Development of a PEM-PET-CT Breast Imaging and Biopsy Device

描述(申请人提供)：正电子发射断层扫描(PET)乳房成像可以潜在地提高对具有放射密度和/或纤维囊性乳房的女性的癌症的检测和诊断。此外，正电子发射计算机断层扫描所提供的定量能力也可能被用来为癌症治疗提供早期和准确的评估。在过去的四年里，我们的团队在美国国立卫生研究院的支持下，开发了一种高分辨率正电子发射乳房X光摄影和断层成像和活检设备(称为PEM-PET)，以检测和指导可疑乳腺病变的活检，并量化组织中的放射性核素浓度。该系统由两套旋转的平面探测头组成。每个探测器头由滨松H8500平板位置灵敏光电倍增管(PSPMT)的4x3阵列组成，该阵列耦合到由2W2W15mm3 Lyso探测器元件(间距=2.1 mm)组成的96W72阵列。图像重建使用3D-OSEM算法进行优化，以在8个CPU的计算机系统上运行，显著减少了图像重建时间。该装置的初步调焦测试在视场中心的空间分辨率为1.87 mm(径向)、1.84 mm(切向)和1.67 mm(轴向)；在距中心7 cm处，结果为1.9 mm(径向)、1.89 mm(切向)和1.69 mm(轴向)。总系统检测灵敏度为363.3kcps/微居里/毫升。在我们乳房成像和活检系统的不断发展中，我们建议进一步优化PET系统；解决我们最初测试制度中发现的一些薄弱领域(例如，计数率性能)。我们还建议在目前的PEM-PET系统中增加一个锥束X射线计算机断层扫描(CT)扫描仪，创建PEM-PET-CT乳腺成像和活检设备。PEM-PET-CT将具有在数据采集过程中连续旋转的独特能力，从而能够快速生成PET和CT图像。通过集成CT成像仪获得的解剖信息将允许乳房和异常区域的结构特征与这些区域的功能信息相关联。因此，这两种方法是相辅相成的。CT图像提供的数据还将用于改进对可能混淆放射性示踪剂浓度定量测量的物理现象的校正。最后，完成的系统将在试点人体试验期间在这两个应用中进行测试，将其性能与全身PET、MRI和MRS进行比较。这些研究的数据将在未来更大规模的人体试验计划中至关重要。我们设想，PEM-PET-CT可以用来检测乳房致密和乳房X光不确定的女性的病变，这些女性有额外的癌症风险因素。它还可以作为评估可疑病变或微钙化的“二次检查”方法用于诊断作用。最后，该系统独特的定量能力有助于将其用于化疗的疗效评估，特别是在小肿瘤中。因此，这一新的多模式系统的开发是一个独特的机会，可以改善乳房护理的一些重要临床方面。公共卫生相关性本申请建议继续开发专用的乳房PET-CT系统。该设备可用于乳腺癌的检测、诊断和治疗评估。

DESCRIPTION (provided by applicant): Positron emission tomography (PET) breast imaging can potentially improve the detection and diagnosis of cancer in women with radiodense and/or fibrocystic breasts. Additionally, the quantitative capabilities afforded by PET may also be exploited to provide early and accurate assessment of cancer treatment. During the last four years, our group, with the support of the National Institutes of Health, have developed a high-resolution positron emission mammography and tomography imaging and biopsy device (called PEM-PET) to detect and guide the biopsy of suspicious breast lesions, and quantify radionuclide concentrations in tissue. The system consists of two sets of rotating planar detector heads. Each detector head consists of a 4x3 array of Hamamatsu H8500 flat panel position sensitive photomultipliers (PSPMTs) coupled to a 96W72 array of 2W2W15mm3 LYSO detector elements (pitch= 2.1mm). Image reconstruction is performed with a 3D-OSEM algorithm optimized to run on an eight CPU computer system, significantly reducing image reconstruction times. Initial testing of the device is focusing yielded a spatial resolution at the center of the FOV of 1.87mm (radial), 1.84mm (tangential) and 1.67mm (axial); at 7cm from the center, the results were 1.9mm (radial), 1.89mm (tangential) and 1.69mm (axial). Total system detection sensitivity is 363.3kcps/microcurie/ml. In the continuing development of our breast imaging and biopsy system we propose the further optimization of the PET system; addressing some areas of weakness (count rate performance, for example) identified in our initial testing regime. We also propose the addition of a cone beam, x-ray computed tomography (CT) scanner to the current PEM-PET system, creating the PEM-PET-CT breast imaging and biopsy device. PEM-PET-CT will have the unique ability to continuously rotate during data acquisition, permitting the ability to rapidly produce PET and CT images. The anatomical information gained by integration of the CT imager will permit the correlation of structural features of the breast and abnormal areas with functional information from these areas. Thus, the two methods complement each other well. The data provided by the CT images will also be used improve corrections for physical phenomena that can confound quantitative measures of radiotracer concentrations. Finally, the completed system be tested in these two application during a pilot human trial, comparing its performance to whole body PET, MRI and MRS. The data from these studies will be crucial in the planning of future larger human trials. We envision that PEM-PET-CT could be used to detect lesions in women with dense breasts and indeterminate mammograms that have additional risks factors for cancer. It could also be used in the diagnostic role as a "second look" method to assess suspicious lesions or micro- calcifications. Lastly, the unique quantitative capabilities of the system could facilitate its use in treatment assessment of chemotherapy, especially in small tumors. Thus, the development of this new multi-modality system is a unique opportunity to improve a number of important clinical aspects of breast care. PUBLIC HEALTH RELEVANCE This application proposes the continued development of a dedicated breast PET-CT system. This device could be instrumental in the detection, diagnosis and treatment assessment of breast cancer.