Use of 18F-FDG PET for primary treatment strategy in patients with squamous cell carcinoma of the oropharynx

Abstract

High tumor uptake of (18)F-FDG is associated with an unfavorable outcome in cancer patients. We evaluated pretreatment (18)F-FDG uptake as guidance for the primary treatment modality in patients with squamous cell carcinoma (SCC) of the oropharynx.

Methods: Fifty-two consecutive patients with newly diagnosed resectable SCC of the oropharynx underwent (18)F-FDG PET before treatment. Primary treatment modalities consisted of surgical resection plus radiotherapy (RT) (surgery group, n=31) or radical RT plus chemotherapy (RT group, n=21). The sex, age, tumor stage, histologic grade, TNM classification, treatment strategy, and maximum standardized uptake value (SUV) categories were analyzed for association with local control (LC) and disease-free survival (DFS). The median follow-up of the surviving patients was 36 mo.

Results: The median SUV was significantly higher in the 11 patients who failed treatment than that in the remaining controlled patients (8.0 vs. 5.4; P=0.021). Patients having tumors with a high SUV > 6.0 had poorer LC and DFS (P<0.05). In multivariate analysis, the SUV remained an independent determinant of LC and DFS (P<0.05). Patients with a SUV > 6.0 in the surgery group had a higher 3-y DFS than that in the RT group (78% vs. 33%; P=0.043).

Conclusion: Pretreatment tumor (18)F-FDG uptake represents an independent prognostic factor in patients with oropharyngeal SCC. Patients with high (18)F-FDG uptake may be better treated by surgery followed by RT with or without chemotherapy, which needs to be verified by a prospective randomized study.