Hybrid imaging PET/CT with application of 18F-Fluorothymidine in patients with head and neck carcinoma undergoing radiotherapy

Abstract

Aim: To introduce the possible benefits of the positron-emission tomography (PET)/computed tomography (CT) with 18F-3'-deoxy-3'-fluorothymidine (18F-FLT) in patients with orofacial carcinomas and its impact to patient management. Materials and Methods: Thirty-six patients with orofacial squamous cell carcinomas underwent 18F-FLT-PET/CT during radiotherapy. Examinations were performed after administration of 18F-FLT (1.8 MBq/kg) including full-diagnostic CT. Analysis of the radiotherapy effect was performed with possible prospect of repeated and focused irradiation. Results: Complete absence of 18F-FLT uptake was found in 20 patients, thus complete response to radiotherapy was reported. Persistence of focal 18F-FLT uptake was observed in 16 patients; in 11 patients, the measured activity was only mild. In five patients, a higher level of 18F-FLT uptake was measured and additional irradiation was performed in defined regions. Repeated follow-up proved complete regression 18F-FLT uptake. Conclusion: It was possible to assess the effect of radiotherapy with the use of 18F-FLT-PET/CT and findings are suitable for radiation dose-escalation planning.