title: Pre-treatment factors associated with detecting additional brain metastases at stereotactic radiosurgery.
abstract: The number of brain metastases identified on diagnostic magnetic resonance imaging (MRI) is a key factor in consideration of stereotactic radiosurgery (SRS). However, additional lesions are often detected on high-resolution SRS-planning MRI. We investigated pre-treatment clinical characteristics that are associated with finding additional metastases at SRS. Patients treated with SRS for brain metastases between the years of 2009-2014 comprised the study cohort. All patients underwent frame-fixed, 1 mm thick MRI on the day of SRS. Patient, tumor, and treatment characteristics were analyzed for an association with increase in number of metastases identified on SRS-planning MRI. 289 consecutive SRS cases were analyzed. 725 metastases were identified on pre-treatment MRI and 1062 metastases were identified on SRS-planning MRI. An increase in the number of metastases occurred in 34 % of the cases. On univariate analysis, more than four metastases and the diameter of the largest lesion were significantly associated with an increase in number of metastases on SRS-planning MRI. When stratified by the diameter of the largest lesion into <2, 2-3, or ≥3 cm, additional metastases were identified in 37, 29, and 18 %, respectively. While this increase in the number of metastases is largely due to the difference in imaging technique, the number and size of the metastases were also associated with finding additional lesions. These clinical factors may be considered when determining treatment options for brain metastases.
authors.affiliation: Department of Radiation Oncology, UT Southwestern Medical Center, 5801 Forest Park Rd, Dallas, TX, 75390-9183, USA.
authors.forename: Zabi
authors.initials: Z
authors.lastname: Wardak
authors.affiliation: Department of Radiation Oncology, UT Southwestern Medical Center, 5801 Forest Park Rd, Dallas, TX, 75390-9183, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Augustyn
authors.affiliation: Department of Clinical Sciences and Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Neurological Surgery, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Mickey
authors.affiliation: Department of Neurological Surgery, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
authors.forename: Louis A
authors.initials: LA
authors.lastname: Whitworth
authors.affiliation: Department of Neurological Surgery, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Madden
authors.affiliation: Department of Neurological Surgery, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
authors.forename: Samuel L
authors.initials: SL
authors.lastname: Barnett
authors.affiliation: Department of Radiation Oncology, UT Southwestern Medical Center, 5801 Forest Park Rd, Dallas, TX, 75390-9183, USA.
authors.forename: Ramzi E
authors.initials: RE
authors.lastname: Abdulrahman
authors.affiliation: Department of Radiation Oncology, UT Southwestern Medical Center, 5801 Forest Park Rd, Dallas, TX, 75390-9183, USA.
authors.forename: Lucien A
authors.initials: LA
authors.lastname: Nedzi
authors.affiliation: Department of Radiation Oncology, UT Southwestern Medical Center, 5801 Forest Park Rd, Dallas, TX, 75390-9183, USA.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Timmerman
authors.affiliation: Department of Radiation Oncology, Inova Dwight and Martha Schar Cancer Institute, 3300 Gallows Road, Falls Church, VA, 22042, USA. choekevin@yahoo.com.
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Choe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001921:Brain / Q000000981:diagnostic imaging*; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000532:radiotherapy* / Q000556:secondary*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery; D011880:Radiotherapy Planning, Computer-Assisted; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents
keywords: Brain metastasis; MRI; Stereotactic radiosurgery