Is there a relation between the radiation dose to the different sub-segments of the lower urinary tract and urinary morbidity after brachytherapy of the prostate with I-125 seeds?

Abstract Background and Purpose To investigate possible relationships between the dose to the sub-segments of the lower urinary tract and lower urinary tract symptoms (LUTS) after brachytherapy of the prostate. Materials and Methods This study involved 225 patients treated for prostate cancer with I-125 seeds. Post-implant dose-volume histograms of the prostate, urethra, bladder wall, bladder neck and external sphincter were determined. Endpoints were the mean and the maximum International Prostate Symptom Score (IPSS) during the first 3 months after the treatment. For binary analysis the patients were stratified in a group with enhanced LUTS and a group with non-enhanced LUTS. Results The dose to 0.5 cm 3 of the bladder neck ‘ D 0.5cc -blne’ ( p  = 0.002 and p  = 0.005), the prostate volume prior to treatment ‘ V pr -0’ ( p  = 0.005 and p  = 0.024) and the pre-treatment IPSS (both p D 0.5cc -blne ⩾ 175 Gy and a V pr -0 ⩾ 42 cm 3 , 68% suffered from enhanced LUTS, against just 30% of the other patients ( p Conclusions Pre-treatment IPSS, prostate volume and dose to the bladder neck are correlated with post-implant IPSS. A combination of a large prostate and a high dose to the bladder neck is highly predictive for enhanced early LUTS.