Evaluation of suspected local recurrence in head and neck cancer: a comparison between PET and PET/CT for biopsy proven lesions.

Background: (18)F-FDG PET has a high accuracy for re-staging of head and neck cancer. The purpose of this study was to determine whether the diagnostic accuracy can be further improved with integrated PET/CT.
Materials and Methods: Forty-nine patients with a mean age of 59+/-18 years were studied retrospectively. Histo-pathological verification was available either from complete tumor resection with or without lymph node dissection (n=27) or direct endoscopic biopsy (n=16) or ultrasound guided biopsy (n=6). Two reviewers blinded to the pathological findings read all PET images in consensus. An experienced radiologist was added for the interpretation of the PET/CT images.
Results: Tissue verification was available for 110 lesions in 49 patients. Sixty-seven lesions (61%) were biopsy positive and 43 (39%) were negative for malignant disease. PET and PET/CT showed an overall accuracy for cancer detection of 84 and 88% (p=0.06), respectively. Sensitivity and specificity for PET were 78 and 93% versus 84 (p=NS) and 95% (p=NS) with PET/CT. A patient-by-patient analysis yielded a sensitivity, specificity and accuracy for PET of 80, 56 and 76%, compared to 88% (p=NS), 78% (p=NS) and 86% (p=0.06) for PET/CT.
Conclusion: The results of this study indicate that PET/CT does not significantly improve the detection of recurrence of head and neck cancer. However, a trend towards improved accuracy was observed (p=0.06).