【作者】 阮婷彦；

【导师】 楚建军；

【作者基本信息】 苏州大学 ， 肿瘤学， 2010， 硕士

【摘要】 目的探讨三维适形照射(3DCRT)模式和急速照射模式对人肝癌细胞株BEL-7402生物效应变化的影响,存活分数及生物学参数的改变情况;观察人肝癌细胞株BEL-7402与人肝细胞株QSG-7701放射敏感性差异,为临床选择合适的放疗时间-剂量分割模式提供理论依据。方法6MV X线两组模式照射人肝癌细胞BEL-7402(包括0,1,2,3,5,7,9,10Gy共8个吸收剂量点,剂量率3Gy/min):(1)急速照射组,照射完成时间0-4min;(2)模拟三维适形照射组:照射完成时间:13-15min。成克隆分析法计算存活分数,多靶单击数学模型拟合曲线,求出SF2,D0,Dq等参数值;6MV X线单次5Gy照射体外培养的人肝癌细胞BEL-7402、人肝细胞QSG-7701 ,采用MTT比色法、流式细胞术测定受照后不同时间(照射后6、12、24、36 h)细胞的存活率、凋亡率、细胞周期。结果人肝癌细胞BEL-7402模拟急速照射组和三维适形照射组D0、Dq、SF2值分别为1.78和1.69;1.45和1.54;0.625和0.654;人肝细胞QSG-7701照后24 h凋亡率最高(18%),而BEL-7402细胞照后12h凋亡率最高(32%),存活率最低(65%),两株细胞照后12 h凋亡率和存活率差异最大(P<0.01)。QSG-7701在照后24h、BEL-7402在照后12h,G2/M期比例显著增高(分别为23.03±4.00%和43.23±6.44%)。结论1.三维适形照射模式下分次照射时间延长,生物效应下降;2.人肝癌细胞株BEL-7402及人肝细胞株QSG-7701在照后存在放射敏感性差异;3.缩短3DCRT每分次照射时间和分次照射的间隔时间(如12h)可能会提高临床肝癌放疗疗效。更多还原

【Abstract】 Objective To investigate the changes of radiobiological effects of BEL-7402 cells irradiated by two irradiation protocols(3-Dimensional conformal radiation therapy and acute irradiation), and its changes of surviving fraction and radiobiological parameters; To observe the differences of radiosensitivity between human hepatocarcinoma cells BEL-7402 and hepatic cells QSG-7701, approach the possible theoretical evidence .Methods BEL-7402 cells irradiated to total doses of 0Gy, 1Gy, 2Gy, 3Gy, 5Gy, 7Gy, 9Gy, 10Gy at a dose rate of 3Gy/min in two different delivery patterns. In modeling acute irradiation, the fraction-delivery-time was 0-4 min; while in modeling 3-Dimensional conformal radiation therapy (3DCRT), the fraction-delivery-time was lasted 13-15 min. The surviving fractions were determined by classical colony forming assay. The radiobiological parameters were calculated, and cell survival curves were plotted according to“the single-hit multi-target model”. The survivability, apoptosis and cell cycles of BEL-7402 and QSG-7701 cells, which cultured in vitro and irradiated by 6MV X-ray with a single dose of 5 Gy, were assessed by methyl thiazole tetrazolium (MTT) assay and flow cytometry ( FCM ) at different time after irradiation.Results The value of D0, Dq, SF2 of BEL-7402 cell line in acute irradiation pattern and 3DCRT irradiation pattern were 1.69 and 1.78 , 1.45 and 1.54, 0.625 and 0.654. The number of apoptotic BEL-7402 cells reached a peak (32 %) and a lowest survival (65%) at the 12h after irradiation, while irradiated apoptotic QSG-7701 cells showed highest (18%) at the 24h. Radiation induced significant differences in apoptosis and survival between the two cell lines at 12h(P<0.01). Cell cycle accumulation at G2/M phase of QSG-7701 cell after 24h exposure to this dose, and of BEL-7402 cell after 12h (23.03±4.00%,43.23±6.44%).Conclusion 1.The radiobiological effectiveness can be influenced by prolonged fraction-delivery-time for 3DCRT. 2. The two cell lines were distinct from each other in radiosensitivity after irradiation. 3. To shorten fractionation schedules may have a beneficial effect of radiotherapy of hepatoma.更多还原