Freimut Juengling MD, PhD, Presenter: Nothing to Disclose

Christian Bieg MD, Abstract Co-Author: Nothing to Disclose

Ralph Peterli MD, Abstract Co-Author: Nothing to Disclose

Ines Valenta, Abstract Co-Author: Nothing to Disclose

Markus Von Flue MD, Abstract Co-Author: Nothing to Disclose

Markus Gass MD, Abstract Co-Author: Nothing to Disclose

To evaluate the prognostic value of early dual-timepoint kinetics in pancreatic malignancies as compared to routine single SUV measurements alone.

In a prospective analysis of  55 consecutive patients with histological or cytological diagnosis of pancreatic cancer, scheduled for FDG-PET/CT, dual-timepoint PET/CT was performed at 60 min. and 90 min. after application of FDG. Images were fused with routine MRI and accordingly, lesional SUV min, SUVavg and SUVmay were respectively measured for each timepoint. Regional changes in SUVs were calculated as previously described. Patients were followed-up for 12-70 months, with death or survival as primary endpoint. For analysis of prognostic significance on survival, patients were assigned to two pairs of groups, according to regional changes in SUV exceeding a cut-off of 3.5 in SUVmax or of 11% change in SUV measurements and Kaplan-Meier survival curves were plotted using MedCalc software. Survival curves were compared using the logrank test.

Comparison of survival rates between groups based on SUVmax >= 3.5 vs. SUVmax < 3.5 (a cutoff proposed by several groups, eg. Hu et al. 2013) did not result in a significant difference between groups (logrank test, P=0.9298), while a regional SUV increase of more than 11% differentiated between a high-mortality group (36% survival probability at 24 months;  22% at 36 months) and a low-mortality group (86% survival probability at 24 months; 68% at 36 months, P=0.0041, logrank test))

Dual timepoint FDG-PET/CT performed as early as 30 minutes after the initial study adds significant prognostic information to standard PET evaluation based on single SUV measurements and differentiates between a high-mortality group and a low-mortality group at 24 and 36 months after initial diagnosis.

The proposed dual-timepoint PET/CT imaging protocol adds significant, prognostic information on survival probability, as compared to standard imaging and SUV measurements. The additional time and effort, consisting in 5 minutes of additional scanning immediately after completion of  routine protocols, is minimal and fits perfectly into the existing, clinical workflow.

Juengling, F, Bieg, C, Peterli, R, Valenta, I, Von Flue, M, Gass, M, Prognostic Value of Simplified Dual-timepoint FDG-PET/CT in Pancreatic Cancer: Comparison to Routine SUV Measurements.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14018080.html