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Papers by shabbir Ahamed

Research paper thumbnail of Body mass index versus bladder and rectal doses using 2D planning for patients with carcinoma of the cervix undergoing HDR brachytherapy

International Journal of Cancer Therapy and Oncology

Purpose: To assess bladder and rectum doses in relation to body mass index of patients undergoing... more Purpose: To assess bladder and rectum doses in relation to body mass index of patients undergoing high dose rate brachytherapy for the treatment of carcinoma of the cervix. Methods: The cohort consists of fifty subjects with carcinoma of the uterine cervix presented with grade II and III. Patient's height and weight was measured before the insertion of applicator in situ. Body mass index (BMI) of the patient was calculated in accordance to World Health Organization definition (weight in Kg/ height in m 2). Adequacy of position and orientation of the applicator was confirmed with the help of orthogonal X-ray images and the same were transferred to the treatment planning system (TPS) to generate treatment plan. Prescription doses were optimized to Point A and to reference lines placed at 0.5 cm apart from the surface of ovoids. The following dose reference points were identified on orthogonal x-ray images for analysis using the rectal marker and Foleys bulb inflated with radio opaque dye Rectal points at the level of femoral heads (RL) and pubis symphysis (RLP), Anorectum Junction (AR Jn) point and Rectosigmoid (RS) point and Bladder point (BL). Pearson regression analysis was used to analyze data from TPS. Results: The mean BMI was 22.7 kg/m 2 and average age was 49.9 years. Analysis showed that RL point dose and BMI were inversely correlated with a coefficient-0.45 (p = 0.001). The trend continued along the rectal tube in cranio-caudal direction, as RLP and AR Jn points showed inversion co-efficiency with increase in BMI,-0.48 (p < 0.01) and-0.51 (p < 0.01) respectively. Bladder point showed weak positive correlation to BMI, 0.12 (p = 0.38). Conclusion: Significant rectal dose reduction is observed with increase in BMI. Bladder dose did not show statistically significant correlation with BMI. Based on the findings, BMI constitutes a confounding factor in the treatment of carcinoma of cervix.

Research paper thumbnail of A dosimetric comparison between applicators used for brachytherapy in carcinoma cervix – A single-institute prospective study

A dosimetric comparison between applicators used for brachytherapy in carcinoma cervix – A single-institute prospective study

Indian Journal of Cancer

INTRODUCTION Cervical cancer is the second most common cancer among Indian women. Radical radioth... more INTRODUCTION Cervical cancer is the second most common cancer among Indian women. Radical radiotherapy with external beam radiation therapy (EBRT) and brachytherapy is the standard treatment for FIGO stage IB2 to IVA. An appropriate selection of brachytherapy applicator is needed according to the patient's anatomy. The two most commonly used applicators for intracavitary radiotherapy (ICR), Fletcher's and Henschke, have dosimetric differences which are not well studied with two-dimensional (2D)-based planning which is the most common method used for women with carcinoma cervix in India. The purpose of our study was to compare and evaluate the dosimetric differences between these two applicators, which would help in better selection of the applicator in cervical cancer patients. MATERIALS AND METHODS This is a single-institute prospective study. Fifty patients randomly included in the study received EBRT and ICR by Ir192 HDR remote afterloading technique with computer-based 2D planning. Fletcher's and Henschke applicators were used alternately for first two fractions. RESULTS The results of the study showed lower bladder and rectal doses with Fletcher's applicator and similar doses to point A for both applicators. However, point B doses are lower with Fletcher's applicator. CONCLUSION Our results showed a favorable dosimetry with Fletcher's applicator in ICR of carcinoma cervix. The feasibility of placement is much better for Henschke but dosimetric advantages of Fletcher's encourage use of Fletcher's applicator for patients with favorable anatomy to reduce organs at risk doses but with the disadvantage of lower dose to point B.

