Department of Radiotherapy/Oncology, Medical School, Democritus University of Thrace, Alexandroupolis 68100, Greece.
Department of Pathology, Medical School, Democritus University of Thrace, Alexandroupolis 68100, Greece.
Crit Rev Oncol Hematol. 2021 Mar;159:103226. doi: 10.1016/j.critrevonc.2021.103226. Epub 2021 Jan 19.
The immune response has been recognized as a major tumor-eradication component of radiotherapy.
This review studies, under a clinical perspective, two contrasting effects of radiotherapy, namely immunosuppression and radiovaccination.
We critically reviewed the available clinical and experimental experience on radiotherapy-induced lymphopenia.
Radiation-induced tumor damage promotes radio-vaccination, enhances cytotoxic immune responses, and potentiates immunotherapy. Nevertheless, radiotherapy induces systemic and intratumoral lymphopenia. The above effects are directly related to radiotherapy fractionation and field size/location, and tumor characteristics.
Hypofractionated stereotactic and accelerated irradiation better promotes radio-vaccination and produces less severe lymphopenia. Adopting cytoprotective policies and combining lympho-stimulatory agents or agents blocking regulatory lymphocyte activity are awaited to unmask the radio-vaccination effect, enhancing the efficacy immuno-radiotherapy.
Radiation-induced lymphopenia and immunosuppression are important issues that should be considered in the design of immuno-radiotherapy clinical trials.
免疫反应已被认为是放射治疗中消除肿瘤的主要组成部分。
本综述从临床角度研究了放射治疗的两种相反作用，即免疫抑制和放射疫苗接种。
我们批判性地回顾了关于放射治疗引起的淋巴细胞减少症的现有临床和实验经验。
放射诱导的肿瘤损伤促进放射疫苗接种，增强细胞毒性免疫反应，并增强免疫疗法。然而，放射治疗会引起全身和肿瘤内的淋巴细胞减少症。上述影响与放射治疗的分割和野的大小/位置以及肿瘤特征直接相关。
低分割立体定向和加速照射更好地促进放射疫苗接种，并产生较少的严重淋巴细胞减少症。采用细胞保护策略并结合淋巴刺激剂或阻断调节性淋巴细胞活性的药物，有望揭示放射疫苗接种的效果，增强免疫放射治疗的疗效。
放射诱导的淋巴细胞减少和免疫抑制是免疫放射治疗临床试验设计中应考虑的重要问题。
