question: My mother was just diagnosed with stage 4 lung cancer that has spread from her left lung to her lymph nodes and a few mets to her brain. A few questions for you how effective is the cyber knife for the brain mets and can the cyber knife be used for lymph nodes. Also she has lost weight and I am wondering if the boost drink is effective with weight gain. By the way my mom is 81 and a former smoker for 61 years.