Document Type : Original Paper
Authors
1
ASSISTANT PROFESSOR, MEDICAL RADIATION PHYSICS PROGRAM, MANIPAL COLLEGE OF HEALTH PROFESSIONS(MCHP), MANIPAL ACADEMY OF HIGHER EDUCATION(MAHE), MANIPAL-576104, KARNATAKA, INDIA
2
Medical Radiation Physics Programme, Department of Radiotherapy and Oncology, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, India.
3
Radiotherapy and Oncology Senior Grade Lecturer Medical Physics Kasturba Medical College Manipal Academy of Higher Education Manipal India
4
Radiotherapy and Oncology Assistant Professor in Medical Physics School of Allied Health Sciences Kasturba Medical College Manipal Academy of Higher Education Manipal 576104
5
KSHEMA, NITTE, MANGALORE
10.22038/ijmp.2024.75913.2336
Abstract
Abstract:
Introduction: This study compares the dosimetric differences between intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT) and intracavitary brachytherapy (ICBT) for cervix carcinoma boost.
Materials and Methods: Thirty patients with cervical cancer treated with 3-dimensional conformal radiation therapy(3DCRT) followed by ICBT for were considered retrospectively for this study. IMRT and VMAT plans were generated for high-risk clinical target (HR-CTV)volume. The dose prescription for VMAT and IMRT plans were same as the ICBT dose, i.e. between 6 to 7.5 Gy per fractions. Target coverage (TC), organ at risk (OAR) doses, conformity index (CI), homogeneity index (HI), and radiobiological indices BED (biologically effective dose) and EQD2(2Gy equivalent dose) were calculated for both plans. Two planning techniques were compared with ICBT using Friedman’s Two-Way Analysis of Variance by Ranks test of SPSS version 22. A p-value of significance level of 0.05 was used.
Results: The external beam radiation therapy (EBRT) plans in comparison to ICBT gave exceptional PTV coverage with minimal difference in V95% coverage. Mean dose and D2cc to bladder and rectum in the EBRT plans were higher than HDR Brachytherapy. Dose to bladder, rectum and femur was high in the EBRT plans with IMRT plans achieving highest dose. Bowel bag in ICBT gets high amount of dose which can be reduced in VMAT and IMRT plans. Conformity of dose to PTV was superior for ICBT in contrast to VMAT and IMRT, however homogeneity in dose distribution was better for the EBRT plans. EQD2 values for bladder and rectum for all the three plans were well within accepted tolerances.
Conclusion: The current study suggests that in absence of HDR Brachytherapy, patients can be treated with EBRT boost with VMAT being the more suitable option to opt for.
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