Research paper thumbnail of Selection of patient for gated treatment based on the information from 4DCT imaging in stereotactic body radiotherapy of non-small cell lung cancer

Selection of patient for gated treatment based on the information from 4DCT imaging in stereotactic body radiotherapy of non-small cell lung cancer

Journal of Radiotherapy in Practice

PurposeStereotactic body radiotherapy (SBRT) is widely used for the treatment of stage-I non-smal... more PurposeStereotactic body radiotherapy (SBRT) is widely used for the treatment of stage-I non-small cell lung cancer (NSCLC). Patient-specific motion correlated with 4DCT could be essential for hypofractionated SBRT. All patients undergoing SBRT do not require motion management during the dose delivery. The objective of this study was to evaluate which patient may benefit from Gated SBRT.Materials and methodsTreatment planning of 20 patients of stage-I NSCLC was analysed. Conventional and 4DCT scans were taken. Internal target volume as well as planning target volume (ITV and PTV) were determined in the CT data sets. PTVall phases created using 4DCT data sets and PTV15mm created using conventional CT data were compared. Also, ITVall phases were compared with ITV created from maximum intensity projections (ITVMIP). Suitability of patients for motion management-based treatment delivery was also evaluated.ResultsThe average ITVMIP to ITVall phases ratio is 1·06 indicating good agreement...

Research paper thumbnail of Incidental radiation dose to internal mammary lymph nodal area in carcinoma breast patients treated with forward planning intensity-modulated radiation therapy technique: A single-institute dosimetric study

Incidental radiation dose to internal mammary lymph nodal area in carcinoma breast patients treated with forward planning intensity-modulated radiation therapy technique: A single-institute dosimetric study

Journal of Cancer Research and Therapeutics

Introduction: Breast cancer (BC) is the most common cancer in Indian females. The irradiation of ... more Introduction: Breast cancer (BC) is the most common cancer in Indian females. The irradiation of internal mammary lymph nodal area (IMLN) is recommended by latest guidelines and literature, even in patients with N1 nodal disease, but it is not routinely done in many institutes due to the risk of late lung and heart toxicities. The incidence of isolated IMLN recurrence <1%. The incidental radiation therapy (RT) dose to axillary lymph nodal area (ALN) could result in lower local recurrences according to literature. The aim of this study is to assess the incidental IMLN area RT dose in patients treated with forward planning intensity-modulated RT (FIF-IMRT). Materials and Methods: The aim of our study is to evaluate the RT dose received by IMLN area incidentally in FIF-IMRT and is a single-institute dosimetric study. The patients planned for RT after breast conservation surgery (BCS) or modified radical mastectomy (MRM) were evaluated for IMLN incidental dose. Results: The mean doses to IMLN area (Dmean) were comparable to literature for both BCS and MRM patients. All other dose parameters (D95, D90) in our study were slightly lower but comparable to literature for the FIF-IMRT planning. Interestingly, the incidental IMLN RT doses in our study are in the same range as the incidental ALN RT doses studied in the literature (48%–68%). Conclusion: The IMLN area receives a major amount of incidental radiation dose during conformal RT by FIF-IMRT and higher doses for MRM than BCS. This RT dose is not in the therapeutic range but is comparable to the incidental dose to ALN area reported in the literature.

Research paper thumbnail of Dose variation due to change in planned position for patients with carcinoma of the cervix undergoing high-dose-rate brachytherapy- 2D dose analysis

International Journal of Cancer Therapy and Oncology, 2015

Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned ti... more Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned time-dose pattern obtained from supine position. Methods: The sample consists of thirty patients with carcinoma of the uterine cervix, Stage II and III. Patients often feel discomfort in supine position (S position) when compared to lithotomy position (M position) due to relaxation of pelvic floor muscles after the insertion of applicator (tandem and ovoids) or before delivery of the treatment. Each patient was imaged with orthogonal X-ray radiographs simultaneously in two positions, i.e. S position and M position. Dwell time and dwell position pattern obtained from the optimized plan in S position was used to generate plan in M position. Following dose reference points (point A, pelvic wall points, bladder points, rectal, anorectum (AR point) and rectosigmoid (RS point) points) were identified for analysis in S and M positions. The dosimetric data for reference points generated by the Brachyvision TPS was analyzed. Results: Pelvic wall points registered lower doses in M position when compared to S position. Mean doses for right pelvic wall point (RPW) and left pelvic wall point (LPW) were reduced by-10.02 % and-11.5% in M position, respectively. International Commission on Radiation Units and Measurements (ICRU) bladder point also registered lower doses in M position with a mean dose of-6.8%. Rectal point showed dose reduction by mean of-6.4%. AR and RS points showed an increased dose in M position by a mean of 16.5% and 10%, respectively. Conclusion: Current dosimetry procedure serves as a model with time-dose pattern planned for S position, but delivered in M position, without dose optimization. Prioritization of comfort and position can be considered in conjunction with optimization of dose.

