Towards a clinical application of ex-situ Boron Neutron Capture Therapy for lung tumors at the RA-3 reactor in Argentina

Many types of lung tumors have a very poor prognosis due to their spread in the whole organ volume. The fact that Boron Neutron Capture Therapy (BNCT) would allow for selective targeting of all the nodules regardless of their position, prompted a pre-clinical feasibility study of ex-situ BNCT at the thermal neutron facility of RA-3 reactor in Buenos Aires, Argentina. Boron biodistribution studies in an adult sheep model and computational dosimetry for a human explanted lung were performed to evaluate the feasibility and the therapeutic potential of this procedure. The present work reports for the first time data supporting the validity of the ovine model as an adequate human surrogate in terms of boron kinetics and uptake in clinically relevant tissues. The experimental results were employed to assess thefeasibility of the clinical application of ex-situ BNCT for the treatment of multiple lung metastases at RA-3.Considering a collapsed human lung-based model and suitable tumor control probability for lung cancer, the expected number of controlled lesions was derived, suggesting a promising overall survival even in the most conservative tumor boron uptake scenario.