title: Iodine-125 seed migration within brain parenchyma after brachytherapy for brain metastasis: case report.
abstract: This case report documents the migration of 3 iodine-125 (125I) seeds from the tumor resection cavity into brain parenchyma over a 7-year period. A 66-year-old woman had a history of metastatic ovarian carcinoma, nickel allergy, and reaction to a titanium hip implant that required reoperation for hardware removal. In this unique case of parenchymal migration, the seed paths seemed to follow white matter tracts, traveling between 18.5 and 35.5 mm from the initial implant site. The patient's initial neurological decline, which was thought to be related to radiation necrosis, appeared to stabilize with medical therapy. She subsequently developed progressive right hemispheric edema that resulted in neurological deterioration and death. Considering her previous reactions to nickel and titanium, the authors now speculate that her later clinical course reflected an allergic reaction to the titanium casing of the125I seeds. Containing a trace amount of nickel,125I seeds can elicit a delayed hypersensitivity reaction in patients with a history of nickel dermatitis. Preoperative patch testing is recommended in these patients, and125I seed implantation should be avoided in those who test positive.
authors.affiliation: Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois;
authors.forename: Bledi
authors.initials: B
authors.lastname: Brahimaj
authors.affiliation: Departments of 2 Radiation Oncology and.|Brain Tumor Center at University of Cincinnati Neuroscience Institute; and.
authors.forename: Michael
authors.initials: M
authors.lastname: Lamba
authors.affiliation: Departments of 2 Radiation Oncology and.|Brain Tumor Center at University of Cincinnati Neuroscience Institute; and.
authors.forename: John C
authors.initials: JC
authors.lastname: Breneman
authors.affiliation: Neurosurgery, University of Cincinnati College of Medicine.|Brain Tumor Center at University of Cincinnati Neuroscience Institute; and.|Mayfield Clinic, Cincinnati, Ohio.
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Warnick
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects*; D001921:Brain; D001932:Brain Neoplasms / Q000532:radiotherapy* / Q000556:secondary*; D005260:Female; D005548:Foreign-Body Migration / Q000209:etiology*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D010051:Ovarian Neoplasms / Q000473:pathology; D000072356:Parenchymal Tissue
chemical_list: D007457:Iodine Radioisotopes
keywords: 125I = iodine-125; I-125 seeds; KPS = Karnofsky Performance Scale; brachytherapy; metastatic brain tumor; nickel allergy; oncology; surgery