Development of Gel Dosimeters for Radiotherapy

描述(申请人提供)：该项目的长期目标是开发一种用于验证复杂的适形放射治疗的三维剂量计。总体标准是，剂量计配方必须与目前可用的剂量计一样灵敏，但比MGS的Bang-3更稳定。对水凝胶和非水聚合物中的可辐射氧化和可还原化合物进行了广泛的筛选研究。从这些研究中，我们确定了几种配方，它们应该符合与Bang-3剂量计相当且更稳定的标准。基于这些初步结果，我们的实验计划要求使用微束层析光学扫描仪进行更多的扩散研究。此外，颜色强度与吸收剂量的关系，浓度对G值的影响，光子能量和剂量率的依赖关系，以及信号稳定性都将在632 nm处使用分光光度计进行测量。如果满足上述标准，将在断层光学扫描系统上对全尺寸剂量计进行照射和评估。 建议的商业应用： 需要开发一种灵敏而稳定的三维放射剂量计来验证复杂的放射治疗计划，特别是针对较新的治疗计划，如调强放射治疗。尽管很难预测每年进行的适形放射治疗的数量，但数量显然在增加。在美国，每年有超过60万名患者需要接受放射治疗。

DESCRIPTION (provided by applicant): The long-term objective of this project is to develop a three-dimensional dosimeter for verifying complex conformal radiotherapeutic treatment. The overall criteria is that the dosimeter formulation must be as sensitive as but more stable than the currently available dosimeter, BANG-3 from MGS. An extensive screening study of radiolytically oxidizable and reducible compounds in aqueous gels and nonaqueous polymers was performed. From these studies we have identified several formulations that should meet the criteria of being equivalent to and more stable than the BANG-3 dosimeter. Based on these preliminary results our experimental plan calls for additional diffusion studies using a micro beam tomographic optical scanner. In addition, the color intensity versus absorbed dose, effect of concentration on G value, dependence of photon energy and dose rate, and signal stability will all be measured using a spectrophotometer at 632 nm. If the above criteria are met a full scale dosimeter will be irradiated and evaluated on a tomographic optical scanning system. PROPOSED COMMERCIAL APPLICATION: There is a need to develop a sensitive and stable 3-D radiation dosimeter to verify complex radiotherapeutic treatment plans, particularl, for the newer treatment plans such as IMRT. Even though it is difficult to predict the annual number of conformal radiotherapies performed it is clearly growing in number. There are over 600,000 patients annually requiring radiation therapy in USA.