Establishment of the radiosensitivity predicting system by comet assay using peripheral lymphocytes

29例乳腺癌患者在全乳房放疗后发生2级急性放射性皮炎，34例未发生放射性皮炎的对照患者进入本研究。将患者淋巴细胞以12 Gy的剂量照射，照射0 ~ 180 min后进行单细胞凝胶碱性电泳（comet assay）。在大多数情况下，标准化尾矩（STM）随着时间的推移而减小，代表了辐射引起的DNA损伤的修复过程。修复半时间（RHT）的平均+/- SE（定义为在0分钟内将STM减少到STM的50%所需的时间）在皮炎组和对照组中分别为31.0 +/- 4.8 min和20.6 +/- 2.5 min（p=0.05）。结果表明，体外彗星测定中代表DNA修复速度的参数RHT可能是全乳房放疗患者放射性皮炎的候选预测因子。进一步的评价这一分析在前瞻性设置表示。

Twenty-nine patients with breast cancer who had developed Grade 2 acute radiation dermatitis following whole breast radiotherapy and 34 control patients who had not developed radiation dermatitis entered the present study. The patients' lymphocytes were irradiated at a dose of 12 Gy, and subjected to the single cell gel alkaline electrophoresis assay(comet assay) 0 to 180 minutes after irradiation. In most cases, standardized tail moment(STM) decreased with time, representing the repair procedure of radiation-induced DNA damage. The mean +/- SE of repair half-time(RHT), defined as the time required to reduce the STM to 50% of the STM at 0 min, in the dermatitis group and the control group was 31.0 +/- 4.8 min and 20.6 +/- 2.5 min(p=0.05), respectively. The results suggested that RHT, a parameter representing DNA repair velocity in ex vivo comet assay, may be a candidate for the radiation dermatitis predictor in patients receiving whole breast radiotherapy. Further evaluation of this assay in a prospective setting is indicated.