Bruce F. Kimler PhD, Abstract Co-Author: Research support, Pfizer Inc Research support, InterGenetics Incorporation Research support, Novartis AG

Greg Kubicek MD, Presenter: Nothing to Disclose

Eashwer K. Reddy MD, Abstract Co-Author: Nothing to Disclose

Cristina Cabrera MD, Abstract Co-Author: Nothing to Disclose

Yelizaveta Shnayder MD, Abstract Co-Author: Nothing to Disclose

Douglas Girod MD, Abstract Co-Author: Nothing to Disclose

Reginald William Dusing MD, Abstract Co-Author: Nothing to Disclose

Terence Tsue MD, Abstract Co-Author: Nothing to Disclose

Fen Wang MD, PhD, Abstract Co-Author: Nothing to Disclose

To examine the role of PET scans in staging and follow-up for patients with head and neck cancer treated with radiation.

Retrospective review of all head and neck cancer patients treated with radiotherapy who have had a PET scan at KUMC. 144 patients and 330 PET scans were analyzed in this study, 93 patients had staging PET scans and 110 patients had follow-up PET scans (227 scans). All of the patients were treated with radiation, 74 patients had adjuvant radiation and 110 patients had concurrent chemotherapy. Median follow-up was 490 days from the end of radiation. 51 patients had surgical staging performed after the PET scan.

Lymph node status was correctly predicted in 48 (94%) of the PET scans with one false negative and two false positives. For all PET scans used for staging, the median SUV uptake in the primary mass was 8.7 SUVs (range 2 to 23) and the median SUV for the lymph nodes was 4.95 (range 1.9 to 17.6). With a median follow-up of 354 days (range 63 days to 4.2 years) 35 recurrences have occurred, with 15 local-regional. There is no statistically significant relation between recurrence and maximum SUV in either the mass or lymph node.110 patients had a follow-up PET scan (227 scans). A total of 70 scans (from 47 patients) were interpreted as having no evidence of disease (NED). Four (8.5%) of these patients had a recurrence (1 local and 3 distant). There were no failures in 25 patients who had NED on PET scans obtained one year after the end of radiation. Patients with NED on post-radiation scans had a statistically significant reduced recurrence rate (P < 0.02) compared to patients who did not have NED on follow-up PET scans.51 patients had areas of increased uptake within the treatment field on the first follow-up PET scan with a median SUV uptake in the treatment field (most commonly in the post-operative site) of 4 (range 2.3 to 10.9). 17 (34.7%) of these patients failed. Patients who failed locally had a median uptake of 5.3 (range 2 to 10.9) and the scan was performed a median of 48 days from the end of therapy. 17 patients had nonspecific increased uptake with a second PET scan, in these patients 13 also had uptake seen on the first exam and 8 of these 13 patients had a recurrence. Of the 4 patients with treatment field uptake not seen on the first PET scan there were 2 failures (1 local and 1 distant). We analyzed several variables (maximum SUV uptake, time from treatment, chemotherapy, extent of surgery, disease site) to determine which patients with post-operative uptake were at increased risk for failure, but no factors were found to be predictive.

PET scans are a valuable staging tool in assessing lymph node status with an accuracy of 94%. Maximum SUV did not correlate with recurrence or OS. PET scans on follow-up that show NED are a statistically significant predictor of reduced recurrence. Follow-up scans with increased uptake in the treatment field remain a diagnostic dilemma. The only variables that appear to predict for patients at an increased risk for recurrence is consistent uptake on a subsequent PET scan or a previously negative PET scan. Based on this we support use of PET scan prior to therapy for staging and the first follow-up PET scan at 6-8 weeks with repeat follow-up scan at six months for patients with uptake in the treatment field and one year for patients with NED.

Kimler, B, Kubicek, G, Reddy, E, Cabrera, C, Shnayder, Y, Girod, D, Dusing, R, Tsue, T, Wang, F, Pet Scans for Staging and Follow-up for Head and Neck Cancers Treated with Radiotherapy.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/6001178.html