Urano M, Kahn J, Kenton L A
Int J Radiat Oncol Biol Phys. 1986 Jan;12(1):45-50. doi: 10.1016/0360-3016(86)90414-1.
Our previous study demonstrated the presence of a thermochemotherapy-resistant cell fraction in a tumor. The present study investigated whether thermochemotherapy-resistant cells are radioresistant and whether thermochemotherapy changes the size of hypoxic cell fraction in the tumor. Early generation isotransplants of a spontaneous fibrosarcoma, FSa-II tumors, were used. A radiation dose that yields 50% tumor control rate in 150 days after local irradiation, TCD50, was determined. Cyclophosphamide (CY) was the test agent. TCD50 values of the 4 mm tumor following gamma-ray alone given under hypoxic conditions or in air were 80.9 or 65.8 Gy, respectively. Thermochemotherapy reduced TCD50 values congruent to 20 Gy, suggesting that thermochemotherapy resistant cells are not identical to the radioresistant cells. Glucose administered 60 min before thermochemotherapy further reduced TCD50 values. Foot-reaction scored in the tumor-controlled animals was significantly less severe following combined thermochemo- and radiotherapy compared to that following radiotherapy alone. Acute foot reaction studies also supported this observation. These results indicated that thermochemotherapy could be an excellent adjuvant to radiotherapy. Further studies using a 6 mm tumor indicated that thermochemotherapy was less effective on the large tumor than on the small tumor. Indirect analysis showed no significant changes in the size of hypoxic cell fraction following thermochemotherapy.
我们之前的研究表明肿瘤中存在热化疗抗性细胞组分。本研究调查了热化疗抗性细胞是否具有放射抗性，以及热化疗是否会改变肿瘤中缺氧细胞组分的大小。使用了自发纤维肉瘤FSa-II肿瘤的早期传代同基因移植瘤。确定了局部照射后150天产生50%肿瘤控制率的辐射剂量，即TCD50。环磷酰胺（CY）为受试药物。在缺氧条件下或空气中单独给予γ射线后，4毫米肿瘤的TCD50值分别为80.9或65.8 Gy。热化疗使TCD50值降至约20 Gy，这表明热化疗抗性细胞与放射抗性细胞并不相同。热化疗前60分钟给予葡萄糖可进一步降低TCD50值。与单纯放疗相比，热化疗联合放疗后肿瘤得到控制的动物足部反应评分明显较轻。急性足部反应研究也支持这一观察结果。这些结果表明热化疗可能是放疗的一种优秀辅助手段。使用6毫米肿瘤的进一步研究表明，热化疗对大肿瘤的效果不如对小肿瘤的效果好。间接分析显示热化疗后缺氧细胞组分大小无显著变化。
