New paper published that provides basis for in-vivo range verification
Protons and carbon ions have been extensively used for radiotherapy treatments, and in comparison to conventional radiotherapy, they allow a more conformal dose to the target tumour, especially in case of deep-seated tumours.
However, the accuracy of hadron therapy treatments is affected by uncertainties in the particle range calculations. Several techniques are under development for in-vivo range verification, one of which consists on measuring the activity distributions of positron emitters, such as 10C, 11C and 15O, which are produced in the patient body during proton and carbon ion treatments.
In a paper that has just been published in EPJ Web Conf 239, OMA Fellow Giulia Aricò and co-workers present a comparison between measured and expected positron emitter activity distributions. They show how this can provide information on the quality of the delivered treatment and accuracy of the particle range calculations.
Production cross sections for 10C originated from proton beams in carbon and oxygen targets as a function of energy. The black filled dots are FLUKA simulations, the green empty symbols are data from the Experimental Nuclear Reaction Data (EXFOR) library, and the blue empty circles are data from Phys. Med. Biol. 64 205012 (2019). Image taken from referenced paper.
In their work the FLUKA production cross sections for 10C, 11C and 15O originated from proton and carbon ion beams in carbon and oxygen targets were compared with experimental data, at low and therapeutic energies.
Their study highlights that some improvements in the FLUKA physics models can be performed in order to achieve an even better agreement with the experimental production cross sections. The effects of such improvements on the activation yields and profile distributions will finally have to be assessed in clinical scenarios. This research is then expected to contribute to a further improvement of radiotherapy treatment at CNAO, where FLUKA is used as reference for PET measurements.
Further information
G. Arico, et al., “Benchmarking of FLUKA production cross sections of positron emission tomography isotopes for in-vivo range verification in hadron therapy”, EPJ Web Conf 239 (2020), https://doi.org/10.1051/epjconf/202023924001