The Role of 18F-FDG PET/CT in the Evaluation of Gastric Cancer Recurrence

Abstract

Objective: F-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has been widely used for staging, re-staging and for monitoring therapy-induced changes and response to therapy in patients with various types of cancer, but its utilization for gastric cancer has been limited. This study aimed to assess the diagnostic performance of 18F-FDG PET/CT for detecting recurrence in gastric cancer patients with radiologic or clinical suspicion of recurrence and its clinical impact on making decision.Methods: We performed a retrospective review of 130 consecutive patients who underwent PET/CT scans for post-treatment surveillance of gastric cancer between January 2008 and March 2012. The mean time between the initial diagnosis of gastric cancer and PET/CT studies was 44 weeks with a median of 18 weeks. The number and site of positive FDG uptake were analyzed and correlated with the final diagnosis by calculating the diagnostic values. We evaluated the diagnostic accuracy of PET/CT for detecting the recurrence in terms of whether or not histology had been SRC/musinous adenocarcinoma. The changes in the clinical management of patients were also evaluated according to the results of PET/CT.Results: Of all 130 patients, 91 patients were confirmed to have true recurrence. The sensitivity, specificity, positive predictive value, negative predictive value and the accuracy of PET/CT for diagnosing true recurrence on a per-person basis were 91.2%, 61.5%, 84.6%, 75.0% and 82.3% respectively. Final diagnoses were confirmed histopathologically in 59 (45.4%) of 130 patients and by clinical and radiological follow-up in the remaining 71 (54.6%) patients. In the subgroup with SRC/mucinous adenocarcinoma differentiation of the primary tumor, there was no statistically significant difference in terms of diagnostic accuracy of PET/CT on a per-person basis. In addition, PET/CT results changed the patients’ management in 20 (15%) cases.Conclusions: 18F-FDG PET/CT can provide useful information in discriminating true recurrence in patients with suspected gastric cancer recurrence and may have significant impact on clinical decisions/patient management in a considerable percentage of patients.

The value of FDG‐PET in the staging of gastric adenocarcinoma: A single institution retrospective review

“…As imaging technology continues to evolve, combining FDG‐PET and CT may become the standard of care for staging cancers like gastric adenocarcinoma where functional and anatomic characteristics can be integrated into a single real‐time imaging modality. Recent data on hybrid FDG‐PET/CT and utilization of new radiotracers in gastric adenocarcinoma suggest improved detection accuracy and surveillance .…”

Diagnostic role of 18F-FDG PET/CT in recurrence detection of surgically treated gastric cancer: a cross-sectional study

“…Fused PET/CT is an important imaging modality for detection of gastric tumoral recurrence as it gives detailed morphologic and metabolic activity compared to single contrast-enhanced CT [6].…”

“…Pathological recurrence has a bad prognosis, and 5-year survival rate remains under 20%. So, early detection of disease recurrence is important and improves the prognosis [4][5][6]. Diagnosis of definite tumoral recurrence is still based on histopathology.…”

“…FDG-PET can display accurate functional information; however, based on its limited spatial resolution, it often makes exact anatomical localization and demarcation of the lesion difficult. The hybrid imaging tool (PET-CT) with fusion of functional with morphological data overcoming the limitations of either modality alone thus will be more valuable in postoperative evaluation of gastric cancer improving the ability to detect and characterize malignant lesions [5][6][7][8][9][10]. Recently, some studies reported the use and importance of integrated PET/CT in evaluation of postoperative gastric cancer patients to exclude or verify recurrence [6].…”

Diagnostic clue of nodular fasciitis mimicking metastasis in papillary thyroid cancer, mismatching findings on 18F-FDG PET/CT and 123I whole body scan: A case report

“…Although distant metastasis in patients with thyroid cancer is not as grave as that in other cancers, it significantly affects survival; therefore, a thorough work-up including 18 F-FDG PET/CT is required (9,15,16). 18 F-FDG PET/CT visualizes glucose metabolism and is widely used to differentiate between benign and malignant lesions, as well as to stage/restage various malignances (17)(18)(19)(20)(21)(22). In a number of cases, the intensity of FDG accumulation is used to differentiate between malignant and benign lesions (23)(24)(25)(26).…”