Objective: The use of 18F-fluoroethylcholine (FEC) PET/ CT in staging and monitoring therapy response of advanced renal cell carcinoma (RCC) was prospectively analysed.
Methods: Preliminary results of two patients with metastatic RCC who underwent tumour nephrectomy as well as FEC PET/CT before and 10 weeks after two cycles of tyrosine kinase inhibitor therapy are presented.
Results: All in all, 18 tumour lesions were detected by baseline PET/CT, of which 10 (56%) were positive in FEC PET and 17 (94%) visible on contrast-enhanced computed tomography (ceCT). Mainly, small lung metastases resulted in the lower detection rate of FEC PET compared with ceCT. In follow-up PET/CT of the first case, progressive disease (PD) occurred with increase in tumour diameters of all metastases but non-uniform metabolic response. In the second case, partial response (PR) was achieved with concordant results of PET and CT. These results were confirmed by further CT in the course of disease.
Conclusions: In this small sample more than half of the RCC metastases were evident in baseline FEC PET. Monitoring therapy, FEC PET showed heterogeneous results in the first case with PD and was consistent with ceCT in the second one displaying PR.