Comparison of four 3D conformal treatment techniques to optimise radiotherapy treatment for anal cancer

Journal of Medical Radiation Sciences

Alison Cray Dip App Sc (Radiotherapy), Grad Dip App Sc (Med Rad)¹  Cathy Markham B Appl Sci (Med Rad)¹  Michelle Ryan B Appl Sci (Med Rad)¹  Alan Herschtal BE (Hons), Post Grad. Dip. (App. Stat.)²  Samuel Y. Ngan MBBS, FRCSEd, FRANZCR³ 

[1] Department of Radiation Therapy Services, Peter MacCallum Cancer Centre, Box Hill, Victoria, Australia;Department of Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia;Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia

关键词: Anal cancer;    conformal radiotherapy;    organ sparing treatments;    organs at risk;   

DOI  :  10.1002/jmrs.83

来源: Wiley

【 摘 要 】

Abstract

Introduction

Chemoradiotherapy is the standard of care for anal cancer. Sizeable target volume leads to significant toxicity. We compared four different 3D conformal radiotherapy (3DCRT) techniques with the aim of finding the best technique to achieve the lowest dose to the organs at risk (OAR) without compromising the planning target volume (PTV) coverage.

Methods

Fifteen computed tomography (CT) data sets from previously treated anal cancer patients (five male and 10 female) were re-contoured according to the Australasian Gastrointestinal Trials Group (AGITG) anal cancer contouring guidelines for N3 disease. Four different 3DCRT plans for each CT data set (standard, V-shape, diamond shape and alternate diamond shape) were generated. Comparisons of the radiation dose to non-rectal bowel (NRB), urinary bladder, genitalia, and femurs were performed.

Results

V-shape technique achieved significantly lower NRB V40 (mean = 59.6% SD = 11%) than diamond (63.8% SD = 13%), standard (63.8% SD = 11%) and alternate diamond (63.6% SD = 12%) techniques. V-shape technique achieved the lowest mean bladder dose (mean = 45.3 Gy SD = 1.4 Gy). Diamond technique achieved the lowest femur V40 (mean = 32.4%) P < 0.001 for all comparisons between diamond and all other techniques. For genitalia V40, diamond technique (mean = 26.4% SD = 20%) and alternate diamond technique (mean = 27.6% SD = 20%) achieved significantly lower dose than V-shape technique (mean = 43.2% SD = 26%) and standard technique (mean = 76.1% SD = 16%) P < 0.001 for all comparisons.

Conclusions

Sophisticated 3DCRT techniques are superior to conventional techniques. Different 3DCRT techniques provide varying levels of dose reduction to OAR, with none of the four techniques investigated capable of reducing dose to all OAR. A combination of techniques may provide the best solution. Further refinement of these techniques should be explored.

【 授权许可】

CC BY-NC-ND   
© 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-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.