Toxicity and risk after using new modalities of radiotherapy in Algeria: retrospective intercomparison study

This study aims to assess different advanced treatments modalities in terms of their toxicity NTCPs and the induced second primary cancers excess absolute risk (EARs) using in-house software "COUPOLE" in case of prostate cancer. A total of 72 patients (GI, GII, GIII, and GIV) were treated using: VMAT1, VMAT2, HT and 3D-CRT. The treatment was planned with 6 MV using VARIAN HDX 2100C, VERSA HD Linear Accelerator, TOMOTHERAPY and ELEKTA Synergy. The prescribed dose was 76 Gy/2 Gy/F for GI and GII and 71.3 Gy/2.3 Gy/F for GIII and GIV. The Normal Tissue Complication Probability NTCPs (%) results for rectum = 9.5, 7.1, 5.18, and 22.46 for GI, GII, GIII, and GIV. The NTCP (%) for bladder = 0.05 for GI; 0.041 for GII; 0.0 and 1.67 for GIII and GIV. The EAR (/10000PY) for rectum and bladder are: 0.07(GII), 1.71(GIII), 1.60(GIV), and 6.30(GI), 0.01 (GII), 0.46(GIII), and 0.46(GIV), respectively. Minor toxicity for OARs when using HT but the risk is significant for bladder for HT and VMAT.