Role of FDG-PET/CT in follow-up of patients treated with resective gastric surgery for tumour

Abstract

Introduction: Gastric cancer has a poor prognosis and a high rate of recurrences after surgery. The optimal method for assessing early recurrences is not defined: conventional imaging (ultrasonography, CT and MRI) have difficulty in detecting them, because they don't give information regarding metabolic features or tumor response to chemotherapy. Actually 18F-fluorodeoxyglucose positron emission (18FDG-PET) has several indications for the primary staging and the follow-up of colon-rectal, lung, breast, neck cancers and lymphoma, but its clinical role in gastric cancer is not assessed. Our study analyzes the role of 18FDG-PET integrated with CT scan in the detection of gastric cancer recurrence.

Materials and methods: We retrospectively reviewed 50 patients which underwent follow-up 18FDG-PET/CT from 2006 to 2009 after radical surgery for gastric adenocarcinoma. Each study was repeated every 6 months for the first two years after surgery and every 12 months for the subsequent three years.

Results: 18FDG-PET/CT was positive for suspected neoplastic disease in 29 (58%) and negative in 21 (42%) patients, with 3 false positive and 3 false negative results. 18FDG-PET/CT showed highly effectiveness in early detection of recurrences, as observed in 17 patients that were totally asymptomatic, allowing the initiation of multimodal treatment resulting in an important increasing of survival.

Conclusions: 18FDG-PET-CT has a very good sensitivity (89.7%) and specificity (85.7%) in detecting local and distant recurrences during post-operative follow-up. Positive 18FDG-PET/CT findings may lead to an early change in the management of these patients, directing them towards rescue surgery or chemotherapy thereby improving their overall survival