暴露于小剂量电离辐射和较高剂量的电离辐射后产生的抵抗力被称为辐射诱导适应性反应（RIAR）。传统上，在细胞系、动物模型和流行病学研究中，人们已经在细胞系、动物模型和人们生活在高自然本底辐射的情况下对 RIAR 现象的诱导进行了检查。早期研究的主要目的是证实 RIAR 的存在和介导通过暴露于低剂量辐射（<500 mGy）作为辐射防护观点的启动剂量所调查的反应的机制。然而，研究的重点已转移到了解这种现象在临床相关设置（Gy 级高剂量）中的相关性，并且可以在放射治疗期间利用，因为 RIAR 被认为是产生放射抗性的机制。尽管细胞水平的分子机制知识在多分割放射治疗方案中已经有了显着的发展，但其在低剂量放射抗性中的相关性仍然难以捉摸。作者在细胞水平上概括了 RIAR 的现有知识，特别是在低剂量暴露作为适应性剂量之后，并讨论了其对临床放疗结果的潜在影响。最近的研究有助于了解信号分子、途径和抑制剂以减轻 RIAR-介导的辐射抵抗和细胞水平上的持久放射耐受性。已提出使用合适的生物标志物在治疗之前、期间和之后监测肿瘤样本或液体活检中的疾病进展，作为将现象转化为临床场景的策略。 Karger AG，巴塞尔。

Development of resistance upon exposure to small doses of ionizing radiation followed by higher doses is known as radiation-induced adaptive response (RIAR). Traditionally, the induction of the RIAR phenomenon at the cellular level has been examined in cell lines, animal models, and epidemiological studies where people live in high natural background radiation.The primary intention of the earlier studies was to corroborate the existence of RIAR and the mechanism involved in mediating the response surveyed by exposure to a low dose of radiation (<500 mGy) as priming dose towards the radiation protection point of view. However, the investigation has shifted the focus to understand the relevance of this phenomenon at clinically relevant set-ups (high doses in the order of Gy) and can be exploited during radiotherapy as RIAR is considered a mechanism for the development of radioresistance. Although the knowledge of molecular mechanisms at the cellular level has evolved significantly in multi-fractionated radiotherapy regimes, its relevance in developing radioresistance at low doses remains elusive. The authors recapitulate the existing knowledge on RIAR at cellular levels, specifically after low-dose exposure as an adaptive dose, and discussed its potential implications in clinical radiotherapy outcomes.Recent studies contributed to understand the signaling molecules, pathways, and inhibitors to mitigate RIAR-mediated radiation resistance and persistent radio-tolerance at the cellular level. Monitoring the disease progression in tumor samples or liquid biopsies before, during, and after therapy with suitable biomarkers has been proposed as a strategy to translate the phenomena into clinical scenario.S. Karger AG, Basel.