Département de médecine nucléaire et de radiobiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec J1H5N4, Canada.
Phys Med Biol. 2009 Oct 7;54(19):5909-17. doi: 10.1088/0031-9155/54/19/016. Epub 2009 Sep 17.
In this study, polyacrylamide gel (PAG) dosimetry is used to quantitatively assess the efficiency of radiation sensitizers. The local dose enhancement caused by the K-edge absorption of certain atoms such as bromine and iodine can be employed to increase the damage to neighboring molecules and cells. Clonogenic assays can assess the radiation survival of cells to evaluate the efficiency of radiation sensitizers, but this technique requires reliable cell growth in culture media and is time consuming. Our purpose is to use PAG dosimetry to investigate the sensitizing potential of radiation sensitizers such as iodinated compounds. Incorporation of iodinated radiation sensitizers such as NaI and an iodinated contrast agent leads to a quantifiable dose enhancement ratio. When irradiated at low energy (approximately 40 keV), the dose enhancement ratio of the iodinated contrast agent at concentrations of 0.01 (3.5 mg ml(-1)), 0.05 (6 mg ml(-1)) and 0.1 (12 mg ml(-1)) M are 1.16 +/- 0.02, 1.39 +/- 0.03 and 1.82 +/- 0.04, respectively. No dose enhancement was observed when the samples were irradiated with 1.25 MeV gamma photons.
在这项研究中，聚丙烯酰胺凝胶（PAG）剂量测定法被用于定量评估辐射增敏剂的效率。某些原子（如溴和碘）的 K 边吸收引起的局部剂量增强，可以用来增加邻近分子和细胞的损伤。集落形成测定法可评估细胞的辐射存活率，以评估辐射增敏剂的效率，但该技术需要在培养基中可靠地培养细胞，且耗时较长。我们的目的是使用 PAG 剂量测定法来研究碘化化合物等辐射增敏剂的增敏潜力。碘化辐射增敏剂（如 NaI 和碘化造影剂）的掺入会导致可量化的剂量增强比。当用低能量（约 40keV）照射时，浓度为 0.01（3.5mg/ml）、0.05（6mg/ml）和 0.1（12mg/ml）M 的碘化造影剂的剂量增强比分别为 1.16 +/- 0.02、1.39 +/- 0.03 和 1.82 +/- 0.04。当用 1.25MeV 伽马光子照射样品时，没有观察到剂量增强。