Research paper thumbnail of Dose variation due to change in planned position for patients with carcinoma of the cervix undergoing high-dose-rate brachytherapy- 2D dose analysis

International Journal of Cancer Therapy and Oncology, 2015

Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned ti... more Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned time-dose pattern obtained from supine position. Methods: The sample consists of thirty patients with carcinoma of the uterine cervix, Stage II and III. Patients often feel discomfort in supine position (S position) when compared to lithotomy position (M position) due to relaxation of pelvic floor muscles after the insertion of applicator (tandem and ovoids) or before delivery of the treatment. Each patient was imaged with orthogonal X-ray radiographs simultaneously in two positions, i.e. S position and M position. Dwell time and dwell position pattern obtained from the optimized plan in S position was used to generate plan in M position. Following dose reference points (point A, pelvic wall points, bladder points, rectal, anorectum (AR point) and rectosigmoid (RS point) points) were identified for analysis in S and M positions. The dosimetric data for reference points generated by the Brachyvision TPS was analyzed. Results: Pelvic wall points registered lower doses in M position when compared to S position. Mean doses for right pelvic wall point (RPW) and left pelvic wall point (LPW) were reduced by-10.02 % and-11.5% in M position, respectively. International Commission on Radiation Units and Measurements (ICRU) bladder point also registered lower doses in M position with a mean dose of-6.8%. Rectal point showed dose reduction by mean of-6.4%. AR and RS points showed an increased dose in M position by a mean of 16.5% and 10%, respectively. Conclusion: Current dosimetry procedure serves as a model with time-dose pattern planned for S position, but delivered in M position, without dose optimization. Prioritization of comfort and position can be considered in conjunction with optimization of dose.

Research paper thumbnail of Diaphragmatic hernia after cesarean section masquerading as hydropneumothorax

Diaphragmatic hernia after cesarean section masquerading as hydropneumothorax

Journal of Anaesthesiology Clinical Pharmacology, 2015

Research paper thumbnail of Dose variation due to change in planned position for patients with carcinoma of the cervix undergoing high-dose-rate brachytherapy- 2D dose analysis

International Journal of Cancer Therapy and Oncology, 2015

Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned ti... more Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned time-dose pattern obtained from supine position. Methods: The sample consists of thirty patients with carcinoma of the uterine cervix, Stage II and III. Patients often feel discomfort in supine position (S position) when compared to lithotomy position (M position) due to relaxation of pelvic floor muscles after the insertion of applicator (tandem and ovoids) or before delivery of the treatment. Each patient was imaged with orthogonal X-ray radiographs simultaneously in two positions, i.e. S position and M position. Dwell time and dwell position pattern obtained from the optimized plan in S position was used to generate plan in M position. Following dose reference points (point A, pelvic wall points, bladder points, rectal, anorectum (AR point) and rectosigmoid (RS point) points) were identified for analysis in S and M positions. The dosimetric data for reference points generated by the Brachyvision TPS was analyzed. Results: Pelvic wall points registered lower doses in M position when compared to S position. Mean doses for right pelvic wall point (RPW) and left pelvic wall point (LPW) were reduced by-10.02 % and-11.5% in M position, respectively. International Commission on Radiation Units and Measurements (ICRU) bladder point also registered lower doses in M position with a mean dose of-6.8%. Rectal point showed dose reduction by mean of-6.4%. AR and RS points showed an increased dose in M position by a mean of 16.5% and 10%, respectively. Conclusion: Current dosimetry procedure serves as a model with time-dose pattern planned for S position, but delivered in M position, without dose optimization. Prioritization of comfort and position can be considered in conjunction with optimization of dose.

