Introduction: We aimed to dosimetrically compare three-dimensional conformal radiotherapy (3D-CRT... more Introduction: We aimed to dosimetrically compare three-dimensional conformal radiotherapy (3D-CRT) and volumetric modulated arc therapy (VMAT) in terms of planning target volume (PTV) coverage, organ at risk (OAR) sparing, and conformity index (CI). Material and Methods: Planning data of 26 high grade glioma (HGG) patients were used. Prescribed dose for 3D-CRT was 46Gy in 23 fractions to low-risk PTV (LR-PTV) and 14 Gy in 7 fractions to high-risk PTV (HR-PTV). VMAT plans were conducted using 46 Gy in 30 fractions to LR-PTV and 60 Gy in 30 fractions to HR-PTV. Results: Tumor locations were frontal, parietal, temporal, and multi-lobed in 27%, 15%, 23%, and 35% of cases, respectively. Histology was glioblastoma multiform in 89% of patients. Mean values of PTV D95 (dose received by 95% volume) in 3D-CRT and VMAT were 96.6% and 98.8% for the LR-PTV and 97.3% and 99% for HR-PTV (P<0.001), respectively. Mean values of CI in 3D-CRT were 0.96 and 0.97 for LR-PTV and HR-PTV and 0.98 and 0....
Polish Journal of Medical Physics and Engineering, 2020
Aim: To conduct a study on the effect of random setup errors inpatient for dose delivery in Inten... more Aim: To conduct a study on the effect of random setup errors inpatient for dose delivery in Intensity Modulated Radiotherapy plans using Octavius 4D phantom.Materials and methods: 11 patients with cancer of H&N were selected for this study. An IMRT plan was created for each patient. The IMRT quality assurance plans were transferred to Mosaiq workstation in a linear accelerator. These plans were delivered at the reference treatment position. Subsequently, the QA plans were delivered on the Octavius 4D phantom after introducing errors in various translational and rotational directions. The setup inaccuracies introduced varied from 1 mm to 5 mm along X, Y. These setup uncertainties were then introduced along X and Y direction simultaneously in equal measures. Similarly, IMRT plans were delivered also after introducing roll and yaw rotation of 1, 2 and 3 degrees in phantom. The deviation of gamma indices at all these positions was analyzed with respect to the reference setup position.Re...
Background Various studies have shown a clinical benefit of pelvic IMRT but included a significan... more Background Various studies have shown a clinical benefit of pelvic IMRT but included a significant number of patients with intact cervix and uterus. Therefore we proposed a prospective study to evaluate the toxicity, feasibility, and tolerance of IMRT in post-operative patients with carcinoma cervix and endometrium. Methods and Material: This was a prospective, single-arm study, conducted from August 2015 to October 2018 including a total of 30 patients (23 cervical and 7 endometrial cancer) who had undergone a total hysterectomy and required adjuvant pelvic irradiation. These patients were treated with pelvic IMRT using a dose of 45-50.4 Gray (Gy) at 1.8-2 Gy per fraction given as 5 fractions per week with/without concurrent chemotherapy (using injection cisplatin 35–40 mg/m2 per week) as per indications. Acute toxicities were recorded at weekly intervals during the treatment followed by the assessment of late toxicities at the time of each follow-up visits using RTOG radiation mor...
Introduction Concurrent chemoradiotherapy (CTRT) remains one of the treatment options in patients... more Introduction Concurrent chemoradiotherapy (CTRT) remains one of the treatment options in patients with muscle invasive bladder cancer (MIBC) unwilling/unsuitable for radical surgery. We evaluated the role of volumetric modulated arc therapy (VMAT) in MIBC patients treated with definitive CTRT. Material and methods 25 patients of histologically proven transitional cell MIBC (T2–T4a, N0, M0) unwilling/unsuitable for radical surgery (after maximal transurethral resection of bladder tumour) were recruited in this prospective study. Primary clinical target volume (CTV) consisted of the gross tumour and whole bladder. Primary planning target volume (PTV) and nodal PTV were prescribed 60 Gy and 54 Gy (both in 30 fractions). Concurrent chemotherapy was cisplatin (40 mg/m2) weekly. Acute toxicities were assessed as per Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Survival estimates were done from the date of registration using the Kaplan-Meier method. Results Median ag...
