A TREATMENT PLANNING STUDY COMPARING VMAT WITH 3D CONFORMAL RADIOTHERAPY FOR PROSTATE CANCER USING PINNACLE PLANNING SYSTEM

In Romania, during the last 40 years the most common method for treating malignant tumours with ionizing radiation was cobaltotherapy, using Co-60 source for radiation dose delivery. Since 2001, dedicated linear accelerators (linac) have been acquired for this type of specialized treatment. The precision, flexibility, and accuracy of the beam produced by the linac had replaced the 60Co utilization. One of the most recent techniques for cancer treatment in Europe is volumetric modulated arc therapy (VMAT), implemented for the first time by Otto Karl in 2008. In this study we are comparing the treatments plans for prostate cancer using 3D conformal radiotherapy (CRT) radiotherapy with VMAT technique. We compared the dose distribution obtained using 3D CRT with 6 static treatment beams with the distribution achieved by using dual arc VMAT optimized with SmartArc algorithm. A dose of 74 Gy was prescribed to prostate and minimum 54 Gy to seminal vesicles, delivered in 37 fractions. Dose distribution for prostate tumours is more easily achieved with VMAT technique than with 3D CRT. As for the concerns regarding the organs at risk (OAR), VMAT provides a better protection by comparison with CRT, concurrently respecting the dose limits, specified in the Radiation Therapy Oncology Group (RTOG) 0415 trial protocol. Also, the time of treatment delivery is shorter for VMAT technique.