Top Doctor
The Top Doctor award is a peer-nominated award for providers who give exceptional care.

Smith Apisarnthanarax, MD

Medical Director, Radiation Oncology
Seattle Cancer Care Alliance
Associate Professor, Department of Radiation Oncology
University of Washington School of Medicine
UW Medicine
Clinical expertise
Gastrointestinal cancers, prostate cancer, liver cancer, pancreatic cancer, proton beam radiation therapy, stereotactic body radiation therapy (SBRT), intensity-modulated radiation therapy (IMRT)
“At SCCA, we really do our best to make sure that we’re always thinking outside the box, doing what’s right for each individual patient.”
— Dr. Apisarnthanarax
Why do you practice radiation oncology?

My first real exposure to cancer was through my grandmother, who lived in Thailand. She had metastatic thyroid cancer that left her paralyzed for most of the time that I knew her, and I think that experience planted the seed for what would become my calling. What I like about radiation oncology is that it’s a very visual field of medicine; we rely on anatomy and imaging, and that speaks to the artist in me. This specialty is also a nice combination of sophisticated technology, biology, direct patient care and teamwork. At SCCA, we really do our best to make sure that we’re always thinking outside the box, doing what’s right for each individual patient.

What personal experiences have informed your approach to care?

Several years ago, I was hospitalized for a life-threatening illness, and it gave me a greater appreciation for what my patients go through. For example, I had to wear compression boots that squeezed my calves every 30 minutes to prevent blood clots from forming. They were standard procedure for someone like me who was in the hospital for a long period of time and couldn’t move around, but they were incredibly uncomfortable and made it impossible to sleep. Sometimes it’s the little things like those cuffs that we as physicians may not think twice about, but they can have a big impact on a person’s well-being. Having had that experience in the hospital, I never dismiss any of my patients’ complaints or concerns as trivial. Being diagnosed with and treated for cancer is one of the most arduous experiences there is; your quality of life is always a priority for me.  

Provider background

Specialties and clinical expertise: Radiation Oncology

Gastrointestinal cancers, prostate cancer

I am a board-certified radiation oncologist with expertise in several radiation modalities including proton therapy, a type of external beam radiation that precisely targets tumors while minimizing exposure to healthy tissue. I treat patients with prostate cancer and gastrointestinal cancers, which can affect organs such as the esophagus, liver and pancreas. Prior to joining SCCA, I was an assistant professor and associate residency program director at the University of Pennsylvania Perelman School of Medicine.

My research is focused on optimizing proton radiation treatments for liver cancer. Historically, radiation wasn’t used to treat liver tumors, so there is much to learn about safely delivering potentially curative radiation doses and how to integrate radiation with other available treatments. I’m also interested in how functional imaging of the liver, which examines the organ’s physiological activities, can be used to improve radiation treatment planning and predict responses to cancer therapy. 

Diseases treated

Education, experience and certifications
Undergraduate Degree
Brown University
Medical Degree
Brown University Warren Alpert Medical School
University of North Carolina, Radiation Oncology
MD Anderson Cancer Center, Radiation Oncology
Board Certification
Radiation Oncology, 2010, American Board of Radiology
Internship, Northwestern University, Evanston Hospital
Seattle magazine's 2020 Top Doctors award

Dr. Apisarnthanarax has been recognized as a Top Doctor in Seattle magazine's annual survey.


Clinical trials

We make promising new treatments available to you through studies called clinical trials led by SCCA doctors. Many of these trials at SCCA have led to FDA-approved treatments and have improved standards of care globally. Together, you and your doctor can decide if a study is right for you.

Study ID:
Sulfur Colloid SPECT/CT in Measuring Liver Function in Patients With Primary or Metastatic Liver Cancer Undergoing Radiation Therapy or Surgery
Complete title
Functional Liver Imaging with Sulfur Colloid SPECT/CT in Primary and Metastatic Liver Cancer Patients Receiving Liver-Directed Treatment: A Pilot Study
Study ID:
Comparing Proton Therapy to Photon Radiation Therapy for Esophageal Cancer
Complete title
Phase III Randomized Trial of Proton Beam Therapy (PBT) Versus Intensity Modulated Photon Radiotherapy (IMRT) for the Treatment of Esophageal Cancer


Many of our SCCA physicians conduct ongoing research to improve standards of patient care. Their work is evaluated by other physicians and selected for publication to the United States National Library of Medicine, the largest medical library in the world. See scientific papers this SCCA provider has written.

Your care team

At SCCA, you receive care from a team of providers with extensive experience in your disease. Your team includes doctors, a team coordinator, a registered nurse, an advanced practice provider and others, based on your needs. You also have access to experts like nutritionists, social workers, acupuncturists, psychiatrists and more who specialize in supporting people with cancer or blood disorders.
Registered nurse (RN)
Your nurse manages your care alongside your physician and assists with care procedures and treatments.
Team coordinator (TC)
Your team coordinator works closely with you and your physician and serves as your scheduler.


SCCA accepts most national private health insurance plans as well as Medicare. We also accept Medicaid for people from Washington, Alaska, Montana and Idaho. We are working to ensure that everyone, no matter what their financial situation, has access to the care they need.