{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"cd08384882f5984f4720163d6164c8fd612b8a624c8839eff37ab61818d55b84","created":"2026-10-03T07:18:06Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"527039cdfab244ba691043d794f6479c7a0fa1459bd388486dbc6407faa85160","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"med.flash.deep-conformal-delivery","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Fast dose is easy to produce near the skin but hard to shape around a deep tumour. The accelerator and delivery physics for doing both at once is unsettled.","posed_since":"2018","precise":"Design and demonstrate a delivery scheme giving a conformal dose distribution to a target at 10 to 20 cm depth with mean dose rate above 4000 rad/s over the whole target and delivery under 200 ms. Candidate routes: very-high-energy electrons at 100 to 250 MeV with magnetic scanning or focusing, transmission or Bragg-peak proton beams with ridge filters, and multi-source photon arrays. An answer is a validated design with measured dose rate, conformality and delivery time.","problem_ref":null,"references":"","settled_by":"Measured three-dimensional dose and dose-rate maps in a phantom meeting target conformality and the dose-rate criterion simultaneously.","status_note":"Proton transmission FLASH has been used in clinical trials, but conformal deep delivery at full dose rate was still a design problem in 2025.","title":"Conformal FLASH delivery to deep-seated tumours","topic_ref":"e183d5a2701f7e11dac3a5238c81e6d9a173fcc98c4f033d2937f114642a72e0"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"9b02a9f260b026e83eb04e129e945b0906448c96d261576f556fa18cef6132b2","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"ac76278d84042e6dd88b728877433f4557cc23b0781ba9ebf3ef040f7d49d9a3","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"INCwbM33e3fwsclYFURYEo6ljJKSIua2Xpr60oRSIGf6p76kR2JhFSJbUekaZTmrQc2QY5aHdOAkMN2vZ5WHAw"},"schema":"pubphys.envelope/1"},"record_hash":"9b02a9f260b026e83eb04e129e945b0906448c96d261576f556fa18cef6132b2","leaf_index":1679}