Deformable registration for image-guided radiotherapy

描述（由申请人提供）：本项目的目的是通过在诊断和治疗计划图像中准确自动配准可变形组织，提高图像引导放射治疗中剂量靶向的准确性和精确度。医学成像和放射治疗的最新进展有可能通过非侵入性地识别癌症的位置和程度以及通过允许医生将放射剂量逐步增加并靶向癌性病变而同时保留周围的健康组织来改善患者护理。为了补偿由于成像要求（如直肠内探头、患者位置差异、体重变化和其他因素）而在诊断和治疗阶段之间发生的显著变化，将开发并验证用于可变形图像配准的新计算工具。给定分割的参考图像和治疗期间获得的图像，该算法将生成组织的3D表示，使用有限元模型估计组织位移和变形，考虑由于未知模型参数引起的不确定性，并输出图像之间的映射。低计算时间对于临床可行性至关重要。新方法将用于将前列腺CT或MRI/MRSI参考图像与使用兆伏锥束GT（MV CBCT）获得的治疗图像配准，MV CBCT是一种正在开发的3D成像模式，用于在治疗床上对患者进行调强放射治疗（IMRT）。将使用骨轮廓并通过测量已植入患者子集前列腺内的标记种子的配准误差来进行方法验证。新的软件工具，针对前列腺癌的治疗，旨在显着改善病人的护理，使临床医生能够提高适形剂量的组织类型在放射治疗。这些改进可以通过降低癌症患者的恢复时间、复发率和治疗费用来显着改善公共卫生。

DESCRIPTION (provided by applicant): The objective of this project is to improve the accuracy and precision of dose targeting in image-guided radiation treatment by accurately and automatically registering deformable tissues in diagnostic and treatment planning images. Recent advances in medical imaging and radiation therapy have the potential to improve patient care by noninvasively identifying the location and extent of cancer and by allowing physicians to escalate and target radiation dose to cancerous lesions while sparing surrounding healthy tissues. To compensate for significant changes that occur between diagnostic and treatment phases due to imaging requirements such as endorectal probes, patient position differences, weight change, and other factors, a new computational tool for deformable image registration will be developed and validated. Given a segmented reference image and an image obtained during treatment, the algorithm will generate a 3D representation of the tissues, estimate tissue displacements and deformations using a finite element model, account for uncertainty due to unknown model parameters, and output a mapping between the images. Low computation time is critical for clinical viability. The new method will be applied to register prostate CT or MRI/MRSI reference images to treatment images obtained using Megavoltage Cone-Beam GT (MV CBCT), a 3D imaging modality being developed to image the patient on the treatment table for Intensity-Modulated Radiation Therapy (IMRT). Validation of the method will be performed using bone outlines and by measuring registration errors for marker seeds that have been implanted inside the prostate in a subset of patients. The new software tool, targeted at prostate cancer treatment, aims to significantly improve patient care by enabling clinicians to improve conformality of dose to tissue types during radiation therapy. These improvements could significantly enhance public health by lowering recovery times, recurrence rates, and treatment costs for cancer patients.