Experience with somatostatin receptor scintigraphy in the management of pulmonary carcinoid tumors.
BACKGROUND
Somatostatin receptor scintigraphy has been used widely for the evaluation of neuroendocrine tumors in the gastrointestinal tract. Its use for detecting and staging thoracic carcinoids is only sporadically reported.


OBJECTIVE
To evaluate the possible roles of SRS in the management of proven or suspected pulmonary carcinoids.


METHODS
We conducted a retrospective study of all patients undergoing SRS for known or suspected pulmonary carcinoids in a tertiary referral center during a 10 year period. During this period 89 patients underwent resection of pulmonary carcinoids and SRS was used for detection, staging or localization purposes in 8 of them (9%). Scans were labeled true positive, true negative, false positive, or false negative in comparison with histologic or follow-up results.


RESULTS
SRS was true positive in 6/6 lung locations; true positive in 2/8, true negative in 4/8 and false positive in 2/8 lymph node locations; and true positive in 1/8, true negative in 6/8 and false negative in 1/8 distant locations. The sensitivity, specificity, positive and negative predictive values and accuracy were 90%, 83%, 83%, 91% and 87% respectively. The scans were strongly positive in the tumors and involved lymph nodes. SRS correctly localized an occult secreting pulmonary carcinoid. Granulomatous and reactive lymph nodes showed increased uptake. SRS was accurate in ruling out distant metastases.


CONCLUSIONS
SRS is effective for visualizing and localizing pulmonary carcinoids. It assists in the staging of these tumors by detecting lymph node involvement and confirming or ruling out distant metastases. Inflammatory areas in the lung or lymph nodes may be falsely positive.
Yellin
Alon
A
Department of Thoracic Surgery, Sheba Medical Center, Tel Hashomer, Israel. ayellin@sheba.health.gov.il
Zwas
S Tzila
ST
Rozenman
Judith
J
Simansky
David A
DA
Goshen
Elinor
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D002276:Carcinoid Tumor / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015282:Octreotide; D011877:Radionuclide Imaging / Q000379:methods; D017481:Receptors, Somatostatin / Q000187:drug effects*; D012189:Retrospective Studies; D013004:Somatostatin; D014055:Tomography, Emission-Computed
D017481:Receptors, Somatostatin; D013004:Somatostatin; D015282:Octreotide