18F-FDG PET Detection of postoperative recurrence of lung carcinoma in patients with CEA elevation

18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) plays an important role in determining disease stage and evaluating treatment response in cancer patients. However, there are few reports concerning the use of FDG PET for diagnosing postoperative recurrence of malignant tumors such as lung cancer. The present study was undertaken to evaluate the usefulness of FDG PET for early detection of the postoperative recurrence of lung cancer. Study subjects were 13 patients treated surgically for non-small cell lung carcinoma who had an elevated carcinoembryonic antigen level after surgery but showed no evidence of postoperative recurrence by chest computed tomography, head magnetic resonance imaging, or abdominal ultrasonography. FDG PET was performed in these patients. FDG PET findings were positive in 10 of the 13 patients and negative in the remaining 3. Of the 10 PET-positive patients, 1 had local recurrence, 6 had metastasis to the mediastinal and/or hilar lymph nodes, and 3 had distant blood-borne metastasis. One patient underwent resection of a metastatic thoracic wall tumor, and the remaining 9 underwent chemoradiotherapy. Of the 3 patients who were PET-negative, 1 was false negative and eventually diagnosed with carcinomatous meningitis, and the other 2 showed no evidence of recurrence. FDG PET in combination with chest computed tomography may facilitate early detection of non-small cell lung carcinoma recurrence in patients showing an elevated tumor marker level after surgery. (author)