Comparison of quality assurance for performance and safety characteristicsof 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 perfo rmance 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 publicati ons for medical electron accelerators. Results: The fundamental differences of clinical dosimetry for medical elec tron accelerators and BNCT are presented and the order of magnitude of dose components and their stability and that of the main other influencing para meter B-10 concentration for BNCT patient treatments. A comparison is given for requirements fur accelerators and BNCT units indicating items which ar e not transferable, equal or additional. Preliminary results of in vivo mea surements done with a set of Mn-55, Cu-63 and Au-197 activation foils for a ll single fields for the four fractions at all 15 treated patients show wit h < +/- 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 d istance. Conclusions: Despite the more complex clinical dosimetry (because of four r elevant dose components, partly of different linear energy transfer (LET)) BNCT can be regulated following the principles of quality assurance procedu res for therapy with medical electron accelerators. The reproducibility of applied neutron fluence (proportional to absorbed doses) and the main safet y aspects are equal for all teletherapy methods including BNCT. (C) 2001 El sevier Science Ireland Ltd. All rights reserved.