Particle number comparisons in target volume for pelvic area radiation irradiation with using high energy photons in radiotherapy

Objective: It's a known fact that so many type and numbers of radioactive particles appear in high energy level photon radiotherapy practices because of the heavy metals used in structure of medical linear accelarator and the materials exist in the room where experiment has made. This study aims that obtaining the particle number that received by a patient for pelvic region during the therapy. Method: Using treatment plans created with using the wedge filters or segments with the computed tomography (CT) images of the human equivalent structural model RANDO phantom, 6 indium foils being stationed inside the target volume in order had been beamed using ELEKTA Synergy and ELEKTA Synergy Platform type linear accelarators. Particle number was detected using germanium semi-conductor detector and Maestro analysis software by the help of a known energy peak. Results: Particle production is observed due to various interactions when high energies are used with a medical linear accelerator. Rise in particle number due to higher energy levels is determined as a result of apropriate evaluations. Particle number measurement results obtained from indium irradiated with 18 MV in segmented plans are in the the maximum value compared to various plans. The measurement result values for 18 MV segmented, 18 MV with wedge filter, 10 MV with wedge filter and 10 MV segmented plans are respectively 1528±42, 970±33, 93±12 ve 62±11. Conclusion: Possible particle radiation contamination during high energy radiotherapy is negligible considering the obtained results. Paticle number increase should be considered thoroughly due to possible increased duration of irradition when different planning techniques and higher energy levels are used.