A medical device for real-time dose localization for more accurate and cost effective proton therapy

Purpose and goal:

The aim of ACCELERATE was to develop a medical device that enables real-time, three-dimensional localization of dose deposition during proton therapy. Careful monitoring of the range of protons in the patient can result in a reduction of range uncertainties and thereby in a more effective and safer treatment option. This has been accomplished through the design and testing of Qualyscan, a quality assurance tool for proton therapy.

Expected results and effects:

The results of the testing in clinical proton beams showed good performance metrics for different use cases of the device: spot-by-spot range measurement precision and accuracy, reproducibility, detector sensitivity, and comparisons between modeled and measured spot delivery. Thus, the device showed an achievable geometrical accuracy better than 1 mm for beam range estimation in homogeneous PMMA phantoms for a wide range of spot weights.

The beam position may be localized with a resolution better than 0.5 mm in both transverse coordinates for clinically-relevant spot weights. Approach and implementation:

The detector part of the Qualyscan is composed of scintillator-based detector modules, providing a spatial resolution of approximately 1 mm. An effective field of view of 500 mm (axial) x 350 mm (diameter) is achieved by rotation and displacement of the detector about the target. The performance of the device has been characterized by irradiating different phantoms with proton pencil beams.

Preliminary results showed that the device has an achievable geometrical accuracy better than 1 mm for beam range estimation.