Monte Carlo GEANT4-based application for in vivo RBE study using small animals at LNS-INFN preclinical hadrontherapy...

Area of Science:

• Radiation oncology
• Preclinical research
• Medical physics

Background:

• Proton therapy offers higher effectiveness than photons, with a standard relative biological effectiveness (RBE) of 1.1.
• In vitro studies indicate RBE is not constant along the spread-out Bragg peak (SOBP), increasing at the distal edge.
• Understanding RBE variations is crucial for optimizing proton therapy, especially in preclinical settings.

Purpose of the Study:

• To prepare for in vivo studies on RBE variations along the SOBP at the LNS-INFN preclinical hadrontherapy facility.
• To determine optimal treatment configurations for small animal studies using GEANT4 simulations.
• To identify configurations maximizing linear energy transfer (LET) differences while minimizing healthy tissue dose.

Main Methods:

• Developed a GEANT4 application to simulate the CATANA proton therapy beam line at LNS-INFN.
• Integrated DICOM-CT image import for target simulation.
• Evaluated RBE using myelopathy as a deterministic radiation damage endpoint, assuming dose-dependency on LET.

Main Results:

• Simulated and analyzed various treatment configurations for small animal proton therapy.
• Identified two configurations that maximize LET differences.
• Minimized dose delivered to surrounding healthy tissues in the selected configurations.

Conclusions:

• The study provides crucial data for planning preclinical in vivo hadrontherapy treatments.
• Findings will guide future in vivo studies on the RBE of protons along the SOBP.
• Optimized configurations are essential for accurate assessment of RBE in preclinical models.