A Positron Emission Mammography/Tomography Biopsy Device

描述(由申请人提供)： 在致密的乳房中检测癌症是X射线乳房X光摄影的一个重大挑战。病变密度和周围乳腺组织的相似之处，加上X射线不透明，限制了对这些患者中中小型肿瘤的有效检测。为了解决这一问题，基于核医学的成像技术，如与18F-氟代脱氧葡萄糖(FDG)一起使用的正电子发射断层扫描(PET)，已经成功地应用于乳房成像。这些方法依赖于肿瘤和正常组织之间代谢活动的差异，而不是密度对比来创建图像。虽然这些技术在检测致密乳房中的乳腺病变方面具有一定的潜力，但它们有限的空间分辨率和特异性并不能保证它们单独用于诊断。最有效的诊断方法仍然是对活检获得的组织样本进行组织学评估。在许多情况下，在X射线钼靶摄影的引导下，对可疑病变进行立体定向核心活检是一种有效的微创方法。然而，在PET在致密乳房最佳检测到病变的情况下，X光技术可能不是活检指导的最佳选择。针对这一需求，我们建议构建一种能够使用PET技术获取高分辨率乳房图像的设备。这些图像将被用来评估放射性示踪剂的摄取，并指导将活检针放置到可疑病变中。针定位的基于图像的验证将通过获取一组立体定向平面正电子发射乳房X光照相(PEM)图像来完成。这种被称为PEM-PET的双模式系统将能够执行三个主要任务：病变检测、放射性示踪剂定量和病变定位。该装置将由两套旋转的大面积平面像素化闪烁体阵列组成。使用旋转平面探测器(而不是更直观的环形几何形状)，以便于在活检过程中进入乳房，同时允许采集PEM和PET图像。闪烁体材料(氧硅酸)和探测器像素大小的选择是基于计算机模拟研究和模型观察者研究。该系统的开发将包括建造探测器单元，以及建立断层摄影和平面图像重建方法。PEM-PET系统将通过从模型和人类观察者研究中获得的任务相关指标以及临床前试验进行优化和评估。在这一项目完成时，将开发和评估一种有效检测和诊断病变的设备，供乳房成像困难的妇女使用。

DESCRIPTION (provided by applicant): Detection of cancer in the dense breast is a significant challenge for x-ray mammography. Similarities between the density of lesions and surrounding breast tissue, in addition to x-ray opacity, limit effective detection of small to medium sized tumors in these patients. To address this concern, nuclear medicine-based imaging techniques, such as positron emission tomography (PET) used with 18F-Fluorodeoxyglucose (FDG), have been applied with some success to breast imaging. These methods rely upon differences in metabolic activity between tumor and normal tissue, instead of density contrasts for creating images. Although these techniques have demonstrated some potential in detecting breast lesions in dense breasts, their limited spatial resolution and specificity does not warrant their sole use for making diagnoses. The most effective method for diagnosis remains histological evaluation of tissue samples acquired from biopsy. In many cases stereotactic core biopsy of suspicious lesions guided by x-ray mammography is an effective and minimally-invasive method for performing these procedures. In the case of lesions optimally detected in a dense breast with PET, however, x-ray techniques may not be optimal for biopsy guidance. In response to this need, we propose the construction of a device that will be capable of acquiring high resolution images of the breast using PET techniques. These images will then be used to assess radiotracer uptake and guide the placement of a biopsy needle into suspicious lesions. Image-based verification of needle positioning will be accomplished by acquiring a set of stereotactic planar, positron emission mammography (PEM) images. This dual modality system called, PEM-PET, will be capable of performing three main tasks: lesion detection, radiotracer quantitation and lesion localization. The apparatus will consist of two sets of rotating, large-area planar pixelated scintillator arrays. The use of rotating planar detectors was adopted (instead of the more intuitive ring geometry) to facilitate access to the breast during biopsy procedures, while permitting acquisition of PEM and PET images. The choices of scintillator material (Lutetium Oxyorthosilicate) and detector pixel size were based on computer simulation studies and model observer studies. Development of the system will include the construction of the detector units, and the creation of tomopraphic and planar image reconstruction methods. The PEM-PET system will be optimized and evaluated with task-dependent metrics obtained from model and human observer studies, and a pre-clincal trial. At the completion of this project an apparatus for the effective detection and diagnosis of lesions for use in the subgroup of women with difficult to image breasts will have been developed and evaluated.