The use of a tissue expander (hydrogel) for sparing of the rectum from increased irradiation during prostate radiotherapy is becoming popular. The goal of this study is to investigate the effect of a tissue expander (hydrogel) on the intrafraction prostate motion during radiotherapy.
Real time prostate motion was analysed for 26 patients and 742 fractions; 12 patients with and 14 patients without hydrogel (SpaceOAR™). The intra-fraction motion was quantified and compared between the two groups.
The average (±standard deviation) of the mean motion during the treatment for patients with and without hydrogel was 1. 5 (±0. 8 mm) and 1. 1 (±0. 9 mm) respectively (p < 0. 05). The average time of motion >3 mm for patients with and without hydrogel was 7. 7 % (±1. 1 %) and 4. 5 % (±0. 9 %) respectively (p > 0. 05). The hydrogel age, fraction number and treatment time were found to have no effect (R (2) < 0. 05) on the prostate motion.
Differences in intrafraction motion in patients with hydrogel and without hydrogel were within measurement uncertainty (
Radiation oncology (London, England). 2015 Oct 24*** epublish ***
Prabhjot Juneja, Andrew Kneebone, Jeremy T Booth, David I Thwaites, Ramandeep Kaur, Emma Colvill, Jin A Ng, Paul J Keall, Thomas Eade
Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, NSW, 2065, Australia. Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, NSW, 2065, Australia. Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, NSW, 2065, Australia. Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, 2006, Australia. 5/161A Willoughby Road, Naremburn, NSW, 2065, Australia. Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, NSW, 2065, Australia. Radiation Physics Laboratory, School of Medicine, University of Sydney, Sydney, NSW, 2006, Australia. Radiation Physics Laboratory, School of Medicine, University of Sydney, Sydney, NSW, 2006, Australia. Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, NSW, 2065, Australia. Thomas.