I AM VERY PLEASED to have been asked by Drs. Geschwind and Soulen to write a foreword for this book, Interventional Oncology: Principles and Practice. I suspect that I have been asked to do this for two reasons. The first is that I am editor-in-chief of the Journal of Clinical Oncology and therefore am very privileged to see the widest possible array of manuscripts and publications each day. Therefore, I can easily see the evolution of oncology from single disciplines to a multidisciplinary approach for patients. Indeed, more important than the proliferation of new drugs or techniques has been the evolution of the care of patients by teams of individuals, each of whom contributes special expertise, with a common endpoint of superior patient care. The second reason I was asked to write this foreword relates to this observation: Dr. Soulen and I have been colleagues for many years, and our own relationship in the care of patients has also evolved. In contrast with the time when radiology was simply a tool for clinicians to use in decision making, radiologists now take an active part in the care of many patients with cancer. As I have learned the benefits and limitations of interventional radiology from Dr. Soulen, I hope that he has also learned from me – throughout more than 30 years of practice in an academic medical center – the aspects of oncology that aid him in helping our mutual patients.