Somatostatin receptor scintigraphy with 111In-octreotide in pulmonary carcinoid tumours correlated with pathological and 18FDG PET/CT findings.
OBJECTIVE
Pulmonary carcinoid (PC) tumors are rare neoplasms of the lung with good prognosis but diagnosis may be demanding since there is no exclusive modality alone to clearly differentiate a PC tumor. The purpose of this study is to establish the diagnostic features of somatostatin receptor scintigraphy (SRS), comparatively (where available) with 18FDG PET/CT (PET/CT) correlated with histopathologic findings.


METHODS
Twenty-one patients who underwent SRS with 111In-octreotide and were diagnosed as having PC tumors were retrospectively studied. Thirteen patients were performed PET/CT. Primary tumour size, Ki-67 indexes, image analysis data of SRS and PET/CT including maximum standardized uptake values (SUVmax) together with false negative, false positive, true positive and true negative lesions were documented and discussed.


RESULTS
Eleven (52.4%) patients were typical (TC) and 10 (47.6%) were atypical carcinoids (AC) with mean Ki-67 indexes of 2.1 and 24%, respectively. Patients underwent SRS for solitary pulmonary nodule (SPN) characterization (n = 12) and determination of disease extension (n = 9). Overall sensitivity and specificity of SRS in the detection of primary tumour, lymph nodes (LN) and distant metastasis (DM) were 76 and 97 %, respectively, whereas, positive and negative predictive values were 95 and 86 %. PET/CT was performed for determining disease spread (n = 3) and metabolic characterization (n = 10) of SPNs. Mean SUVmax in the primary pulmonary lesion in TCs and ACs were 2.9 ± 0.8 and 7.9 ± 5.4, respectively. Nodal involvement (n = 5) and DM (n = 3) were also detected. Sensitivity and specificity of PET/CT in the detection of primary tumour, LNs and DM were 85 and 89.4 %, respectively.


CONCLUSIONS
SRS is useful in the diagnosis and monitoring of PC tumors when incorporated with 18FDG PET/CT as a primary staging tool particularly in the determination of disease spread.
Department of Nuclear Medicine, Istanbul Medical Faculty, Istanbul University, 34390, Fatih, Istanbul, Turkey. srkuyumcu@gmail.com
Serkan
S
Kuyumcu
Isik
I
Adalet
Yasemin
Y
Sanli
Cuneyt
C
Turkmen
Zeynep Gozde
ZG
Ozkan
Dilek
D
Yilmazbayhan
D000293:Adolescent; D000328:Adult; D000368:Aged; D002276:Carcinoid Tumor / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009362:Neoplasm Metastasis; D015282:Octreotide / Q000031:analogs & derivatives*; D049268:Positron-Emission Tomography; D011379:Prognosis; D017481:Receptors, Somatostatin / Q000378:metabolism*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
D019394:Ki-67 Antigen; D017481:Receptors, Somatostatin; C094279:indium-111-octreotide; D019788:Fluorodeoxyglucose F18; D015282:Octreotide