Hypofractionated radiation therapy (66 Gy in 22 fractions at 3 Gy per fraction) for favorable-risk prostate cancer: Long-term outcomes - Abstract

PURPOSE: To report long-term outcomes of low- and intermediate-risk prostate cancer patients treated with high-dose hypofractionated radiation therapy (HypoRT).

METHODS AND MATERIALS: Patients with low- and intermediate-risk prostate cancer were treated using 3-dimensional conformal radiation therapy to a dose of 66 Gy in 22 daily fractions of 3 Gy without hormonal therapy. A uniform 7-mm margin was created around the prostate for the planning target volume, and treatment was prescribed to the isocenter. Treatment was delivered using daily ultrasound image-guided radiation therapy. Common Terminology Criteria for Adverse Events, version 3.0, was used to prospectively score toxicity. Biochemical failure was defined as the nadir prostate-specific antigen level plus 2 ng/mL.

RESULTS: A total of 129 patients were treated between November 2002 and December 2005. With a median follow-up of 90 months, the 5- and 8-year actuarial biochemical control rates were 97% and 92%, respectively. The 5- and 8-year actuarial overall survival rates were 92% and 88%, respectively. Only 1 patient died from prostate cancer at 92 months after treatment, giving an 8-year actuarial cancer-specific survival of 98%. Radiation therapy was well tolerated, with 57% of patients not experiencing any acute gastrointestinal (GI) or genitourinary (GU) toxicity. For late toxicity, the worst grade ≥2 rate for GI and GU toxicity was 27% and 33%, respectively. There was no grade >3 toxicity. At last follow-up, the rate of grade ≥2 for both GI and GU toxicity was only 1.5%.

CONCLUSIONS: Hypofractionation with 66 Gy in 22 fractions prescribed to the isocenter using 3-dimensional conformal radiation therapy produces excellent biochemical control rates, with moderate toxicity. However, this regimen cannot be extrapolated to the intensity modulated radiation therapy technique.

Written by:
Patel N, Faria S, Cury F, David M, Duclos M, Shenouda G, Ruo R, Souhami L.   Are you the author?
Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec, Canada.

Reference: Int J Radiat Oncol Biol Phys. 2013 Apr 15. pii: S0360-3016(13)00171-5.
doi: 10.1016/j.ijrobp.2013.02.010

PubMed Abstract
PMID: 23597418

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