2Radiotherapy Unit, VM Medical Park Kocaeli Hospital, Kocaeli-Türkiye
3Department of Biomedical Engineering, Kocaeli University, Kocaeli-Türkiye DOI : 10.5505/tjo.2024.4332 OBJECTIVE
In this study, different fraction sizes in prostate cancer will be examined using a radiobiological model.
METHODS
Fifty patients diagnosed with low-risk prostate cancer who were treated between 2009 and 2021 were
identified retrospectively. Conventional (CF) and ultra-hypofractionated (HF) volume-adjusted arc plans
were calculated for selected prostate patients. Mathematical formulations were created for radiobiological
modeling of tumor control probability (TCP) and normal tissue complication probability (NTCP) in the
Matlab program. Dose-volume histogram (DVH) data of the plans were examined in the Matlab program.
RESULTS
Bladder and rectum NTCP values were significantly lower in the HF technique compared to the CF technique
(p<0.05). For femoral heads, NTCP was similar (p=0.317). For the planned target volume, TCP
values obtained with the HF technique are significantly higher compared to the CF technique (p=0.000).
CONCLUSION
Higher TCP values were obtained with the HF technique. It has been observed that normal tissues receive
lower doses. This may be associated with high local control rates while providing similar toxicity.
HF treatment may be preferred in prostate cancer because the total treatment duration is shorter and
the dose applied to critical organs is lower. Radiobiological models are very instructive for comparing
treatment schemes in radiotherapy plans. The Matlab program we created is a very helpful tool for the
radiation oncologist and medical physicist to evaluate their plans.