Urinary tract symptoms that should be improved to enhance post-operative urinary quality of life in patients treated with low-dose-rate brachytherapy for prostate cancer: An importance–performance analysis

Purpose:
To evaluate international prostate symptom score and urinary quality of life in patients with prostate cancer who underwent low-dose-rate brachytherapy, and to identify lower urinary tract symptoms that must be improved to enhance post-operative urinary quality of life and factors associated with lower urinary tract symptoms.

Material and methods:
This study included 193 patients who underwent low-dose-rate brachytherapy alone (145 Gy). Importance–performance analysis was conducted to identify lower urinary tract symptoms that should be prioritized to improve urinary quality of life. Association between lower urinary tract symptom scores and each factor was investigated. Receiver operating characteristic curve analysis was used to evaluate dosimetric parameters related to lower urinary tract symptom score to predict an average score of ≥ 3. Cut-off values were determined.

Results:
One to nine months post-implantation was a period of significantly increased urinary quality of life scores compared with baseline (p < 0.05 each). The importance–performance analysis conducted for 1-9 months revealed that frequency, nocturia, and weak stream required improvement. Multivariate analysis showed that each lower urinary tract symptom score presented a significant association with its baseline value (p < 0.001 each, positive correlation). Frequency, incomplete emptying, urgency, and straining scores were significantly associated with prostate volume, whereas weak stream and intermittency scores were associated with dose covering 90% of the prostate and dose covering 90% of the urethra, respectively (p < 0.05 each, positive correlations). Cut-off values for these doses were 167.01 Gy and 136.84 Gy, respectively.

Conclusions:
This study highlights the importance of prioritizing specific lower urinary tract symptoms for improvement in post-operative urinary quality of life, and identifies the associated factors that can help in personalized treatment planning and goal-setting for better patient satisfaction.