Diagnostic Role of 18F-Fluorodeoxyglucose Positron Emission Tomography in Gastric Mesenchymal Tumors

• Main Authors: Masaya Iwamuro, Koji Miyahara, Chihiro Sakaguchi, Ryuta Takenaka, Sayo Kobayashi, Hirokazu Mouri, Shigetomi Tanaka, Tatsuya Toyokawa, Shouichi Tanaka, Mamoru Nishimura, Kenji Yamauchi, Takehiro Tanaka, Hiroyuki Okada
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: Journal of Clinical Medicine
• Subjects: 18F-fluorodeoxyglucose-positron emission tomography; mesenchymal tumor; gastric neoplasms; gastrointestinal stromal tumor; schwannoma
• Online Access: https://www.mdpi.com/2077-0383/9/5/1301

There have been no comparative studies investigating the results of 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) in patients with gastric mesenchymal tumors, including leiomyomas, leiomyosarcomas, schwannomas, and gastrointestinal stromal tumors (GISTs). We retrospectively reviewed the data of 142 patients with pathologically diagnosed gastric mesenchymal tumors treated at 11 institutions. We analyzed the correlation between the maximum standardized uptake value (SUVmax) evaluated using fluorodeoxyglucose-positron emission tomography (FDG-PET) and the tumor size. The correlation between the SUVmax and mitotic index was also investigated in GISTs. The SUVmax (mean ± standard deviation) was 0.5 ± 0.6 in very low-risk GISTs (<i>n</i> = 42), 2.1 ± 0.7 in low-risk GISTs (<i>n</i> = 26), 4.9 ± 0.8 in intermediate-risk GISTs (<i>n</i> = 22), 12.3 ± 0.8 in high-risk GISTs (<i>n</i> = 20), 1.0 ± 1.0 in leiomyomas (<i>n</i> = 15), 6.9 ± 1.2 in schwannomas (<i>n</i> = 10), and 3.5 in a leiomyosarcoma (<i>n</i> = 1). The SUVmax of GISTs with an undetermined risk classification was 4.2 ± 1.3 (<i>n</i> = 8). Linear associations were observed between the SUVmax and tumor size in GISTs, leiomyomas, and schwannomas. The SUVmax of GISTs with a high mitotic index was significantly higher than that of GISTs with a low mitotic index (9.6 ± 7.6 vs. 2.4 ± 4.2). In conclusion, we observed positive correlations between the SUVmax and tumor size in GISTs, leiomyomas, and schwannomas. The SUVmax also positively correlated with the mitotic index and risk grade in GISTs. Schwannomas showed a higher FDG uptake than GISTs and leiomyomas.