FDG PET/CT in detection of adrenal metastasis in patients with renal cell carcinoma.

Objective: Adrenal metastasis in renal cell carcinoma (RCC) is uncommon. The present study was aimed to evaluate the role of fluoro-deoxy-glucose positron emission tomography (FDG PET)/computed tomography (CT) in the detection of adrenal metastasis in patients with RCC.

Methods: A total of 9 FDG PET/CT scans were performed in 4 patients (3 males, 1 female; median age: 53.5 years, range: 52-73 years). Of 9 PET/CT scans, 2 scans were done for initial staging, 2 for restaging, and 5 for evaluation of treatment response. PET/CT image interpretation and analysis was performed qualitatively (visually) and semiquantitatively. Absence of uptake in postchemotherapy PET/CT scan was considered as complete response and a fall in SUV by more than 50% of baseline value, as significant response.

Results: Patients 1 and 2 underwent staging FDG PET/CT. Patient 1 had undergone left radical nephrectomy 13 years back for left-sided RCC. Current FDG PET/CT revealed appearance of right RCC with adrenal metastasis. PET/CT of patient 2 demonstrated right adrenal and distant metastases. PET/CT done for restaging in patient 3, revealed right adrenal and abdominal lymph nodal metastasis. In patient 4, PET/CT revealed solitary adrenal metastasis. Magnetic resonance imaging findings were consistent with adrenal metastasis in this patient. Patient 1 received sunitinib and interferon chemotherapy along with radiotherapy and showed partial response on PET/CT scans done at 6, 17, 23, and 33 months from the initial study. PET/CT of patient 3 demonstrated the progression of disease (nonresponder).

Conclusions: FDG PET/CT appears to be useful for staging, treatment response evaluation, and recurrence detection in patients with RCC having adrenal metastasis.