Improving precision of radiotherapy for prostate and bladder cancer

Aims: The aim of this thesis is to demonstrate how the use of volumetric images could improve the precision of bladder and prostate radiotherapy.

Methods: A series of studies, including seven in silico analyses, one prospective study, and two systematic reviews, were conducted in collaboration with a multidisciplinary team on using volumetric images to improve the precision of bladder and prostate radiotherapy. The findings from these studies were presented in the ten peer-reviewed publications included in this thesis. Each publication was critically evaluated and categorized under the following themes: 1) Tracking the target; 2) Adapting to the target and Organs at Risk (OARs) and 3) Estimating the delivered dose to the target and OARs.

Results: The ability to track the target using volumetric images facilitates the generation of a patient specific treatment volume for bladder radiotherapy to reduce irradiation of OARs (Publication 1 and 2). Its clinical adoption was supported by evidence generated from various quality assurance studies (Publication 3-5). Findings on the various aspects of the adaptation workflow for bladder radiotherapy were categorized using the R-IDEAL framework to recognize the amount of evidence available to demonstrate its technical feasibility and efficacy and the need for more clinical studies for validation (Publication 6). Adaptation for prostate was compared against tracking, enabling the identification of factors affecting the effectiveness of adaptation (Publication 7). The delivered dose estimation workflow was developed based on information synthesized from a literature review (Publication 8) and was applied in pre-clinical and quality improvement studies to demonstrate the feasibility of alternative intervention in clinical studies and support changes in clinical practice (Publication 9-10).

Conclusion: The publications presented in this thesis have shown how I have significantly contributed to the knowledge of using volumetric images to improve the precision of bladder and prostate radiotherapy through tracking, adaptation and estimation of delivered dose.