicting the normal pelvic anatomy and rectal cancer,was shown to be feasible.Within the clinical context,3D models were used to identify vascular anomalies,for surgical planning and navigation in lateral pelvic wall lymph node dissection and in management of recurrent rectal cancer.Both physical and virtual 3D models were found to be valuable in surgical education,with a preference for 3D printed models.The main limitations of the current technology identified in the studies were related to the restrictions of the segmentation process and the lack of 3D printing materials that could mimic the soft and deformable tissues.CONCLUSION 3D modelling technology has potential to be utilised in multiple aspects of rectal cancer surgery,however,it is still at the experimental stage of application in this setting.
文摘In single photon emission computed tomography-based three-dimensional radiotherapy(SPECT-B-3DCRT), im-ages of Tc-99 m galactosyl human serum albumin(GSA), which bind to receptors on functional liver cells, are merged with the computed tomography simulation im-ages. Functional liver is defined as the area of normal liver where GSA accumulation exceeds that of hepato-cellular carcinoma(HCC). In cirrhotic patients with a gigantic, proton-beam-untreatable HCC of ≥ 14 cm in diameter, the use of SPECT-B-3DCRT in combination with transcatheter arterial chemoembolization achieved a 2-year local tumor control rate of 78.6% and a 2-year survival rate of 33.3%. SPECT-B-3DCRT was applied to HCC to preserve as much functional liver as possible. Sixty-four patients with HCC, including 30 with Child B liver cirrhosis, received SPECT-B-3DCRT and none ex-perienced fatal radiation-induced liver disease(RILD). The Child-Pugh score deteriorated by 1 or 2 in > 20% of functional liver volume that was irradiated with ≥ 20 Gy. The deterioration in the Child-Pugh score decreased when the radiation plan was designed to irradiate ≤ 20% of the functional liver volume in patients givendoses of ≥ 20 Gy(FLV20Gy). Therefore, FLV20 Gy ≤ 20% may represent a safety index to prevent RILD during 3DCRT for HCC. To supplement FLV20 Gy as a qualitative index, we propose a quantitative indicator, F 20 Gy, which was calculated as F 20 Gy = 100% ×(the GSA count in the area irradiated with ≥ 20 Gy)/(the GSA count in the whole liver).
文摘Objective:To study the correlation between tumor size,radiation source intensity,prescription dose,and source dwell time in afterloading treatment plan,and to establish a rapid quality control method for afterloading treatment plan.Methods:A total of 181 patients with gynecological tumor were enrolled in our hospital.A total of 84 patients were installed with three tubes of Fletcher'applicator,58 patients with single uterine tube and 39 patients with vaginal applicator.Each patient was scanned with CT before treatment,and the target area and organs were delineated by doctors.The treatment plan was optimized by IPSA.The planned source intensity,prescription dose,source residence time and tumor volume of each case were recorded and the CI,RV,and k value were calculated,The CI distribution characteristics and the relationship with RV value were analyzed.In addition,46 cases of gynecological tumor patients'afterloading plan used this method for quality control verification.Results:The CI of the three kinds of applicators was normal distribution.The average Ci of Fletcher applicator was 0.720±0.067,k=1394,r=0.894,the average CI of Fletcher applicator was 0.697±0.076,k=1428,r=0.940,the average CI of vaginal applicator was 0.742±0.067,k=1362,r=0.909.Conclusion:Using this method,we could quickly evaluate the target volume,radiation source intensity,prescription dose and treatment time,to determine the cause of deviation according to the feedback results,ensuring that the afterloading treatment plan can be implemented efficiently quickly,and accurately in accordance with the clinical requirements.
文摘Brachytherapy(BT)is an excellent ablative treatment modality capable of delivering extremely high radiation doses precisely to the tumor.Nevertheless,despite its significant potential,the conventional two-dimensional intracavitary BT often faces various challenges,such as inaccurate targeting of the tumor and excessive irradiation of adjacent organs,which can lead to reduced tumor control and increased radiotoxic toxicities,thereby limiting its widespread clinical adoption and implementation.The emergence of four-dimensional image-guided adaptive BT,complemented by interstitial intercalation as well as three-dimensional(3D)-printed patient-specific applicators and implant templates,has brought about a highly individualized,precise,conformal,and tissue-preserving approach to BT.These advanced techniques enhance the accuracy of BT,ensuring that the dose is concentrated within the tumor while rapidly decreasing outside the target.As a result,image-guided adaptive BT can be effectively utilized in multiple tumor types.Moreover,magnetic resonance imaging(MRI)is widely recognized as the most optimal guiding imaging modality for distinguishing between malignant and healthy tissues in BT.However,the clinical application of MRI in BT is currently hindered by challenges related to MRI-compatible applicators and interstitial needles,which require further innovation to enable more extensive utilization.Future developments in BT are expected to focus on personalized dose optimization strategies and dose-guided BT strategies.Additionally,achieving consensus among medical professionals and driving technological innovations to overcome the limitations of current imaging modalities will be crucial for the continuous evolution of BT.
基金supported by grants from the National High Level Hospital Clinical Research Funding(2022-PUMCH-A-101)the National High Level Hospital Clinical Research Funding(2022-PUMCH-B-052),China.
文摘Objective:To evaluate the physical properties of commonly used 3D-printed materials and the dose attenuation around a high-dose-rate ^(192)Ir source,in order to provide a reference for selecting appropriate 3D-printed materials for brachytherapy.Methods:Fifteen 3D-printed materials(12 non-metallic material and 3 metallic material)were assessed.Each material was fabricated into a wafer with a diameter of 30 mm and thickness of 3 mm using 3D printing.The CT number of each material was measured,and attenuation measurements were conducted with a Valencia skin applicator and well-type ionization chamber.192Ir was used as the radioactive source,and the attenuated ionization charges were normalized against that obtained in the presence of a solid water phantom at the same depth.Results:The CT number of nylon was(-7.78±3.36)HU,closest to water among all materials.The CT numbers of the other 11 non-metallic materials were below 300 HU.Moreover,the CT number of the Al alloy was(1,350.89±374.55)HU,while the CT numbers of the Ti alloy and stainless steel exceeded 2,976 HU,reaching the upper limit of the CT number range.The results of the attenuation measurements were normalized with the solid water phantom.The average attenuation coefficients of a polyamide,epoxy resin,photosensitive resin,carbon fiber,silica gel,Al alloy,Ti alloy,and stainless steel were 1.003,0.994,0.992,0.995,0.995,0.967,0.939,and 0.866,respectively.Conclusions:Among the common 3D-printed materials with a density similar to that of water,nylon exhibited the best performance,while the metallic materials caused significant dose attenuation and exhibited CT number distortion.As a result,care should be taken when metallic materials are used as 3D-printed materials for brachytherapy.
