DETERMINANTS OF SIGNIFICANT VOIDING DYSFUNCTION AFTER IODINE-125 BRACHYTHERAPY FOR LOCALIZED PROSTATE CANCER AT THE KORLE BU TEACHING HOSPITAL.

Abstract

Background: Prostate cancer is the second most commonly diagnosed cancer amongst men after lung cancer accounting for 14.1% of cancers in men. Both incidence and mortality vary tremendously across geographic regions and populations reflecting multifactorial impacts of genetic variation; diet, lifestyle, environmental factors, access to care and variations in use of prostate specific antigen (PSA)-based screening policies. With the increasing use of PSA as a screening tool in Sub Saharan Africa many more cases of localized cancer of the prostate are being diagnosed. Radical prostatectomy and radiation therapy remain the main options for active treatment of localized cancer of the prostate. Low dose rate brachytherapy has recently (2008) become available in Ghana. Patients are therefore able to participate in the decision making process on which form of treatment they should undergo. With largely similar oncologic outcomes from radical prostatectomy and brachytherapy, the complications associated with each procedure plays a major role in deciding on the treatment option. Studies in other jurisdictions have pointed at urinary morbidity as the main complication from brachytherapy. Furthermore, some studies point to different factors as predicting which patients are most at risk of significant urinary morbidity after low dose rate brachytherapy. Local data for this sub-region would be important to guide local practice. Objective: To determine the factors that are associated with significant voiding dysfunction at one month after I-125 prostate brachytherapy of men undergoing the procedure at the Korle Bu Teaching Hospital. Methodology: Patients presenting for prostate brachytherapy were recruited into this prospective study. Basic demographic and disease related data were taken including the pre –operative International Prostate Symptom Score(IPSS). Peri-operative data such as u30 and D90 were also documented. The post-operative IPSS were evaluated monthly for 4 months and documented together with any other complaints at one month. Post-operative follow up evaluation was done via phone interviews. Results: Significant voiding dysfunction at 1month post brachytherapy occurred in 67.7% of the study population. Two persons representing 2.8% had Acute Retention of Urine (AROU) with both occurring within 2 days of the procedure. The most common complaints at 1month were related to the urinary system. At one month, the median IPSS score had increased from 5 to 11. It gradually declined thereafter but did not reach pre-procedure levels during the four month follow up period. Digital Rectal Examination (p= 0.686), Gleason score (p= 0.799), prostate volume (p= 0.137), Pre-biopsy PSA (p= 0.949), number of needles used (p= 0.465), number of seeds implanted (p=0.724) and u30 (p= 0.9310) all showed no statistical correlation with the occurrence of significant voiding dysfunction at 1month. Pre-operative IPSS and the prior use of tamsulosin both showed statistical significance on bivariate regression analysis with p= 0.001 and p<0.011 respectively. However these two parameters failed to show statistical significance when subjected to multivariate regression analysis (p= 0.635 and p= 0.069 for pre-operative IPSS and prior use of tamsulosin respectively). D90 and pre-operative nocturia (as scored on IPSS) were predictive of occurrence of significant voiding dysfunction at one month both on bivariate and multivariate regression analysis. The D90 scores analysis yielded p=0.009 and p=0.037 on bivariate and multivariate analysis respectively. With regards the pre-operative nocturia score, p<0.001 and p=0.002 on bivariate and multivariate analysis respectively. Conclusion: The study confirmed that prostate brachytherapy significantly worsens voiding function at one month. D90 and preoperative nocturia value on IPSS scoring were predictors of significant voiding dysfunction at one month.