To investigate long-term changes in lower urinary tract symptoms (LUTS) in patients with prostate cancer (PC) who underwent low-dose-rate brachytherapy with iodine-125 (LDR-BT).

In this retrospective study, 313 patients with localized PC underwent LDR-BT at Gifu University hospital between August 2004 and December 2013. The International Prostate Symptom Score (IPSS), Overactive Bladder Symptom Score (OABSS), and quality of life due to urinary symptoms (IPSS-QOL) were measured before LDR-BT; at 1, 3, 6, 9, 12, 24, 36, 48, and 60 months after LDR-BT; and annually thereafter. Study endpoints were chronological changes in IPSS, OABSS, and IPSS-QOL compared to pretreatment values. A multivariable non-linear regression model with robust sandwich estimator evaluated association between outcomes and time with adjustment for covariates.

All scores worsened immediately after LDR-BT compared to preoperative scores. However, symptoms improved with time and returned to baseline in 18-36 months. After a 5-year follow-up after LDR-BT, OABSS significantly worsened in almost all patients compared to baseline although there were gradual improvements in less than 5 years after LDR-BT.

Our results may be of clinical importance in selecting treatment modalities for patients with localized PC and long-term survival after definitive therapy.