高低氧放疗分次照射对小鼠肿瘤及正常组织的剂量效应

目的：研究高低氧放疗分次照射对小鼠肿瘤及正常组织的剂量效应关系。方法：实验肿瘤为Ｔ７３９小鼠ＬＡ７９５自发性肺腺癌，以生长延缓为观察指标。正常组织以昆明鼠右后肢的皮肤反应作观察指标。实验分为单纯空气组、单纯高氧组、高低氧组。结果分次照射肿瘤放射增敏比（ＳＥＲ）高低氧组及高氧组分别为１．３４、１．６４，皮肤反应ＳＥＲ高低氧组及高氧组分别为１．１９、１．４９，高低氧组治疗获得系数（ＴＧＦ）为１．１３，

Fractionated radiosensitization of murine tumor and normal tissue by carbogen plus low concentration oxygen radiotherapy

Objective To Study the dose response relationships of murine tumor and normal tissue in fractionated carbogen plus low concentration oxygen radiotherapy (CPLCOR). Methods The experiments included three groups: air, carbogen (95%O 2 5%CO 2), and carbogen plus low concentration oxygen (10%O 2 85%N 2 5%CO 2), five fractions were given to animals using a biological equivalence dose formula. The transplantable spontaneous tumor LA759 in inbred T739 mice was used for tumor response studies and the skin radiation reaction was evaluated with Douglas and Fowler grading method. Results In fractionated schedule, the sensitivity enhancement ratios (SER) were 1.34 and 1.64 for CPLCOR and carbogen alone groups respectively. In skin response, the CPLCOR group showed a relatively milder reaction than the carbogen group did: their SER were 1.19 and 1.49 and the therapeutic gain factors (TGFs) for fractionated schedule were 1.13 and 1.10 respectively. Conclusions Compared with the results of single dose studies, TGF decreases during fractionated irradiation, indicating that the CPLCOR has fewer advantage than carbogen radiotherapy.