Background:Dysphagia after radiotherapy in head and neck malignancies can severely impact a patient’s physical,social and psychological quality of life.Aspiration remains the major cause of non-disease related mortal...Background:Dysphagia after radiotherapy in head and neck malignancies can severely impact a patient’s physical,social and psychological quality of life.Aspiration remains the major cause of non-disease related mortality in treated patients.The purpose of this study was to analyze the dosimetric correlates in a selective Asian subset of patients who are most eligible for Dysphagia aspiration related structure(DARS)sparing.Materials and Methods:Thirty patients with Oral or Oropharyngeal malignancies treated from March 2014 to September 2017 were analyzed for dosimetric parameters to DARS.A dosimetric and volumetric evaluation of dose parameters to the dysphagia and Aspiration associated normal structures were analyzed.The National cancer institute Common toxicity criteria for adverse events Version-3 was used to grade late dysphagia.Subjective evaluation of dysphagia was done with University of Washington Head and Neck related quality of life Questionnaire.Dosimetric comparison between IMRT and 3DCRT technique was done and correlated to toxicity.Results:Greater than Grade 2 dysphagia was observed in 10 patients(33%).In the 3DCRT cohort Grade 3&4 toxicity was higher,50%vs.25%.A threshold Mean dose of 63 Gy was identified as a significant parameter above which observed Gr 3/4 toxicity was 33%(P value=0.028).The maximum dose to the base of tongue(BOT)and Superior constrictor(SC)were dosimetric parameters which achieved significance(P value=0.013&0.005).There was no difference in the dose delivered to DARS between 3DCRT and IMRT.However,the patient reported Dysphagia scores were higher for pain(P=0.0014)in the 3DCRT cohort and can be attributed to a higher percentage of patients exceeding Parotid tolerance(70%vs.40%).The impact of Gr 3/4 toxicity on all aspects of quality of life parameters were significantly impaired with maximum compromise on late chewing,swallowing and general perception of well-being(P value=0.001).Conclusion:This suggests that a threshold mean dose(MD)of 63 Gy to the constrictors is statistically correlated to significant Gr 3/4 late toxicity.The high doses to the BOT and SC independently contribute to late toxicity.IMRT is more efficient in reducing severe late toxicity with a better patient reported quality of life parameters and should be the preferred treatment of choice.展开更多
Considering the simple Wong formula,simple Wong formula with deformed choice of nuclear potential,symmetric-asymmetric Gaussian barrier distribution(SAGBD)model,and coupled channel approach,this work investigates the ...Considering the simple Wong formula,simple Wong formula with deformed choice of nuclear potential,symmetric-asymmetric Gaussian barrier distribution(SAGBD)model,and coupled channel approach,this work investigates the fusion mechanism of^(40)Ca+^(46,48,50)Ti systems.For these reactions,the roles of internal structural degrees of freedom of collision partners and diffuseness parameter associated with Woods-Saxon potential in fusion dynamics are investigated.For the chosen systems,simple Wong formula-based calculations are found to be unable to describe actual fusion data at sub-barrier energies.The inclusion of quadrupole deformation with an additional radius parameter AR in deformed choice of nuclear potential along with the simple Wong formula is capable of retracing experimental data.In the SAGBD model,the simple Wong formula is weighted by a Gaussian function.The SAGBD model with different choices of diffuseness has been explored,and fusion yields have been found to be relatively sensitive to the choice of diffuseness of Woods-Saxon potential.SAGBD outcomes with Winther and AkyüzWinther diffuseness are unable to retrieve experimental data.To improve theoretical predictions,the diffuseness is optimized relative to Winther and Akyüz-Winther value,and theoretical outcomes with an optimized diffuseness parameter within SAGBD model address the fusion behaviour of^(40)Ca+^(46,48,50)Ti reactions well.Coupled channel analysis of given reactions,wherein the influences of low-lying vibrational states of participants are directly considered,readily reproduced the fusion data for all studied systems.The low-lying vibrational 2+and 3-states are found to be sufficient to reproduce the fusion data for^(40)Ca+46,48Ti reactions.However,for^(40)Ca+50Ti reactions,in addition to low-lying 2^(+)and 3^(-)vibrational states,the considerations of a pair neutron transfer channel is required to addre ss sub-barrier fusion data.展开更多
