Factors affecting urinary frequency after low‐dose‐rate brachytherapy for prostate cancer

Abstract

Objectives Lower urinary tract symptoms are transiently exacerbated by low‐dose‐rate brachytherapy (LDR‐BT) for prostate cancer and recover to pretreatment levels 1 year thereafter. Generally, these symptoms are influenced by temperature. We aimed to search for factors affecting the lower urinary tract symptoms after seed implant including seasons. Methods We retrospectively enrolled 812 patients who underwent LDR‐BT at Nara Medical University Hospital from January 2010 to December 2018 and for whom the International Prostate Symptom Score, Overactive Bladder Symptom Score, and frequency volume charts were available. We investigated the relationships between lower urinary tract symptoms, 24‐hours urinary frequency, 24‐hours urinary volume before and after seed implant, radiation dose, and season of seed implant. Results The mean age was 69.5 years. The mean prostate volume was 24.2 mL. The International Prostate Symptom Score, Overactive Bladder Symptom Score, and 24‐hours urinary frequency increased until 3 months and gradually decreased over 6 months after seed implant. Multiple linear regression analysis revealed that 24‐hours urinary frequency at 3 months after seed implant was significantly influenced by external beam radiotherapy, larger prostate volume before implant, higher 24‐hours urinary frequency at baseline, larger 24‐hours urinary volume at 3 months after implant, and performance of implant in summer. Conclusions Lower urinary tract symptoms worsened 3 months after seed implant of LDR‐BT regardless of the season of implant. The urinary frequency 3 months after seed implant was slightly lower when seed implant was performed in the summer.

Prognostic Factors for Resolution Delay of Lower Urinary Tract Symptoms in Patients with Prostate Cancer after Low-Dose-Rate Brachytherapy

“…A relatively large number of previous studies examining chronological changes regarding LUTS after LDR-BT have been reported [ 8 , 9 , 18 , 19 , 21 , 22 , 23 , 24 , 25 ]. Onishi et al [ 8 ] reported that patients who experienced acute dysuria 3 months after LDR-BT gradually improved over time and returned to baseline after 36 months.…”

“…Previous reports have shown an association between GU toxicity after LDR-BT and the delayed resolution of OABSS, and combination therapy with LDR-BT and EBRT has been associated with late GU toxicity and LUTS [ 8 , 17 , 19 , 21 , 23 , 24 ]. Tanaka et al reported that the incidence of urinary frequency and urgency of GU toxicity were significantly higher in patients treated with LDR-BT alone at 3 and 12 months following operation; however, there was no difference in the incidence of GU toxicity at 24 and 36 months [ 19 ].…”

“…Similarly, patients treated with a combination of LDR-BT and EBRT showed a worsening OABSS at 24 and 36 months following operation, but this was not seen in those treated with LDR-BT alone [ 8 ]. Uematsu et al [ 21 ] also showed that the urinary frequency 3 months after LDR-BT, using a frequency volume chart, was higher in combination therapy with EBRT. This may be due to the higher doses to the urethra and bladder in patients who received combined LDR-BT and EBRT than in those who received LDR-BT alone.…”

“…This may be due to the higher doses to the urethra and bladder in patients who received combined LDR-BT and EBRT than in those who received LDR-BT alone. Therefore, BED and UD30 are known to affect LUTS after LDR-BT [ 17 , 21 , 23 , 24 ]. A large American cohort study reported that BED, combined EBRT and LDR-BT, ADT, patient age, and PV did not affect long-term LUTS [ 27 ].…”