Somatostatin receptor scintigraphy (SRS) has been used for the detection of gastroenteropancreatic (GEP) tumors. This study evaluates the clinical impact of SRS in GEP tumor detection and its therapeutic implications on patient management.
Methods: We prospectively studied 160 patients with biologically and/or histologically proven GEP tumors. Before SRS, patients were classified into three groups: gastrointestinal (Group 1; n = 90) patients without known metastases; (Group 2; n = 59) patients with metastases limited to the liver; (Group 3; n = 11) patients with known extrahepatic metastases. The scintigraphic data were compared to the radiological findings.
Results: In Group 1, without known metastases, conventional imaging detected 53 primary sites in 44 patients: SRS was positive in 68% of these sites and discovered 4 additional primary tumors in 3 patients and 16 metastases in 14 patients. Conventional imaging was negative in 46 patients: SRS discovered 47 new sites in 36 patients. In Group 2, SRS confirmed liver metastases in 95% of patients and discovered 45 new sites in 36 of these patients. In Group 3, SRS disclosed 11 new sites in 7 patients. These results modified patient classification in 38 cases (24%). Surgical therapeutic strategy was changed in 40 patients (25%).
Conclusion: Somatostatin receptor scintigraphy improves tumor detection, has major clinical significance and should be performed systematically for staging and therapeutic decision making in patients with GEP tumors.