Somatostatin receptor-targeted DOTATATE PET/CT in breast cancer and breast lesions: a systematic review of detection, incidental findings and theranostic potential

Background Somatostatin receptor 2 (SSTR2) is expressed by a subset of breast cancers, particularly oestrogen receptor (ER)-positive tumours. DOTATATE PET/CT, the reference standard for neuroendocrine tumour (NET) imaging, is increasingly relevant to breast cancer staging, incidental findings and theranostic selection. We systematically reviewed its clinical performance. Methods Following PRISMA 2020 (PROSPERO CRD420261508548), Embase, Scopus and PubMed were searched to 16 September 2026, supplemented by citation searching. Studies reporting DOTATATE PET findings in breast cancer or breast lesions were included. Risk of bias was assessed with QUADAS-2 and Joanna Briggs Institute tools, certainty with GRADE, and findings were synthesised narratively. Results Nineteen studies (four prospective, two retrospective cohorts, three case series, ten case reports) including 107 patients with breast carcinoma were analysed. In head-to-head comparisons (n = 56), DOTATATE detected disease in most patients and matched 18 F-FDG for skeletal (252 vs 255 lesions) and nodal metastases, but identified half as many visceral metastases (134 vs 262), particularly in the liver. Uptake favoured ER-positive, lobular and neuroendocrine tumours. Focal breast uptake occurred on 1.1% of scans performed for other indications; 21.4% of characterised lesions were malignant and SUVmax did not discriminate benign from malignant lesions. Krenning scores ≥ 3 were found in 15/76 (19.7%) patients across three prospective studies. Certainty of evidence was very low. Conclusions DOTATATE PET/CT complements, but cannot replace, 18 F-FDG for breast cancer staging, and is less established than 18 F-FES. Incidental breast uptake warrants standard breast work-up regardless of intensity. Around one-fifth of patients with ER-positive metastatic disease show high SSTR expression, although whether this has therapeutic relevance remains uncertain.