2024 Health Care Champions Physician: Dr. Nathan Y. Tonlaar

Dr. Nathan Y. Tonlaar fills many roles at Mercy Hospital Springfield and in the community. No matter how many hats he wears or titles he holds, he says his first priority is the patients to whom he provides specialized cancer care as a radiation oncologist.

“I strive to provide excellent clinical care, helping patients understand their diagnosis, options for treatment, design quality treatment plans and help patients navigate the difficult process of receiving a cancer treatment,” he says.

Tonlaar graduated with honors from Calvin University with a bachelor’s degree in biology and biotechnology before earning his medical degree from University of Chicago Pritzker School of Medicine. He completed an internship and residency in radiation oncology at Oakland University’s William Beaumont School of Medicine. He also holds a Master of Health Administration degree from Missouri State University.

Tonlaar began providing care at Mercy in 2016 where he later assumed leadership roles as medical director of radiation oncology services, a cancer care tri-chair and his current role as regional service line chair for cancer care in the southwest Missouri region. Tonlaar is a visionary leader of expanding cancer care techniques and technology. He introduced the SpaceOar hydrogel placement for prostate cancer radiation and expanded the hospital’s Cyberknife radiation treatment platform with the only Cyberknife S7 model in the region. Under his direction, pelvic floor physical therapy services have expanded by more than 200% and he has been principal investigator on numerous research trials.

“I have worked together with my colleagues to build a patient-centered cancer program focusing on the delivery of quality cancer care, improving access to care and delivering exceptional patient experience,” he says.

Tonlaar brings education and care to the community through presenting at Rotary clubs and other public forums including Bass Pro Shops’ men’s health sessions. He improved Mercy’s tumor board process, is actively engaged in recruiting specialist oncologists and continually identifies ways to provide patients with social support and navigation resources. Tonlaar serves on the Mercy Health Foundation board and dedicates time to the American Cancer Society, Breast Cancer Foundation of the Ozarks and Praise Assembly. He is a member of the American Society for Radiation Oncology and American College of Radiation Oncology.

As a child in Ghana, Tonlaar’s family did not have access to health care due to social stratification that created vast access disparity. This history drives his passion to deliver exceptional care.

“I’m deeply committed to providing the same quality of care and service I would reserve for my family for every patient who walks through our doors,” he says.