Permanent I prostate brachytherapy for castration-resistant prostate cancer.

Objective: To evaluate the clinical significance of permanent I prostate brachytherapy in patients with castration-resistant prostate cancer.

Methods: A retrospective study of 45 patients with castration-resistant prostate cancer from the Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, China was carried out. Patients were divided into two groups according to different treatments: 21 patients received endocrine therapy alone (control group), and 24 patients underwent brachytherapy combined with endocrine therapy (treatment group). Prostate-specific antigen progression-free survival, cancer-specific survival, overall survival and quality of life of the two groups were compared.

Results: The median prostate-specific antigen progression-free survival and cancer-specific survival of the treatment group were 29 months (interquartile range 25-37 months) and 37 months (interquartile range 30-50 months), respectively. These were significantly longer than those of the control group (both P < 0.05). Prostate-specific antigen (before androgen deprivation therapy and before brachytherapy), prostate volume, Gleason score, clinical stage and brachytherapy were associated with prostate-specific antigen progression-free survival and cancer-specific survival on univariate analysis. For the quality of life after treatment, urinary symptoms/problems at 1 month after brachytherapy compared with the control group had a statistically significant difference and clinically relevant deterioration, but after 6 months there were no statistically significant differences and clinically relevant deterioration. Compared with the control group, the physical functioning, social functioning, global health and general physical discomfort of the treatment group were significantly improved.

Conclusions: Brachytherapy with I seed implantation can effectively prolong survival of patients with castration-resistant prostate cancer and, to a certain extent, improve patients' quality of life.