Preoperative Positron Emission Tomography for Node-Positive Head and Neck Cutaneous Squamous Cell Carcinoma

Abstract

Objectives Surgery is the primary treatment modality for node-positive cutaneous squamous cell carcinoma of the head and neck with no distant disease (HNcSCC-M0). The role of preoperative positron emission tomography/computed tomography (PET/CT) scan for these patients is unclear. We compared preoperative PET/CT with final histopathology among patients undergoing lymphadenectomy and/or parotidectomy for HNcSCC-M0. Study Design Case series with chart review. Setting Single Australian center. Subjects and Methods Investigation included disease parameters and preoperative CT and PET/CT findings of 64 patients with node-positive HNcSCC without distant metastatic disease. Fisher’s exact test was used to test for a difference in the proportion of patients with chronic lymphocytic leukemia between the false- and true-negative PET/CT subgroups. Results Of 64 patients who underwent PET/CT prior to surgery for node-positive HNcSCC-M0, 56 underwent a neck dissection and 30, a parotidectomy. Of these, 13 neck dissections and 2 parotidectomies were performed in the absence of FDG-avid (18F-fludeoxyglucose) nodes in these nodal fields. The PET/CT positive predictive value of the neck was 91.1%. The negative predictive values in the neck and parotid regions were 60%. Of the false-negative subgroup, 66.7% had chronic lymphocytic leukemia, compared with 11.1% of the true-negative subgroup ( P = .09). Based on PET/CT findings, surgical plans according to preoperative CT were changed for 6.25% of patients. Conclusion Use of PET/CT for surgical candidates with node-positive HNcSCC-M0 has high specificity and positive predictive value with relatively low sensitivity and negative predictive value. A statistical trend toward a higher rate of chronic lymphocytic leukemia among patients with false-negative results is suggested.