Incidental detection of breast cancer by 68Ga-DOTATOC-PET/CT in women suffering from neuroendocrine tumours

Abstract

Summary Aim: Somatostatin receptor (sstr) imaging using 68Ga- DOTATOC-PET/CT in neuroendocrine tumors (NET) is promising, suggesting a more sensitive detection of lesions with a low sstr-expression. This is also important for other sstr positive tumors, especially breast cancer whose incidence and age-range is similar to that of NET. Patients, methods: The PET/CT data of 33 consecutive women with NET (age: 33–78 years, mean 59) who underwent whole-body staging with 68Ga-DOTATOC was retrospectively analyzed for breast lesions. The data was read separately, side-byside and as fused images. Focal tracer uptake in the breast was semiquantitatively analyzed by comparing the lesional SUVmax to normal breast tissue using Wilcoxon's rank sum test. Breast cancer lesions were compared visually to concomitant NET- lesions. Results: In six of 33 patients (18%) breast lesions were observed on the CT-scans and classified in four patients (12%) as suspicious. The same lesions also showed a pathological tracer uptake on the corresponding PET-scan, visually and semiquantitatively (p<0.01). Histological reevaluation of the suspicious lesions revealed two patients with NET metastases. Two patients had primary breast cancer with lower tracer uptake than concomitant abdominal NET-lesions. Breast cancer diagnosis resulted in a change of the therapeutic regimen. Conclusion: 68Ga- DOTATOC-PET/CT not only improves the staging of NET-patients, but also increases the chance to detect sstr-positive breast cancer. Although these lesions may show a lower tracer uptake than NET, they must not be overlooked or misinterpreted as metastases. Further imaging and clarification by histopathology is warranted, as the confirmation of a secondary malignoma has great impact on further therapeutic proceedings.

Formation and Characterization of Gallium(III) Complexes with Monoamide Derivatives of 1,4,7‐Triazacyclononane‐1,4,7‐triacetic Acid: A Study of the Dependency of Structure on Reaction pH

“…[3] DOTA contains four amine groups and four carboxylic acid groups that can act as coordination sites, but only six of these (four amine and two carboxylic acid groups) are involved in complex formation to produce a hexacoordinated chelate complex with Ga III , [4] which allows for the conjugation of a biomolecule to DOTA by formation of an amide bond between the biomolecule and one of the free DOTA carboxylic acid groups ( Figure 1). …”

Metastatic Esophageal Adenocarcinoma Showing 68Ga-DOTATATE Uptake

“…5 Nevertheless, although 68 Ga-DOTATATE uptake has been described in many nonneuroendocrine tumors, no case of esophageal adenocarcinoma displaying 68 Ga-DOTATATE uptake has been reported before. [6][7][8][9] This particular case of metastatic esophageal adenocarcinoma showing 68 Ga-DOTATATE uptake highlights the potential of 68 Ga-DOTATATE PET/CT in imaging nonneuroendocrine tumors.…”

Case report: Uncommon multiple metastases from occult breast cancer revealed by 68Ga-DOTATATE PET/CT

“…Another case report showed a primary invasive lobular breast carcinoma lesion with 68 activity, which was not 18 F-FDG-avid (11). About 50% of breast tumors express SSR, 68 Ga-DOTA peptide PET/CT examination can incidentally detect breast tumors (15)(16)(17). However, the report about 68 Ga-DOTATAE PET/ CT detection of occult breast cancer remain rare.…”