SBRT, 7 year study, quality of life and toxicity

OBJECTIVES: Stereotactic body radiation therapy (SBRT) yields excellent disease control for low- and intermediate-risk prostate cancer by delivering high doses of radiation in a small number of fractions.

Our report presents a 7-year update on treatment toxicity and quality of life (QOL) from 515 patients treated with prostate SBRT.

METHODS: From 2006 to 2009, 515 patients with clinically localized, low-, intermediate-, and high-risk prostate cancer were treated with SBRT using Cyberknife technology. Treatment consisted of 35-36.25 Gy in 5 fractions. Seventy-two patients received hormone therapy. Toxicity was assessed at each follow-up visit using the expanded prostate cancer index composite (EPIC) questionnaire and the radiation therapy oncology group urinary and rectal toxicity scale.

RESULTS: Median follow-up was 72 months. The actuarial 7-year freedom from biochemical failure was 95.8, 89.3, and 68.5% for low-, intermediate-, and high-risk groups, respectively (p < 0.001). No patients experienced acute Grade 3 or 4 acute complications. Fewer than 5% of patients had any acute Grade 2 urinary or rectal toxicity. Late toxicity was low, with Grade 2 rectal and urinary toxicity of 4 and 9.1%, respectively, and Grade 3 urinary toxicity of 1.7%. Mean EPIC urinary and bowel QOL declined at 1 month post-treatment, returned to baseline by 2 years and remained stable thereafter. EPIC sexual QOL declined by 23% at 6-12 months and remained stable afterwards. Of patients potent at baseline evaluation, 67% remained potent at last follow-up.

CONCLUSION: This study suggests that SBRT, when administered to doses of 35-36.25 Gy, is efficacious and safe. With long-term follow-up in our large patient cohort, we continue to find low rates of late toxicity and excellent rates of biochemical control.

Written by: 
Katz AJ, Kang J.   Are you the author? 
Flushing Radiation Oncology Services, Flushing, NY, USA; Department of Medicine, NYU Langone Medical Center, New York, NY, USA.

 

Reference: Front Oncol. 2014 Oct 28;4:301. 
doi: 10.3389/fonc.2014.00301

PubMed Abstract
PMID: 25389521

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