Dosimetric comparison of IMRT (ıntensity modulated radiotherapy) and 3-DCRT (three-dimension conformal radiotherapy) plans in the treatment of prostate cancers

The goal for treatment prostate cancer is to maximize tumor control while minimizing toxicity Intensity Modulated Radiotherapy allows dose escalation for the target volume, produces sharp dose gradient around the target volume and enables radiation oncologists to increase radiation doses homogeneously within the target volume without exceeding the tolerance doses in organs at risk. At this thesis, in Cukurova University Radiation Oncology 10 prostate cancer patients' plans, which treated with 3 Dimension conformal radiotherapy tecniques, was be made and calculated with Intensity Modulated Radiotherapy techniques again. Then Dose Volume Histograms was be compared of this plans Tumor doses and critical organ doses was be looked in these comparisons. Intensity Modulated Radiotherapy plans was be evaluated using electronic portal imaging device. Treatments of the ten prostate cancer patients was be planned by using Varian Eclipse treatment planning system (TPS) over the volumes which had been contoured by the radiation oncologist. 3D-CRT plans was be made for 56 Gy and 20 Gy added as a boost, at the IMRT plans, main plan was be made for 56 Gy and boost plan was be made for 20 Gy , total dose is 76 Gy for treatmen plans. Number of fields was be decided as 7 main plan and boost plan at 3D-CRT tecnique and 18 MV will be chosen as photon energy. Main plan with calculated intensity modulated radiotherapy technique has 7 fields and there were be 5 fields at boost plan.6 MV photon energy was be chosen for intensity modulated radiotherapy plans. As a result of the study, according to 3BKRT, IMRT technique that is more homogeneous dose distribution for target volumes is provided, rectum, bladder and femoral heads were better preserved. Key words: Dosimetric, conformal, prostate cancer, radiotherapy, intensity modulated