{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T05:05:31Z","timestamp":1784696731378,"version":"3.55.0"},"reference-count":18,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T00:00:00Z","timestamp":1784678400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Oncol."],"abstract":"<jats:p>Sacral metastasis with neural canal invasion may cause severe pain and progressive neurological dysfunction, while local treatment is challenging because of the proximity of the sacral nerve roots, lumbosacral plexus, rectum, and bladder. We report a 65-year-old man with lung adenocarcinoma and a progressive sacral metastasis causing radiating pain, sensory impairment, lower-extremity weakness, and difficulty walking despite systemic treatment. CT-guided permanent iodine-125 seed implantation was performed with a prescription dose of 140 Gy. A total of 84 seeds, each with an activity of 0.5 mCi, were implanted. An exploratory postoperative CT-based analysis of the anatomically estimated neural region yielded a calculated mean dose of 316 Gy and a maximum voxel dose of 907 Gy; however, interpretation of these values was limited by the highly heterogeneous dose distribution, contouring uncertainty, and the use of a point or voxel-based maximum dose. At 2 weeks after implantation, the Visual Analogue Scale score decreased to 3, and at 1 month it decreased to 1. Lower-extremity muscle strength improved to grade 4, and the patient regained independent ambulation. During the available 12-month follow-up, imaging showed a marked metabolic response and no radiographic evidence of local progression. No new or worsening clinically apparent neurological deficit attributable to the procedure was identified. This case suggests that CT-guided iodine-125 seed implantation may be a feasible local treatment option for selected patients with sacral metastasis involving neural structures. However, a single case with 12 months of follow-up cannot establish long-term neural tolerance or support modification of existing neural dose constraints.<\/jats:p>","DOI":"10.3389\/fonc.2026.1773723","type":"journal-article","created":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T04:44:38Z","timestamp":1784695478000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["CT-guided iodine-125 brachytherapy for sacral metastasis with neural canal invasion: a case report of clinical outcome and dosimetry"],"prefix":"10.3389","volume":"16","author":[{"given":"Qiyu","family":"Sun","sequence":"first","affiliation":[{"name":"Department of Radiology, Linyi People\u2019s Hospital","place":["Linyi, China"]},{"name":"The 960th Hospital of PLA","place":["Jinan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaolin","family":"Pan","sequence":"additional","affiliation":[{"name":"The 960th Hospital of PLA","place":["Jinan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuai","family":"Li","sequence":"additional","affiliation":[{"name":"The 960th Hospital of PLA","place":["Jinan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhiqian","family":"Sun","sequence":"additional","affiliation":[{"name":"Shandong Second Medical University","place":["Weifang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bowen","family":"Tang","sequence":"additional","affiliation":[{"name":"Shandong Provincial Third Hospital","place":["Jinan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hankui","family":"YU","sequence":"additional","affiliation":[{"name":"Shandong Provincial Third Hospital","place":["Jinan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chao","family":"Zhou","sequence":"additional","affiliation":[{"name":"Shandong Provincial Third Hospital","place":["Jinan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanbo","family":"Hu","sequence":"additional","affiliation":[{"name":"Department of Radiology, Linyi People\u2019s Hospital","place":["Linyi, China"]},{"name":"The 960th Hospital of PLA","place":["Jinan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaowen","family":"Ma","sequence":"additional","affiliation":[{"name":"The 960th Hospital of PLA","place":["Jinan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Min","family":"Li","sequence":"additional","affiliation":[{"name":"The 960th Hospital of PLA","place":["Jinan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,7,22]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.3389\/fonc.2021.640933","article-title":"Surgical treatment of sacral metastatic tumors","volume":"11","author":"Sun","year":"2021","journal-title":"Front Oncol"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.26355\/eurrev_202203_28237","article-title":"Prognostic factors affecting overall survival in patients with spinal metastasis due to lung cancer: a systematic review and meta-analysis","volume":"26","author":"Wu","year":"2022","journal-title":"Eur Rev Med Pharmacol Sci"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1007\/s10072-022-05951-x","article-title":"Neoplastic nerve