@article {Kim544, author = {Soo Jeong Kim and Young Seok Cho and Seung Hwan Moon and Jae Moon Bae and Sung Kim and Yearn Seong Choe and Byung-Tae Kim and Kyung-Han Lee}, title = {Primary Tumor 18F-FDG Avidity Affects the Performance of 18F-FDG PET/CT for Detecting Gastric Cancer Recurrence}, volume = {57}, number = {4}, pages = {544--550}, year = {2016}, doi = {10.2967/jnumed.115.163295}, publisher = {Society of Nuclear Medicine}, abstract = {The usefulness of 18F-FDG PET in gastric cancer recurrence is limited by low sensitivity. Given that detectability by PET is dependent on the tumor{\textquoteright}s metabolic characteristics, we tested whether the performance of PET for gastric cancer recurrence is enhanced in patients with 18F-FDG{\textendash}avid primary tumors. Methods: Three hundred sixty-eight patients with advanced gastric cancer underwent 18F-FDG PET/CT for initial staging and for recurrence surveillance after curative surgery. On initial PET/CT, primary tumors were 18F-FDG{\textendash}avid if they displayed focal uptake with an SUVmax 4 or more. Follow-up 18F-FDG PET/CT was evaluated for recurrent disease. Results: On initial PET/CT, the primary tumor was 18F-FDG{\textendash}avid in 236 of 368 (64.1\%) and nonavid in 132 patients (35.9\%). During follow-up for 18.9 {\textpm} 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 18F-FDG{\textendash}avid and nonavid primary tumors, respectively. PET sensitivity was higher in scans of patients with 18F-FDG{\textendash}avid than nonavid tumors for all recurrences (81.0\% vs. 52.4\%; P = 0.018) and nonanastomosis site recurrences (82.1\% vs. 47.4\%; P = 0.006). The 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 18F-FDG avidity further enhanced PET sensitivity. Conclusion: Surveillance 18F-FDG PET/CT after resection of gastric cancer has significantly higher sensitivity in patients with 18F-FDG{\textendash}avid primary tumors and may have greater value in this group.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/57/4/544}, eprint = {https://jnm.snmjournals.org/content/57/4/544.full.pdf}, journal = {Journal of Nuclear Medicine} }