Comparison of quality assurance for performance and safety characteristics of the facility for Boron Neutron Capture therapy in Petten/NL with medical electron accelerators

Background and purpose: The European Council Directive on health protection 97/43/EURATOM requires radiotherapy quality assurance programmes for performance and safety characteristics including acceptance and repeated tests. For Boron Neutron Capture therapy (BNCT) at the High Flux Reactor (HFR) in Petten/NL such a programme has been developed on the basis of IEC publications for medical electron accelerators. Results: The fundamental differences of clinical dosimetry for medical electron accelerators and BNCT are presented and the order of magnitude of dose components and their stability and that of the main other influencing parameter B-10 concentration for BNCT patient treatments. A comparison is given for requirements fur accelerators and BNCT units indicating items which are not transferable, equal or additional. Preliminary results of in vivo measurements done with a set of Mn-55, Cu-63 and Au-197 activation foils for all single fields for the four fractions at all 15 treated patients show with < +/- 4% up to now a worse reproducibility than the used dose monitoring systems (+/- 1.5%) caused by influence of hair position on the foil-skull distance. Conclusions: Despite the more complex clinical dosimetry (because of four relevant dose components, partly of different linear energy transfer (LET)) BNCT can be regulated following the principles of quality assurance procedures for therapy with medical electron accelerators. The reproducibility of applied neutron fluence (proportional to absorbed doses) and the main safety aspects are equal for all teletherapy methods including BNCT. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.