Positron Emission Mammography: High-Resolution Biochemical Breast Imaging

Abstract

Positron emission mammography (PEM) provides images of biochemical activity in the breast with spatial resolution matching individual ducts (1.5 mm full-width at half-maximum). This spatial resolution, supported by count efficiency that results in high signal-to-noise ratio, allows confident visualization of intraductal as well as invasive breast cancers. Clinical trials with a full-breast PEM device have shown high clinical accuracy in characterizing lesions identified as suspicious on the basis of conventional imaging or physical examination (sensitivity 93%, specificity 83%, area under the ROC curve of 0.93), with high sensitivity preserved (91%) for intraductal cancers. Increased sensitivity did not come at a cost of reduced specificity. Considering that intraductal cancer represents more than 30% of reported cancers, and is the form of cancer with the highest probability of achieving surgical cure, it is likely that the use of PEM will complement anatomic imaging modalities in the areas of surgical planning, high-risk monitoring, and minimally invasive therapy. The quantitative nature of PET promises to assist researchers interested studying the response of putative cancer precursors (e.g., atypical ductal hyperplasia) to candidate prevention agents.

Effects of multiple‐interaction photon events in a high‐resolution PET system that uses 3‐D positioning detectors

“…However, the 16 layers of 1 mm photon interaction depth resolution mitigate this effect of limited-angle tomography compared to dual-panel systems that do not have interaction depth resolution. 23,24 So far the results suggest that as far as FWHM sphere resolution, CRC, rate of contrast recovery, and CNR are concerned, the MIPEs-ML method consistently outperforms its variations, i.e., the MIPEs-ML without threshold and MIPEshybrid methods, and its performance is at least as good as using only single LSO array events. This allows us to narrow our focus to the MIPEs-ML algorithm in the discussion of quantifiable benefits of employing MIPEs in PET.…”

Experimental characterization of the 192 channel Clear-PEM frontend ASIC coupled to a multi-pixel APD readout of LYSO:Ce crystals

“…Spatial resolution in whole-body PET is limited to 0.5-1 cm which has prevented the use of PET imaging exclusively for breast cancer screening purposes [4]. At the light of the current limitations of whole-body PET scanners for breast cancer detection and motivated by the fact that PET facilities have a low patient turnover and high cost for mass screening, in terms of the required equipment and personnel, dedicated specially tailored PET systems have been advocated [3,5,6]. Such devices, generally named Positron Emission Mammography (PEM), are designed to image the breast region by favoring high-resolution and detection sensitivity over the general purpose of whole-body scanners.…”

“…Almost all exams were carried out with a wholebody PET scanner, which may justify that although sensitivity was about 90% for tumors larger than 2 cm [2] it decreases to 25% when lesions with diameters less than 1 cm are considered. The decrease in small breast tumors detectability performance is mostly due to the suboptimal spatial resolution of current wholebody PET scanners [3]. Spatial resolution in whole-body PET is limited to 0.5-1 cm which has prevented the use of PET imaging exclusively for breast cancer screening purposes [4].…”

Detection and characterization of breast tumours by time-domain scanning optical mammography

“…Positron emission mammography [9,10] allows to directly probe metabolic activity of breast cancer, e.g., its glucose demand using 2-( 18 F)-fluorodeoxyglucose as a tracer. In contrast to the low spatial resolution of the whole body PET scanners, dedicated positron emission mammography cameras achieve in-plane spatial resolutions of about 2 mm, allowing high resolution biochemical imaging of the breast [11].…”