{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T04:23:58Z","timestamp":1787027038350,"version":"build-2736575974"},"reference-count":41,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2022,12,1]],"date-time":"2022-12-01T00:00:00Z","timestamp":1669852800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Oncol."],"abstract":"\n Objective<\/jats:title>\n \n Fibroblast activation protein (FAP)-targeting radiopharmaceutical based on the FAP-specific inhibitor (FAPI) is considered as a potential alternative agent to FDG for tumor-specific imaging. However, FAP is also expressed in normal adult tissues. The aim of this study was to explore the image features of non-tumoral regions with high uptake of\n 68<\/jats:sup>\n Ga-FAPI-04 in positron emission tomography (PET) imaging and to reveal the physiological mechanisms of these regions.\n <\/jats:p>\n <\/jats:sec>\n \n Material<\/jats:title>\n \n A total of 137 patients who underwent whole-body\n 68<\/jats:sup>\n Ga-FAPI-04 PET\/MR (n=46) or PET\/CT (n=91) were included in this retrospective study. Three experienced nuclear medicine physicians determined the non-tumoral regions according to other imaging modalities (CT, MRI,\n 18<\/jats:sup>\n F-FDG PET, or ultrasound), clinical information, or pathological results. The regions of interest (ROIs) were drawn manually, and the maximum standardized uptake value (SUV\n max<\/jats:sub>\n ) was measured.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n A total of 392 non-tumoral uptake regions were included in this study. The included physiological regions were uterus (n=38), submandibular gland (n=118), nipple (n=37), gingiva (n=65), and esophagus (n=31). The incidence of\n 68<\/jats:sup>\n Ga-FAPI-04 uptake in physiological regions was independent of age, the tracer uptakes in the gingiva and esophagus were more common in male patients (\n p<\/jats:italic>\n =0.006, 0.009), while that in the nipple was more common in female patients (\n p<\/jats:italic>\n &lt; 0.001). The included benign regions were inflammatory lymph node (n =10), pneumonia (n=13), atherosclerosis (n=10), pancreatitis (n=18), osteosclerosis (n=45), and surgical scar (n=7). No significant difference was observed in SUV\n max<\/jats:sub>\n between physiological and benign regions.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions<\/jats:title>\n \n A number of organs exhibit physiological uptakes of\n 68<\/jats:sup>\n Ga-FAPI-04. Our study showed that regions with high\n 68<\/jats:sup>\n Ga-FAPI-04 uptake did not necessarily represent malignancy. Being familiar with physiological and typical benign\n 68<\/jats:sup>\n Ga-FAPI-04 uptake regions can be helpful for physicians to interpret images and to make an accurate diagnosis.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fonc.2022.989595","type":"journal-article","created":{"date-parts":[[2022,12,1]],"date-time":"2022-12-01T11:21:20Z","timestamp":1669893680000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":18,"title":["Non-tumoral uptake of 68Ga-FAPI-04 PET: A retrospective 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