I am Director of GK Dermatology, PC, in Weymouth, Clinical Associate Professor of Dermatology at Brown University, and Professor of Dermatology at Jundiaí Medical School, Brazil. My practice focuses on Medical Dermatology, Phototherapy, and Laser Surgery. I have authored more than 100 articles and chapters and edited 2 monographs and 3 books.

William Tollefsen, MD is the EMS and MIH Medical Director for South Shore Health. Dual-boarded in Emergency Medicine and EMS Medicine, Dr. Tollefsen works clinically as an Emergency Physician at South Shore Health in addition to his role as EMS Medical Director.

One of few physicians in the country to receive the prestigious "FAEMS" recognition, Dr. Tollefsen is also the Medical Director for OEMS Region IV, serving 61 cities and towns of the Metro-Boston EMS Council. As the current EMS Medical Director for eight municipal and three private ambulance services on the South Shore, Dr. Tollefsen interacts and provides oversight for over 400 Paramedics.

Dr. Tollefsen graduated from New York Medical College and completed residency training in Emergency Medicine at Harvard University, Brigham and Women's, and Massachusetts General Hospital. He completed a fellowship in Emergency Medical Services and Critical Care Transport at the University of Massachusetts, where he worked as an Emergency Physician and Flight Physician for UMASS LifeFlight. He completed an MBA at the Isenberg School of Management at UMASS Amherst, and holds a Master of Medical Science degree from the Boston University School of Medicine.

A former pre-hospital provider, he is actively involved in EMS system design, paramedic education and Critical Care Transport Systems. He works closely with multiple EMS, Fire and Law Enforcement agencies throughout Massachusetts.

His research interests include systems of care, resuscitation, airway management, and paramedic education.

My mission is to provide exceptional care to hematology and oncology patients, and support patients and their families when they are at their most vulnerable. 

It is a privilege and an honor to have the opportunity to establish meaningful, long-term relationships with my patients and their families. I believe in open, honest communication and a patient-centered model when formulating a treatment plan. I look forward to supporting my patients not only physically, but mentally and emotionally as well. 

Outside of work, I enjoy spin classes, going to the beach, and spending time with family and friends.