Comparison of substitute support cushion materials used for patient treatment in radiation therapy

Abstract

Background: Radiation therapy is one of the most common treatment options for cancer. An accuracy and precision of patient positioning is required for radiotherapy. Support cushion is used to provide stabilization and comfort during treatment in every fractionated radiotherapy.

Objective: To compare the dose attenuation and patient comfort of each support material among commercial (Macromedics mattress) and other replacement materials.
Material and methods: The TPE Yoga Mat, Latex mattress, EVA foam and rug were selected to study. There were two procedures to study the suitability of these materials. The first process was the radiation dose attenuation test measured by 0.6 cc Farmer-type ionization chamber. The 20-cm thick of solid water phantom was used and the source to surface distance of 87 cm was set.  Then, radiation dose comparison of 3D, IMRT and VMAT plans was performed among different types of material support and the dose attenuation of each material was calculated. The second part was the survey of patient comfort from 26 volunteers after 5-minute resting on the support materials.

Results: The results from radiation dose attenuation test showed that the TPE yoga mat (0.19%-1.08%)  and the rug (0.23%-0.70%) had the same radiation dose attenuation with the Macromedics mattress (0.06%-0.57%), while the latex mattress showed the highest dose attenuation (0.77%-2.19%). The results from comfortable test showed that latex mattress was the most comfortable material with the comfortable factor of 0.08±0.27, followed by the rug (1.23±0.91), while there was no significant difference in comfortable level between TPE yoga mat (0.65±0.75) and Macromedics mattress (1.23±0.99). 

Conclusion: The most suitable materials to replace Macromedics mattress are the rug, TPE yoga mat and EVA foam, respectively.