What is the best hospital in New York City for cancer (leukemia) ?

To make a longer story short, a friend from Seoul and I are flying to NYC on thursday because of the state with N. Korea for a few weeks at least. My father is in South Africa now but is being transferred over to the Midde East as a translator/doctor for an emby. I have been visiting one of the best oncologists in Tokyo for leukemia, but I know little about the health care in NYC. My APL leukemia is now in remission but I have to get a check up every other week. Do you have any recommendations?