Prospective evaluation of 68Ga-DOTA-NOC PET-CT in patients with recurrent medullary thyroid carcinoma: comparison with 18F-FDG PET-CT.

Abstract

OBJECTIVE:

To prospectively evaluate the role of Ga-labelled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-NaI-octreotide (Ga-DOTA-NOC) PET-CT in patients with recurrent medullary thyroid carcinoma (MTC) and compare the same with F-fluorodeoxyglucose (F-FDG) PET-CT.

MATERIALS AND METHODS:

Fifty-two consecutive patients with recurrent MTC based on raised serum calcitonin levels underwent Ga-DOTA-NOC PET-CT. In addition, 41 patients also underwent F-FDG PET-CT. PET-CT images were evaluated by two experienced nuclear medicine physicians both qualitatively and quantitatively (standardized uptake value). Histopathology (when available), correlation with conventional imaging modalities (ultrasonography/CT/MRI) and subsequent clinical/imaging follow-up were used as reference standard. Serum calcitonin levels were correlated with findings of PET-CT.

RESULTS:

Overall, Ga-DOTA-NOC PET-CT showed a sensitivity of 80.7% [95% confidence interval (CI) 67.4-90.3] and a positive predictive value of 100% (95% CI 91.5-100) for detecting recurrent MTC. When both were available (n=41), Ga-DOTA-NOC PET-CT proved superior to F-FDG PET-CT with a higher sensitivity (75.61 vs. 63.4%). However, the difference was statistically not significant (P=0.179). Ga-DOTA-NOC PET-CT was superior to F-FDG PET-CT for detecting recurrence in cervical lymph nodes (P<0.001). Both modalities were concordant in 75% of cases. No significant cut-off level of calcitonin could be derived for either Ga-DOTA-NOC or F-FDG PET-CT.

CONCLUSION:

Both Ga-DOTA-NOC PET-CT and F-FDG PET-CT are able to localize disease recurrence in patients with MTC, and their role appears to be complementary for this purpose.

• Authors: Niraj Naswa, Punit Sharma, Sudhir Suman Kc, Sneh Lata, Rakesh Kumar, Arun Malhotra, Chandrasekhar Bal
• Journal: Nuclear medicine communications (Nucl Med Commun) Vol. 33 Issue 7 Pg. 766-74 (Jul 2012) ISSN: 1473-5628 [Electronic] England
• PMID: 22531829 (Publication Type: Comparative Study, Journal Article)

Chemical References

• 68Ga-DOTANOC
• Organometallic Compounds
• Radiopharmaceuticals
• Fluorodeoxyglucose F18

Topics

• Adult
• Aged
• Carcinoma, Medullary (diagnostic imaging)
• Female
• Fluorodeoxyglucose F18
• Humans
• Lymph Nodes (diagnostic imaging)
• Male
• Middle Aged
• Multimodal Imaging (methods)
• Neck
• Neoplasm Recurrence, Local (diagnostic imaging)
• Organometallic Compounds
• Positron-Emission Tomography
• Prospective Studies
• Radiopharmaceuticals
• Reproducibility of Results
• Sensitivity and Specificity
• Thyroid Neoplasms (diagnostic imaging)
• Tomography, X-Ray Computed