Role Of Fdg-Pet For Staging In Head And Neck Cancer

The role of positron emission tomography with CT attenuation correction (PET) scanning in the staging of head and neck cancer (HNC) is unclear. The NCCN guidelines do not recommend PET as a routine of standard workup, and the extent to which PET scan changes management is not as well documented as compared to other cancer sites. The purpose of this report is to examine the role of FDG-PET imaging in altering management and providing prognostic information for HNC. Retrospective review of HNC patients who had a staging PET scan performed at either Thomas Jefferson University or University of Kansas Medical Center between the years 2001 and 2007. A total of 274 PET scans were reviewed; 213 PET scans in patients who went on to receive definitive radiotherapy. One hundred ten patients had a neck dissection after the PET scan was performed for evaluation of lymph node status. The median follow-up time for the 213 patients undergoing definitive radiation was 469 days, with 79 recurrences (44 local, 35 distant). Ten of 183 (6%) patients who were clinically M0 (ie, negative clinical exam and CXR) had metastatic disease diagnosed on the staging PET scan with 1 false negative and 12 false positives for a PPV of 33.3% and NPV of 99.5%. In the 110 patients with a post-PET neck dissection, the PPV and NPV for PET scans in determining lymph node status was 94% and 89%, respectively. The median standard uptake value (SUV) for the tumor mass and lymph nodes were evaluated in 160 patients. Patients with extracapsular extension (ECE) of the lymph node had a higher lymph node SUV versus patients negative for ECE (11.5 vs 6.3, p = 0.0002). SUV values of the tumor mass or lymph nodes were not predictive for overall or local recurrence, but SUV of the lymph node was predictive for distant recurrence at 1 year with median SUV values of 10.4 for patients with distant failure vs 7.0 without (p = 0.0495). PET scans are a valuable tool in staging HNC. PET scans have good accuracy and predictive value in determining lymph node status. SUV of the lymph node is predictive for ECE and also for distant recurrence. This has treatment implications in that patients with higher lymph node SUVs receiving definitive radiation may warrant higher doses for treatment of the more aggressive ECE. Also, since lymph node SUV is predictive for distant recurrence, this can allow stratification for patients who would be more likely to benefit from induction chemotherapy.