Predictive value of suvmax changes between two sequential post-therapeutic FDG-pet in head and neck squamous cell...

Area of Science:

• Oncology
• Nuclear Medicine
• Radiology

Background:

• 18-fluorodeoxyglucose positron emission tomography (FDG-PET) with CT or MRI is standard for cancer staging and response assessment.
• The prognostic significance of changes in metabolic activity on sequential post-therapeutic FDG-PET scans remains under-investigated.

Purpose of the Study:

• To investigate the hypothesis that an increase in metabolic activity, measured by maximum standardized uptake value (SUVmax), on sequential FDG-PET scans predicts recurrence in head and neck squamous cell carcinoma.
• To assess the impact of changes in SUVmax between 3 and 9 months post-treatment on recurrence-free survival.

Main Methods:

• Retrospective analysis of 337 patients with oral, oropharyngeal, laryngeal, and hypopharyngeal squamous cell carcinoma treated between 2010 and 2018.
• FDG-PET scans were performed at 3 and 9 months post-treatment.
• SUVmax of local tumor and regional lymph nodes was measured; changes between scans were correlated with recurrence using Kaplan-Meier analysis.

Main Results:

• An increase in local and/or regional SUVmax between 3 and 9 months post-treatment was associated with significantly poorer recurrence-free survival (Log rank, P=0.001).
• An increase in local SUVmax between 3 and 9 months correlated with a 4.17-fold increased hazard of recurrence (95% CI 1.89-9.2, P=0.0003).
• During follow-up, 20.2% of patients experienced local recurrence and 15.7% experienced regional recurrence.

Conclusions:

• An increase in metabolic activity (SUVmax) on sequential post-therapeutic FDG-PET scans is a significant predictor of tumor recurrence in head and neck squamous cell carcinoma.
• Such an increase warrants further investigation, preferably histological examination, to confirm recurrence.