Evaluation of dose perturbation at the interface of two different density medium using GAFCHROMIC film EBT2 and Monte Carlo code EGSnrc for Co-60 beam
| Autor: | Teerth Raj Verma, N K Painuly, Arun Chairmadurai, Archana Saily, Mohan C. Pant, Navin Singh, Lalit Narendra Chaudhari |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Dose perturbation
Materials science Interface (computing) Monte Carlo method Radiation lcsh:RC254-282 Thoracic region inhomogeneity Optics Dosimetry Humans Radiology Nuclear Medicine and imaging Cobalt Radioisotopes Radiometry Monte Carlo simulation business.industry Radiotherapy Dosage General Medicine lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens Oncology Film dosimetry Monte carlo code Gamma Rays Head and Neck Neoplasms business Nuclear medicine Monte Carlo Method Beam (structure) |
| Zdroj: | Journal of Cancer Research and Therapeutics, Vol 11, Iss 4, Pp 775-779 (2015) |
| ISSN: | 1998-4138 |
| Popis: | Introduction: Accurate dosimetry at the interface of two different density medium (e.g., air cavity in the head and neck cancers and lungs in thoracic region) is a major cause of concern in external beam radiation therapy. It has been observed that there is dose variation in and around air cavities, which occur as a result of the loss of both longitudinal and lateral electronic equilibrium. Heterogeneous structures with spatial differences in functionality and sensitivity for radiation pose challenge to radiation dosimetry. This study is an attempt to evaluate the dose perturbations produced at the interface of two medium for C0-60 gamma radiation. Materials and Methods: Low density polyethene foam has been used to mimic air cavity. GAFCHROMIC EBT2 dosimetry film was used for the measurement of dose at different locations. Simulation studies were performed using DOSRZnrc user code that comes with EGSnrc V4 2.4.0. Cylindrical geometry is used for all the simulations. Results and Discussion: We observed significant variation in dose for smaller fields. There is a dose build down in the backward region and a dose build up in the forward direction. In the region of electronic disequilibrium, dose reduction near interface (proximal end) will have negative impact if target region is embedded there, on the contrary, it would be beneficial if there is normal tissue/critical organ adjacent to it. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|