In-111 DTPA-octreotide scintigraphy for disease detection in metastatic thyroid cancer: comparison with F-18 FDG positron emission tomography and extensive conventional radiographic imaging.
OBJECTIVE
The utility of In-111 DTPA octreotide scintigraphy (SRS) for disease detection in patients with metastatic thyroid carcinoma (TCA) remains controversial. The authors compared the sensitivity of In-111-based SRS, F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET), and extensive conventional radiographic imaging (CRI) in this type of cancer.


METHODS
SRS, FDG PET, and CRI were performed concurrently in 21 patients (age, 56.4 +/- 12.9 years) who had aggressive TCA. Concordance rates % of lesion positivity among pairs of different techniques (A and B) were calculated as the ratio of the number of lesions positive with both techniques divided by the sum of the total number of lesions positive with technique A + total number of lesions positive with technique B, which was then multiplied by 200.


RESULTS
The combined use of CRI, FDG PET, and SRS resulted in the detection of 105 lesions, presumed to be due to metastatic deposits. Sensitivities for SRS and FDG-PET imaging were 49.5% and 67.6%, respectively. The lesion detection concordance rates were as follows: CRI versus FDG PET, 80.8%; CRI versus SRS, 74.2%; and FDG-PET versus SRS, 58.6%. Importantly, SRS detected five unexpected lesions, which were negative by both CRI and FDG-PET imaging. In two representative patients, a positive correlation (Spearman's rank = 0.71; = 0.0576) existed between the percentage of lesional In-111 DTPA octreotide uptake and the standard uptake value in eight concordant lesions.


CONCLUSIONS
Although SRS has only moderate sensitivity for disease detection in metastatic TCA, sometimes it can reveal lesions that otherwise would be undetectable by either CRI or FDG-PET imaging.
Sarlis
Nicholas J
NJ
Division of Intramural Research, National Institutes of Diabetes, Bethesda, Maryland, USA. NJSarlis@mdanderson.org
Gourgiotis
Loukas
L
Guthrie
Lori C
LC
Galen
Barbara
B
Skarulis
Monica C
MC
Shawker
Thomas H
TH
Patronas
Nicholas J
NJ
Reynolds
James C
JC
D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000556:secondary*; D015331:Cohort Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D008207:Lymphatic Metastasis; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D008875:Middle Aged; D015282:Octreotide / Q000031:analogs & derivatives*; D004369:Pentetic Acid / Q000031:analogs & derivatives*; D010997:Pleural Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D011859:Radiography; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging*; D014055:Tomography, Emission-Computed / Q000379:methods
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C071632:SDZ 215-811; D004369:Pentetic Acid; D015282:Octreotide