Novel Conformal Iodine-125 Ophthalmic Plaques

描述(申请人提供)：脉络膜黑色素瘤是最常见的原发眼部恶性肿瘤，在美国每年约有1500例新病例报告。这些肿瘤既危及视力，又危及生命。COMS对中度脉络膜黑色素瘤的试验表明，125碘放射性斑块单独治疗，而不摘除眼球，并不会增加死亡率。中型脉络膜黑色素瘤可通过应用125碘近距离放射治疗来治疗，并保留眼睛和部分视力。然而，目前使用的“种子”斑块所产生的剂量分布是不均匀的，并且高度复杂。如果不是不可能的话，在眼睛内甚至肿瘤内的不同点准确地获得所需的辐射剂量分布是极其困难的。治疗后，超过40%的眼睛经历了与放射相关的严重眼部并发症。这一第二阶段计划旨在开发一种用于治疗脉络膜黑色素瘤的改进的近距离放射治疗斑块。放射源将通过一种工艺制造，通过该工艺，可以将斑块表面的125碘分布设计为提供规定的剂量分布。这种发展将提供比目前的种子斑更好的剂量均匀度，并将允许剂量分布轮廓符合特定的肿瘤。这样的开发还将为斑块设计提供一定的定制措施，提供围绕视神经等干扰的调节和间隙。此外，这种斑块将实现高度定制的剂量率，允许在非常窄的范围内指定治疗时间。这种斑块将比目前的种子斑块更薄，这将给患者带来较小程度的不适。这种斑块将被设计为可重复使用，极大地降低了这部分治疗的成本。使用125碘的适形近距离放射治疗斑块可以成为治疗这种癌症的有效工具。

DESCRIPTION (provided by applicant): Choroidal melanoma is the most common primary ocular malignancy, with some 1500 new cases reported yearly in the United States. These tumors are both sight- and life-threatening. The COMS trial for medium choroidal melanomas, demonstrated that 125Iodine radioactive plaque treatment alone, without enucleation, does not increase mortality. Medium-sized choroidal melanomas can be treated and the eye and some vision preserved by application of 125Iodine brachytherapy. However, the dose distribution generated by the currently used "seeded" plaques is non-uniform and highly complex. It is extremely difficult if not impossible to accurately achieve the desired radiation dose distribution at varying points within the eye and even within the tumor. After treatment, greater than 40% of eyes have experienced significant radiation associated ocular complications. This Phase II program intends to develop an improved brachytherapy plaque for the treatment of choroidal melanoma. The source would be manufactured through a process by which the 125Iodine distribution on the surface of the plaque could be designed to provide a prescribed dose distribution. Such development would provide better dose uniformity than the current seed plaque and would permit the dose distribution to be contoured to conform to the specific tumor. Such development would also provide a measure of customization to the plaque design, providing accommodations and clearances around interferences such as the optic nerve. Additionally, such plaques would achieve a high degree of customization of the dose rate, allowing the treatment time to be specified within very narrow limits. This plaque would be thinner than the current seeded plaques, which would provide a lesser degree of discomfort to the patient. This plaque would be designed to be reusable, greatly reducing the cost for this portion of the treatment. A conformal brachytherapy plaque using 125Iodine can be an effective treatment device for this cancer.