Lower urinary tract morbidity after prostate brachytherapy with cesium-131.

Abstract

97 Background: Cesium-131 is a relatively new radioisotope for prostate brachytherapy (PB), with limited long-term data for toxicity profiles. Here we report our 1-year follow up for severity and time to resolution of lower urinary tract toxicity using American Urological Association (AUA) and Expanded Prostatic Cancer Index Composite (EPIC) scoring. Methods: 186 patients with prostate cancer [NCCN risk category: Low (n=79), Intermediate (n=83), and High (n=24)] treated with cesium-131 PB alone (n=128) or combined with external beam radiation therapy (EBRT) + PB (n=58) were followed as part of a longitudinal prospective study. Patients completed AUA and EPIC surveys pre-operatively and at 2 weeks, 4 weeks, 3, 6, 9, and 12 months post-operatively. The mean prostatic volume was 41.3 cm3 (range 14.9 – 89.1) and the mean prostate D90 and V100 were 105.7% and 92.4%, respectively. Outcomes were analyzed using descriptive statistics and student t-tests, with an AUA score increase > 4 and EPIC score decrease > 10 points considered clinically significant. Results: Results are shown in the table below. As expected, there was acute urinary toxicity associated with PB. This is seen in the urinary summary score as well as in every one of the subset scales. These were most significant at the 2 and 4 week marks. The urinary summary score and every subscale improved to within 10 points of baseline by 3 months and stayed there through the 12 months of follow-up. Similar findings were reflected in the AUA scores. Conclusions: For men undergoing PB with cesium-131, results for AUA and EPIC scoring are concordant with no clinically significant differences in lower urinary tract symptoms are observed after 3 months relative to pre-operative values. The largest decreases in symptomatology scoring were witnessed in the irritative/obstructive subset, while the smallest changes relative to pre-operative values were noted in the incontinence subset. [Table: see text] No significant financial relationships to disclose.