RT Journal Article
SR Electronic
T1 <sup>68</sup>Ga-DOTA-Tyr<sup>3</sup>-Octreotide PET in Neuroendocrine Tumors: Comparison with Somatostatin Receptor Scintigraphy and CT
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 508
OP 518
DO 10.2967/jnumed.106.035667
VO 48
IS 4
A1 Michael Gabriel
A1 Clemens Decristoforo
A1 Dorota Kendler
A1 Georg Dobrozemsky
A1 Dirk Heute
A1 Christian Uprimny
A1 Peter Kovacs
A1 Elisabeth Von Guggenberg
A1 Reto Bale
A1 Irene J. Virgolini
YR 2007
UL http://jnm.snmjournals.org/content/48/4/508.abstract
AB The aim of this study was to evaluate the diagnostic value of a new somatostatin analog, 68Ga-labeled 1,4,7,10-tetraazacyclododecane-N,N′,N″,N″′-tetraacetic acid-d-Phe1-Tyr3-octreotide (68Ga-DOTA-TOC), for PET in patients with known or suspected neuroendocrine tumors. PET was compared with conventional scintigraphy and dedicated CT. Methods: Eighty-four patients (48 men, 36 women; age range, 28–79 y; mean age ± SD, 58.2 ± 12.2 y) were prospectively studied. For analysis, patients were divided into 3 groups: detection of unknown primary tumor in the presence of clinical or biochemical suspicion of neuroendocrine malignancy (n = 13 patients), initial tumor staging (n = 36 patients), and follow-up after therapy (n = 35 patients). Each patient received 100–150 MBq 68Ga-DOTA-TOC. Imaging results of PET were compared with 99mTc-labeled hydrazinonicotinyl-Tyr3-octreotide (99mTc-HYNIC-TOC) and 111In-DOTA-TOC. CT was also performed on every patient using a multidetector scanner. Each imaging modality was interpreted separately by observers who were unaware of imaging findings before comparison with PET. The gold standard for defining true-positive (TP), true-negative (TN), false-positive (FP), and false-negative (FN) results was based on all available histologic, imaging, and follow-up findings. Results: PET was TP in 69 patients, TN in 12 patients, FP in 1 patient, and FN in 2 patients, indicating a sensitivity of 97%, a specificity of 92%, and an accuracy of 96%. The FP finding was caused by enhanced tracer accumulation in the pancreatic head, and the FN results were obtained in patients with a tumor of the gastrointestinal tract displaying liver metastases. 68Ga-DOTA-TOC showed higher diagnostic efficacy compared with SPECT (TP in 37 patients, TN in 12 patients, FP in 1 patient, and FN in 34 patients) and diagnostic CT (TP in 41 patients, TN in 12 patients, FP in 5 patients, and FN in 26 patients). This difference was of statistical significance (P &lt; 0.001). However, the combined use of PET and CT showed the highest overall accuracy. Conclusion: 68Ga-DOTA-TOC PET shows a significantly higher detection rate compared with conventional somatostatin receptor scintigraphy and diagnostic CT with clinical impact in a considerable number of patients.