{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"58cc77505e0ed851a5ced9cf2e4d4c3726f3dc8ec3f15f74fcdbdb3da5b45afa","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":["ai:gpt-5.5"],"kind":"seed"},"parents":["1d83b71734906bbc3afa0057857fa7c7532f6a679ab9c83e2015f323e431b083","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"b8dec6e13c2427ff91938cb0b9e7eeba6772af7af4e321b3e23cf5f9c91bacbe","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":["ai:gpt-5.5"],"external_id":"med.bnct.mixed-field-weighting","kind":"well-posed","literature_status":"contested","n":"2","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":"1d83b71734906bbc3afa0057857fa7c7532f6a679ab9c83e2015f323e431b083","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":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"4e211a6d6cd33f3382780aea0ed10e599957062a31ad824c0953b52649ee6125","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"07ff43c0345ac42d2089a8a100bb57d0e1b28265da0e33a4e3c6863aed9757b6","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"M3MifJwOspiBvg1wHIl1ogk0u2v7_am8Mr5WWaQrFBjIP4dNVkS7WdrUzzDqNKTzQXiHg19JyPCKkV_ZoKa-Ag"},"schema":"pubphys.envelope/1"},"record_hash":"4e211a6d6cd33f3382780aea0ed10e599957062a31ad824c0953b52649ee6125","leaf_index":3462}