Evaluation of PET imaging in treatment decision making for early stage head and neck squamous cell cancer

Abstract

e17017 Background: Positron emission tomography (PET) scanning is widely used in staging of patients (pts.) with head and neck squamous cell cancers (HNSCC). However, the role of PET scan in pts. with early stage disease and clinically negative nodes remains controversial. The purpose of our study was to correlate preoperative PET scan findings in early stage disease with operative pathological findings of neck dissection. Methods: A retrospective review of medical records of all pts. treated at Long Island Jewish Medical Center with T1N0 HNSCC from 2002 to 2008 was undertaken. Institutional Review Board approval was obtained for this study. Eligibility criteria included: clinically staged T1N0, documented pre-operative PET scans and primary surgical management including a neck lymph node dissection as part of initial treatment. Data collected included age, gender, physical examination findings, PET scan results, operative pathology and modalities of treatment. Results: Sixty six pts with early stage T1N0 HNSCC were identified. Twelve of sixty six pts met eligibility criteria for this study. Median age was 61 years (range: 27 to 84 yrs), M:F ratio was 1:1. Primary sites of tumor were: tongue (n = 8) 67%; oral cavity (n = 3) 25%; larynx (n = 1) 8%. Preoperative PET scan was positive at primary sites in all pts (n = 12). Additionally, PET positivity was noted in regional lymph node sites in six of twelve pts. Operative pathology confirmed tumor presence in all primary sites. However, nodal involvement was not found in any pt. Median numbers of lymph nodes dissected were 25 (range:13–34). Based on these clinical data, the calculated statistical parameters for preoperative PET scan in detecting occult neck lymph node metastases were: negative predictive value: 100%; positive predictive value: 50%: specificity: 50%; sensitivity: 0%. Conclusions: The clinical application of PET scans in early stage (T1N0) HNSCC may be limited by its high false positive rate. A high negative predictive value suggests that a negative result can exclude metastatic lymph nodes involvement in this group of pts. with early stage disease. Correlation with SUV values of the PET scans and comparisons between the relative PET avidity of the primary tumors and the nodal uptake are ongoing. No significant financial relationships to disclose.