Opinions on Dr. Burzynski-Antineoplastons

my son had brain cancer we look in to Dr Burzynski. We talked with all of our sons doctors and did some reseach online and found that it would not help our son due to all of the complications he was having with the location of the cancer. we also found out from a friend with a child who did do the trearments with above doctor, she still had tumor growth after he said that she was in remission, he said this because it did not grow to the expected size from the one MRI to the next, It is also very expensive and he does not take insurance as it is not approved by the fda so insurance will not cover any of it.