Spiral CT joins forces with scintigraphy to stage digestive endocrine tumors

CT studies can add valuable information to traditional scintigraphy staging of patients with digestive endocrine tumors, according to Italian researchers.

After comparing spiral CT with somatostatin receptor scintigraphy (SRS), traditional gold standard for preoperative staging of these tumors, imagers at University La Sapienza in Rome discovered that CT rounded out the staging information provided by SRS.

"Spiral CT is more predictive for therapeutic surgical strategy, such as determining whether a tumor lesion is resectable or nonresectable," said Dr. Gianfranco Delle Fave, a professor of gastroenterology at La Sapienza.

Delle Fave and colleagues used both spiral CT and SRS to stage 60 patients before surgery. They reported SRS sensitivity of 77% for primary lesions, 48% for lymph nodes, and 67% for liver lesions. Sensitivity for spiral CT was 94% for primary lesions, 69% for lymph nodes, and 94% for liver lesions.

Overall, spiral CT correctly staged 92% of the patients compared with 75% for SRS. Results of the study were published in the April 2003 issue of the Annals of Oncology.

"Spiral CT detected all detectable lesions," Delle Fave said. "SRS only detected the somatostatin-positive lesions."

Although CT demonstrated a higher sensitivity than SRS, he said that it should be considered a complement to SRS and not a replacement. Future studies should focus on a possible fusion of the two imaging modalities to determine their direct relationship.

"SRS is crucial for determining the presence of somatostatin receptors and indicating if a patient can or cannot be treated with somatostatin analogs or radiometabolic therapy," Delle Fave said.