Local relapses after prostatic curie-therapy by permanent implants: radio-resistant prostate cancers or bad quality implant

The assessment of the quality of a permanent implant of grains for a prostate cancer treatment is based on the dosimetric plan performed before the grain implantation or shortly after. The authors report a study of the correlation between 'under-dosed' areas assessed at the time of relapse, and intra-prostatic relapse sites. The study is based on 24 cases of proved intra-prostatic relapse. The prostatic volume has been divided into 12 areas, and three types of under-dosing have been defined. Parameters are the dose received by 90 per cent of the volume, and the volume receiving 100 per cent of the dose. A correlation appears between positive biopsies and 'under-dosing'. This corresponds to a bad quality implantation of grains for patients in a situation of prostatic relapse after implantation. Short communication