Feasibility of simultaneous integrated boost for high-dose treatment of high-risk prostate cancer

Background . Radiation therapy for high-risk prostate cancer presents a challenge radiotherapists. The improvement of treatment outcomes is associated with radiation dose escalation and prophylactic irradiation lymph nodes, therefore, the development new schemes needed. Simultaneous integrated boost technique based on volumetric modulated arc most efficient option. Material Methods anatomical data 10 patients was used dosimetry-based planning. Both simultaneous sequential were considered. planning goal to deliver equivalent 96 Gy at 2 per fraction ( EQD =96 Gy) (α/β=1.5 prostate, =62.5 seminal vesicles =50 nodes avoiding damaging organs risk, mainly bladder rectum. two partially coplanar arcs rotations each arc. obtained distributions compared respect dose-volume histograms uniform doses (EUD). Results In case boost, minimal delivered equal 95.9 ± 2.1 Gy, EUD=104.9 1.7 Gy. cm 3 D 2cc ) 97.4 2.0 Normal tissue complication probability (NTCP) 1.64 %. cm3 rectum 103.4 9.2 NTCP 27.4 90.4 2.3 EUD =103.9 1.3 as high =96.1 5.2 =0.176 0.132 %, - =81.1 6.0 =2.34 1.92 Conclusion Volumetric along have shown feasibility up prescribed values without significant over risk (OARs). Dose in tumor may result higher control value should be considered clinical trials.