Speaker
Description
In hadron therapy, accurate measurement of radiation quality remains a critical unmet need. While treatment planning systems (TPS) increasingly implement variable relative biological effectiveness (RBE) models for protons, for carbon ions, even if a variable RBE is applied, the clinical QA focuses almost exclusively on physical dose. Radiation quality, which strongly drives RBE and consequently the biological equivalent dose, is simulated but never experimentally verified in routine practice.
Microdosimetry offers a direct experimental solution to characterize the radiation quality by probing the stochastic of the energy deposition process at subcellular scales, closely linked to biological effectiveness. Existing microdosimeters, however, face limitations: solid-state devices handle high particle fluxes but lack sensitivity and simulate large volumes, whereas tissue-equivalent proportional counters (TEPCs) provide high sensitivity in small simulated volumes but cannot operate in single-event mode under clinical beam conditions.
The INFN-funded Young Researcher Project AtoMiQA aims to address this gap with a novel dual-mode TEPC. In single-event mode, it delivers high-resolution microdosimetric measurements; in multi-event mode, combined with the variance–covariance technique, it extracts single-event quantities even at high particle fluxes. By integrating sensor, front-end electronics, and data acquisition into a compact device, the device developed in the AtoMiQA project could offer a practical and clinically viable approach to measure radiation quality in clinical conditions.
This presentation will highlight the design, development, and preliminary performance of AtoMiQA device, demonstrating its potential to close the long-standing gap between simulated and measured radiation quality, complement routine dose verification, and provide the first practical tool for microdosimetric QA in proton and carbon ion therapy. AtoMiQA represents a critical step toward more biologically informed QA and opens new opportunities for integrating radiation quality measurements into clinical workflows.