Scintimammography with dedicated breast camera in unifocal and multifocal/multicentric primary breast cancer detection: A comparative study with SPECT

Abstract

The aim of this study was to assess the usefulness of planar scintimammography (SM) with a high-resolution dedicated breast camera (DBC) compared to SPECT in unifocal and multifocal/multicentric primary breast cancer (BC) detection. DBC planar SM and conventional SPECT were acquired using 99m Tc-tetrofosmin as radiotracer in 85 consecutive patients suspect for BC at conventional imaging and clinical examination. Scintigraphic data were related to histology in all cases. BC was proven in 74/85 patients, unifocal in 56/74 cases and multifocal/multicentric in 18/74; 90 carcinomas were ascertained. Benign lesions were found in 12 cases, including one who also had BC in the contralateral breast. DBC planar SM and SPECT were true-positive in 72/74 and in 70/74 BC patients, respectively, and globally detected 96.7% and 92.2% of carcinomas. DBC and SPECT sensitivity were, respectively, 90.3% and 80.6% in ≤10-mm carcinomas and 100% and 98.3% in larger ones; sensitivity values in non-palpable carcinomas were 92.6% and 77.8%, respectively, and 98% for both procedures in palpable ones. DBC planar SM and SPECT correctly assessed multifocality/ multicentricity in 91.7% and 83.3% of cases, respectively. Sensitivity differences were not significant. Both procedures showed only a false-positive result. DBC planar SM and SPECT proved highly sensitive and specific in BC detection, representing a useful complementary tool to mammography. However, DBC planar SM showed technical advantages and better clinical performance than SPECT in both subcentrimetric carcinoma detection and multifocal/multicentric disease assessment. Thus, DBC planar SM should be preferred, but SPECT remains a useful alternative when DBC is unavailable.

Breast Scintigraphy with Breast-Specific γ-Camera in the Detection of Ductal Carcinoma In Situ: A Correlation with Mammography and Histologic Subtype

“…Preliminary studies have demonstrated that BSGC scintigraphy may also be useful in the detection of DCIS, with sensitivity similar to or even higher than that of mammography, in comparative studies (10,11). In a series of 13 patients with 13 surgically proven DCISs, scintigraphy and mammography showed the same sensitivity (92.3%), with 1 DCIS evidenced only at scintigraphy and 1 DCIS ascertained only at mammography (10). In another series of 20 patients with 22 biopsy-proven DCISs, 91% of lesions were detected by BSGC scintigraphy and 82% by mammography, with 2 DCISs evidenced only at BSGC (11).…”

“…Preliminary studies have demonstrated that BSGC scintigraphy may also be useful in the detection of DCIS, with sensitivity ranging from 87.5% to 92.3% (10)(11)(12).…”

Nuclear Imaging and Early Breast Cancer Detection

“…low intrinsic spatial resolution and poor energy resolution) and technical (i.e. high dead space at the edge of the field of view, large distance between detector and breast, poor visualization of medial and posterior breast areas, impact of scatter radiation from organ near the breast) [8,9]. As recently demonstrated by Spanu et al [10], these limitations can be over passed by a dedicated breast camera (DBC), that is a high resolution small field of view dedicated breast camera mounted on a mammography unit.…”

The importance of standardized interpretation of molecular breast imaging with dedicated gamma cameras

“…In fact, the detector can be placed directly against the chest and a mild compression is possible, to reduce breast thickness and improve the camera's sensitivity. Moreover, by design, these specific cameras are also able to provide better intrinsic and extrinsic spatial resolution than standard ones, with an enhancement in contrast resolution for small lesions [4], and to acquire projections similar to those of mammography (craniocaudal, mediolateral oblique and true lateral).Studies comparing standard and breast-specific cameras have provided clinical evidence that the dedicated ones show better accuracy in molecular breast imaging, especially in increasing the sensitivity for subcentimetre lesions [4][5][6]. It is worth noting that a recent retrospective review of one institution's experience with breast-specific gamma imaging (BSGI) has indicated that this test is not only both sensitive (93%) and specific (79%) for the identification of BC, but it is also helpful as an adjunct to standard breast imaging modalities for problem solving in indeterminate cases [7].…”

“…Studies comparing standard and breast-specific cameras have provided clinical evidence that the dedicated ones show better accuracy in molecular breast imaging, especially in increasing the sensitivity for subcentimetre lesions [4][5][6]. It is worth noting that a recent retrospective review of one institution's experience with breast-specific gamma imaging (BSGI) has indicated that this test is not only both sensitive (93%) and specific (79%) for the identification of BC, but it is also helpful as an adjunct to standard breast imaging modalities for problem solving in indeterminate cases [7].…”