Value of positron emission tomography (PET) scan in treatment decision making for nodal metastases in head and neck squamous cell cancer

Abstract

5577 Background: Management of neck disease in patients with Head and Neck Squamous cell cancer (HNC) who are initially treated with combined radiation and chemotherapy (CRT) remains controversial. Standard treatment options include neck dissection (ND) or close observation. More recently PET scans have been used to stage and monitor response to therapy in patients with HNC. We performed a retrospective analysis of patients diagnosed with HNC stages N2b or higher, treated with combined CRT, and who were monitored for disease response by PET scans. Our observations on the utility of PET scans in monitoring response to therapy and in determining the role of elective NDs in this setting are reported. Methods: A retrospective review of medical records of all patients diagnosed at our institution with HNC Stages TxN2b, N2c or N3 between the years 2002 and 2005 was undertaken. IRB approval was obtained for this study.To be eligible for this analysis, patients must have had baseline and follow up PET scans at the end of CRT and prior to ND. Data regarding age, gender, primary tumor site, stage, baseline and follow up PET scan results, operative pathology of ND when performed, and local control were recorded. Results: Fifteen patients were identified. Median age was 55 years (range 37–76). Male: Female ratio was 13:2. Primary site of tumor was Pharynx (Base of tongue: n = 3, tonsil: n = 11); Lip and oral cavity: n = 1. Stages: IVa : n = 12; IVb: n = 3. N stage: N2b: n = 12; N2c: n = 1; N3: n = 2. Post CRT, all patients were followed with serial clinical examinations, PET ± CT scans. 13 of 15 patients had negative PET activity in the neck at the completion of CRT and remain disease free in the neck at a median follow up of one year. Post treatment PET scans were positive at the primary site in 2 of 15 patients; and positive in the neck in 2 of 15 patients. These 4 patients underwent ND after completing CRT. Operative pathology was positive for nodal disease in 2 of 4 patients who had persistent mild or significant activity on PET scan either at the primary site or in the neck. Conclusions: Post CRT PET negativity in the neck and at the site of primary tumor is associated with continued disease free status in the neck and these patients may be managed conservatively without requiring a neck dissection. No significant financial relationships to disclose.