Somatostatin receptor-positive breast lesions on 68Ga-DOTATATE PET/CT

Abstract

Objective This study sets out to evaluate patients with increased uptake in breast lesions on 68 Ga-DOTATATE PET/CT (DOTA PET) and determine the clinical significance of somatostatin receptor (SSTR) positive breast lesions. Methods We retrospectively evaluated all patients with increased SSTR uptake in breast lesions on DOTA PET. Patients with physiological (e.g., lactation) or normal variant breast uptake (e.g., mild diffuse glandular uptake) were excluded. The maximum standard uptake value (SUVmax) was calculated using a manually drawn region of interest in the most intense uptake of breast lesions. All lesions were correlated with breast imaging, including mammography and ultrasonography. Histopathological correlation was performed if the lesion was suspicious for malignancy. Lesions were followed up radiologically (1–8\xa0years). Results Out of 1573 retrospectively analyzed DOTA PET scans, the incidence of SSTR\u2009+\u2009breast lesions was measured as 1.1% ( n \u2009=\u200918); however, 4 of 18 patients were excluded due to the lack of final diagnosis of lesions. The median age was 35 (range 14–58\xa0years), and all patients were female. The median SUVmax of SSTR\u2009+\u2009breast lesions was 5.2 (range 1.5–12.6) for a total of 14 patients. Twelve patients had a single SSTR\u2009+\u2009breast lesion, while 2 patients had multiple SSTR\u2009+\u2009lesions on bilateral breasts. In 6 patients, single SSTR\u2009+\u2009lesions were considered as fibroadenoma; in 2 patients, multiple SSTR\u2009+\u2009lesions were considered as metastases of NET, based on correlative breast imaging. In 6 patients, histopathological confirmation was needed for the final diagnosis. Histopathologic findings confirmed fibroadenoma in 4 patients by biopsy, in 1 patient with surgical removal of the lesion. The last patient who had a history of IDC was diagnosed with a recurrence of IDC with biopsy. The median SUVmax was 5.1 (range 1.5–9.4) for malignant breast lesions and 5.4 (range 2.2–12.6) for benign breast lesions. Conclusion SSTR\u2009+\u2009breast lesions on DOTA PET are rarely seen in clinical practice. Uptakes of breast lesions in our cases were variable and not useful for differential diagnosis of lesions. It seems that SSTR\u2009+\u2009breast lesions should be evaluated with clinical and radiological characteristics, and correlative breast imaging and/or histopathological verification should be performed for suspicious lesions to avoid misdiagnosis.