Molecular Breast Imaging: A Scientific Review

Molecular breast imaging (MBI) is a nuclear medicine technique that has evolved considerably over the past two decades. Technical advances have allowed reductions in administered doses to the point that they are now acceptable for screening. The most common radiotracer used in MBI, 99mTc-sestamibi, has a long history of safe use. Biopsy capability has become available in recent years, with early clinical experience demonstrating technically successful biopsies of MBI-detected lesions. MBI has been shown to be an effective supplemental screening tool in women with dense breasts and is also utilized for breast cancer staging, assessment of response to neoadjuvant chemotherapy, problem solving, and as an alternative to breast MRI in women who have a contraindication to MRI. The degree of background parenchymal uptake on MBI shows promise as a tool for breast cancer risk stratification. Radiologist interpretation is guided by a validated MBI lexicon that mirrors the BI-RADS lexicon. With short interpretation times, a fast learning curve for radiologists, and a substantially lower cost than breast MRI, MBI provides many benefits in the practices in which it is utilized. This review will discuss the current state of MBI technology, clinical applications of MBI, MBI interpretation, radiation dose associated with MBI, and the future of MBI.

Molecular breast imaging and background uptake of fibroglandular tissue as tools to predict neoplasms in dense breasts

The sensitivity of mammography as a screening method is low in dense breasts, which are associated with a high risk of developing tumors. Thus, molecular breast imaging (MBI) with background uptake (BPU) of fibroglandular tissue can be used as a complementary method. The aim of this review was to synthesize the existing evidence on these important diagnostic imaging tools. Three electronic databases were searched to identify original articles, including publications dating from September 2010 and September 2020, in English, conducted in any location, and addressing at least one aspect related to dense breasts and Breast-specific gamma-imaging (BSGI). In total, 22 studies were reviewed. Several advantages of MBI and BPU as complementary methods of screening for dense breasts were found. Among them, we can mention the increase in breast cancer detection rate, easy implementation in clinical practice, high patient satisfaction, low cost and good reproducibility. In view of the good results found in our review, we can conclude that the implementation of MBI, especially with BPU, can be a promising complementary tool for screening of dense breasts.

Comparison of BSGI , MRI, mammography, and ultrasound for the diagnosis of breast lesions and their correlations with specific molecular subtypes in Chinese women

Background: Breast cancer is a leading cause of cancer in females, and is the second leading cancer-related cause of death in this group. Early diagnosis is essential to breast cancer to be effectively treated, and ultrasound, mammography, and magnetic resonance imaging (MRI) represent three key technologies that are utilized for the diagnosis of breast lesions. Breast-specific gamma imaging (BSGI) is an approach to molecular breast imaging that allows for high-resolution radio-imaging that is not adversely impacted by breast tissue density. This study was therefore designed to assess the relative diagnostic efficacy of BSGI, MRI, mammography, and ultrasound in different molecular subtypes of breast cancer among Chinese women. Methods: Diagnostic findings from 390 patients that had undergone diagnosis and treatment in our breast surgery department were retrospectively reviewed. Patients had been diagnosed via BSGI, mammography, ultrasound, and MRI. The diagnostic efficacy of these different imaging modalities and their associated biological characteristics were compared in the present study. Results: A total of 229 of these 390 patients (58.7%) were diagnosed with malignant breast cancer, with the remaining 161 (41.3%) cases having been found to be benign. BSGI, MRI, mammography, and ultrasound yielded respective sensitivity values of 91.7%, 92.5%, 77.3%, and 82.1%, while the respective specificity values for these imaging modalities were 80.7%, 69.7%, 74.5%, and 70.8%. For lesions > 1 cm, BSGI offered a sensitivity of 92.5%. For mammographic breast density A, B, C, and D, BSGI offered a sensitivity of 93.3%, 94.0%, 91.5%, and 89.3%, respectively. BSGI also yielded a significantly higher lesion-to-normal lesion ratio (LNR) for malignant lesions relative to benign lesions (2.76±1.32 vs 1.46±0.49). Conclusions: These findings confirm that BSGI is highly sensitive and is superior to mammography in the detection and diagnosis of ductal carcinomas in situ (DCIS). Such diagnostic efficacy can be further improved by using BSGI as an auxiliary modality to mammography and ultrasound, potentially improving the reliability of breast lesion diagnosis, thereby ensuring that patients receive rapid and effective treatment without the risk of misdiagnosis or unnecessary surgical treatment.

Molecular Breast Imaging-guided Percutaneous Biopsy of Breast Lesions: A New Frontier on Breast Intervention

Molecular breast imaging (MBI) is an increasingly recognized nuclear medicine imaging modality to detect breast lesions suspicious for malignancy. Recent advances have allowed the development of tissue sampling of MBI-detected lesions using a single-headed camera (breast-specific gamma imaging system) or a dual-headed camera system (MBI system). In this article, we will review current indications of MBI, differences of the two single- and dual-headed camera systems, the appropriate selection of biopsy equipment, billing considerations, and radiation safety. It will also include practical considerations and guidance on how to integrate MBI and MBI-guided biopsy in the current breast imaging workflow.