Interpretation of Incidental Head and Neck Uptakes on PET/CT in Patients with Lung Cancer

Abstract

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 positron emission tomography (PET)/computed tomography (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 retrospectively 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:

A total of 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 was done in 10 patients. In 4 (0.68%) patients, these lesions were proven of second primary malignancy: 2 squamous cell carcinoma (larynx and oral cavity), 1 undifferenciated 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 was found in 2 (0.34%) patients.

Conclusions:

PET/CT detected unexpected head and neck primary malignant tumors in at least 0.68% of patients with lung cancer. Among patients who underwent clinical investigations, 26.1% had a head and neck malignant tumor.