Polish Journal of Medical Physics and Engineering, 2016
Aim: To demonstrate a simple technique of cranio-spinal irradiation (CSI) in supine position usin... more Aim: To demonstrate a simple technique of cranio-spinal irradiation (CSI) in supine position using inter fraction moving field junctions to feather out any potential hot and cold spots.Materials and Methods: Fifteen patients diagnosed with medulloblastoma were treated during the period February 2011 to June 2015 were included in this study. Out of fifteen patients in the study nine were male and 6 were female with a median age of 13.4 years (range 5-27 years). All the patients were positioned supine on CT simulation, immobilized using thermoplastic mask and aligned using room based laser system. Two parallel opposed lateral fields for the whole brain using an asymmetrical jaw with isocenter at C2 vertebral body. A posterior field also placed to cover the cervical and dorsal field using the same isocenter at C2. The second isocenter was placed at lumbar vertebral region to cover the remaining dorsal, lumbar and sacral region using an inter-fraction moving junction. Field-in-field and...
Introduction
Microarray analysis has revolutionized the role of genomic prognostication in breas... more Introduction
Microarray analysis has revolutionized the role of genomic prognostication in breast cancer. However, most studies are single series studies, and suffer from methodological problems. We sought to use a meta-analytic approach in combining multiple publicly available datasets, while correcting for batch effects, to reach a more robust oncogenomic analysis.
Aim
The aim of the present study was to find gene sets associated with distant metastasis free survival (DMFS) in systemically untreated, node-negative breast cancer patients, from publicly available genomic microarray datasets.
Methods
Four microarray series (having 742 patients) were selected after a systematic search and combined. Cox regression for each gene was done for the combined dataset (univariate, as well as multivariate – adjusted for expression of Cell cycle related genes) and for the 4 major molecular subtypes. The centre and microarray batch effects were adjusted by including them as random effects variables. The Cox regression coefficients for each analysis were then ranked and subjected to a Gene Set Enrichment Analysis (GSEA).
Results
Gene sets representing protein translation were independently negatively associated with metastasis in the Luminal A and Luminal B subtypes, but positively associated with metastasis in Basal tumors. Proteinaceous extracellular matrix (ECM) gene set expression was positively associated with metastasis, after adjustment for expression of cell cycle related genes on the combined dataset. Finally, the positive association of the proliferation-related genes with metastases was confirmed.
Conclusion
To the best of our knowledge, the results depicting mixed prognostic significance of protein translation in breast cancer subtypes are being reported for the first time. We attribute this to our study combining multiple series and performing a more robust meta-analytic Cox regression modeling on the combined dataset, thus discovering 'hidden' associations. This methodology seems to yield new and interesting results and may be used as a tool to guide new research.
Introduction: We aimed to dosimetrically compare three-dimensional conformal radiotherapy (3D-CRT... more Introduction: We aimed to dosimetrically compare three-dimensional conformal radiotherapy (3D-CRT) and volumetric modulated arc therapy (VMAT) in terms of planning target volume (PTV) coverage, organ at risk (OAR) sparing, and conformity index (CI). Material and Methods: Planning data of 26 high grade glioma (HGG) patients were used. Prescribed dose for 3D-CRT was 46Gy in 23 fractions to low-risk PTV (LR-PTV) and 14 Gy in 7 fractions to high-risk PTV (HR-PTV). VMAT plans were conducted using 46 Gy in 30 fractions to LR-PTV and 60 Gy in 30 fractions to HR-PTV. Results: Tumor locations were frontal, parietal, temporal, and multi-lobed in 27%, 15%, 23%, and 35% of cases, respectively. Histology was glioblastoma multiform in 89% of patients. Mean values of PTV D95 (dose received by 95% volume) in 3D-CRT and VMAT were 96.6% and 98.8% for the LR-PTV and 97.3% and 99% for HR-PTV (P<0.001), respectively. Mean values of CI in 3D-CRT were 0.96 and 0.97 for LR-PTV and HR-PTV and 0.98 and 0....
