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

Original languageEnglish (US)
Pages (from-to)1-7
Number of pages7
JournalJournal of Neuro-Oncology
Publication statusAccepted/In press - Mar 10 2016



  • Brain metastasis
  • MRI
  • Stereotactic radiosurgery

ASJC Scopus subject areas

  • Clinical Neurology
  • Cancer Research
  • Oncology
  • Neurology

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