Dosimetric comparison of treatment plans created with different photon energies in prostate cancer stereotactic body radiotherapy

This study addressed the fundamental need for improved treatment strategies aimed at improving therapeutic outcomes while reducing side effects by comparing dosimetric aspects of treatment plans using different photon energies in stereotactic body radiotherapy (SBRT) for prostate cancer. A retrospective analysis was performed using computed tomography (CT) scans of 10 male patients with low- and intermediate-risk prostate cancer who underwent prostate SBRT at the Department of Radiation Oncology, Health Sciences University Adana Şehir Training and Research Hospital. The CT images were processed through the Monaco treatment planning system to facilitate dosimetric comparisons, which is the focus of this research. Treatment plans were developed by identifying both target and critical organ structures on these images. Dose calculations were then performed for each photon energy in the treatment plans and dose-volume histograms (DVHs) were analyzed to evaluate the results. According to the results obtained; the mean conformity and heterogeneity index values for the planned target volume (PTV) did not show significant differences between the photon energies evaluated. This suggests that the choice of photon energy has a limited impact on achieving optimal dose conformity and homogeneity. For various dose thresholds, no significant differences were found between photon energies related to rectum and bladder volumes. The specific volumes receiving 50% (18.125 Gy) of the predicted dose (36.25 Gy) for both right and left femoral heads also did not differ significantly between the photon energy groups. When 6MV-FF and 6MV-FFF, 10MV-FF and 10MV-FFF and 6MV-FFF and 10MV-FFF photon energies were evaluated within themselves, no significant difference was found between them. When 6MV-FF and 10MV-FF photon energies were evaluated within themselves, a significant difference was found between them. When 6MV-FF and 6MV-FFF, 10MV-FF and 10MV-FFF, 6MV-FF and 10MV-FF and 6MV-FFF and 10MV-FFF photon energies were evaluated within themselves, a significant difference was found between them. Keywords: Photon Energy, Prostate, Flattening Filter (FF), Flattening Filter Free (FFF) , Stereotactic Body Radiotherapy(SBRT).