F-18 FDOPA poised for primary neuroendocrine tumor imaging

F-18 labeled fluorodihydroxyphenylalanine (F-18 FDOPA) appears to find more cancer for patients with neuroendocrine tumors who have had negative conventional and somatostatin receptor scintigraphy, according to a study published Dec. 16 in the Journal of Nuclear Medicine.

Alessio Imperiale, MD, from the department of biophysics and nuclear medicine at Hautepierre University Hospital in Strasbourg, France, and colleagues conducted a retrospective study of 27 patients with neuroendocrine tumors at two different cancer centers who had undergone F-18 FDOPA PET/CT imaging to evaluate F-18 FDOPA’s ability to provide information about neuroendocrine tumor origin and differentiation.

“F-18 FDOPA PET appears to be a sensitive functional imaging tool for the detection of primary [neuroendocrine tumors] occult on [somatostatin receptor scintigraphy], especially tumors with a well-differentiated pattern and serotonin secretion,” wrote Imperiale et al.

Of the 27 subjects, 23 were imaged with F-18 FDOPA PET/CT at initial staging another four were imaged at follow-up. Primary neuroendocrine tumors were found in 12 patients for an overall sensitivity of 44 percent and a slightly higher 52 percent for patients who were imaged at the time of diagnosis.

F-18 FDOPA PET/CT led to the discovery of more tumors than somatostatin receptor scintigraphy for 17 patients. All patients with positive F-18 FDOPA scans went in for tumor resection.