Electronic brachytherapy

Abstract

New radiotherapy techniques have been innovative in recent decades with the aim of maximizing the dose to tumor tissue and reducing the dose to healthy tissue. One of the modalities that has gained prominence, using low-energy beams, is intraoperative radiotherapy (IORT), as it is a method based on high radiation doses (10–20 Gy) administered to the tumor bed immediately after surgical excision. IORT can be achieved through treatment with low-energy X-ray beams with some devices available on the market. However, such devices provide little dosimetric information and lack a calibration protocol. According to the recently updated recommendations of the TRS 398 standard (2024), for the use of low-energy beams, the ideal is to use a parallel plate ionization chamber calibrated in terms of absorbed dose in water. Based on TRS 398, this work established a calibration protocol for parallel plate dosimeters in terms of absorbed dose in water at the Center for Ionizing Radiation Metrology (CEMRI) of the Institute for Energy and Nuclear Research (IPEN).