Polish Journal of Medical Physics and Engineering, 2020
Aim: To conduct a study on the effect of random setup errors inpatient for dose delivery in Inten... more Aim: To conduct a study on the effect of random setup errors inpatient for dose delivery in Intensity Modulated Radiotherapy plans using Octavius 4D phantom.Materials and methods: 11 patients with cancer of H&N were selected for this study. An IMRT plan was created for each patient. The IMRT quality assurance plans were transferred to Mosaiq workstation in a linear accelerator. These plans were delivered at the reference treatment position. Subsequently, the QA plans were delivered on the Octavius 4D phantom after introducing errors in various translational and rotational directions. The setup inaccuracies introduced varied from 1 mm to 5 mm along X, Y. These setup uncertainties were then introduced along X and Y direction simultaneously in equal measures. Similarly, IMRT plans were delivered also after introducing roll and yaw rotation of 1, 2 and 3 degrees in phantom. The deviation of gamma indices at all these positions was analyzed with respect to the reference setup position.Re...
Background Various studies have shown a clinical benefit of pelvic IMRT but included a significan... more Background Various studies have shown a clinical benefit of pelvic IMRT but included a significant number of patients with intact cervix and uterus. Therefore we proposed a prospective study to evaluate the toxicity, feasibility, and tolerance of IMRT in post-operative patients with carcinoma cervix and endometrium. Methods and Material: This was a prospective, single-arm study, conducted from August 2015 to October 2018 including a total of 30 patients (23 cervical and 7 endometrial cancer) who had undergone a total hysterectomy and required adjuvant pelvic irradiation. These patients were treated with pelvic IMRT using a dose of 45-50.4 Gray (Gy) at 1.8-2 Gy per fraction given as 5 fractions per week with/without concurrent chemotherapy (using injection cisplatin 35–40 mg/m2 per week) as per indications. Acute toxicities were recorded at weekly intervals during the treatment followed by the assessment of late toxicities at the time of each follow-up visits using RTOG radiation mor...
Introduction Concurrent chemoradiotherapy (CTRT) remains one of the treatment options in patients... more Introduction Concurrent chemoradiotherapy (CTRT) remains one of the treatment options in patients with muscle invasive bladder cancer (MIBC) unwilling/unsuitable for radical surgery. We evaluated the role of volumetric modulated arc therapy (VMAT) in MIBC patients treated with definitive CTRT. Material and methods 25 patients of histologically proven transitional cell MIBC (T2–T4a, N0, M0) unwilling/unsuitable for radical surgery (after maximal transurethral resection of bladder tumour) were recruited in this prospective study. Primary clinical target volume (CTV) consisted of the gross tumour and whole bladder. Primary planning target volume (PTV) and nodal PTV were prescribed 60 Gy and 54 Gy (both in 30 fractions). Concurrent chemotherapy was cisplatin (40 mg/m2) weekly. Acute toxicities were assessed as per Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Survival estimates were done from the date of registration using the Kaplan-Meier method. Results Median ag...
Polish Journal of Medical Physics and Engineering, 2016
Aim: To demonstrate a simple technique of cranio-spinal irradiation (CSI) in supine position usin... more Aim: To demonstrate a simple technique of cranio-spinal irradiation (CSI) in supine position using inter fraction moving field junctions to feather out any potential hot and cold spots.Materials and Methods: Fifteen patients diagnosed with medulloblastoma were treated during the period February 2011 to June 2015 were included in this study. Out of fifteen patients in the study nine were male and 6 were female with a median age of 13.4 years (range 5-27 years). All the patients were positioned supine on CT simulation, immobilized using thermoplastic mask and aligned using room based laser system. Two parallel opposed lateral fields for the whole brain using an asymmetrical jaw with isocenter at C2 vertebral body. A posterior field also placed to cover the cervical and dorsal field using the same isocenter at C2. The second isocenter was placed at lumbar vertebral region to cover the remaining dorsal, lumbar and sacral region using an inter-fraction moving junction. Field-in-field and...
Introduction
Microarray analysis has revolutionized the role of genomic prognostication in breas... more Introduction
Microarray analysis has revolutionized the role of genomic prognostication in breast cancer. However, most studies are single series studies, and suffer from methodological problems. We sought to use a meta-analytic approach in combining multiple publicly available datasets, while correcting for batch effects, to reach a more robust oncogenomic analysis.
Aim
The aim of the present study was to find gene sets associated with distant metastasis free survival (DMFS) in systemically untreated, node-negative breast cancer patients, from publicly available genomic microarray datasets.