Research paper thumbnail of Dose variation due to change in planned position for patients with carcinoma of the cervix undergoing high-dose-rate brachytherapy- 2D dose analysis

International Journal of Cancer Therapy and Oncology, 2015

Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned ti... more Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned time-dose pattern obtained from supine position. Methods: The sample consists of thirty patients with carcinoma of the uterine cervix, Stage II and III. Patients often feel discomfort in supine position (S position) when compared to lithotomy position (M position) due to relaxation of pelvic floor muscles after the insertion of applicator (tandem and ovoids) or before delivery of the treatment. Each patient was imaged with orthogonal X-ray radiographs simultaneously in two positions, i.e. S position and M position. Dwell time and dwell position pattern obtained from the optimized plan in S position was used to generate plan in M position. Following dose reference points (point A, pelvic wall points, bladder points, rectal, anorectum (AR point) and rectosigmoid (RS point) points) were identified for analysis in S and M positions. The dosimetric data for reference points generated by the Brachyvision TPS was analyzed. Results: Pelvic wall points registered lower doses in M position when compared to S position. Mean doses for right pelvic wall point (RPW) and left pelvic wall point (LPW) were reduced by-10.02 % and-11.5% in M position, respectively. International Commission on Radiation Units and Measurements (ICRU) bladder point also registered lower doses in M position with a mean dose of-6.8%. Rectal point showed dose reduction by mean of-6.4%. AR and RS points showed an increased dose in M position by a mean of 16.5% and 10%, respectively. Conclusion: Current dosimetry procedure serves as a model with time-dose pattern planned for S position, but delivered in M position, without dose optimization. Prioritization of comfort and position can be considered in conjunction with optimization of dose.

Research paper thumbnail of Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB), Jan 19, 2017

To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan q... more To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan quality and report changes induced by progressive resolution optimizer algorithm (PRO3) to the dynamic parameters of RapidArc. Ten cases of carcinoma hypopharynx were retrospectively planned in three phases without using MU tool. Replicas of these baseline plans were reoptimized using "Intermediate dose" feature and "MU tool" to reduce MUs by 20%, 35%, and 50%. Overall quality indices for target and OAR, integral dose, dose-volume spread were assessed. All plans were appraised for changes induced in RapidArc dynamic parameters and pre-treatment quality assurance (QA). With increasing MU reduction strength (MURS), MU/Gy values reduced, for all phases with an overall range of 8.6-34.7%; mean dose rate decreased among plans of each phase, phase3 plans recorded greater reductions. MURS20% showed good trade-off between MUs and plan quality. Dose-volume spread below 5Gy was ...

Research paper thumbnail of Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB), Jan 19, 2017

To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan q... more To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan quality and report changes induced by progressive resolution optimizer algorithm (PRO3) to the dynamic parameters of RapidArc. Ten cases of carcinoma hypopharynx were retrospectively planned in three phases without using MU tool. Replicas of these baseline plans were reoptimized using "Intermediate dose" feature and "MU tool" to reduce MUs by 20%, 35%, and 50%. Overall quality indices for target and OAR, integral dose, dose-volume spread were assessed. All plans were appraised for changes induced in RapidArc dynamic parameters and pre-treatment quality assurance (QA). With increasing MU reduction strength (MURS), MU/Gy values reduced, for all phases with an overall range of 8.6-34.7%; mean dose rate decreased among plans of each phase, phase3 plans recorded greater reductions. MURS20% showed good trade-off between MUs and plan quality. Dose-volume spread below 5Gy was ...

Research paper thumbnail of Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB), Jan 19, 2017

To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan q... more To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan quality and report changes induced by progressive resolution optimizer algorithm (PRO3) to the dynamic parameters of RapidArc. Ten cases of carcinoma hypopharynx were retrospectively planned in three phases without using MU tool. Replicas of these baseline plans were reoptimized using "Intermediate dose" feature and "MU tool" to reduce MUs by 20%, 35%, and 50%. Overall quality indices for target and OAR, integral dose, dose-volume spread were assessed. All plans were appraised for changes induced in RapidArc dynamic parameters and pre-treatment quality assurance (QA). With increasing MU reduction strength (MURS), MU/Gy values reduced, for all phases with an overall range of 8.6-34.7%; mean dose rate decreased among plans of each phase, phase3 plans recorded greater reductions. MURS20% showed good trade-off between MUs and plan quality. Dose-volume spread below 5Gy was ...

