{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"4b14367f49797a9322342c29e7c7fa5555562063cce77e3699f28b6d5c02dd18","created":"2026-10-03T07:18:06Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"afe75a70ca797f859e941f99e1c4aa11a716da334041eacba67748fd7286b0f7","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"med.bnct.mixed-field-weighting","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"The patient receives a mixture of $\\alpha$ particles, lithium nuclei, protons from nitrogen, fast neutrons and $\\gamma$ rays, each with a different biological effect. How to add them into one effective dose is disputed.","posed_since":"","precise":"Construct a model converting the absorbed dose components of a neutron capture field (B-10(n,alpha)Li-7 at about 2.3 MeV total kinetic energy, N-14(n,p) protons at 0.58 MeV, fast-neutron recoil protons and photons) into a photon-isoeffective dose that predicts tumour control and normal-tissue complication, replacing fixed compound and relative biological effectiveness factors. The model must include the boron microdistribution relative to the nucleus and dose-rate effects over treatment times of 30 to 60 min. An answer is a validated weighting scheme with stated uncertainty.","problem_ref":null,"references":"","settled_by":"Prospective comparison of predicted and observed responses across patients or animal models with measured boron microdistribution and beam spectra.","status_note":"Fixed-factor and photon-isoeffective dose models give different prescriptions for the same treatment and both remain in use.","title":"Biological weighting of the neutron capture mixed field","topic_ref":"0c8039c980b31f825989ca36e1cd7529f5aab83d616e66638b0e9746fc03ac15"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"1d83b71734906bbc3afa0057857fa7c7532f6a679ab9c83e2015f323e431b083","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"2f876643d7d566360f66592c5661ac459986031a42b0665863fa2b46d51acb7f","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"uVGgfsxRaCVnz1MXmwSsdzwxRBq1LGzogl1W1EC1YbZxtbEIFuNkgNGdi5tTao1iEomSO4sz85tBZ7Ql9D-MDw"},"schema":"pubphys.envelope/1"},"record_hash":"1d83b71734906bbc3afa0057857fa7c7532f6a679ab9c83e2015f323e431b083","leaf_index":1668}