Prognostic value of MRI and delayed ¹⁸FDG-PET/CT for tumor persistence in patients with loco-regionally advanced head and neck squamous cell carcinoma treated with curative intent

Introduction More than 50 % of patients treated for loco-regionally advanced head and neck cancer (LAHNC) experience tumor persistence (< 6 months after the end of treatment) or recurrence ( >6 months after the end of treatment), of which around 20-40 % can be successfully salvaged. For this reason, close follow-up is of crucial importance. The frequency and modalities of follow-up, including imaging, are variable within and among countries.

Methods Retrospective analysis of patients with LAHNC (stage III-IVB according to UICC 7 ed.), treated after implementation of a standardized institutional follow-up schedule in 2015. It includes post-treatment MRI and ¹⁸FDG-PET/CT acquisitions 3 and 4 months, respectively, after the end of therapy. Included are all patients with a follow-up of 12 months after the end of treatment or death. The prognostic value of MRI and delayed ¹⁸FDG-PET/CT was investigated for PFS in combination with patient and tumor characteristics. Multivariate Cox proportional hazards model was used to identify independent variables including patient and tumor characteristics.

Results A total of 220 cases were analyzed. Preliminary results show that delayed ¹⁸FDG-PET/CT has increased sensitivity as well as specificity compared to MRI. Moreover, suspicious imaging findings more frequently led to the diagnosis of tumor persistence than clinical examination.

Conclusion Despite the higher cost, delayed ¹⁸FDG-PET/CT is an accurate response evaluation tool in advanced LAHNC. It is not clear whether its main advantage over MRI is due to technical difference of two modalities or because of the 1-month difference.

Poster-PDF A-1569.PDF

Publication History

Article published online:
10 June 2020