Clinical usefulness of 18F-FDG PET/CT in the restaging of esophageal cancer after surgical resection and radiotherapy

Abstract

Aim: To evaluate the clinical usefulness of (18)F-fluorodeoxyglucose positron emission and computed tomography ((18)F-FDG PET/CT) in restaging of esophageal cancer after surgical resection and radiotherapy.

Methods: Between January 2007 and Aug 2008, twenty histopathologically diagnosed esophageal cancer patients underwent 25 PET/CT scans (three patients had two scans and one patient had three scans) for restaging after surgical resection and radiotherapy. The standard reference for tumor recurrence was histopathologic confirmation or clinical follow-up for at least ten months after (18)F-FDG PET/CT examinations.

Results: Tumor recurrence was confirmed histopathologically in seven of the 20 patients (35%) and by clinical and radiological follow-up in 13 (65%). (18)F-FDG PET/CT was positive in 14 patients (68.4%) and negative in six (31.6%). (18)F-FDG PET/CT was true positive in 11 patients, false positive in three and true negative in six. Overall, the accuracy of (18)F-FDG PET/CT was 85%, negative predictive value (NPV) was 100%, and positive predictive value (PPV) was 78.6%. The three false positive PET/CT findings comprised chronic inflammation of mediastinal lymph nodes (n = 2) and anastomosis inflammation (n = 1). PET/CT demonstrated distant metastasis in 10 patients. (18)F-FDG PET/CT imaging-guided salvage treatment in nine patients was performed. Treatment regimens were changed in 12 (60%) patients after introducing (18)F-FDG PET/CT into their conventional post-treatment follow-up program.

Conclusion: Whole body (18)F-FDG PET/CT is effective in detecting relapse of esophageal cancer after surgical resection and radiotherapy. It could also have important clinical impact on the management of esophageal cancer, influencing both clinical restaging and salvage treatment of patients.

Figure 1

A 56-year-woman who had esophageal cancer resection 5 years ago. PET/CT displayed multi-retroperitoneal lymph node recurrence (arrows in A and B). The patient accepted retroperitoneal lymph node resection, which was later verified as esophageal cancer metastasis by histopathology. PET/CT Follow-up 10 mo after her second operation demonstrated no new recurrent lesions (C, D).

Figure 2

A 62-year-women had esophageal cancer resection. She underwent three PET/CT scans (1.5, 4.5 and 11 mo after treatment, respectively) as part of routine post-operative surveillance. The first PET/CT imaging (1.5 mo) revealed hypermetabolic activity in the anastomosis and supraclavicular lymph nodes (arrows, A, B). The second PET/CT imaging (4.5 mo) showed decreasing of hypermetabolic activity at anastomosis and supraclavicular lymph nodes (arrows, C, D). The third PET/CT imaging (11 mo) showed no abnormal FDG uptake at anastomosis, but revealed new focal hypermetabolic activity at left supraclavicular lymph nodes (arrows, E, F). Inflammation of lymph nodes and anastomosis at the first and second PET/CT scan were confirmed by the third PET/CT examination. New relapse at the left supraclavicular lymph nodes was later verified by biopsy.

Figure 3

A 40-year-old asymptomatic man who had esophageal cancer resection 30 mo ago underwent PET/CT as part of routine post-operative surveillance. The first PET/CT revealed hypermetabolic activity at the anastomosis (arrows, A, B) 5 mo after treatment. The second PET/CT showed hypermetabolic activity at the anastomosis (arrows, C, D) 30 mo after treatment. The final diagnosis by endoscopic biopsy was anastomotic inflammation.