One prospective study (Niwinska 2010) assessed outcomes in HER2-positive breast cancer patients with occult brain metastases compared with patients with symptomatic brain metastases.110 Occult brain metastases were detected in 36% of the screening group. The median time between recurrence (distant and/or locoregional) and the diagnosis of occult brain metastases was 9 months.110 Twenty-six patients were given WBRT, with 24 patients available for assessment of radiological response. At three months follow-up, MRI found that 29% of patients were in complete remission, 63% were in partial remission, and there was no change in the brain for 8%. At the time of analysis, complete remission was maintained for two of the five survivors.110