MR Image Guided Gynecologic Brachytherapy

描述（由申请人提供）：骨盆部位的妇科癌症患者可以用放射治疗。使用近距离放射疗法，在外部光束照射后，将放射性种子直接放置在肿瘤中心，允许剂量上升到肿瘤，导致肿瘤成功消退和根除。然而，在肿瘤附近，包括小肠、乙状结肠、直肠和膀胱在内的关键正常组织结构可能位于可接受高剂量辐射的区域。在美国的大多数中心，简单的成像（x射线或CT）和剂量规定到一个点是标准的护理。正常组织不是由它们的实际尺寸来定义的，而是由它们的近似位置来定义的。为了成功地确定肿瘤的位置及其与正常组织结构的关系，以最大限度地减少对它们的剂量，有必要在近距离放射治疗应用器放置期间对骨盆进行成像。MRI比其他成像方式更精确地描绘骨盆中的肿瘤和桨叶。在这项临床试验中，除了DWI MRI外，还将研究3tt2加权MRI成像的效用，以及这些图像与活检证实的癌症存在的相关性。

DESCRIPTION (provided by applicant): Patients with gynecologic cancers localized to the pelvis may be curatively treated with radiation. The use of brachytherapy, the placement of radioactive seeds directly into the center of the tumor, after external beam radiation, permits dose escalation to the tumor, resulting in successful regression and eradication of the tumor. However, adjacent to the tumor, critical normal tissue structures including the small bowel, sigmoid, rectum, and bladder may rest in regions that can receive high doses of radiation. In most centers in the U.S., simple imaging (X-ray or CT) with doses prescribed to a single point are the standard of care. Normal tissues are not defined by their actual dimensions, rather by points that approximate their location. In order to successfully determine the location of the tumor and its relationship to the normal tissues structures in order to minimize the dose to them, it is necessary to image the pelvis during brachytherapy applicator placement. MRI delineate tumor and OAR in the pelvis with much more precision than other imaging modalities. In this clinical trial, the utility of 3T T2- weighted MRI imaging, in addition to DWI MRI, and how the images correlate with biopsy-confirmed presence of cancer will be studied.