What is the clinical impact of PET/CT in evaluating patients for recurrent pancreatic cancer, and is it a useful tool in suspicious pancreatic lesions?

Abstract

e14704 Background: Recurrence of pancreatic cancer after surgery is difficult to detect with conventional computed scan (CT) which has limited ability to distinguish local recurrence from postoperative changes. FDG – (18-fluorine deoxyglucose) positron emission tomography/computed tomography (PET/CT) evaluates biologic tumor activity related to glucose metabolism. Hence, it may improve the diagnostic accuracy postoperatively for pancreatic carcinoma. PET/CT can also evaluate suspicious pancreatic lesions to predict their malignant potential. Methods: 31 PET/CT scans were reviewed retrospectively for 18 patients with pancreatic lesions found on abdominal CT. Results: 14 of 18 patients had documented pancreatic cancer. 9 patients underwent resection; 7 had Whipple procedure; 2 had distal pancreatectomy with splenectomy. All 9 patients who underwent resection had recurrent disease; 4 (44%) of them had recurrence detected by PET/CT that was not detected on CT performed within 4 weeks of the PET/CT, potentially altering their management and prognosis. 1 patient had a recurrent lesion resected and 3 patients were started on chemotherapy or chemo-radiation therapy. In 2 cases with recurrence, PET/CT was able to distinguish pancreatic bed recurrence from postsurgical changes in comparison with CT. 4 of 18 patients had suspicious pancreatic findings on CT. PET/CT in these patients showed no FDG avid pancreatic lesion. Among these 4 patients, 1 had no pancreatic biopsy performed due to comorbidity and is still alive 3.5 years later. 1 had benign finding on pancreatic biopsy. 2 had a non diagnostic pancreatic biopsy. 1 expired 2 years later due to sepsis, and the other patient was 86 years old and expired a year later of unknown cause. Conclusions: FDG PET/CT is valuable in evaluating patients with suspected recurrent pancreatic carcinoma. PET/CT is helpful in managing patients with a suspicious CT pancreatic lesion who lack histologic confirmation. If the lesion is not metabolically active, this may allow follow up with observation and reduction in unnecessary intervention in selected patients.