Utility of ¹¹C-choline imaging as a supplement to F-18 FDG PET imaging for detection of thyroid carcinoma.

Objective: We present 4 patients with thyroid carcinoma who underwent ¹¹C-choline PET/CT for the detection of their primary tumor and its metastases. Previous F-18 FDG PET had shown no abnormal tracer uptake in the lesions in 3 patients and only mild uptake in 1 patient.

Methods: Four patients aged between 24 and 59 years (2 newly diagnosed and 2 with recurrence) underwent whole-body F-18 FDG PET/CT. The patients then underwent regional ¹¹C-choline PET/CT imaging on a separate day.

Results: All of the lesions in 4 patients were ¹¹C-choline avid except for a few small lung metastases. The SUVmax of the lesions was 7.94 ± 4.93. ¹¹C-choline imaging detected 3 primary tumors in 4 patients, 1 tumor in the tracheal wall in 1 patient, 7 cervical lymph nodes metastases in 3 patients, and several lung metastases in 1 patient.

Conclusions: ¹¹C-choline PET/CT may be a promising supplement to F-18 FDG PET/CT in the detection of thyroid carcinoma and its metastases.