The Committee V of INFN recently funded the three-year project NEPTUNE (Nuclear process-driven Enhancement of Proton Therapy UNraVeled).
The project will start in 2019 with the main aim to study and understand the recently observed increase of protontherapy effectiveness for irradiations occurring in the presence of 11B atoms. A role in this effect should be played by the high-LET alpha particles mainly generated by the p(11B,alpha)2alpha channel, which has a cross section of the order of 1 barn at low energy. However, analytical calculations indicate that the number of alphas produced is too low to yield the observed biological effects.
The main objectives of NEPTUNE will be the consolidation of these results, extending them to include another nuclear reaction between protons and 19F and focussing on understanding all the physical and biological mechanisms involved. A physical characterization of the radiation field will be performed with tissue-equivalent detectors of various types, all based on micro- and nanodosimetry techniques. At the same time, biological measurements will be performed for different cell lines using several endpoints. New biological approaches will be to considered to study the problem from different points of view, which could reveal mechanisms not yet taken into account. All experimental data will be compared with predictions from analytical and Monte Carlo models. The project is divided into four main Working Packages: WP1, modelling; WP2: imaging and quantification; WP3: microdosimetry and WP4: radiobiology. An additional group (WP5) coordinates all the foreseen experimental activities.