Scott Hanvey1, John Foster2
1Radiotherapy Physics, Beatson West of Scotland Cancer Centre, Glasgow, Lanarkshire, United Kingdom; 2MRI Physics, Beatson West of Scotland Cancer Centre, Glasgow, United Kingdom
Accurate localisation of the planning target volume (PTV) is vitally important in radiotherapy. The excellent soft tissue contrast of MRI makes it an ideal imaging modality for radiotherapy of the head and neck. Registration of MRI with CT can be problematic since patients are not positioned in the same way. The following study compared the accuracy of the registration of MRI with CT in 20 head and neck patients receiving an MRI in the typical curved table and within an immobilisation device. It also measured the PTVs of patients in the normal and radiotherapy position in MRI.