Vikren Sarkar | Searcharxiv

arXiv2026

Dosimetry for Proton Therapy Using a β-Ga$_2$O$_3$ Metal-Semiconductor-Metal Detector with Low-Noise Amplification

Intensity-modulated proton therapy (IMPT) employs proton radiation rather than conventional X-rays to treat cancerous tumors. This approach offers significant advantages by minimizing the radiation exposure of surrounding healthy tissue, leading to improved patient outcomes and reduced side effects compared to traditional X-ray therapy. To ensure patient safety, each treatment plan must be experimentally validated before clinical implementation. However, current dosimetry devices face limitations in performing angled beam measurements and obtaining multi-depth assessments, both of which are essential for verifying IMPT treatment plans. In this study, the performance of a β-Ga$_2$O$_3$-based metal-semiconductor-metal (MSM) detector with a low-noise amplifier is studied and evaluated under various proton radiation doses and energy levels delivered by a MEVION S250i proton accelerator. The detector performance is also compared with that of an ionization chamber. The β-Ga$_2$O$_3$ detector exhibits a linear response with proton dose for single-spot irradiations, and its response to varying proton energies closely matches both the ion chamber data and simulated dose distributions. These findings highlight the potential of β-Ga$_2$O$_3$-based detectors as robust dosimetry devices for IMPT applications.

physics.med-ph↗

arXiv2025

$β$-Ga$_2$O$_3$--Based Radiation Detector for Proton Therapy

Intensity modulated proton therapy (IMPT) is an advanced cancer treatment modality that offers significant advantages over conventional X-ray therapies, particularly in its ability to minimize radiation dose beyond the tumor target. This reduction in unnecessary irradiation exposure significantly lowers the risk to surrounding healthy tissue and reduces side effects compared to conventional X-ray treatments. However, due to the high complexity of IMPT plans, each plan must be independently validated to ensure the safety and efficacy of the radiation exposure to the patient. While ion chambers are currently used for this purpose, their limitations-particularly in angled-beam measurements and multi-depth assessments-hinder their effectiveness. Silicon-based detectors, commonly used in X-ray therapy, are unsuitable for IMPT due to their rapid degradation under proton irradiation. In this study, a $β$-Ga$_2$O$_3$-based metal-semiconductor-metal (MSM) detector was evaluated and compared with a commercial ion chamber using a MEVION S250i proton accelerator. The $β$-Ga$_2$O$_3$ detector demonstrated reliable detection of single-pulse proton doses as low as 0.26 MU and exhibited a linear charge-to-dose relationship across a wide range of irradiation conditions. Furthermore, its measurement variability was comparable to that of the ion chamber, with improved sensitivity observed at higher bias voltages. These results highlight the strong potential of $β$-Ga$_2$O$_3$ as a radiation-hard detector material for accurate dose verification in IMPT.

physics.med-ph↗