MR Image Guided Gynecologic Brachytherapy

描述(申请人提供)：位于骨盆的妇科癌症患者可以接受放射治疗。使用近距离放射治疗，将放射性粒子直接放置到肿瘤中心，在外照射后，允许肿瘤的剂量递增，导致肿瘤成功消退和根除。然而，在肿瘤附近，关键的正常组织结构，包括小肠、乙状结肠、直肠和膀胱，可能位于可以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光或CT)和规定的单点剂量是护理的标准。正常组织不是由它们的实际尺寸来定义的，而是由接近它们位置的点来定义的。为了成功地确定肿瘤的位置及其与正常组织结构的关系，以便将对肿瘤的剂量降至最低，在放置近距离放射治疗敷贴器时，有必要对骨盆进行成像。MRI显示骨盆内的肿瘤和OAR比其他成像方法更精确。在这项临床试验中，除了DWI MRI外，还将研究3T T2加权MRI成像的实用性，以及这些图像与活检证实的癌症存在之间的相关性。

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.