Radiotherapy (RT) is a highly effective treatment modality for cancer and used for treating more than half of all cancer patients in Denmark. State-of-the-art RT modalities, including particle therapy, allow for delivery of high doses to the tumor while minimizing radiation to healthy tissue i.e. enabling high rates of tumor control while reducing radiation to organs at risk.

Doses that patients receive are planned and delivered with a high spatial precision and it is a challenge to measure the spatial distribution of radiation with sufficient accuracy in three dimensions.

Medical physicists at Aarhus University Hospital and Danish Centre for Particle Therapy have teamed up with optical/material physicists at Department of Physics and Astronomy, AU, in an interdisciplinary collaboration to develop new dose-sensitive materials. The new materials are based on two radiosensitive components integrated in a silicone matrix. One is a so-called radiochromic dye, i.e. a dye which changes color upon irradiation. The other is based on embedded particles exhibiting the phenomenon optically-stimulated luminescence (OSL). Both allow for optical readout and can provide a 3D measurement in high resolution of a given dose distribution. On top of this, the OSL-based material also has the potential of being reused many times.

The silicone base opens a potential for the dosimeter to be moulded into life-like (anthropomorphic) phantoms and to be deformed to investigate organ motion. The radiochromic dosimeter has already demonstrated its capabilities in proton therapy and in photon irradiations, including in the presence of magnetic fields.

The overall aim of the project is to investigate the potential of the new dosimeters and to bring them closer toward implementation in clinical workflow.

The 3D dosimetry project is funded by the Novo Nordic foundation 2019-2023.