High SUVmax on Routine Pre-Operative FDG-PET Predicts Early Recurrence in Pancreatic and Peri-Ampullary Cancer.

Background: SUVmax of a primary pancreatic tumour on FDG-PET/CT (SUVmax-p) may predict early post-operative recurrence. This has not been tested in the context of routine pre-operative FDG-PET/CT. It is also unknown whether this association exists independent of local residual tumour. Methods: FDG-PET/CT was performed routinely prior to resection of pancreatic or peri-ampullary adenocarcinoma between 2008 and 2012 as part of a previous prospective study. We compared SUVmax-p according to whether recurrence was diagnosed within 6 months of resection. We also determined the odds ratio for recurrence within 6 months for multiple cut-points of SUVmax-p. This analysis was repeated exclusively for patients who had resection with clear surgical margins (R0). Results: Of 56 patients from the initial study 23 underwent resection and were eligible. Recurrence within 6 months was associated with higher median SUVmax-p (5.9 vs 3.5; p = 0.04). This was also observed in 12 patients who underwent R0 resection (6.5 vs 2.2; p = 0.05). The cut-point with the highest odds for recurrence within 6 months for both groups was SUVmax-p >= 5.5 (OR = 10.8, CI = 1.56-109; OR[R0] = 24.0, CI = 1.64- 1020). Conclusion: SUVmax-p on routine FDG-PET/CT is useful for identifying patients likely to benefit from additional pre-operative staging or neoadjuvant therapy, even where clear margins can confidently be achieved.