Joint Segmentation of MR and CT scans for Gynecologic Cancer Brachytherapy

妇科癌症近距离放射治疗中 MR 和 CT 扫描的联合分割

• 批准号: 8177424
• 负责人: Tina Kapur
• 金额: $ 8.92万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-15 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8177424
• 关键词: Algorithms; Anatomic structures; Anesthesia procedures; Appearance; Area; Bladder; Brachytherapy; Brain; Cervix Uteri; Characteristics; Communities; Computer software; Databases; Dose; Female Genital Neoplasms; Film; Funding; Future; Goals; Gray unit of radiation dose; Gynecologic; Hospitals; Hour; Image; Image Analysis; Imagery; Joints; Knee; Knowledge; Label; Licensing; Magnetic Resonance Imaging; Malignant Female Reproductive System Neoplasm; Malignant Neoplasms; Malignant neoplasm of cervix uteri; Methods; Modality; Noise; Normal tissue morphology; Operating Rooms; Organ; Patients; Pelvis; Positioning Attribute; Probability; Procedures; Process; Prospective Studies; Radiation; Radiation Oncologist; Radiation Oncology; Radiation therapy; Radioisotopes; Rectum; Relative (related person); Research; Research Project Grants; Risk; Scanning; Sigmoid colon; Signal Transduction; Small Intestines; Structure; Techniques; Testing; Therapeutic Studies; Three-Dimensional Image; Tissues; Toxic effect; Translating; Vagina; Validation; Variant; Work; X-Ray Computed Tomography; design; expectation; human female; image registration; imaging Segmentation; imaging modality; improved; infancy; killings; neoplastic cell; open source; spatial relationship; treatment planning; tumor

DESCRIPTION (provided by applicant): The placement of radioactive isotopes directly into a cancer of the uterine cervix or vagina in order to eradicate the cancer, requires insertion of a hollow applicator into the tumor. Though previously plain x-ray film depicted the position of the applicator, and was used to calculate the dose to deliver to an area around the applicator, 3D CT revolutionized tumor visualization in the 1990s. However, MRI more clearly defines gynecologic tumors, though the application of MRI to gynecologic brachytherapy is in its infancy. Research in the last five years has shown that using CT alone overestimates the extent of normal tissue that surrounds the cancer compared to MR. In comparison MR allows the radiation oncologist to draw tighter boundaries around the target volume that should receive the highest radiation dose, while sparing larger amounts of surrounding normal tissue. Current practice at our hospital after applicator insertion in the operating room is to obtain a 3D image to guide radiation treatment planning. Patients with large tumors undergo both a CT and an MRI. Commercial software aligns the MRI and CT to each other, and is used to outline target cancer and surrounding organs at risk. A treatment plan is generated and radiation is delivered to the patient using this plan. Current alignment and contouring methods require significant expert input from the radiation oncologist and physicist while the patient waits for treatment under anesthesia. This project will improve the efficiency of this workflow using advanced image analysis methods as follows. 1) We will develop an EM-ESP segmenter to simultaneously segment registered MR and CT scans for gynecologic brachytherapy planning. This segmenter will construct and use joint prior probability distributions on image intensities and the geometry of key anatomic structures relative to the brachytherapy applicator, which is clearly visible in the images. 2) We will apply the EM-ESP segmenter retrospectively on a database of 25 patients who were treated during 2004-2006 using MR guided brachytherapy by Dr. Akila Viswanathan, Chief of Gynecologic Radiation Oncology at our hospital. Contours were drawn manually on these scans, and we will test our method against these. The result of this project will be an algorithm that can automatically delineate the cervix, the bladder, the rectum, the sigmoid colon, and the small bowel in MR and CT images for gynecologic brachytherapy. To the best of our knowledge, the proposed algorithm will be the first to provide this functionality. ( ( ! PUBLIC HEALTH RELEVANCE: Magnetic resonance images have proven to identify the extent of cancer in gynecologic cancer better than other imaging modalities. The better the cancer can be differentiated from the surrounding bladder, rectum, and small bowel, the more accurately high doses of radiation can be given to kill the tumor cells while minimizing the toxic effects of radiation on normal tissue. This project will develop algorithms will automatically identify the boundaries of the cancer and surrounding normal organs of the human female pelvis so that MR-guided radiation therapy can be carried out efficiently and accurately.

描述（由申请人提供）：将放射性同位素直接置入宫颈癌或阴道癌中以根除癌症，需要将中空施源器插入肿瘤中。虽然以前的普通X射线胶片描绘了施加器的位置，并用于计算施加器周围区域的剂量，但3D CT在20世纪90年代彻底改变了肿瘤可视化。然而，MRI更清楚地定义了妇科肿瘤，尽管MRI在妇科近距离放射治疗中的应用尚处于起步阶段。过去五年的研究表明，与MR相比，单独使用CT会高估癌症周围正常组织的范围。相比之下，MR允许放射肿瘤学家在应该接受最高辐射剂量的靶体积周围绘制更严格的边界，同时保留更多周围正常组织。我们医院目前的做法是在手术室插入施源器后获得3D图像，以指导放射治疗计划。大肿瘤患者同时接受CT和MRI检查。商业软件将MRI和CT相互对齐，并用于勾勒出目标癌症和周围有风险的器官。生成治疗计划，并使用该计划向患者输送辐射。当前的对准和轮廓绘制方法需要来自放射肿瘤学家和物理学家的重要专家输入，而患者在麻醉下等待治疗。该项目将使用先进的图像分析方法提高该工作流程的效率，如下所示。1)我们将开发一种EM-ESP分割器，用于同时分割配准的MR和CT扫描，用于妇科近距离放射治疗计划。该分割器将构建并使用图像强度的联合先验概率分布以及与近距离放射治疗施源器相关的关键解剖结构的几何形状，其在图像中清晰可见。2)我们将在2004-2006年期间由我院妇科放射肿瘤科主任Akila Viswanathan博士使用MR引导近距离放射治疗治疗的25例患者的数据库中回顾性应用EM-ESP分割器。在这些扫描上手动绘制轮廓，我们将测试我们的方法。该项目的结果将是一种算法，可以自动描绘子宫颈，膀胱，直肠，乙状结肠，和小肠的MR和CT图像的妇科近距离放射治疗。据我们所知，该算法将是第一个提供此功能的算法。( ( ! 公共卫生相关性：磁共振成像已被证明是确定在妇科癌症的程度比其他成像方式更好。癌症与周围的膀胱、直肠和小肠区分得越好，就可以更准确地给予高剂量的辐射来杀死肿瘤细胞，同时最大限度地减少辐射对正常组织的毒性作用。该项目将开发算法，自动识别癌症和人类女性骨盆周围正常器官的边界，以便有效和准确地进行MR引导的放射治疗。