A Beam Monitor for Ion Beam Therapy based on HV-CMOS Pixel Detectors

TL;DR

This paper evaluates HV-CMOS pixel detectors as a fast, high-resolution beam monitoring system for ion beam therapy, addressing limitations of traditional methods and considering future challenges like magnetic fields and vibrations.

Contribution

It introduces and assesses HV-CMOS detectors for beam monitoring in particle therapy, demonstrating their potential advantages over existing technologies.

Findings

HV-CMOS detectors show promising spatial and temporal resolution.

Feasibility studies confirm suitability for therapeutic beam monitoring.

Potential for integration into large-scale clinical systems.

Abstract

Particle therapy is a well established clinical treatment of tumors. More than one hundred particle therapy centers are in operation world wide. The advantage of using hadrons like protons or carbon ions as particles for tumor irradiation is the distinct peak in the depth dependent energy deposition, which can be exploited to accurately deposit dose in the tumor cells. To guarantee this, high accuracy of monitoring and control of the particle beam is of utmost importance. Before the particle beam enters the patient, it traverses a monitoring system which has to give fast feedback to the beam control system on position and dose rate of the beam while minimally interacting with the beam. The multi-wire chambers mostly used as beam position monitor have their limitations when fast response time is required (drift time). Future developments like MRI-guided ion beam therapy pose additional challenges for the beam monitoring system like tolerance of magnetic fields and acoustic noise (vibrations). Solid-state detectors promise to overcome these limitations and the higher resolution they offer can create additional benefits. This article presents the evaluation of an HV-CMOS detector for beam monitoring, provides results from feasibility studies in a therapeutic beam and summarizes the concepts towards the final large-scale assembly and readout system.