Validation of planned radiation absorbed dose for breast cancer treatment using radiometric film dosimeter

Abstract

The essential role of radiotherapy is to ensure detection and treatment of breast cancers using appropriate doses, these seem not to harm patients under review. Unintended detriments in the treatment and the risk of secondary cancers are mostly associated with delivering much higher doses than planned dose. This study focused on using phantoms for the determination, and comparison of planned doses with actual doses delivered to the breast, during radiation treatment. Adelaide phantoms were constructed using locally procured materials to mimic the surrounding tissues of the human female thoracic cavity. Balloons, mango seed, cassava stick and candle were radiologically assessed and used as surrogates for the lung, heart, spinal cord and glandular tissue of the breast respectively. EBT3 film dosimeter was used with the standard (anthropomorphic) and Adelaide phantoms to measure doses absorbed by the breast and non-target organs; the doses were delivered from Co-60 and linear accelerator systems. Monte Carlo N-Particle transport code was also used on a virtual phantom to compute the dose distribution from the cobalt machine. The spinal cord absorbed the lowest dose of 0.03±0.02 Gy and 0.05±0.01 Gy, while the left lung received the highest doses of 0.74±0.04 Gy and 0.78±0.01 Gy for Co-60 and LINAC respectively. Based on the findings, it was clearly determined that the target organ received the expected dose within the acceptable tolerance level of 5%. Additionally, the non-target organs equally received a minimuim radiation dose according to required standards. A non-clinical significance differences of planned and delivered doses were achievable following appropriate quality control both with anthropomorphic and constructed phantoms.