It is very common and understandable for a family facing cancer to want to find the very best doctor in a particular field. There are several things to be aware of when you make this request.

1. There are medical experts who focus on research. Often, these doctors are widely published in their field, but don’t have much patient contact. You will see their names popping up in the literature, but they may not take appointments. Sometimes it is just as helpful to visit the facility they are doing research in and meet the doctors who do see patients there. You can find which hospitals are involved in ‘cutting-edge’ research by using the clinical trials database. You can search by treatment (i.e. antiangiogenesis) without naming a diagnosis. 
2. It is easier to find out if a physician is ‘bad’ than if they are good. That is, it is public information if a doctor has been sanctioned in some way by the licensing board of their state. Disciplinary actions can include malpractice, wrongful death lawsuits, and licensure revoking. For Ohio medical board, go to: http://www5.state.oh.us/med/