18F-FDG PET of patients with Hurthle cell carcinoma

Hurthle cell carcinoma is an uncommon differentiated thyroid cancer characterized by an aggressive clinical course and low avidity for I-131. Treatment usually involves an aggressive surgical approach often combined with I-131. F-18-FDG PET has been helpful in the staging and evaluation of many types of aggressive malignancy. No reports to date have described the utility of PET in a series of patients with Hurthle cell cancer. We reviewed our experience with F-18-FDG PET in the care of patients with Hurthle cell carcinoma to determine the likelihood of uptake in these cancers and the effect of F-18-FDG PET on patient care. Methods: Patients with Hurthle cell cancer who were seen between June 2000 and April 2002 and were imaged with 18F-FDG PET were included. Imaging and clinical data were reviewed. PET results were compared with the results of anatomic imaging (CT, sonography, or MRI) and I-131 imaging when performed. Patient charts were reviewed to identify any change in management that resulted from the F-18-FDG PET findings. Results: Fourteen F-18-FDG PET scans of 12 patients were obtained in the time frame indicated. All patients had documented Hurthle cell carcinoma. PET showed intense F-18-FDG uptake in all known Hurthle cell cancer lesions but one. PET showed disease not identified by other imaging methods in 7 of the 14 PET scans. PET identified distant metastatic disease (5) or local disease (2) that was more extensive than otherwise demonstrated. In 7 of the 14 scans, the information provided by PET was used to guide or change therapy. Conclusion: Hurthle cell carcinoma demonstrates intense uptake on F-18-FDG PET images. PET improves disease detection and disease management in patients with Hurthle cell carcinoma relative to anatomic or iodine imaging. F-18-FDG PET should be recommended for the evaluation and clinical management of patients with Hurthle cell carcinoma.