Direct tumour tracking during radiation therapy

Abstract

Lung cancer stereotactic ablative body radiation therapy is one of the cancer treatment success stories. However, treatment outcomes and efficacy are limited by the fact that patients move, breathe, and their hearts beat, causing tumour and healthy tissue motion during imaging and radiation treatment. Direct tumour tracking is a novel method to visualise tumours during radiation therapy to improve treatment accuracy and healthy tissue sparing in the presence of internal anatomic motion. Direct tumour tracking is an affordable technology that is compatible with 95% of existing radiation therapy systems and can improve the outcomes of cancer patients globally. Avoiding the cost and risk of surgically inserted fiducial markers, direct tumour tracking provides the ability to track tumour motion on a conventional linear accelerator at the time that is needed most – in real-time during radiation treatment delivery. This work removes several barriers to widespread clinical implementation of direct tumour tracking by addressing and delivering solutions for four research topics: (i) the development of a clinically feasible approach for direct tumour tracking using intra-fraction kilovoltage projections, (ii) the integration into the lung cancer radiation therapy workflow on a conventional linear accelerator and the preparation for deployment in clinical trials, (iii) the proof of feasibility to track tumour and organsat- risk simultaneously and (iv) the benchmarking of the global direct tumour tracking landscape to enable the placement of new technologies and further assist the safe clinical implementation of direct tumour tracking globally. This work paves the way for the widespread clinical use of image-guided radiation therapy on conventional linear accelerators.