How do you approach a patient with a solitary brain metastasis from small cell lung cancer s/p resection with otherwise limited thoracic disease?

This is rather an uncommon situation but can happen if a patient presents with a synchronous solitary brain metastasis (with or w/o symptom) and undergoes craniotomy and resection only to find out that it is small cell lung cancer. Additional information is needed on the volume of intra-thoracic dis...