Participants will undergo their radiation therapy treatment for HNC as planned and per the routine clinical management protocol. As part of this routine treatment, multiple x-ray images will be acquired to assist in accurate positioning of the patient for their planned radiation therapy. Normally these images are stored for a few days and then discarded. This study will be collating, storing and analysing these images. These X-ray images will be paired with the corresponding pre-treatment CT scan that is routinely acquired for each patient, as well as the locations of organs of interest, such as the tumour and surrounding structures. The patient treatment plan will also be collated, as it will allow for analysis of how any motion affects the accuracy of dose delivery. The patient radiation treatment delivery record will be collected to help sort and categorise the acquired images. Information on potential confounding or interacting factors will be collected: demographic information will be collected including sex, age, tumour stage and histology.
The primary objective of this observational study is to quantify the translation, rotation, and deformation of patient head positions of head and neck cancer patients over the course of a radiation therapy treatment for head and neck cancer. This objective will be achieved by comparing X-ray images collected during each treatment session with those obtained from the planning CT scan. Secondary objectives include (1) the use of the collected X-ray images to develop realistic artificial X-ray images where patient movement can be simulated and (2) to determine whether motion can be detected from individual X-ray images acquired during radiation therapy treatment.