<qa>  What is the minimum time period for asymptomatic brain metastases?11. Patients with asymptomatic brain metastases that have been treated are eligible if the following criteria are met: No history of seizures in the preceding 6 months. Definitive treatment must have been completed 4weeks prior to registration. Subjects must be off steroids that were being administered because of brain metastases or related symptoms for 2 weeks. Post-treatment imaging within 2 weeks of registration must demonstrate stability or regression of the brain metastases. 