Repeatability of gallium-68 DOTATOC positron emission tomographic imaging in neuroendocrine tumors.

Abstract

OBJECTIVE:

To evaluate the repeatability of gallium-68 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic (DOTA)-D-Phe1-Try3-octreotide (68Ga-DOTATOC) positron emission tomography (PET) in neuroendocrine tumors.

METHODS:

Five patients with neuroendocrine tumors were imaged with 68Ga-DOTATOC PET twice within 5 days. Maximum and mean standardized uptake values (SUVmax and SUVmean) and kinetic parameters (K-Patlak and K-influx) of target lesions were measured. The repeatability of these measurements was investigated.

RESULTS:

Forty-seven target lesions were identified on whole-body PET and 21 lesions on dynamic images. There was excellent repeatability with intraclass correlation coefficient of 0.99 for SUVmax, SUVmean, and K-Patlak, and 0.85 for K-influx. The median absolute percent differences and the interquartile ranges (IQR) between 2 scans for SUVmax and SUVmean were 7.4% (IQR, 14.1%) and 9.3% (IQR, 10.6%), respectively. The median absolute percent differences for K-Patlak and K-influx were 12.5% (IQR, 12.6%) and 29.9% (IQR, 22.4%), respectively. The SUVmax of target lesions did not differ by more than 25% between the 2 scans.

CONCLUSIONS:

68Ga-DOTATOC PET imaging of neuroendocrine tumors is highly reproducible. A difference of more than 25% in SUVmax represents a change that is larger than the measurement error observed on repeated studies and should reflect a significant change in the biological character of the tumor.

• Authors: Yusuf Menda, Laura L Boles Ponto, Michael K Schultz, Gideon K D Zamba, G Leonard Watkins, David L Bushnell, Mark T Madsen, John J Sunderland, Michael M Graham, Thomas M O'Dorisio, M Sue O'Dorisio
• Journal: Pancreas (Pancreas) Vol. 42 Issue 6 Pg. 937-43 (Aug 2013) ISSN: 1536-4828 [Electronic] United States
• PMID: 23587853 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Ga(III)-DOTATOC
• Gallium Radioisotopes
• Organometallic Compounds
• Octreotide

Topics

• Adult
• Aged
• Female
• Gallium Radioisotopes
• Humans
• Male
• Middle Aged
• Neuroendocrine Tumors (diagnosis)
• Octreotide (analogs & derivatives)
• Organometallic Compounds
• Positron-Emission Tomography (methods)
• Reproducibility of Results
• Sensitivity and Specificity