Humerus absorbed dose in breast cancer postoperative radiotherapy. Simulation with FOTELP-VOX code and comparison with treatment planning system

Determining the dose of scattered radiation absorbed by specific body organs and tissues in radiotherapy is very important. In this study, we chose the humerus to determine the absorbed dose in female breast cancer patients who have undergone postoperative radiotherapy. In addition to direct dosimetry, another way to determine the absorbed dose to an identified organ of the human body is the FOTELP-VOX simulation. Selected five patients were treated at the Centre for Radiation Oncology, University Clinical Center Kragujevac during 2021. All plans were done on the treatment planning system ECLIPSE-Version 15.6 (Varian). Treatment has been performed using the 3D-CRT technique. The results of the comparison of the calculated dose in the tumor and humerus using simulations show that the bulk dose to the humerus did not exceed the set expected maximums. However, clinicians need to be aware of the risk in order to expose the humerus as little as possible. The FOTELP-VOX code, a modification of the general-purpose FOTELP code, used in this study has proven to be a valid practical way to perform accurate calculations of three-dimensional dose distribution from the interactions of particles in a complex target.