Work

Commissioning of a precision preclinical 200 kV x‐ray irradiator based on modular adaptations

Year: 2025

Type: article

Abstract: Background Preclinical research in radiation oncology encompasses a range of methodologies, including in vitro cell studies and in vivo small animal experiments, as well as in silico studies to evaluate radiation‐induced side effects and tumor responses. Purpose This study addresses the need for high‐precision x‐ray irradiation solutions as reference for preclinical research. Modifications of an industrial kilovoltage x‐ray unit, along with the commissioning of a commercial treatment planning system (TPS), aimed to enable reliable irradiation of small animals in a horizontal beam geometry. All advancements enhancing the irradiation framework are made available, offering cost‐effective upgrades for existing systems. Methods An industrial kilovoltage x‐ray unit was equipped with a dual collimation system, featuring a fixed primary and variable secondary collimators with aperture diameters of 5 to 30 mm. Additional modular adaptations were designed and manufactured, including a multimodal mouse bedding unit, a dedicated dosimetry phantom and a quality assurance (QA) phantom. Output factors, percentage depth dose curves and lateral dose profiles were acquired to generate a beam model in the ‐RayStation 8B (RaySearch Laboratories, Stockholm, Sweden), using a diamond detector and radiochromic films. Treatment plans for 10 mice were created, evaluated via dose‐volume metrics and the homogeneity index and subsequently dosimetrically compared to QA measurements through a gamma analysis with a 1%/ acceptance criterion. Results The resulting beam model was validated within a maximum dose deviation of 1.7%. Aperture diameters close to potential target diameters were found to be effective for achieving sufficient target coverage in silico, as demonstrated for a 5 mm target with a homogeneity index of (9.9 0.7)%. Dedicated QA measurements revealed a maximum dose deviation of 1.9% from the TPS and a median gamma passing rate of 100%, confirming the suitability of the proposed solution. Conclusions Cost‐effective adaptations for an kilovoltage x‐ray irradiation framework were designed, manufactured and commissioned, and contribute to the accessibility of preclinical irradiation research. These components are integrated into a comprehensive preclinical particle beam platform.

Source: Medical Physics

DOI: 10.1002/mp.17758

Authors: Lorenz Wolf, Peter Kuess, Sabine Leitner, Dietmar Georg, Barbara Knäusl

Institutions: MedAustron, Medical University of Vienna, Fachhochschule Wiener Neustadt

Language: English

Topic: Advanced Radiotherapy Techniques

Subfield: Radiation

Field: Physics and Astronomy

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $3,360