Evaluating the effectiveness of tadalafil for the treatment of lower urinary tract symptoms and erectile dysfunction after low-dose-rate brachytherapy for prostate cancer

This study investigated the effectiveness of phosphodiesterase-5 (PDE5) inhibitor tadalafil (Cialis) for the treatment of lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) after low-dose-rate (LDR) brachytherapy (BT) in patients with localized prostate cancer. The data showed that tadalafil improved the LUTS and ED outcomes in these patients after LDR-BT.

Localized prostate cancer (PCa) is a form of cancer that has not spread beyond the prostate gland. It can be treated by surgery, radiation, or hormone therapy. LDR-BT is a type of radiation therapy that uses a radioactive implant device into the cancer tissue. It slowly releases radiation at low doses and kills cancer cells over time. However, these patients often experience LUTS and ED.

LUTS may include involuntary loss of urine (incontinence), needing to pass urine frequently, or discomfort when passing urine. Tamsulosin is commonly used to treat LUTS. It works by relaxing the muscles in the prostate and the bladder.

PDE5 inhibitors such as tadalafil (Cialis) have been shown to improve LUTS and ED symptoms in patients with benign prostatic hyperplasia. Tadalafil works by increasing the blood flow to the penis and helps to maintain an erection. Whether tadalafil improves both LUTS and ED outcomes in patients treated with LDR-BT for PCa is unknown.

This study involved 95 patients with PCa who received LDR-BT. The patients were split into two groups. 45 patients in group 1 received tamsulosin and 50 patients in group 2 received tadalafil. The International Prostate Symptom Score (IPSS) was measured before and after treatment. This questionnaire can be used to screen for, rapidly diagnose, and track the symptoms of LUTS. Quality of life, erectile function, maximum urine flow rate, and the volume of urine left in the bladder after urination were also measured. Patients were followed every 3 months up to 1 year.

The average total IPSS scores improved in both groups at 1 year. There was a slightly higher improvement in the tadalafil group all time-points. At 9 months the total and storage score for IPSS was significantly better in the tadalafil group compared to the tamsulosin group.  

The Sexual Health Inventory for Men (SHIM) score (to measure the erectile function) in the tadalafil group was significantly better than that in the tamsulosin group at 6, 9, and 12 months after LRT-BT. There were no significant differences in the maximum urine flow rate and the volume of urine left in the bladder after urination between the 2 groups.

This study concluded that tadalafil could be an effective option for the management of LUTS and ED outcomes after low-dose-rate brachytherapy in patients with PCa.

This study had a very small number of patients. Also, it included only Japanese men. Larger studies on more diverse populations are needed for more conclusive results.