Comparing four volumetric modulated arc therapy beam arrangements for the treatment of early‐stage prostate cancer

Journal of Medical Radiation Sciences

Craig A. Elith BMRS (RT), BSc (Hons)²  Shane E. Dempsey PhD (Med. Rad. Sci) GradDipClinEpi, GradCertHEd, DipAppSci (MRT)¹ 

[1] School of Health Sciences, University of Newcastle, Callaghan, NSW, Australia;British Columbia Cancer Agency, Fraser Valley Centre, Surrey, BC, Canada

关键词: Prostate;    radiation therapy;    RapidArc;    VMAT;   

DOI  :  10.1002/jmrs.52

来源: Wiley

【 摘 要 】

Abstract

Introduction

This study compared four different volumetric modulated arc therapy (VMAT) beam arrangements for the treatment of early-stage prostate cancer examining plan quality and the impact on a radiotherapy department's resources.

Methods

Twenty prostate cases were retrospectively planned using four VMAT beam arrangements (1) a partial arc (PA), (2) one arc (1A), (3) one arc plus a partial arc (1A + PA) and (4) two arcs (2A). The quality of the dose distributions generated were compared by examining the overall plan quality, the homogeneity and conformity to the planning target volume (PTV), the number of monitor units and the dose delivered to the organs at risk. Departmental resources were considered by recording the planning time and beam delivery time.

Results

Each technique produced a plan of similar quality that was considered adequate for treatment; though some differences were noted. The 1A, 1A + PA and 2A plans demonstrated a better conformity to the PTV which correlated to improved sparing of the rectum in the 60–70 Gy range for the 1A + PA and 2A techniques. The time needed to generate the plans was different for each technique ranging from 13.1 min for 1A + PA to 17.8 min for 1A. The PA beam delivery time was fastest with a mean time of 0.9 min. Beam-on times then increased with an increase in the number of arcs up to an average of 2.2 min for the 2A technique.

Conclusion

Which VMAT technique is best suited for clinical implementation for the treatment of prostate cancer may be dictated by the individual patient and the availability of departmental resources.

【 授权许可】

CC BY-NC   
© 2014 The Authors. Journal of Medical Radiation Sciences published by Wiley Publishing Asia Pty Ltd on behalf of Australian Institute of Radiography and New Zealand Institute of Medical Radiation Technology.

Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.