lesions","volume":"43","author":"Patel","year":"2022","journal-title":"Neurological Sci"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.2174\/1573405618666220817144728","article-title":"A sciatic neuralgia case of an entrapment neuropathy mimicking piriformis syndrome due to soft tissue hemangioma","volume":"19","author":"Arik \u015e","year":"2023","journal-title":"Curr Med Imaging"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1007\/s00264-021-05006-4","article-title":"Total sacrectomy with a combined antero-posterior surgical approach for Malignant sacral tumours","volume":"45","author":"Pu","year":"2021","journal-title":"Int Orthopaedics"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.7759\/cureus.20939","article-title":"Radiation therapy for Malignant lumbosacral plexopathy: a case series","volume":"14","author":"Sanuki","year":"2022","journal-title":"Cureus"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.3389\/fonc.2021.717180","article-title":"Radioactive iodine-125 in tumor therapy: advances and future directions","volume":"11","author":"Wei","year":"2021","journal-title":"Front Oncol"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2023.04.031","article-title":"Evaluation of dosimetry formalisms in intraoperative radiation therapy of glioblastoma","volume":"117","author":"Ayala Alvarez","year":"2023","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1097\/md.0000000000039145","article-title":"Low molecular weight 35\u2009kDa hyaluronan fragment HA35 in the treatment of bone metastasis pain: a case report","volume":"103","author":"Zhang","year":"2024","journal-title":"Medicine"},{"key":"B10","doi-asserted-by":"publisher","first-page":"191","DOI":"10.1186\/s13256-025-05223-0","article-title":"Advance imaging with magnetic resonance neurography for the diagnosis of unusual extensive pelvic perineural spread in colorectal cancer: a case report","volume":"19","author":"Richart","year":"2025","journal-title":"J Med Case Rep"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1159\/000534477","article-title":"Management and morbidity of major pelvic hemorrhage in complex abdominopelvic surgery","volume":"64","author":"Aytac","year":"2023","journal-title":"Eur Surg Res Europaische Chirurgische Forschung Recherches Chirurgicales Europeennes"},{"key":"B12","doi-asserted-by":"publisher","first-page":"13497","DOI":"10.1038\/s41598-025-98142-5","article-title":"Epidemiologic investigation on neurological complications following neuraxial anesthesia in 2.7 million cases in Southwest China","volume":"15","author":"Shu","year":"2025","journal-title":"Sci Rep"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1016\/j.radonc.2022.04.007","article-title":"Definitive high-dose, proton-based radiation for unresected mobile spine and sacral chordomas","volume":"171","author":"Banfield","year":"2022","journal-title":"Radiotherapy Oncol"},{"key":"B14","doi-asserted-by":"publisher","first-page":"31","DOI":"10.1038\/s41698-024-00522-z","article-title":"Targeting M2-like tumor-associated macrophages is a potential therapeutic approach to overcome antitumor drug resistance","volume":"8","author":"Wang","year":"2024","journal-title":"NPJ Precis Oncol"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1002\/advs.202412263","article-title":"Hydrogen-generating magnesium alloy seed strand sensitizes solid tumors to iodine-125 brachytherapy","volume":"12","author":"Hu","year":"2025","journal-title":"Advanced Sci (Weinheim Baden-Wurttemberg Germany)"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1002\/smll.202411193","article-title":"Nanoscale CaO(2)-loaded surface-engineered iodine-125 seed with sustained self-oxygenation for sensitized tumor brachytherapy","volume":"21","author":"Wang","year":"2025","journal-title":"Small (Weinheim der Bergstrasse Germany)"},{"key":"B17","article-title":"Stereotactic ablative brachytherapy with or without assistance of 3D-printing templates for inoperable locally recurrent or oligometastatic soft-tissue sarcoma: a multicenter real-world study","volume":"13","author":"Chen","year":"2023","journal-title":"Am J Cancer Res"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1016\/j.jconrel.2025.114231","article-title":"Bilayer nanofiber-coated stent integrating internal radiation and spatiotemporal IL-12 release promotes antitumor immune response","volume":"387","author":"Qin","year":"2025","journal-title":"J Controlled Release"}],"container-title":["Frontiers in Oncology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2026.1773723\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T04:44:52Z","timestamp":1784695492000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2026.1773723\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,22]]},"references-count":18,"alternative-id":["10.3389\/fonc.2026.1773723"],"URL":"https:\/\/doi.org\/10.3389\/fonc.2026.1773723","relation":{},"ISSN":["2234-943X"],"issn-type":[{"value":"2234-943X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,22]]},"article-number":"1773723"}}