I really do not recommend Dr. David Chan for anyone diagnosed with lung cancer. There were signs that my father was forgetting things, could not speak in complete sentences and personality change. I told Dr. Chan on three different occasions this fact, and did not do anything until it was way too late. My father's MRI (which should have been taken 6 months ago) showed several tumors throughout his brain, one being an inch in diameter. I did research online, and it says everywhere how with stage 4 lung cancer, there is a huge chance it will metastasize in the brain.Why Dr. Chan didn't know this, I don't know. In addition, when Dr. Chan requested a radiation treatment, he spoke as if my father was going to come back to normal after the end of treatment. He never told us that there would be a chance that the radiation would kill him faster and put him through more pain, nausea, and weakness. My father would have lived longer if the brain tumors were caught early. Also, he would of had a better quality of life without the radiation treatment. He was basically a vegetable towards the end of his treatment, which all happened within two weeks. My father died on 1/25/13. My father was a great man. He was working towards world peace and encouraged so many people all over. More than 300 people will be attending his memorial service.