{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,17]],"date-time":"2026-01-17T07:36:01Z","timestamp":1768635361408,"version":"3.49.0"},"reference-count":12,"publisher":"Oxford University Press (OUP)","issue":"1135","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["BJR"],"published-print":{"date-parts":[[2022,7,1]]},"abstract":"<jats:sec><jats:title>Objectives:<\/jats:title><jats:p> The purpose of this study was to investigate the changes of tumor-to-liver signal ratio in a 0.35T MRI-guided radiotherapy system and to evaluate the usefulness and pitfalls of superparamagnetic iron oxide (SPIO) administration for visualization of liver tumors. <\/jats:p><\/jats:sec><jats:sec><jats:title>Methods:<\/jats:title><jats:p> Forty-two patients treated with MRI-guided stereotactic ablative radiotherapy (SABR) for liver tumors were included in this study. The tumor-to-liver signal ratios before and after SPIO administration were retrospectively assessed and compared on true fast imaging with steady-state precession (FISP). <\/jats:p><\/jats:sec><jats:sec><jats:title>Results:<\/jats:title><jats:p> Before SPIO administration, liver tumors were either invisible or barely visible in 15 cases (36%), but all tumors became visible after SPIO administration. The mean values of tumor-to-liver signal ratio before and after SPIO administration were 0.939 \u00b1 0.201 and 1.336 \u00b1 0.300, respectively (mean \u00b1 standard deviation, p &lt; 0.001). In six (14%) patients, liver tumors were visible on true FISP imaging before SPIO administration, but became invisible after administration. <\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions:<\/jats:title><jats:p> This study showed that liver tumors that are invisible on true FISP imaging can be made visible by administration of SPIO, and that MRI-guided SABR can be performed accurately. <\/jats:p><\/jats:sec><jats:sec><jats:title>Advances in knowledge:<\/jats:title><jats:p> This is the first report to examine the usefulness of liver-specific contrast agent superparamagnetic iron oxides in 0.35T MRI-guided radiation therapy. Liver tumors that are invisible on true fast imaging with steady-state precession can be made visible by administration of superparamagnetic iron oxides. <\/jats:p><\/jats:sec>","DOI":"10.1259\/bjr.20211131","type":"journal-article","created":{"date-parts":[[2022,3,25]],"date-time":"2022-03-25T16:06:46Z","timestamp":1648224406000},"source":"Crossref","is-referenced-by-count":7,"title":["SPIO-enhanced 0.35T MRI-guided radiotherapy for liver malignancies: usefulness in tumor visualization"],"prefix":"10.1093","volume":"95","author":[{"given":"Yukihiro","family":"Hama","sequence":"first","affiliation":[{"name":"Department of Radiation Oncology, Tokyo-Edogawa Cancer Centre, Edogawa Hospital, Edogawa, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Etsuko","family":"Tate","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Tokyo-Edogawa Cancer Centre, Edogawa Hospital, Edogawa, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"286","reference":[{"key":"b1","doi-asserted-by":"publisher","DOI":"10.3389\/fonc.2021.616027"},{"key":"b2","first-page":"470","volume":"26","author":"Hama Y","year":"2021","journal-title":"Rep Pract Oncol Radiother"},{"key":"b3","doi-asserted-by":"publisher","DOI":"10.1148\/radiology.196.2.7617864"},{"key":"b4","doi-asserted-by":"publisher","DOI":"10.21037\/qims.2017.02.09"},{"key":"b5","doi-asserted-by":"publisher","DOI":"10.1148\/radiology.175.2.2326480"},{"key":"b6","doi-asserted-by":"publisher","DOI":"10.1007\/s00330-002-1721-7"},{"key":"b7","doi-asserted-by":"publisher","DOI":"10.1002\/jcb.23432"},{"key":"b8","doi-asserted-by":"publisher","DOI":"10.1038\/nri3531"},{"key":"b9","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejso.2021.12.467"},{"key":"b10","doi-asserted-by":"publisher","DOI":"10.1148\/radiol.2283020376"},{"key":"b11","doi-asserted-by":"publisher","DOI":"10.1007\/s00432-021-03788-z"},{"key":"b12","doi-asserted-by":"publisher","DOI":"10.1016\/S1470-2045(20)30034-6"}],"container-title":["The British Journal of Radiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.birpublications.org\/doi\/pdf\/10.1259\/bjr.20211131","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,1,12]],"date-time":"2024-01-12T16:43:22Z","timestamp":1705077802000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/bjr\/article\/7477243"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,7,1]]},"references-count":12,"journal-issue":{"issue":"1135","published-print":{"date-parts":[[2022,7,1]]}},"alternative-id":["10.1259\/bjr.20211131"],"URL":"https:\/\/doi.org\/10.1259\/bjr.20211131","relation":{},"ISSN":["0007-1285","1748-880X"],"issn-type":[{"value":"0007-1285","type":"print"},{"value":"1748-880X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,7,1]]},"article-number":"20211131"}}