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Improved irritative voiding symptoms 3 years after stereotactic body radiation therapy for prostate cancer.
By Z. Rana, R.A. Cyr, L.N. Chen, B.S. Kim, R.A. Moures, T.M. Yung, S. Lei, B.T. Collins, S Suy, A. Dritschilo, J.H. Lynch and S.P. Collins.
Frontier in Oncology, Volume 21, Issue 4, Article 290, 2014, pages 1-8
Stereotactic Body Radiation Therapy (SBRT) is an ablative procedure for clinically localized prostate cancer, which eliminates both cancerous and normal epithelium, thus inducing a decrease in the prostate size of about 35% within the first 2 years following completion of the procedure.
SBRT is followed by acute irritative voiding symptoms (storage symptoms), and the incidence is comparable to other external radiotherapy modalities, and may be less than brachytherapy .
In this study the Authors examined the incidence and prevalence of storage symptoms, following SBRT in patients affected by clinically localized prostate cancer in a long term follow up. Patients eligible for this study underwent SBRT without supplemental conventional radiation therapy and showed a minimum follow up of 3 years.
Urinary symptoms were assessed by the International prostate Symptoms Score (IPSS). For the examination of nocturia, the patients’ response was classified into four clinically relevant categories (none, 1 time, 2 times, and ≥3 times). Quality of life was investigated on the first day of SBRT treatment and during follow up every 3 months for the first year and every six months for the second and third year.
An acute increase in irritative symptoms was observed after the procedure in the majority of patients, at 1 month after treatment, with frequency urgency and nocturia all increasing in the same manner. The symptoms returned to baseline within 3 months in the majority of cases. This effect is thought to be caused by inflammation of the bladder neck/uretra induced by the procedure. With regards to nocturia, patients presented with a pre-treatment incidence of the symptom of 38.4% (1 time per night) and 25.6% (2 times per night). This confirmed the high incidence of nocturia in elderly patients with prostate cancer. After treatment, nocturia increased transiently at 1 month and then again at 12 months, but came back to pretretament values at three years follow up.
The Authors concluded that, although urinary symptoms and particularly symptoms of the filling phase of the bladder are frequent and more bothersome, they remain underinvestigated. They indicated that a more comprehensive understanding of urinary conditions after SBRT would help both physicians and patients to have more realistic expectations from treatment.
Irritative voiding symptoms are common in elderly men and following prostate radiotherapy. There is limited clinical data on the impact of hypofractionated treatment on irritative voiding symptoms. This study sought to evaluate urgency, frequency, and nocturia following stereotactic body radiation therapy (SBRT) for prostate cancer.
Patients treated with SBRT monotherapy for localized prostate cancer from August 2007 to July 2011 at Georgetown University Hospital were included in this study. Treatment was delivered using the CyberKnife® with doses of 35–36.25 Gy in five fractions. Patient-reported urinary symptoms were assessed using the International Prostate Symptom Score (IPSS) before treatment and at 1, 3, 6, 9, and 12 months post-treatment and every 6 months thereafter.
Two hundred four patients at a median age of 69 years received SBRT with a median follow-up of 4.8 years. Prior to treatment, 50.0% of patients reported moderate to severe lower urinary tract symptoms (LUTS) and 17.7% felt that urinary frequency was a moderate to big problem. The mean prostate volume was 39 cc and 8% had prior procedures for benign prostatic hyperplasia. A mean baseline IPSS-irritative (IPSS-I) score of 4.8 significantly increased to 6.5 at 1 month (p < 0.0001), however returned to baseline at 3 months (p = 0.73). The IPSS-I score returned to baseline in 91% of patients by 6 months and 96% of patients by 2 years. Transient increases in irritative voiding symptoms were common at 1 year. The mean baseline IPSS-I score decreased to 4.4 at 24 months (p = 0.03) and 3.7 at 36 months (p < 0.0001). In men with moderate to severe LUTS (IPSS ≥ 8) at baseline, the mean IPSS-I decreased from a baseline score of 6.8–4.9 at 3 years post-SBRT. This decrease was both statistically (p < 0.0001) and clinically significant (minimally important difference = 1.45). Only 14.6% of patients felt that urinary frequency was a moderate to big problem at 3 years post-SBRT (p = 0.23).
Treatment of prostate cancer with SBRT resulted in an acute increase in irritative urinary symptoms that peaked within the first month post-treatment. Irritative voiding symptoms returned to baseline in the majority of patients by 3 months post-SBRT and were actually improved from baseline at 3 years post-SBRT.