Half-time Tc-99m sestamibi imaging with a direct conversion molecular breast imaging system

Abstract

BackgroundIn an effort to reduce necessary acquisition time to perform molecular breast imaging (MBI), we compared diagnostic performance of MBI performed with standard 10-min-per-view acquisitions and half-time 5-min-per-view acquisitions, with and without wide beam reconstruction (WBR) processing.MethodsEighty-two bilateral, two-view MBI studies were reviewed. Studies were performed with 300 MBq Tc-99 m sestamibi and a direct conversion molecular breast imaging (DC-MBI) system. Acquisitions were 10 min-per-view; the first half of each was extracted to create 5-min-per-view datasets, and WBR processing was applied.The 10-min-, 5-min-, and 5-min-per-view WBR studies were independently interpreted in a randomized, blinded fashion by two radiologists. Assessments of 1 to 5 were assigned; 4 and 5 were considered test positive. Background parenchymal uptake, lesion type, distribution of non-mass lesions, lesion intensity, and image quality were described.ResultsConsidering detection of all malignant and benign lesions, 5 min-per-view MBI had lower sensitivity (mean of 70% vs. 85% (p ≤ 0.04) for two readers) and lower area under curve (AUC) (mean of 92.7 vs. 99.6, p ≤ 0.01) but had similar specificity (p = 1.0). WBR processing did not alter sensitivity, specificity, or AUC obtained at 5 min-per-view.Overall agreement in final assessment between 5-min-per-view and 10-min-per-view acquisition types was near perfect (κ = 0.82 to 0.89); however, fair to moderate agreement was observed for assessment category 3 (probably benign) (κ = 0.24 to 0.48). Of 33 malignant lesions, 6 (18%) were changed from assessment of 4 or 5 with 10-min-per-view MBI to assessment of 3 with 5-min-per-view MBI. Image quality of 5-min-per-view studies was reduced compared to 10-min-per-view studies for both readers (3.24 vs. 3.98, p < 0.0001 and 3.60 vs. 3.91, p < 0.0001). WBR processing improved image quality for one reader (3.85 vs. 3.24, p < 0.0001).ConclusionsAlthough similar radiologic interpretations were obtained with 10-min- and 5-min-per-view DC-MBI, resulting in substantial agreement in final assessment, notable exceptions were found: (1) perceived image quality at 5 min-per-view was lower than that for 10-min-per-view studies and (2) in a number of cases, assessment was downgraded from a recommendation of biopsy to that of short interval follow-up.

Patient Acceptance of Half-dose Vs. Half-time Molecular Breast Imaging

“…Regions of interest were drawn to encompass the breast tissue, excluding the pectoralis muscle, with the average counts per pixel recorded. A reader also provided an overall assessment of diagnostic image quality and noise level as previously described [16] and an assessment of motion artifacts. Image quality was scored using the following 1-5 scale: 1 (poor, non-diagnostic); 2 (suboptimal, worse than routine); 3 (acceptable, noisier than routine); 4 (good, same as routine), and 5 (excellent, better than routine).…”

Direct-Conversion Molecular Breast Imaging of Invasive Breast Cancer: Imaging Features, Extent of Invasive Disease, and Comparison Between Invasive Ductal and Lobular Histology

“…In the diagnostic setting, prior studies have shown similar sensitivities (> 90%) in patients recommended for biopsy [1,4,[14][15][16]. In recent years, several innovations in detector and collimator configuration of the direct-conversion molecular breast imaging system allow the same performance at a substantially lower dose of 99m Tc-sestamibi-300 MBq compared with 740-1100 MBq previously used [7,[17][18][19][20]. Because of the high sensitivity achieved at lower doses, combined with relatively high specificity, ranging from 86% to 94%, breast gamma imaging may be a valuable tool in the evaluation of breast cancer [8,18].…”

“…Molecular breast imaging usually refers to a configuration of two detectors made of a semiconductor cadmium zinc telluride that directly converts gamma ray energy into electronic signals [5]. The term "direct-conversion molecular breast imaging" has been introduced to specify the dualhead semiconductor configuration [6,7].Multiple possible uses for breast gamma imaging are being actively investigated, including screening [8,9], diagnostic problem solving [1,5], evaluation of extent of disease and contralateral screening for patients with newly diagnosed breast cancer [10][11][12], and prediction and evaluation of response to neoadjuvant chemotherapy [6,13]. In the screening setting, adjunctive molecular breast imaging in combination with…”

“…Molecular breast imaging usually refers to a configuration of two detectors made of a semiconductor cadmium zinc telluride that directly converts gamma ray energy into electronic signals [5]. The term "direct-conversion molecular breast imaging" has been introduced to specify the dualhead semiconductor configuration [6,7].…”

Synthesis, radioiodination and biological evaluation of a novel phthalimide derivative

“…Single-photon emission computed tomography (SPECT) represents one of the standard technologies for most nuclear medicine departments [7,8]. Recently, research has focused on radioiodinated and 99m Tc labeled radiopharmaceuticals for targeting solid tumor [9][10][11][12][13][14][15][16][17][18][19]. The introduction of new radiopharmaceuticals, which target specific receptor in solid tumor, could potentially have high tumor uptake and high solid tumor to normal muscle (T/NT) ratio which result in potential diagnostic radiopharmaceuticals with a high quality [20].…”