It is the discretion of the investigator whether the patient is a candidate for post-operative treatment which is considered to be in the best interest of the patients. It is recommended that patients with positive margins or residual tumor after surgery should receive radiation therapy. Patients after surgery will receive long-term follow-up -- chest CT scan，abdominal abdominal ultrasound every 3 months, brain MRI every 6 months, bone scan (ECT) every 12 months -- for up to 5 years.