Dietrich Harder Master's Thesis Award 2022 for Helium-Beam Radiography Research

This year's winner is Margareta Metzner. She completed her master's thesis titled "Helium-beam radiography using thin silicon pixel detectors: Establishment of calibration curves and quantitative imaging of an anthropomorphic head phantom" at the German Cancer Research Center (DKFZ) in Heidelberg. In her paper, she presents a novel method for quantitative ion-beam imaging and demonstrates and evaluates the working method using an anthropomorphic head phantom. The ion-beam radiograph of the phantom was recorded at the Heidelberg Ion-Beam Therapy Center (HIT) using helium-ion beams and a unique imaging system based on thin pixel detectors. The methods developed for quantitative imaging include high-precision calibrations that enable the measured energy deposition to be converted into water-equivalent thickness (WET), the clinically relevant quantity. The results presented in the master's thesis show the advantages of this imaging modality. They indicate that the long-term use of ion-beam radiography in the clinic is recommended since it offers the additional possibility of recognizing uncertainties in the radiation plan or anatomical changes before each treatment fraction compared to conventional positioning X-ray images.

Margareta Metzner, MSc., studied physics at the universities of Ulm, Uppsala (Sweden) and Heidelberg. She wrote her master's thesis in 2022 in the Department of Medical Physics in Radiation Therapy at the DKFZ in Heidelberg. Since October 2022 she has been working as a doctoral student at the DKFZ, where she will continue her research on the development of a new imaging system for helium-beam radiography in high-precision ion-beam therapy.