Procedural and practical applications of radiation measurements for BNCT at the HFR Petten

Since October 1997, a clinical trial of Boron Neutron Capture Therapy (BNCT) for glioblastoma patients has been in progress at the High Flux Reactor, Petten, the Netherlands. The trial is a European Organisation for Research and Treatment of Cancer (EORTC) protocol (#11 961) and, as such, must be conducted following the highest quality management and procedures, according to good clinical practice and also other internationally accepted codes. The complexity of BNCT involves not only strict international procedures, but also a variety of techniques to measure the different aspects of the irradiation involved when treating the patient. Applications include: free beam measurements using packets of activation foils; in-phantom measurements for beam calibration using ionisation chambers, pn-diodes and activation foils; monitoring of the irradiation beam during patient treatment using fission chambers and GM-counters; boron in blood measurements using prompt gamma ray spectroscopy; radiation protection of the patient and staff using portable radiation dosimeters and personal dosimeters; and in vivo measurements of the boron in the patient using a prompt gamma ray telescope. The procedures and applications of such techniques are presented here, with particular emphasis on the importance of the quality assurance/quality control procedures and its reporting.