Quantitative Modeling of Cerenkov Light Production Efficiency from Medical Radionuclides

TLDR

Interest in using Cerenkov radiation for biological applications has grown, and understanding its production efficiency across radionuclides is essential for assessing feasibility and selecting suitable isotopes. The study aimed to generate such efficiency data by developing models of Cerenkov production based on the Frank‑Tamm equation and Monte‑Carlo simulations of photon and β‑particle transport. These models were validated against direct measurements with multiple radionuclides and then applied to commonly used biomedical isotopes. We found that Ac‑225 and In‑111 do not produce Cerenkov radiation directly, and we propose a simple calibration approach for high‑sensitivity luminescence imaging that appears more accurate than routine methods.

Abstract

There has been recent and growing interest in applying Cerenkov radiation (CR) for biological applications. Knowledge of the production efficiency and other characteristics of the CR produced by various radionuclides would help in accessing the feasibility of proposed applications and guide the choice of radionuclides. To generate this information we developed models of CR production efficiency based on the Frank-Tamm equation and models of CR distribution based on Monte-Carlo simulations of photon and β particle transport. All models were validated against direct measurements using multiple radionuclides and then applied to a number of radionuclides commonly used in biomedical applications. We show that two radionuclides, Ac-225 and In-111, which have been reported to produce CR in water, do not in fact produce CR directly. We also propose a simple means of using this information to calibrate high sensitivity luminescence imaging systems and show evidence suggesting that this calibration may be more accurate than methods in routine current use.