Positron emission tomography/computed tomography after primary transoral robotic surgery for oropharyngeal squamous cell carcinoma

Objectives/HypothesisTo assess the first post-treatment positron emission tomography/computed tomography (PET/CT) in prediction of disease-free survival after primary transoral robotic surgery (TORS) for oropharyngeal squamous cell carcinoma (OPSCC) with or without adjuvant chemoradiation. Study DesignRetrospective review. MethodsNinety-five patients with OPSCC treated with primary TORS from 2010 to 2014 at a single tertiary academic center were evaluated with PET/CT. Imaging was performed between 2 and 7 months after completing all treatment. Radiology findings were categorized as 1) negative, noting either complete resolution of foci without evidence of disease or anatomical changes likely attributed to treatment; 2) equivocal, noting equal likelihood of malignancy versus treatment-related changes; or 3) positive, noting either findings concerning for malignancy or new hyperactivity not attributed to treatment-related changes. The median follow-up time was 31 months (range, 23-63 months). Recurrence was defined as biopsy-proven invasive malignancy or clinical suspicion sufficient to initiate treatment occurring within 3 years of the completion of all treatment. ResultsOf 95 total patients with at least 2 years of follow-up records, 26 had positive post-treatment PET/CT results, with five experiencing actual recurrences. Of 69 patients with negative post-treatment PET/CT results, none experienced recurrences. These results indicate a sensitivity of 100%, specificity of 77%, positive predictive value of 19%, and negative predictive value of 100%. ConclusionsA majority of TORS patients (73%) will have a negative first post-treatment PET/CT. A single negative post-treatment PET/CT is strongly correlated with 2-year disease-free survival in patients treated with primary TORS and may warrant decreased surveillance imaging. Level of Evidence4 Laryngoscope, 127:2050-2056, 2017