HIGH DOSE RATE BRACHYTHERAPY AS MONOTHERAPY FOR PROSTATE CANCER: FIVE YEAR RESULTS

Abstract

Purpose: the aim of the study is to assess the effectiveness and safety of prostate cancer treatment (PCa) with high dose rate brachytherapy (BT-HDR) in monotherapy on 5 years of follow-up. Materials and methods: BT-HDR is performed in 198 patients of PCa. The fractionation schedule was presented by two options: two fractionations of 13 Gy in the first group (67 people) and three fractionations of 11.5 Gy in the second (131 patients). The treatment was carried out with 192Ir (Microselectron). Results: the median for patient care was: I group - 59.2 (41.4-90.3), II - 56.1 (39.4-86.4) months. During the follow-up, no patients died from the progression of the PCa. The three-year survival rate without biochemical progression was 98.5%, while the second group had 92.8%; 88.8% and 88.1%, respectively. There were no significant differences in survival rates between the BT-HDR fractionation regimes compared. In most cases, late genito-urinary radiation toxicity was represented by changes that could be characterized as 1st degree. A total of 161 patients with a three-year follow-up period had three cases (1.8%) radiation-induced stenosis urethra (complications of 3 degrees): two of them in the first group, one in the second group. Only one patient (I group) (1.5%) recorded late recto-intestinal toxicity of the 2nd degree. There were no third or higher violations in the observed groups. Conclusions: the studied mono-modes of fractionation of BT- HDR PCa (two factions of 13 Gy and three factions of 11.5 Gy) demonstrated quite acceptable indicators of effectiveness and safety with a five-year period of observation. It has been established that there are no significant differences in the frequency of biochemical relapses, as well as the severity of early and late radiation toxicity in the groups compared.