Kilovoltage intrafraction monitoring (KIM): a novel real-time targeting system for cancer radiotherapy

In cancer radiotherapy, there is a need for a highly accurate, widely applicable, cost effective real-time tumour localization modality with a low barrier to clinical implementation. This thesis documents the bench-to-bedside translation of Kilovoltage Intrafraction Monitoring (KIM), a novel real-time localization modality. This thesis consists of three main studies, each with specific aims which, when combined, culminate in the clinical implementation of real-time KIM. The first study aimed to implement KIM clinically but in a retrospective manner. This was to ascertain if KIM could determine intrafraction prostate motion in a clinical setting. The second study aimed to calculate the additional imaging dose delivered by KIM to determine if KIM uses a safe quantity of imaging dose. The third study aimed to develop a Quality Assurance framework for real-time KIM to ensure that it can be delivered safely and effectively in a clinical setting. KIM was successfully implemented for the first time in a 10 patient prostate cancer clinical trial. KIM could only determine prostate motion retrospectively, i.e. not in real-time. This meant that real-time adaptation could not be made. However, this study proved that KIM could determine intrafraction prostate motion accurately in a clinical setting. KIM delivers additional kV imaging dose. This dose was quantified. We found that the additional dose delivered was within clinically acceptable limits for patients. This study proved that KIM could be used on patients with no additional risk from dose. Significant efforts were made to enable real-time capability for KIM. A Quality Assurance framework was adapted and developed to assess real-time KIM. This study proved that KIM could be implemented safely and effectively in a clinical setting. These three studies enabled the first clinical implementation of real-time KIM. The first patient was treated on 16 September 2014. At the time of writing, three patients are undergoing treatment.