Methods
Four microarray series (having 742 patients) were selected after a systematic search and combined. Cox regression for each gene was done for the combined dataset (univariate, as well as multivariate – adjusted for expression of Cell cycle related genes) and for the 4 major molecular subtypes. The centre and microarray batch effects were adjusted by including them as random effects variables. The Cox regression coefficients for each analysis were then ranked and subjected to a Gene Set Enrichment Analysis (GSEA).
Results
Gene sets representing protein translation were independently negatively associated with metastasis in the Luminal A and Luminal B subtypes, but positively associated with metastasis in Basal tumors. Proteinaceous extracellular matrix (ECM) gene set expression was positively associated with metastasis, after adjustment for expression of cell cycle related genes on the combined dataset. Finally, the positive association of the proliferation-related genes with metastases was confirmed.
Conclusion
To the best of our knowledge, the results depicting mixed prognostic significance of protein translation in breast cancer subtypes are being reported for the first time. We attribute this to our study combining multiple series and performing a more robust meta-analytic Cox regression modeling on the combined dataset, thus discovering 'hidden' associations. This methodology seems to yield new and interesting results and may be used as a tool to guide new research.
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Papers by Shantanu Sapru
Microarray analysis has revolutionized the role of genomic prognostication in breast cancer. However, most studies are single series studies, and suffer from methodological problems. We sought to use a meta-analytic approach in combining multiple publicly available datasets, while correcting for batch effects, to reach a more robust oncogenomic analysis.
Aim
The aim of the present study was to find gene sets associated with distant metastasis free survival (DMFS) in systemically untreated, node-negative breast cancer patients, from publicly available genomic microarray datasets.
Methods
Four microarray series (having 742 patients) were selected after a systematic search and combined. Cox regression for each gene was done for the combined dataset (univariate, as well as multivariate – adjusted for expression of Cell cycle related genes) and for the 4 major molecular subtypes. The centre and microarray batch effects were adjusted by including them as random effects variables. The Cox regression coefficients for each analysis were then ranked and subjected to a Gene Set Enrichment Analysis (GSEA).
Results
Gene sets representing protein translation were independently negatively associated with metastasis in the Luminal A and Luminal B subtypes, but positively associated with metastasis in Basal tumors. Proteinaceous extracellular matrix (ECM) gene set expression was positively associated with metastasis, after adjustment for expression of cell cycle related genes on the combined dataset. Finally, the positive association of the proliferation-related genes with metastases was confirmed.
Conclusion
To the best of our knowledge, the results depicting mixed prognostic significance of protein translation in breast cancer subtypes are being reported for the first time. We attribute this to our study combining multiple series and performing a more robust meta-analytic Cox regression modeling on the combined dataset, thus discovering 'hidden' associations. This methodology seems to yield new and interesting results and may be used as a tool to guide new research.
Microarray analysis has revolutionized the role of genomic prognostication in breast cancer. However, most studies are single series studies, and suffer from methodological problems. We sought to use a meta-analytic approach in combining multiple publicly available datasets, while correcting for batch effects, to reach a more robust oncogenomic analysis.
Aim
The aim of the present study was to find gene sets associated with distant metastasis free survival (DMFS) in systemically untreated, node-negative breast cancer patients, from publicly available genomic microarray datasets.
Methods
Four microarray series (having 742 patients) were selected after a systematic search and combined. Cox regression for each gene was done for the combined dataset (univariate, as well as multivariate – adjusted for expression of Cell cycle related genes) and for the 4 major molecular subtypes. The centre and microarray batch effects were adjusted by including them as random effects variables. The Cox regression coefficients for each analysis were then ranked and subjected to a Gene Set Enrichment Analysis (GSEA).
Results
Gene sets representing protein translation were independently negatively associated with metastasis in the Luminal A and Luminal B subtypes, but positively associated with metastasis in Basal tumors. Proteinaceous extracellular matrix (ECM) gene set expression was positively associated with metastasis, after adjustment for expression of cell cycle related genes on the combined dataset. Finally, the positive association of the proliferation-related genes with metastases was confirmed.
Conclusion
To the best of our knowledge, the results depicting mixed prognostic significance of protein translation in breast cancer subtypes are being reported for the first time. We attribute this to our study combining multiple series and performing a more robust meta-analytic Cox regression modeling on the combined dataset, thus discovering 'hidden' associations. This methodology seems to yield new and interesting results and may be used as a tool to guide new research.