Research paper thumbnail of Body mass index versus bladder and rectal doses using 2D planning for patients with carcinoma of the cervix undergoing HDR brachytherapy

International Journal of Cancer Therapy and Oncology

Purpose: To assess bladder and rectum doses in relation to body mass index of patients undergoing... more Purpose: To assess bladder and rectum doses in relation to body mass index of patients undergoing high dose rate brachytherapy for the treatment of carcinoma of the cervix. Methods: The cohort consists of fifty subjects with carcinoma of the uterine cervix presented with grade II and III. Patient's height and weight was measured before the insertion of applicator in situ. Body mass index (BMI) of the patient was calculated in accordance to World Health Organization definition (weight in Kg/ height in m 2). Adequacy of position and orientation of the applicator was confirmed with the help of orthogonal X-ray images and the same were transferred to the treatment planning system (TPS) to generate treatment plan. Prescription doses were optimized to Point A and to reference lines placed at 0.5 cm apart from the surface of ovoids. The following dose reference points were identified on orthogonal x-ray images for analysis using the rectal marker and Foleys bulb inflated with radio opaque dye Rectal points at the level of femoral heads (RL) and pubis symphysis (RLP), Anorectum Junction (AR Jn) point and Rectosigmoid (RS) point and Bladder point (BL). Pearson regression analysis was used to analyze data from TPS. Results: The mean BMI was 22.7 kg/m 2 and average age was 49.9 years. Analysis showed that RL point dose and BMI were inversely correlated with a coefficient-0.45 (p = 0.001). The trend continued along the rectal tube in cranio-caudal direction, as RLP and AR Jn points showed inversion co-efficiency with increase in BMI,-0.48 (p < 0.01) and-0.51 (p < 0.01) respectively. Bladder point showed weak positive correlation to BMI, 0.12 (p = 0.38). Conclusion: Significant rectal dose reduction is observed with increase in BMI. Bladder dose did not show statistically significant correlation with BMI. Based on the findings, BMI constitutes a confounding factor in the treatment of carcinoma of cervix.

Research paper thumbnail of A dosimetric comparison between applicators used for brachytherapy in carcinoma cervix – A single-institute prospective study

A dosimetric comparison between applicators used for brachytherapy in carcinoma cervix – A single-institute prospective study

Indian Journal of Cancer

INTRODUCTION Cervical cancer is the second most common cancer among Indian women. Radical radioth... more INTRODUCTION Cervical cancer is the second most common cancer among Indian women. Radical radiotherapy with external beam radiation therapy (EBRT) and brachytherapy is the standard treatment for FIGO stage IB2 to IVA. An appropriate selection of brachytherapy applicator is needed according to the patient's anatomy. The two most commonly used applicators for intracavitary radiotherapy (ICR), Fletcher's and Henschke, have dosimetric differences which are not well studied with two-dimensional (2D)-based planning which is the most common method used for women with carcinoma cervix in India. The purpose of our study was to compare and evaluate the dosimetric differences between these two applicators, which would help in better selection of the applicator in cervical cancer patients. MATERIALS AND METHODS This is a single-institute prospective study. Fifty patients randomly included in the study received EBRT and ICR by Ir192 HDR remote afterloading technique with computer-based 2D planning. Fletcher's and Henschke applicators were used alternately for first two fractions. RESULTS The results of the study showed lower bladder and rectal doses with Fletcher's applicator and similar doses to point A for both applicators. However, point B doses are lower with Fletcher's applicator. CONCLUSION Our results showed a favorable dosimetry with Fletcher's applicator in ICR of carcinoma cervix. The feasibility of placement is much better for Henschke but dosimetric advantages of Fletcher's encourage use of Fletcher's applicator for patients with favorable anatomy to reduce organs at risk doses but with the disadvantage of lower dose to point B.

