Use of PET-MR in Head and Neck Cancer Patients - Diagnostic and Therapeutic Applications

The primary research question to be answered in this project is "Are patients with locally-advanced head and neck cancer able to tolerate a PET-MRI scan when they are immobilised in a radiotherapy treatment shell?" This will be assessed by measuring the proportion of patients that complete the full scanning protocol and by obtaining participant feedback on their experience of completing the scan. The secondary question is "Can a PET-MRI scan fused with a planning CT scan improve the accuracy in radiotherapy planning of patients with head and neck cancer? Accuracy will be assessed by: 1. Comparing the radiotherapy target volumes and radiotherapy plans with and without the use of a PET-MRI scan. 2. Comparing inter- and intra-observer variability in treatment contours with and without the use of a PET-MRI scan within and between oncologists and implications of that.