Purpose/objective(s)Stereotactic body radiation therapy (SBRT) is emerging as a minimally invasive alternative to brachytherapy to deliver highly conformal, dose-­escalated radiation therapy (RT) to the prostate. SBRT alone may not adequately cover the tumor extensions outside the prostate commonly seen in unfavorable prostate cancer. External beam radiation therapy (EBRT) with high dose rate brachytherapy boost is a proven effective therapy for unfavorable prostate cancer. This study reports on early prostate-specific antigen and prostate cancer-specific quality of life (QOL) outcomes in a cohort of unfavorable patients treated with intensity-modulated radiation therapy (IMRT) and SBRT boost.Materials/methodsProstate cancer patients treated with SBRT (19.5 Gy in three fractions) followed by fiducial-guided IMRT (45–50.4 Gy) from March 2008 to September 2012 were included in this retrospective review of prospectively collected data. Biochemical failure was assessed using the Phoenix definition. Patients completed the expanded prostate cancer index composite (EPIC)-26 at baseline, 1 month after the completion of RT, every 3 months for the first year, then every 6 months for a minimum of 2 years.ResultsOne hundred eight patients (4 low-, 45 intermediate-, and 59 high-risk) with median age of 74 years completed treatment, with median follow-up of 4.4 years. Sixty-four percent of the patients received androgen deprivation therapy prior to the initiation of RT. The 3-year actuarial biochemical control rates were 100 and 89.8% for intermediate- and high-risk patients, respectively. At the initiation of RT, 9 and 5% of men felt their urinary and bowel function was a moderate to big problem, respectively. Mean EPIC urinary and bowel function and bother scores exhibited transient declines, with subsequent return to near baseline. At 2 years posttreatment, 13.7 and 5% of men felt their urinary and bowel function was a moderate to big problem, respectively.ConclusionAt 3-year follow-up, biochemical control was favorable. Acute urinary and bowel symptoms were comparable to conventionally fractionated IMRT and brachytherapy. Patients recovered to near their baseline urinary and bowel function by 2 years posttreatment. A combination of IMRT with SBRT boost is well tolerated with minimal impact on prostate cancer-specific QOL.

BackgroundStereotactic body radiation therapy (SBRT) delivers high doses of radiation to the prostate while minimizing radiation to the adjacent critical organs. Large fraction sizes may increase urinary morbidity due to unavoidable treatment of the prostatic urethra. This study reports rates of acute urinary morbidity following SBRT for localized prostate cancer with prophylactic alpha-adrenergic antagonist utilization and urethral dose reduction (UDR).MethodsFrom April 2013 to September 2014, 102 patients with clinically localized prostate cancer were treated with robotic SBRT to a total dose of 35–36.25 Gy in five fractions. UDR was employed to limit the maximum point dose of the prostatic urethra to 40 Gy. Prophylactic alpha-adrenergic antagonists were initiated 5 days prior to SBRT and continued until resolution of urinary symptoms. Quality of life (QoL) was assessed before and after treatment using the American Urological Association Symptom Score (AUA) and the Expanded Prostate Cancer Index Composite-26 (EPIC-26). Clinical significance was assessed using a minimally important difference (MID) of one half SD change from baseline.ResultsOne hundred two patients underwent definitive prostate SBRT with UDR and were followed for 3 months. No patient experienced acute urinary retention requiring catheterization. A mean baseline AUA symptom score of 9.06 significantly increased to 11.83 1-week post-SBRT (p = 0.0024) and 11.84 1-month post-SBRT (p = 0.0023) but returned to baseline by 3 months. A mean baseline EPIC-26 irritative/obstructive score of 87.7 decreased to 74.1 1-week post-SBRT (p < 0.0001) and 77.8 1-month post-SBRT (p < 0.0001) but returned to baseline at 3 months. EPIC-26 irritative/obstructive score changes were clinically significant, exceeding the MID of 6.0. At baseline, 8.9% of men described their urinary function as a moderate to big problem, and that proportion increased to 37.6% 1 week following completion of SBRT before returning to baseline by 3 months.ConclusionStereotactic body radiation therapy for localized prostate cancer with utilization of prophylactic alpha-adrenergic antagonist and UDR was well tolerated as determined by acute urinary function and bother, and symptoms were comparable to those observed following conventionally fractionated external beam radiation therapy (EBRT). Longer follow-up is required to assess long-term toxicity and efficacy following SBRT with UDR.