Research paper thumbnail of Selection of patient for gated treatment based on the information from 4DCT imaging in stereotactic body radiotherapy of non-small cell lung cancer

Selection of patient for gated treatment based on the information from 4DCT imaging in stereotactic body radiotherapy of non-small cell lung cancer

Journal of Radiotherapy in Practice

PurposeStereotactic body radiotherapy (SBRT) is widely used for the treatment of stage-I non-smal... more PurposeStereotactic body radiotherapy (SBRT) is widely used for the treatment of stage-I non-small cell lung cancer (NSCLC). Patient-specific motion correlated with 4DCT could be essential for hypofractionated SBRT. All patients undergoing SBRT do not require motion management during the dose delivery. The objective of this study was to evaluate which patient may benefit from Gated SBRT.Materials and methodsTreatment planning of 20 patients of stage-I NSCLC was analysed. Conventional and 4DCT scans were taken. Internal target volume as well as planning target volume (ITV and PTV) were determined in the CT data sets. PTVall phases created using 4DCT data sets and PTV15mm created using conventional CT data were compared. Also, ITVall phases were compared with ITV created from maximum intensity projections (ITVMIP). Suitability of patients for motion management-based treatment delivery was also evaluated.ResultsThe average ITVMIP to ITVall phases ratio is 1·06 indicating good agreement...

Research paper thumbnail of Incidental radiation dose to internal mammary lymph nodal area in carcinoma breast patients treated with forward planning intensity-modulated radiation therapy technique: A single-institute dosimetric study

Incidental radiation dose to internal mammary lymph nodal area in carcinoma breast patients treated with forward planning intensity-modulated radiation therapy technique: A single-institute dosimetric study

Journal of Cancer Research and Therapeutics

Introduction: Breast cancer (BC) is the most common cancer in Indian females. The irradiation of ... more Introduction: Breast cancer (BC) is the most common cancer in Indian females. The irradiation of internal mammary lymph nodal area (IMLN) is recommended by latest guidelines and literature, even in patients with N1 nodal disease, but it is not routinely done in many institutes due to the risk of late lung and heart toxicities. The incidence of isolated IMLN recurrence <1%. The incidental radiation therapy (RT) dose to axillary lymph nodal area (ALN) could result in lower local recurrences according to literature. The aim of this study is to assess the incidental IMLN area RT dose in patients treated with forward planning intensity-modulated RT (FIF-IMRT). Materials and Methods: The aim of our study is to evaluate the RT dose received by IMLN area incidentally in FIF-IMRT and is a single-institute dosimetric study. The patients planned for RT after breast conservation surgery (BCS) or modified radical mastectomy (MRM) were evaluated for IMLN incidental dose. Results: The mean doses to IMLN area (Dmean) were comparable to literature for both BCS and MRM patients. All other dose parameters (D95, D90) in our study were slightly lower but comparable to literature for the FIF-IMRT planning. Interestingly, the incidental IMLN RT doses in our study are in the same range as the incidental ALN RT doses studied in the literature (48%–68%). Conclusion: The IMLN area receives a major amount of incidental radiation dose during conformal RT by FIF-IMRT and higher doses for MRM than BCS. This RT dose is not in the therapeutic range but is comparable to the incidental dose to ALN area reported in the literature.

Research paper thumbnail of Dose variation due to change in planned position for patients with carcinoma of the cervix undergoing high-dose-rate brachytherapy- 2D dose analysis

International Journal of Cancer Therapy and Oncology, 2015

Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned ti... more Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned time-dose pattern obtained from supine position. Methods: The sample consists of thirty patients with carcinoma of the uterine cervix, Stage II and III. Patients often feel discomfort in supine position (S position) when compared to lithotomy position (M position) due to relaxation of pelvic floor muscles after the insertion of applicator (tandem and ovoids) or before delivery of the treatment. Each patient was imaged with orthogonal X-ray radiographs simultaneously in two positions, i.e. S position and M position. Dwell time and dwell position pattern obtained from the optimized plan in S position was used to generate plan in M position. Following dose reference points (point A, pelvic wall points, bladder points, rectal, anorectum (AR point) and rectosigmoid (RS point) points) were identified for analysis in S and M positions. The dosimetric data for reference points generated by the Brachyvision TPS was analyzed. Results: Pelvic wall points registered lower doses in M position when compared to S position. Mean doses for right pelvic wall point (RPW) and left pelvic wall point (LPW) were reduced by-10.02 % and-11.5% in M position, respectively. International Commission on Radiation Units and Measurements (ICRU) bladder point also registered lower doses in M position with a mean dose of-6.8%. Rectal point showed dose reduction by mean of-6.4%. AR and RS points showed an increased dose in M position by a mean of 16.5% and 10%, respectively. Conclusion: Current dosimetry procedure serves as a model with time-dose pattern planned for S position, but delivered in M position, without dose optimization. Prioritization of comfort and position can be considered in conjunction with optimization of dose.

