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.

Keywords: PET/CT; fluorothymidine; head and neck cancer; radiotherapy.