Tang Tien T, Rendon David A, Zawaski Janice A, Afshar Solmaz F, Kaffes Caterina K, Sabek Omaima M, Gaber M Waleed
Department of Bioengineering, Rice University, Houston, Texas, United States of America.
Hematology-Oncology Section, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America.
PLoS One. 2017 Jan 4;12(1):e0169082. doi: 10.1371/journal.pone.0169082. eCollection 2017.
Positron emission tomography using 18F-Fluro-deoxy-glucose (18F-FDG) is a useful tool to detect regions of inflammation in patients. We utilized this imaging technique to investigate the kinetics of gastrointestinal recovery after radiation exposure and the role of bone marrow in the recovery process. Male Sprague-Dawley rats were either sham irradiated, irradiated with their upper half body shielded (UHBS) at a dose of 7.5 Gy, or whole body irradiated (WBI) with 4 or 7.5 Gy. Animals were imaged using 18F-FDG PET/CT at 5, 10 and 35 days post-radiation exposure. The gastrointestinal tract and bone marrow were analyzed for 18F-FDG uptake. Tissue was collected at all-time points for histological analysis. Following 7.5 Gy irradiation, there was a significant increase in inflammation in the gastrointestinal tract as indicated by the significantly higher 18F-FDG uptake compared to sham. UHBS animals had a significantly higher activity compared to 7.5 Gy WBI at 5 days post-exposure. Animals that received 4 Gy WBI did not show any significant increase in uptake compared to sham. Analysis of the bone marrow showed a significant decrease of uptake in the 7.5 Gy animals 5 days post-irradiation, albeit not observed in the 4 Gy group. Interestingly, as the metabolic activity of the gastrointestinal tract returned to sham levels in UHBS animals it was accompanied by an increase in metabolic activity in the bone marrow. At 35 days post-exposure both gastrointestinal tract and bone marrow 18F-FDG uptake returned to sham levels. 18F-FDG imaging is a tool that can be used to study the inflammatory response of the gastrointestinal tract and changes in bone marrow metabolism caused by radiation exposure. The recovery of the gastrointestinal tract coincides with an increase in bone marrow metabolism in partially shielded animals. These findings further demonstrate the relationship between the gastrointestinal syndrome and bone marrow recovery, and that this interaction can be studied using non-invasive imaging modalities.
使用18F-氟脱氧葡萄糖（18F-FDG）的正电子发射断层扫描是检测患者炎症区域的有用工具。我们利用这种成像技术来研究辐射暴露后胃肠道恢复的动力学以及骨髓在恢复过程中的作用。将雄性Sprague-Dawley大鼠分为假照射组、上半身屏蔽（UHBS）照射组（剂量为7.5 Gy）或全身照射（WBI）组（剂量为4或7.5 Gy）。在辐射暴露后第5、10和35天使用18F-FDG PET/CT对动物进行成像。分析胃肠道和骨髓的18F-FDG摄取情况。在所有时间点收集组织进行组织学分析。7.5 Gy照射后，与假照射组相比，胃肠道炎症显著增加，表现为18F-FDG摄取显著更高。暴露后5天，UHBS组动物的活性显著高于7.5 Gy WBI组。与假照射组相比，接受4 Gy WBI的动物摄取没有任何显著增加。骨髓分析显示，7.5 Gy组动物照射后5天摄取显著降低，而4 Gy组未观察到这种情况。有趣的是，随着UHBS组动物胃肠道的代谢活性恢复到假照射水平，骨髓的代谢活性也随之增加。暴露后35天，胃肠道和骨髓的18F-FDG摄取均恢复到假照射水平。18F-FDG成像可用于研究胃肠道的炎症反应以及辐射暴露引起的骨髓代谢变化。在部分屏蔽的动物中，胃肠道的恢复与骨髓代谢的增加同时发生。这些发现进一步证明了胃肠道综合征与骨髓恢复之间的关系，并且这种相互作用可以使用非侵入性成像方式进行研究。
