Dose-response in radiotherapy for localized prostate cancer: Results of the Dutch multicenter randomized phase III trial comparing 68 Gy of radiotherapy with 78 Gy

Stephanie TH Peeters, WD Heemsbergen, PCM Koper, Wim Putten, A Slot, MFH Dielwart, JMG Bonfrer, Luca Incrocci, Joos V Lebesque*

*Corresponding author for this work

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Abstract

Purpose
To determine whether a dose of 78 Gy improves outcome compared with a conventional dose of
68 Gy for prostate cancer patients treated with three-dimensional conformal radiotherapy.
Patients and Methods
Between June 1997 and February 2003, stage T1b-4 prostate cancer patients were enrolled onto
a multicenter randomized trial comparing 68 Gy with 78 Gy. Patients were stratified by
institution, age, (neo)adjuvant hormonal therapy (HT), and treatment group. Four treatment
groups (with specific radiation volumes) were defined based on the probability of seminal
vesicle involvement. The primary end point was freedom from failure (FFF). Failure was
defined as clinical failure or biochemical failure, according to the American Society of
Therapeutic Radiation Oncology definition. Other end points were freedom from clinical failure
(FFCF), overall survival (OS), and toxicity.
Results
Median follow-up time was 51 months. Of the 669 enrolled patients, 664 were included in the
analysis. HT was prescribed for 143 patients. FFF was significantly better in the 78-Gy arm
compared with the 68-Gy arm (5-year FFF rate, 64% v 54%, respectively), with an adjusted hazard
ratio of 0.74 (P .02). No significant differences in FFCF or OS were seen between the treatment
arms. There was no difference in late genitourinary toxicity of Radiation Therapy Oncology Group
and European Organisation for Research and Treatment of Cancer grade 2 or more and a slightly
higher nonsignificant incidence of late gastrointestinal toxicity of grade 2 or more.
Conclusion
This multicenter randomized trial shows a significantly improved FFF in prostate cancer patients
treated with a higher dose of radiotherapy.
Original languageUndefined/Unknown
Pages (from-to)1990-1996
Number of pages7
JournalJournal of Clinical Oncology
Volume24
Issue number13
DOIs
Publication statusPublished - May 2006

Research programs

  • EMC MM-03-32-04

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