Advanced squamous cell carcinoma of the oropharynx: efficacy of positron emission tomography and computed tomography for determining primary tumor response during induction chemotherapy.

Abstract

To evaluate the efficacy of fluorine-18-fluorodeoxyglucose emission tomography (FDG-PET) and CT versus endoscopy with biopsy under general anesthesia for estimating tumor volume reduction among patients treated with induction chemotherapy for advanced squamous cell carcinoma (SCC) of the oropharynx. Twelve patients with oropharyngeal SCC nested in a phase II, induction chemoradiation, organ preservation trial (University of Michigan Cancer Center 9921) underwent tumor volume reduction estimation as assessed by FDG-PET, CT, and endoscopy with biopsy. In 9 of 12 patients, FDG-PET, CT, and endoscopy demonstrated agreement in estimation of tumor reduction. Two patients had discordant results, whereas 1 patient was inadequately evaluated with FDG-PET. The kappa value for PET versus endoscopy was 0.62, which is categorized as substantial agreement. The kappa value for CT versus endoscopy was 0.40, which is categorized as fair agreement. FDG-PET may be as efficacious as endoscopy with biopsy under general anesthesia for estimating tumor volume reduction with induction chemotherapy.