Phase II study of hypofractionated image-guided radiotherapy for localized prostate cancer: Outcomes of 55Gy in 16 fractions at 3.4Gy per fraction

Wu, Jackson S.Y.; Brasher, Penelope M.A.; El-Gayed, Ali; Pervez, Nadeem; Tai, Patricia T.; Robinson, John; Skarsgard, David; Joseph, Kurian; Sia, Michael A.; Pearcey, Robert G.

doi:10.1016/j.radonc.2011.12.020

« Previous Next »Radiotherapy & Oncology
Volume 103, Issue 2 , Pages 210-216, May 2012

Phase II study of hypofractionated image-guided radiotherapy for localized prostate cancer: Outcomes of 55Gy in 16 fractions at 3.4Gy per fraction☆

Jackson S.Y. Wu
- Department of Oncology, University of Calgary, Alberta, Canada
- Corresponding author. Address: Tom Baker Cancer Centre, 1331 – 29th St. NW, Calgary, Alberta, Canada T2N 4N2.
Penelope M.A. Brasher
- Centre for Clinical Epidemiology and Evaluation, University of British Columbia, Vancouver, Canada
Ali El-Gayed
- Department of Radiation Oncology, University of Saskatchewan, Saskatoon, Canada
Nadeem Pervez
- Department of Radiation Oncology, University of Alberta, Edmonton, Canada
Patricia T. Tai
- Department of Radiation Oncology, Allan Blair Cancer Centre, Saskatchewan, Canada
John Robinson
- Department of Oncology, University of Calgary, Alberta, Canada
David Skarsgard
- Department of Oncology, University of Calgary, Alberta, Canada
Kurian Joseph
- Department of Radiation Oncology, University of Alberta, Edmonton, Canada
Michael A. Sia
- Department of Oncology, University of Calgary, Alberta, Canada
Robert G. Pearcey
- Department of Radiation Oncology, University of Alberta, Edmonton, Canada

Received 27 June 2011; received in revised form 17 November 2011; accepted 28 December 2011. published online 27 January 2012.

Abstract

Purpose

To estimate the late morbidity of a novel, hypofractionated external beam radiotherapy schedule of 55Gy in 16 fractions (4 fractions/week, 3.4Gy per fraction) for localized prostate cancer.

Methods and materials

A multi-center phase 2 study enrolled seventy-three patients between September 2004 and June 2006. After insertion of fiducial gold markers, they were treated with image-guidance (IGRT) using conformal techniques with intensity-modulation, if necessary, and then followed every 6months for toxicity rating and PSA. Patient reported outcomes were collected yearly. Median follow up was 4.6years.

Results

At 4years post-radiotherapy, the cumulative incidence of combined urinary and bowel grade 3 toxicity was 7% (95% CI 3–16%) and grade 2+ was 33% (95% CI 24–46%). All except two patients recovered from their grade 3 events. Patient-reported reduction of function was most pronounced at year two for urinary function (mean −7, SD 16), and at year one for bowel function (mean −7, SD 21). The cumulative incidence of biochemical (PSA nadir+2) or biopsy-proven relapse at 4years was 9% (95% CI 4–18%).

Conclusions

Hypofractionated radiotherapy is clinically feasible and more convenient than conventional schedules for patients with localized prostate cancer. Phase 3 multicenter studies are on-going (NCT00126165).

Keywords: Hypofractionation, Image-guided radiotherapy, Prostate cancer, Clinical trial, Patient-reported outcomes