Generally speaking, bone scanning is not done when lung cancer is not diagnosed, because the purpose of bone scanning is mainly to know whether bone metastasis has occurred. When lung cancer is not diagnosed, relevant examinations should be improved to clarify the diagnosis. If lung cancer is confirmed, bone scan can be performed because lung cancer is easy to metastasize to the bone. Lung cancer patients need to do bone scan when the following situations occur: 1. when lung cancer patients need to undergo staging examination before surgery, or when localized bone pain symptoms appear. 2. Lung cancer later than stage IIa should be given routine bone scanning examination because of its high sensitivity and specificity in detecting bone metastasis. Since bone scan can be false negative and false positive, those with positive bone scan can be verified by MRI.