Usefulness of PET/CT for detecting a second primary cancer after treatment for squamous cell carcinoma of the head and neck.

PURPOSE: Patients with squamous cell carcinoma of the head and neck have been reported to have a high rate of second primary cancer of the upper aerodigestive tract. This study was performed to determine whether positron emission tomography/computed tomography (PET/CT) is useful for detecting a second primary cancer after treatment for squamous cell carcinoma of the head and neck. METHODS AND MATERIALS: The PET/CT findings in 279 consecutive patients (211 men, 68 women; mean age 62 years) who had been treated for squamous cell carcinomas of the head and neck were examined and compared with the findings obtained by other imaging modalities, the biopsy results, and the clinical data. RESULTS: Thirty second primary cancers were documented in 28 of the 279 subjects. Based on PET/CT findings, the overall risk of a second primary cancer in 1 year was 9.9% and the risk in the upper aerodigestive tract region was 6.8% (19/279). CONCLUSIONS: PET/CT enabled early detection of a second cancer in patients treated for head and neck cancer.