Background and aims: Echo-enhanced power Doppler sonography is a noninvasive procedure that has been increasingly used for the differential diagnosis of pancreatic tumors. However, to our knowledge, the diagnostic accuracy of this procedure in comparison with somatostatin receptor scintigraphy for the differentiation of neuroendocrine lesions from other pancreatic tumors has never been investigated in a prospective, controlled study.
Subjects and methods: One hundred thirty-seven patients were included in the study; the patients were selected from 190 consecutive patients (mean age, 59.8 years; range, 16-85 years) who presented to our department from January 1998 through June 2001 with suspicion of a pancreatic tumor. An experienced examiner who was unaware of the patients' clinical diagnoses performed sonography. Twenty-nine patients with sonographically and/or clinically suspected neuroendocrine tumors were investigated additionally by somatostatin receptor scintigraphy. The exact diagnosis was based upon histologic evidence from biopsy examination (surgical and transabdominal fine-needle biopsy) or a follow-up of at least 18 months.
Results: The sensitivity of echo-enhanced power Doppler sonography for diagnosing a neuroendocrine pancreatic tumor was 94%, and its specificity was 96%. The corresponding values for somatostatin receptor scintigraphy were 54% and 81%, respectively.
Conclusions: Echo-enhanced power Doppler sonography has high sensitivity and high specificity for the differentiation of neuroendocrine lesions from other pancreatic tumors. However, histologic evidence is the standard of reference for the differential diagnosis of pancreatic tumors.