Primary Tumor FDG Avidity Affects the Performance of FDG PET/CT for Detecting Gastric Cancer Recurrence

The usefulness of FDG PET in gastric cancer recurrence is limited by low sensitivity. Given that detectability by PET is dependent on the tumor's metabolic characteristics, we tested whether the performance of PET for gastric cancer recurrence is enhanced in patients with FDG avid primary tumors. Methods: Subjects were 368 patients with advanced gastric cancer who underwent FDG PET/CT for initial staging and for recurrence surveillance following curative surgery. On initial PET/CT, primary tumors were FDG avid if they displayed focal uptake with SUV_max ≥ 4. Follow up FDG PET/CT was evaluated for recurrent disease. Results: On initial PET/CT, the primary tumor was FDG avid in 236/368 (64.1%) and non -avid in 132 patients (35.9%). During follow-up for 18.9 ± 13.3 mo, 72 patients (19.6%) had recurrence. Of the 63 PET scans with recurrence, 42 (66.7%) and 21 (33.3%) were scans of patients with FDG avid and non-avid primary tumors, respectively. PET sensitivity was higher in scans of patients with FDG avid than non-avid tumors for all recurrences (81.0% vs. 52.4%, P = 0.018) and non-anastomosis site recurrences (82.1% vs. 47.4%; P = 0.006). Sensitivity for detecting peritoneal recurrence was also higher for the avid tumor group. PET specificity was similarly high (97.1% and 97.5%) for both groups. Adding cell type and Lauren classification to tumor FDG avidity did further enhance PET sensitivity. Conclusion: Surveillance FDG PET/CT following resection of gastric cancer has significantly higher sensitivity in patients with FDG avid primary tumors, and may have greater value in this group.

from #Medicine via ola Kala on Inoreader http://ift.tt/1MkwyZT
via IFTTT