Changes in morphologic patterns over a time course following radiation and their corresponding PSA levels were investigated. A total of 60 patients with prostatic adenocarcinoma treated with brachytherapy between 1993 and 2003, who had at least one positive post-radiation biopsy, were evaluated for their morphologic patterns as well as the associated PSA levels. A total of 86 positive post-radiation biopsies were performed. There were 17 patients with more than 1 positive post-radiation biopsy and 43 patients with single positive biopsy. Among the 17 with more than 1 positive biopsy, the morphologic patterns of treatment effect were commonly followed by patterns without treatment effect on subsequent biopsies. The morphology without treatment effect followed by treatment effect was infrequent. Furthermore, over a time course, the later the positive post-radiation biopsy, the much more common the morphologic pattern without treatment effect was observed. Compared to the morphologic pattern with treatment effect, the morphology without treatment effect was associated with a significantly higher PSA level (mean 0.69 versus 2.78 ng/ml,
