High SUVmax of a Primary Pancreatic Malignancy on Routine Pre-Operative FDG-PET Is Associated with Recurrence within 6 Months of Resection

Abstract

Introduction: Oncological pancreatic resection is a costly and morbid procedure. A significant proportion of patients who undergo this treatment will have recurrence within 6 months and therefore have not received benefit from their surgery. More clinical parameters which aid patient selection are needed. Methods: All patients with potentially resectable pancreatic or peri-ampullary adenocarcinoma were eligible to undergo pre-operative FDG-PET/CT. Maximum standardized uptake value of the primary tumour (SUVmax-p) was compared between those with recurrence within 6 months of resection and those without. Using increments of 0.5 we divided the full range of SUVmax-p into discrete cut-points and determined the odds ratio of recurrence within 6 months for each. We repeated the same analysis exclusively for patients who had resection with clear surgical margins. Results: 23 patients who underwent resection of a pancreatic or peri-ampullary malignancy were included. Median SUVmax-p was 4.0 (IQR: 2.5-5.9). Recurrence within 6 months was associated with higher median SUVmax-p (5.9 vs 3.5; p=0.04). The cut-point with the highest odds ratio for recurrence within 6 months was SUVmax-p ≥ 5.5 (OR: 10.8; 95% CI: 1.56-109; p=0.01). 12 patients underwent margin negative resection. Recurrence within 6 months for this group remained associated with higher median SUVmax-p (6.5 vs 2.2; p=0.48), and SUVmax-p ≥ 5.5 remained the cut-point with the highest odds ratio for recurrence (OR: 24.0; 95% CI: 1.64-1020; p=0.02). Conclusion: SUVmax-p determined on routine pre-operative FDG-PET/CT is useful for identifying patients unlikely to benefit from pancreatic resection, irrespective of whether clear surgical margins can be achieved.