BackgroundRecent data suggest that intensity-modulated radiation therapy (IMRT) plus brachytherapy boost for unfavorable prostate cancer provides improved biochemical relapse-free survival over IMRT alone. Stereotactic body radiation therapy (SBRT) may be a less invasive alternative to brachytherapy boost. Here, we report the 3-year gastrointestinal (GI) and genitourinary (GU) toxicities of IMRT plus SBRT boost.Materials and methodsBetween March 2008 and September 2012, patients with prostate cancer were treated with robotic SBRT (19.5 Gy in three fractions) followed by fiducial-guided IMRT (45–50.4 Gy) on an institutional protocol. Toxicity was prospectively graded using the common terminology criteria for adverse events version 4.0 (CTCAEv.4) at the start of and at 1- to 6-month intervals after therapy. Rectal telangiectasias were graded using the Vienna Rectoscopy Score (VRS).ResultsAt a median follow-up of 4.2 years (2.4–7.5), 108 patients (4 low-, 45 intermediate-, and 59 high-risk) with a median age of 74 years (55–92) were treated with SBRT plus IMRT, with 8% on anticoagulation and an additional 48% on antiplatelet therapy at the start of therapy. The cumulative incidence of late ≥grade 2 GI toxicity was 12%. Of these, 7% were due to late rectal bleeding, with six patients requiring up to two coagulation procedures. One patient with rectal telangiectasias was treated with hyperbaric oxygen (grade 3 toxicity). No rectal fistulas or stenoses were observed. Ten patients had multiple non-confluent telangiectasias (VRS grade 2), and three patients had multiple confluent telangiectasias (VRS grade 3). The cumulative incidence of late grade 3 GU toxicity was 6%. Most late toxicities were due to hematuria requiring bladder fulguration. There were no late ≥grade 4 GU toxicities.ConclusionRates of clinically significant GI and GU toxicities are modest following IMRT plus SBRT boost. Future studies should compare cancer control, quality of life, and toxicity with other treatment modalities for patients with high-risk prostate cancer.

Background: 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.Methods: 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.Results: 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).Conclusion: 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.

BackgroundProctitis following prostate cancer radiation therapy is a primary determinant of quality of life (QOL). While previous studies have assessed acute rectal morbidity at 1 month after stereotactic body radiotherapy (SBRT), little data exist on the prevalence and severity of rectal morbidity within the first week following treatment. This study reports the acute bowel morbidity 1 week following prostate SBRT.Materials and methodsBetween May 2013 and August 2014, 103 patients with clinically localized prostate cancer were treated with 35–36.25 Gy in five fractions using robotic SBRT delivered on a prospective clinical trial. Bowel toxicity was graded using the Common Terminology Criteria for Adverse Events version 4.0 (CTCAEv.4). Bowel QOL was assessed using the EPIC-26 questionnaire bowel domain at baseline, 1 week, 1 month, and 3 months. Time-dependent changes in bowel symptoms were statistically compared using the Wilcoxon signed-rank test. Clinically significant change was assessed by the minimally important difference (MID) in EPIC score. This was defined as a change of 1/2 standard deviation (SD) from the baseline score.ResultsOne-hundred and three patients with a minimum of 3 months of follow-up were analyzed. The cumulative incidence of acute grade 2 gastrointestinal (GI) toxicity was 23%. There were no acute ≥ grade 3 bowel toxicities. EPIC bowel summary scores maximally declined at 1 week after SBRT (−13.9, p < 0.0001) before returning to baseline at 3 months after SBRT (+0.03, p = 0.94). Prior to treatment, 4.9% of men reported that their bowel bother was a moderate to big problem. This increased to 28.4% (p < 0.0001) 1 week after SBRT and returned to baseline at 3 months after SBRT (0.0%, p = 0.66). Only the bowel summary and bowel bother score declines at 1 week met the MID threshold for clinically significant change.ConclusionThe rate and severity of acute proctitis following prostate SBRT peaked at 1 week after treatment and returned to baseline by 3 months. Toxicity assessment at 1 week can therefore minimize recall bias and should aid in the design of future clinical trials focused on accurately capturing and minimizing acute morbidity following SBRT.