Quantification of log-based QA uncertainties based on measurements in proton PBS beams

Details

Supervisors

Sterpin, Edmond

Faculty

Faculté des sciences

Degree label

Master [120] en sciences physiques, à finalité spécialisée: physique médicale

Abstract

Proton therapy requires a detailed treatment plan based on patient anatomy and tumor location. The Treatment Planning System (TPS) calculates the 3D dose distribution, and a pencil beam is used to deliver the treatment layer by layer. To ensure accuracy, Patient-Specific Quality Assurance (PSQA) is performed to validate the TPS plan. While measurement-based quality assurance using a 2D detector is commonly used, it is time-consuming and limited in capturing the patient's specific anatomy. To address these limitations, log-based Quality Assurance (QA) has emerged as a promising alternative. Log files, which store treatment history, provide comprehensive information about the delivery process. By utilizing Monte Carlo computations and log files, the actual dose delivered to the patient can be assessed without the need for additional detectors. However, challenges such as uncertainties in position must be carefully accounted for in the log-based QA process. The objective of this thesis is to enhance the quality assurance of proton treatment by incorporating log files corrected by measurements from a flat panel detector. This approach aims to develop an error model that captures and quantifies uncertainties to improve the reliability and accuracy of log-based QA.