Does the outcome of prostate cancer patients with large prostates differ from small prostate size in permanent seed, low dose-rate brachytherapy?

Objective: Brachytherapy has good results in the treatment of early prostate cancer (PC). The procedure is challenging in large prostates, and the optimal prostate volume for brachytherapy was previously defined as ≤40 ml. This study analysed the outcome of PC patients with small (group A) and large (group B) prostate volume in prospective data.

Material and methods: The material consisted of 535 consecutive patients treated with brachytherapy in Kuopio University Hospital. The mean follow-up time was nearly 6 years. Prostate-specific antigen (PSA) failure was defined as PSA rising ≥2.0 μg/l above nadir. A PSA bounce was defined as a rise in PSA of ≥0.2 μg/l. The causes of death were recorded.

Results: A bounce was recorded more frequently in group A (30%) than in group B (18%) (p = 0.006). A bounce correlated with young age predicted a favourable outcome in both groups. PSA failure rate was similar in both groups: 13% and 12% in groups A and B, respectively. Post-treatment PSA ≤0.5 μg/l was the only independent prognostic factor associated with PSA failure in both groups (p < 0.0001, both groups). PC survival was 98.4% in both groups. Overall survival was 91% and 94% in groups A and B, respectively (p = not significant).

Conclusions: There were no differences between the PC patients with small and large prostate volumes treated with brachytherapy with respect to PSA failure rate, PC survival or overall survival. All patients, independent of prostate size, are potential candidates for brachytherapy.