文摘Background:Dysphagia after radiotherapy in head and neck malignancies can severely impact a patient’s physical,social and psychological quality of life.Aspiration remains the major cause of non-disease related mortality in treated patients.The purpose of this study was to analyze the dosimetric correlates in a selective Asian subset of patients who are most eligible for Dysphagia aspiration related structure(DARS)sparing.Materials and Methods:Thirty patients with Oral or Oropharyngeal malignancies treated from March 2014 to September 2017 were analyzed for dosimetric parameters to DARS.A dosimetric and volumetric evaluation of dose parameters to the dysphagia and Aspiration associated normal structures were analyzed.The National cancer institute Common toxicity criteria for adverse events Version-3 was used to grade late dysphagia.Subjective evaluation of dysphagia was done with University of Washington Head and Neck related quality of life Questionnaire.Dosimetric comparison between IMRT and 3DCRT technique was done and correlated to toxicity.Results:Greater than Grade 2 dysphagia was observed in 10 patients(33%).In the 3DCRT cohort Grade 3&4 toxicity was higher,50%vs.25%.A threshold Mean dose of 63 Gy was identified as a significant parameter above which observed Gr 3/4 toxicity was 33%(P value=0.028).The maximum dose to the base of tongue(BOT)and Superior constrictor(SC)were dosimetric parameters which achieved significance(P value=0.013&0.005).There was no difference in the dose delivered to DARS between 3DCRT and IMRT.However,the patient reported Dysphagia scores were higher for pain(P=0.0014)in the 3DCRT cohort and can be attributed to a higher percentage of patients exceeding Parotid tolerance(70%vs.40%).The impact of Gr 3/4 toxicity on all aspects of quality of life parameters were significantly impaired with maximum compromise on late chewing,swallowing and general perception of well-being(P value=0.001).Conclusion:This suggests that a threshold mean dose(MD)of 63 Gy to the constrictors is statistically correlated to significant Gr 3/4 late toxicity.The high doses to the BOT and SC independently contribute to late toxicity.IMRT is more efficient in reducing severe late toxicity with a better patient reported quality of life parameters and should be the preferred treatment of choice.
基金Samiksha is supported by Council of Scientific and Industrial Research,New Delhi for funding JRF(09/1347(16516)/2023-EMR-I)。
文摘Considering the simple Wong formula,simple Wong formula with deformed choice of nuclear potential,symmetric-asymmetric Gaussian barrier distribution(SAGBD)model,and coupled channel approach,this work investigates the fusion mechanism of^(40)Ca+^(46,48,50)Ti systems.For these reactions,the roles of internal structural degrees of freedom of collision partners and diffuseness parameter associated with Woods-Saxon potential in fusion dynamics are investigated.For the chosen systems,simple Wong formula-based calculations are found to be unable to describe actual fusion data at sub-barrier energies.The inclusion of quadrupole deformation with an additional radius parameter AR in deformed choice of nuclear potential along with the simple Wong formula is capable of retracing experimental data.In the SAGBD model,the simple Wong formula is weighted by a Gaussian function.The SAGBD model with different choices of diffuseness has been explored,and fusion yields have been found to be relatively sensitive to the choice of diffuseness of Woods-Saxon potential.SAGBD outcomes with Winther and AkyüzWinther diffuseness are unable to retrieve experimental data.To improve theoretical predictions,the diffuseness is optimized relative to Winther and Akyüz-Winther value,and theoretical outcomes with an optimized diffuseness parameter within SAGBD model address the fusion behaviour of^(40)Ca+^(46,48,50)Ti reactions well.Coupled channel analysis of given reactions,wherein the influences of low-lying vibrational states of participants are directly considered,readily reproduced the fusion data for all studied systems.The low-lying vibrational 2+and 3-states are found to be sufficient to reproduce the fusion data for^(40)Ca+46,48Ti reactions.However,for^(40)Ca+50Ti reactions,in addition to low-lying 2^(+)and 3^(-)vibrational states,the considerations of a pair neutron transfer channel is required to addre ss sub-barrier fusion data.
