Assessment of PET-CT as a supplement to CT/MRI for detection of nodal metastasis in hypopharyngeal squamous cell carcinoma patients with palpably negative neck

Abstract

PURPOSE: To determine the diagnostic value of 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) compared with CT or magnetic resonance (MR) imaging for detecting nodal metastasis in hypopharyngeal squamous cell carcinoma (SCC) patients with palpably negative neck and to assess the supplementary role of PET-CT to CT/MR. MATERIALS AND METHODS: A total of 39 patients with palpably negative neck (36 men and 3 women; average age 65.4 years) underwent tumor resection and neck dissection as a primary treatment. Preoperatively evaluated PET-CT, CT and/or MR, were retrospectively reviewed. The diagnostic performance of PET-CT, CT/MR and a combination of PET-CT and CT/MR was assessed with histopathologic results as a gold standard. RESULTS: Twenty (51.3%) of our 39 patients were found to have neck metastases. On a level based analysis, the sensitivity of PET-CT, CT/MR, and combined interpretation of the two was 65.7%, 57.1%, and 65.7%, respectively, but without statistical significance. After the patients were categorized as cN0 neck based on CT/MR findings as well as palpation, 4 of the 6 patients who were falsely diagnosed as negative on CT/MR were still missed on PET-CT. CONCLUSION: The addition of PET-CT examination to the anatomic imaging including CT and MR could not provide additional benefit for the preoperative evaluation of cervical nodal metastasis in hypopharyngeal SCC patients with non-palpable neck, showing insufficient results to spare elective neck dissection.