Accepted for/Published in: JMIR Research Protocols
Date Submitted: Aug 10, 2022
Open Peer Review Period: Aug 9, 2022 - Aug 17, 2022
Date Accepted: Oct 4, 2022
Date Submitted to PubMed: Oct 7, 2022
(closed for review but you can still tweet)
FLASH Radiotherapy for the Treatment of Symptomatic Bone Metastases (FAST-01): Protocol for the First Prospective Feasibility Study
ABSTRACT
Background:
In preclinical studies, FLASH therapy (radiation delivered at ultra-high dose rates ≥40 Gy/second) has been shown to cause less injury to normal tissues than radiotherapy delivered at conventional dose rates. This first-in-human clinical investigation is designed to assess the workflow feasibility of proton FLASH therapy treatment in a clinical setting for the treatment of painful bone metastases in the extremities. A single dose of 8 Gy will be administered, as this dose is well established for palliative therapy from prior investigations using conventional dose-rate photon radiotherapy. Use of this dose regimen will permit an assessment of FLASH treatment efficacy and toxicity relative to the historical comparators.
Objective:
The FAST-01 study is a prospective, single-center study. Primary endpoints include assessing the workflow feasibility as well as the toxicities of FLASH treatment. The secondary endpoint is pain response at the treated site(s) as measured by patient reported pain scores, use of pain medication, and any flare in bone pain after treatment.
Methods:
Following informed consent, 10 subjects ≥18 years old with up to 3 painful bone metastases in the extremities (excluding feet, hands, wrists) will be enrolled. A treatment field selected from a pre-defined library of plans with fixed field sizes (from 7.5 cm x 7.5 cm up to 7.5 cm x 20 cm) will be used for treatment, and subjects will receive 8 Gy in a single fraction. A FLASH-enabled Varian ProBeam™ Proton Therapy unit will be used to deliver treatment to the target volume at a dose rate of ≥40 Gy/sec using the plateau (transmission) portion of the proton beam. After treatment, patients will be assessed for pain response as well as any side-effects of FLASH radiation.
Results:
Results will be compared to historically reported results with conventional dose-rate photon radiotherapy using the same radiation dose and fractionation.
Conclusions:
The results of this investigation will contribute to further developing and optimizing the FLASH- enabled ProBeam™ Proton Therapy System workflow. The pain response and toxicity data acquired on this study will provide greater understanding of FLASH treatment effects on tumor response and normal tissue toxicities, and they will inform future FLASH trial design. Clinical Trial: ClinicalTrials.gov NCT04592887
Citation
Request queued. Please wait while the file is being generated. It may take some time.
Copyright
© The authors. All rights reserved. This is a privileged document currently under peer-review/community review (or an accepted/rejected manuscript). Authors have provided JMIR Publications with an exclusive license to publish this preprint on it's website for review and ahead-of-print citation purposes only. While the final peer-reviewed paper may be licensed under a cc-by license on publication, at this stage authors and publisher expressively prohibit redistribution of this draft paper other than for review purposes.