Optimising the clinical use of tomotherapy

Sammanfattning: Radiotherapy is one of the major tools for treating cancer. Through research and technical development radiotherapy is becoming more advanced with new treatment techniques emerging. In the work presented in this thesis, well-known methods have been used, or modified for use, and new methods have been introduced in order to optimise the clinical use of an advanced radiotherapy treatment technique, specifically tomotherapy. In the presented work, tools used for fallback planning are evaluated. Methods are developed for the commissioning of them, evaluating the quality of the treatment plans (describes how patients are to be treated) they produce, and measurements are performed to ensure that the resulting treatments can be accurately delivered to the patients. These could assure an uninterrupted patient treatment with specialised treatment techniques. The results show that fallback planning is useful as it in many cases prevents a prolongation of the treatment which can have clinically significant impact. It should be an important time-saving complement, especially for clinics with a single specialised treatment unit such as tomotherapy, as they are more affected by its downtime. A method called clinical grading analysis (CGA) is presented as a way of comparing radiotherapy treatment plans. A CGA study takes advantage of the radiation oncologists’ clinical assessments to identify the clinical relevant differences between treatment plans. These subjective assessments are quantified in a CGA study, and used to decide which patients have a clinical benefit from treatment with one or the other of the advanced treatment techniques available to them. The results indicate that a CGA study provides a supporting framework for decision making regarding treatment techniques which helps to ensure a more optimal use of the clinic’s advanced treatment resources. Beam commissioning, plan quality assessment, and treatment deliverability measurements are important when introducing new techniques into the clinic. However, the work presented in this thesis shows that despite performing such investigations thoroughly, unexpected treatment side effects might occur. Hence, patient follow-up is of utmost importance when introducing new treatment techniques as it enables treatment adjustment to optimise the treatment outcome.