Wilson Joseph D, Hammond Ester M, Higgins Geoff S, Petersson Kristoffer
Department of Oncology, The Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom.
Radiation Physics, Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden.
Front Oncol. 2020 Jan 17;9:1563. doi: 10.3389/fonc.2019.01563. eCollection 2019.
Radiotherapy is a cornerstone of both curative and palliative cancer care. However, radiotherapy is severely limited by radiation-induced toxicities. If these toxicities could be reduced, a greater dose of radiation could be given therefore facilitating a better tumor response. Initial pre-clinical studies have shown that irradiation at dose rates far exceeding those currently used in clinical contexts reduce radiation-induced toxicities whilst maintaining an equivalent tumor response. This is known as the FLASH effect. To date, a single patient has been subjected to FLASH radiotherapy for the treatment of subcutaneous T-cell lymphoma resulting in complete response and minimal toxicities. The mechanism responsible for reduced tissue toxicity following FLASH radiotherapy is yet to be elucidated, but the most prominent hypothesis so far proposed is that acute oxygen depletion occurs within the irradiated tissue. This review examines the tissue response to FLASH radiotherapy, critically evaluates the evidence supporting hypotheses surrounding the biological basis of the FLASH effect, and considers the potential for FLASH radiotherapy to be translated into clinical contexts.
放射治疗是癌症治愈性和姑息性治疗的基石。然而，放射治疗受到辐射诱导毒性的严重限制。如果这些毒性能够降低，就可以给予更高剂量的辐射，从而促进更好的肿瘤反应。最初的临床前研究表明，以远远超过目前临床使用的剂量率进行照射可降低辐射诱导的毒性，同时保持同等的肿瘤反应。这被称为FLASH效应。迄今为止，有一名患者接受了FLASH放射治疗以治疗皮下T细胞淋巴瘤，结果实现了完全缓解且毒性极小。FLASH放射治疗后组织毒性降低的机制尚待阐明，但目前提出的最突出假说是照射组织内会发生急性氧耗竭。本综述探讨了组织对FLASH放射治疗的反应，批判性地评估了支持围绕FLASH效应生物学基础假说的证据，并考虑了FLASH放射治疗转化为临床应用的潜力。
