Monte Carlo simulation of the ISOLPHARM gamma camera for Ag-111 imaging

TL;DR

This paper presents a Monte Carlo simulation using Geant4 to optimize a gamma camera for Ag-111 imaging in targeted radionuclide therapy, demonstrating promising resolution and sensitivity for preclinical applications.

Contribution

The work introduces a detailed Geant4-based Monte Carlo simulation to optimize gamma camera design specifically for Ag-111, a novel radionuclide for TRT.

Findings

Estimated spatial resolution of ~4 mm

Sensitivity of approximately 19 cps/MBq

Ability to resolve lesions with 4:1 activity ratio

Abstract

Targeted Radionuclide Therapy (TRT) is a well-established technique for cancer treatment. In this approach, radionuclides are bound to specific drugs that selectively transport them to the tumor site. Within the ISOLPHARM project, a radiopharmaceutical for TRT based on the innovative radionuclide Ag-111 is currently under development. Ag-111 has a half-life of 7.45 days and decays by emitting both electrons and gamma-rays. The emission of gamma-rays, predominantly at an energy of 342 keV, enables the visualization of Ag-111 using a gamma camera. In this work, we describe a Monte Carlo simulation developed to optimize the design parameters of such an imaging device. The simulation is based on the Geant4 toolkit, which accurately models the interactions between particles and matter. The estimated spatial resolution and sensitivity of the system are approximately 4 mm and 19 cps/MBq, respectively. The simulated device is able to resolve lesions with a lesion-to-background activity ratio of 4:1 under in-vivo-like conditions. These results indicate that the proposed gamma camera can provide cost-effective imaging capabilities for preclinical radiopharmaceutical studies.