Considerations for a dosimetry code of practice for BNCT

This article acts as an introduction to the challenges involved in the development of a code of practice for the dosimetry of BNCT beams. It seeks to identify the key components that would require consensus agreement including the appropriate reference conditions and a selection of potentially suitable technologies. The article draws on the extensive experience of the authors in dosimetry applied to BNCT beams. The highly complex radiation field and mix of dose components that varies with depth in phantom brings specific challenges. Overall BNCT requires approaches to dosimetry that have some commonalities with other radiotherapy modalities, but also some areas of considerable difference. The requirement for a code of practice to manage this novel situation is identified, along with the requirement to accommodate methodologies and technologies that have already achieved a degree of acceptance in sections of the BNCT community. Provisional guidance is provided on the scope of a Code of Practice for BNCT beams, and on approaches to manage the unique characteristics of the delivered dose and the mix of dose components. The relatively unique role of full transport simulations in BNCT is also highlighted as an area of difference with more established radiotherapy modalities. The particular challenge of accurate dosimetry for the fast neutron component at the patient surface is identified. The need for broadly-based community support for a code of practice is identified. The next stage of development of this project will require the mobilisation of a group of experts from within the BNCT community and also from dosimetry experts more familiar with conventional radiotherapy.