A randomised comparison of three different immobilisation devices for thoracic and abdominal cancers

Patient immobilisation is critically important for both highly conformal conventionally fractionated radiotherapy and for stereotactic body radiotherapy. Different immobilisation devices are available to maintain patient position for radiotherapy but the most suitable one remains unknown. Methods Forty‐five patients were randomly allocated to one of three immobilisation devices; the Q fix arm shuttle, Body FIX without wrap or Body FIX with wrap. Patients were imaged before and after treatment to ascertain intra‐fraction and inter‐fraction motion. Bony anatomy was used for matching to determine the positional accuracy of each device. Treatments were timed using a standard method. Patient comfort and staff satisfaction questionnaires were also issued to determine comfort, ease of use and preferences for each device. Results The Body FIX without wrap was the more accurate device; however, the differences between the devices were not statistically significant. The Body FIX with wrap was found to take significantly longer to set up and set down compared to the arm shuttle and the Body FIX without wrap (all P < 0.001). Patients (37%) marginally preferred the Body FIX with wrap. Most (81%) staff preferred the Body FIX without wrap. Conclusion Immobilisation using the Body FIX without wrap was deemed to be suitable for clinical use. It was a clinically accurate device, the more efficient in terms of set up and set down time, the most preferred by staff and was accepted by patients.