Research paper thumbnail of Dose variation due to change in planned position for patients with carcinoma of the cervix undergoing high-dose-rate brachytherapy- 2D dose analysis

International Journal of Cancer Therapy and Oncology, 2015

Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned ti... more Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned time-dose pattern obtained from supine position. Methods: The sample consists of thirty patients with carcinoma of the uterine cervix, Stage II and III. Patients often feel discomfort in supine position (S position) when compared to lithotomy position (M position) due to relaxation of pelvic floor muscles after the insertion of applicator (tandem and ovoids) or before delivery of the treatment. Each patient was imaged with orthogonal X-ray radiographs simultaneously in two positions, i.e. S position and M position. Dwell time and dwell position pattern obtained from the optimized plan in S position was used to generate plan in M position. Following dose reference points (point A, pelvic wall points, bladder points, rectal, anorectum (AR point) and rectosigmoid (RS point) points) were identified for analysis in S and M positions. The dosimetric data for reference points generated by the Brachyvision TPS was analyzed. Results: Pelvic wall points registered lower doses in M position when compared to S position. Mean doses for right pelvic wall point (RPW) and left pelvic wall point (LPW) were reduced by-10.02 % and-11.5% in M position, respectively. International Commission on Radiation Units and Measurements (ICRU) bladder point also registered lower doses in M position with a mean dose of-6.8%. Rectal point showed dose reduction by mean of-6.4%. AR and RS points showed an increased dose in M position by a mean of 16.5% and 10%, respectively. Conclusion: Current dosimetry procedure serves as a model with time-dose pattern planned for S position, but delivered in M position, without dose optimization. Prioritization of comfort and position can be considered in conjunction with optimization of dose.

Research paper thumbnail of Diaphragmatic hernia after cesarean section masquerading as hydropneumothorax

Diaphragmatic hernia after cesarean section masquerading as hydropneumothorax

Journal of Anaesthesiology Clinical Pharmacology, 2015

Research paper thumbnail of Dose variation due to change in planned position for patients with carcinoma of the cervix undergoing high-dose-rate brachytherapy- 2D dose analysis

International Journal of Cancer Therapy and Oncology, 2015

Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned ti... more Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned time-dose pattern obtained from supine position. Methods: The sample consists of thirty patients with carcinoma of the uterine cervix, Stage II and III. Patients often feel discomfort in supine position (S position) when compared to lithotomy position (M position) due to relaxation of pelvic floor muscles after the insertion of applicator (tandem and ovoids) or before delivery of the treatment. Each patient was imaged with orthogonal X-ray radiographs simultaneously in two positions, i.e. S position and M position. Dwell time and dwell position pattern obtained from the optimized plan in S position was used to generate plan in M position. Following dose reference points (point A, pelvic wall points, bladder points, rectal, anorectum (AR point) and rectosigmoid (RS point) points) were identified for analysis in S and M positions. The dosimetric data for reference points generated by the Brachyvision TPS was analyzed. Results: Pelvic wall points registered lower doses in M position when compared to S position. Mean doses for right pelvic wall point (RPW) and left pelvic wall point (LPW) were reduced by-10.02 % and-11.5% in M position, respectively. International Commission on Radiation Units and Measurements (ICRU) bladder point also registered lower doses in M position with a mean dose of-6.8%. Rectal point showed dose reduction by mean of-6.4%. AR and RS points showed an increased dose in M position by a mean of 16.5% and 10%, respectively. Conclusion: Current dosimetry procedure serves as a model with time-dose pattern planned for S position, but delivered in M position, without dose optimization. Prioritization of comfort and position can be considered in conjunction with optimization of dose.

