Comprehensive quality control process for high precision intensity modulated adaptive proton therapy

The thesis focuses on development and clinical implementation of comprehensive and overlaying quality control process aimed at supporting introduction of high precision adaptive IMPT workflows. The thesis consists of seven chapters, covering topics on quality control for proton range accuracy, reconstruction, and accumulation of delivered dose distributions longitudinally throughout the proton therapy course and independent dose recalculation/predictive outcome-based patient specific quality assurance procedures.
A proton range probing method as a quality control tool for range accuracy validation has been proposed and applied for range accuracy assessments in animal tissue samples covering a broad range of tissue types. A fraction-wise 4D dose reconstruction and accumulation procedure utilizing treatment delivery log files and patient-specific daily breathing patterns has been proposed and implemented in clinical practice. Validation of the procedure in controlled conditions with a 4D phantom revealed ability to spatially reconstruct the dose distributions with submillimeter accuracy. Eventually, an alternative approach for in-beam measurement-based patient specific quality assurance (PSQA) procedure has been investigated, developed, and introduced in clinical practice.
By incorporating the developed range probing QC procedure as a validation tool for synthetic CTs and utilizing developed dose reconstruction and accumulation workflow, it enables possibility to establish a comprehensive longitudinal patient specific quality control process to monitor the treatment delivery in an environment of adaptive proton therapy.
Introduction of more adaptive treatment procedures and availability of online adaptive workflows in proton therapy might be the next major advancement needed to take full advantage of the physical characteristics of the proton beam.