Objectives

• This multicenter case-control study assessed the impact of systematic post-treatment follow-up with 18F-FDG PET/CT on overall survival (OS) in patients treated for head and neck squamous cell carcinoma (HNSCC).
• The study found that the use of 18F-FDG PET/CT as an alternative to annual chest CT in the follow-up of HNSCC is associated with a survival benefit at 3 years.
• The 3-year OS was significantly better in the PET/CT group (83.5±2.8%) than in the conventional follow-up (CFU) group (73.4±2.1%, p=0.008).

Methodology

• This was a multicenter case-control study.
• Patients were divided into two groups: conventional follow-up (CFU) and CFU + systematic annual 18F-FDG PET/CT.
• The CFU group received clinical examinations, nasofibroscopy, and annual chest CT scans.
• The PET/CT group received CFU and systematic annual 18F-FDG PET/CT instead of chest CT.
• 18F-FDG PET/CT imaging was performed on Biograph-mCT systems, following EANM guidelines.
• Statistical analysis included Fisher’s exact test, Mann-Whitney test, Kaplan-Meier method, log-rank test, and Cox regression model.

Results

• A total of 697 patients were included (508 in the CFU group and 189 in the PET/CT group).
• Cox regression analysis showed a protective effect of 18F-FDG PET/CT (HR=0.56, 95%CI:0.397–0.795, p=0.001).
• The 3-year OS in the PET/CT group was better than in the CFU group (83.5±2.8% vs. 73.4±2.1%, p=0.008).
• The 3-year OS after recurrence was significantly better in the PET/CT group (64.5±9.8% vs. 38.2±5.2%, p=0.005).
• Subgroup analysis by AJCC stage and primary tumor location also showed significant survival benefits in certain groups.

Discussions

• The study is limited by its retrospective nature and the non-randomized allocation of patients to the two follow-up strategies.
• The choice of follow-up modality was determined by clinicians’ choice, introducing potential selection bias.
• The heterogeneity of the imaging modalities used for the 3-month evaluation (MRI, 18F-FDG PET/CT, or CT scan) in the CFU group could have influenced the results.
• The study's follow-up period was limited to 3 years. A longer follow-up duration is needed to fully assess the long-term impact of 18F-FDG PET/CT surveillance.
• Future prospective studies with randomized controlled trials are needed to confirm these findings and determine the optimal schedule and duration of 18F-FDG PET/CT follow-up.

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Reference: 3 year overall survival benefit of systematic follow up with 18F FDG PET CT in asymptomatic patients treated for head and neck squamous cell carcinoma a multicenter study