Research paper thumbnail of Dose variation due to change in planned position for patients with carcinoma of the cervix undergoing high-dose-rate brachytherapy- 2D dose analysis

International Journal of Cancer Therapy and Oncology, 2015

Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned ti... more Purpose: To assess the dosimetry to organs at risk (OARs) in lithotomy position with a planned time-dose pattern obtained from supine position. Methods: The sample consists of thirty patients with carcinoma of the uterine cervix, Stage II and III. Patients often feel discomfort in supine position (S position) when compared to lithotomy position (M position) due to relaxation of pelvic floor muscles after the insertion of applicator (tandem and ovoids) or before delivery of the treatment. Each patient was imaged with orthogonal X-ray radiographs simultaneously in two positions, i.e. S position and M position. Dwell time and dwell position pattern obtained from the optimized plan in S position was used to generate plan in M position. Following dose reference points (point A, pelvic wall points, bladder points, rectal, anorectum (AR point) and rectosigmoid (RS point) points) were identified for analysis in S and M positions. The dosimetric data for reference points generated by the Brachyvision TPS was analyzed. Results: Pelvic wall points registered lower doses in M position when compared to S position. Mean doses for right pelvic wall point (RPW) and left pelvic wall point (LPW) were reduced by-10.02 % and-11.5% in M position, respectively. International Commission on Radiation Units and Measurements (ICRU) bladder point also registered lower doses in M position with a mean dose of-6.8%. Rectal point showed dose reduction by mean of-6.4%. AR and RS points showed an increased dose in M position by a mean of 16.5% and 10%, respectively. Conclusion: Current dosimetry procedure serves as a model with time-dose pattern planned for S position, but delivered in M position, without dose optimization. Prioritization of comfort and position can be considered in conjunction with optimization of dose.

Research paper thumbnail of Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB), Jan 19, 2017

To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan q... more To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan quality and report changes induced by progressive resolution optimizer algorithm (PRO3) to the dynamic parameters of RapidArc. Ten cases of carcinoma hypopharynx were retrospectively planned in three phases without using MU tool. Replicas of these baseline plans were reoptimized using "Intermediate dose" feature and "MU tool" to reduce MUs by 20%, 35%, and 50%. Overall quality indices for target and OAR, integral dose, dose-volume spread were assessed. All plans were appraised for changes induced in RapidArc dynamic parameters and pre-treatment quality assurance (QA). With increasing MU reduction strength (MURS), MU/Gy values reduced, for all phases with an overall range of 8.6-34.7%; mean dose rate decreased among plans of each phase, phase3 plans recorded greater reductions. MURS20% showed good trade-off between MUs and plan quality. Dose-volume spread below 5Gy was ...

Research paper thumbnail of Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB), Jan 19, 2017

To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan q... more To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan quality and report changes induced by progressive resolution optimizer algorithm (PRO3) to the dynamic parameters of RapidArc. Ten cases of carcinoma hypopharynx were retrospectively planned in three phases without using MU tool. Replicas of these baseline plans were reoptimized using "Intermediate dose" feature and "MU tool" to reduce MUs by 20%, 35%, and 50%. Overall quality indices for target and OAR, integral dose, dose-volume spread were assessed. All plans were appraised for changes induced in RapidArc dynamic parameters and pre-treatment quality assurance (QA). With increasing MU reduction strength (MURS), MU/Gy values reduced, for all phases with an overall range of 8.6-34.7%; mean dose rate decreased among plans of each phase, phase3 plans recorded greater reductions. MURS20% showed good trade-off between MUs and plan quality. Dose-volume spread below 5Gy was ...

Research paper thumbnail of Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB), Jan 19, 2017

To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan q... more To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan quality and report changes induced by progressive resolution optimizer algorithm (PRO3) to the dynamic parameters of RapidArc. Ten cases of carcinoma hypopharynx were retrospectively planned in three phases without using MU tool. Replicas of these baseline plans were reoptimized using "Intermediate dose" feature and "MU tool" to reduce MUs by 20%, 35%, and 50%. Overall quality indices for target and OAR, integral dose, dose-volume spread were assessed. All plans were appraised for changes induced in RapidArc dynamic parameters and pre-treatment quality assurance (QA). With increasing MU reduction strength (MURS), MU/Gy values reduced, for all phases with an overall range of 8.6-34.7%; mean dose rate decreased among plans of each phase, phase3 plans recorded greater reductions. MURS20% showed good trade-off between MUs and plan quality. Dose-volume spread below 5Gy was ...