Metabolic assessment of intracranial tuberculomas using 11C-methionine and 18F-FDG PET/CT.

Abstract

BACKGROUND:

18F-fluorodeoxyglucose (18F-FDG) has limited specificity in the evaluation of intracranial lesions as it is taken up by inflammatory and granulomatous lesions as well. 11C-methionine is known to have a higher specificity in tumor detection, delineation, and differentiation of benign from malignant lesions. However, its uptake in granulomatous lesions remains unclarified.

OBJECTIVE:

The aim of this study was to explore the value of 11C-methionine PET/CT and 18F-FDG in the evaluation of intracranial tuberculomas.

METHODS:

11C-methionine PET/CT followed by 18F-FDG PET/CT study was performed on 12 patients with intracranial tuberculomas. The diagnosis was confirmed for all cases on histopathological evaluation and/or follow-up. Quantitative analysis was performed for all cases by measuring the lesion-to-normal gray matter uptake ratio.

RESULTS:

A high lesion-to-normal gray matter uptake ratio was observed on both 11C-methionine (1.8 ± 0.38) and 18F-FDG scans (1.64 ± 0.26) in all newly diagnosed cases. Lesion detection and delineation was superior on 11C-methionine PET/CT. In addition, 11C-methionine appeared to be a more sensitive indicator for assessing early therapeutic response and incomplete therapeutic response in intracranial tuberculomas. There was complete concordance in the number and sites of lesions detected on 11C-methionine PET/CT and radiological imaging modalities (namely, CT and MRI).

CONCLUSION:

This preliminary study suggests that in newly diagnosed, untreated intracranial tuberculomas, 11C-methionine, like 18F-FDG, may have limited specificity in distinguishing it from a neoplastic lesion. However, it may play an important role in assessing the response to antitubercular treatment. Further studies are warranted to explore the potential of 11C-methionine in this regard.

• Authors: Maria Mathew D'Souza, Rajnish Sharma, Abhinav Jaimini, Puja Panwar, Abhishek Bansal, Madhavi Tripathi, Raunak Varshney, Santosh Pandey, Anupam Mondal
• Journal: Nuclear medicine communications (Nucl Med Commun) Vol. 33 Issue 4 Pg. 408-14 (Apr 2012) ISSN: 1473-5628 [Electronic] England
• PMID: 22301451 (Publication Type: Journal Article)

Chemical References

• Carbon Radioisotopes
• Radiopharmaceuticals
• Fluorodeoxyglucose F18
• Methionine

Topics

• Adolescent
• Adult
• Brain Diseases (diagnostic imaging)
• Carbon Radioisotopes (pharmacokinetics)
• Child
• Child, Preschool
• Diagnosis, Differential
• Female
• Fluorodeoxyglucose F18 (pharmacokinetics)
• Humans
• Male
• Methionine (pharmacokinetics)
• Multimodal Imaging (methods)
• Positron-Emission Tomography
• Radiopharmaceuticals (pharmacokinetics)
• Tomography, X-Ray Computed
• Tuberculoma, Intracranial (diagnostic imaging)
• Young Adult