Objective
To evaluate the role of combination of 18F-FDG PET-CT scan and 68Ga DOTA-TOC PET-CT scan in differentiating bronchial tumors observed in contrast enhanced computed tomography scan of chest.
Study design: Prospective observational study.
Place of study: All India Institute of Medical Sciences, New Delhi, India.
Methods
7 patients with bronchial mass detected in computed tomography scan of the chest were included in this study. All patients underwent 18F-FDG PET-CT scan, 68Ga DOTA-TOC PET-CT scan and fiberoptic bronchoscope guided biopsy followed by definitive surgical excision. The results of functional imaging studies were analyzed and the results are correlated with the final histopathology of the tumor.
Results
Histopathological examination of 7 bronchial masses revealed carcinoid tumors (2 typical, 1 atypical), inflammatory myofibroblastic tumor (1), mucoepidermoid carcinoma (1), hamartoma (1), and synovial cell sarcoma (1). The typical carcinoids had mild 18F-FDG uptake and high 68Ga DOTA-TOC uptake. Atypical carcinoid had moderate uptake of 18F-FDG and high 68Ga DOTA-TOC uptake. Inflammatory myofibroblastic tumor showed high uptake of 18F-FDG and no uptake of 68Ga DOTA-TOC. Mucoepidermoid carcinoma showed mild 18F-FDG uptake and no 68Ga DOTA-TOC uptake. Hamartoma showed no uptake on either scans. Synovial cell sarcoma showed moderate 18F-FDG uptake and mild focal 68Ga DOTA-TOC uptake.
Conclusion
This initial experience with the combined use of 18F-FDG and 68Ga DOTA-TOC PET-CT scan reveals different uptake patterns in various bronchial tumors. Bronchoscopic biopsy will continue to be the gold standard; however, the interesting observations made in this study merits further evaluation of the utility of the combination of 18F-FDG PET-CT scan and 68Ga DOTA-TOC PET-CT scan in larger number of patients with bronchial masses.