Clinical interpretation of incidental head and neck findings on PET/CT studies for patients with lung cancer

Objectives Smoking is the major risk factor for lung and head and neck cancer. The purpose of this study is to determine the clinical impact of the incidental head and neck PET/CT findings in patients undergoing investigation for lung cancer.

Methods The reports from PET/CT studies for patients with lung cancer from September 2005 and April 2012 were retrospectevely reviewed. The incidental head and neck findings were interpreted as suggestive of second primary malignancy. These incidental findings were compared with the final diagnosis obtained from clinical and histological investigations.

Results 592 patients were investigated for lung cancer in the study period. Head and neck PET/CT positive lesions suggestive of second primary malignancy were found in 65 (11%) patients. Twenty-three patients had nasoendoscopy, and a biopsy were realized on 10 patients. In 4 (0,68%) patients, these lesions were proven of second primary malignancy: 2 squamous cell carcinoma (larynx and oral cavity), 1 undifferencied carcinoma (parotid), 1 osteosarcoma (mandible). At a median follow-up of 13 months, 3 of 4 patients with a second primary died from a malignancy and 1 had no evidence of disease. Metastasis from lung adenocarcinoma were found in 2 (0,34%) patients.

Conclusions PET/CT detected new unexpected head and neck malignant tumors in at least 0,68% of patients with lung cancer.