C. Jillian Tsai, MD, PhD

About Me

I am a board-certified radiation oncologist who specializes in safely and effectively delivering radiation therapy while minimizing side effects. I see patients at both Memorial Sloan Kettering Commack on Long Island, and at Memorial Hospital in Manhattan. I enjoy meeting members of the community and am honored to provide exceptional, personalized care close to home for my patients. I also conduct research at MSK’s Manhattan location.

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I am passionate about creating personalized care plans for each of my patients. I work closely with a multidisciplinary team of medical and surgical oncologists, pathologists, and radiologists to make that happen. Treating cancer is a group effort, and the patient is the most important participant.

When creating a care plan, I highly value the input of my patients. I make it a priority to address their concerns before, during, and after treatment. I believe it’s critical to discuss expectations, possible side effects, and the great support systems we have in place at MSK Commack and to work through them together.

In the clinic, I use advanced radiation techniques. These methods include intensity modulated radiation therapy, image-guided radiation therapy, and stereotactic body radiation therapy. They allow me to deliver radiation directly to a precise area, while minimizing damage to healthy tissue. 

I also provide palliative care to people with metastatic cancers to help manage their pain and control their disease. 

I also conduct cancer research. I am interested in health outcomes, cancer epidemiology, survivorship, and the use of new technologies in clinical care. I am currently involved in several cancer clinical trials to assess new radiation techniques in combination with other targeted therapies. I am confident these trials will result in better outcomes for my patients.

I know that radiation therapy can be scary. When patients leave my office, my goal is for them to feel informed, empowered, and supported. I use this goal as the basis for my clinical practice.

  • Clinical Expertise: Head and Neck Cancer; Skin Cancer; Gynecologic Malignancies; Thoracic Malignancies; Palliative Care, Intensity Modulated Radiation Therapy; Image-Guided Radiation Therapy; Stereotactic Body Radiation Therapy
  • Languages Spoken: English; Mandarin
  • Education: MD, Vanderbilt University; PhD, Stanford University
  • Residencies: Radiation Oncology - MD Anderson Cancer Center
  • Board Certifications: Radiation Oncology

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Making an appointment

Call 631-623-4269


Visit PubMed for a full listing of C. Jillian Tsai’s journal articles

Pubmed is an online index of biomedical articles maintained by the U.S. National Library of Medicine and the National Institutes of Health.

Clinical Trials

Research is integral to our mission at Memorial Sloan Kettering, and clinical trials help us discover better forms of patient care and treatment. For you, this could mean access to a new therapy or therapy combination. Click to see a list of the trials I’m currently leading.

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Clinical Trials Led by C. Jillian Tsai


Most major health insurers offer plans that include MSK as one of their in-network providers. If MSK is in-network, it means all our doctors are too. Medicaid and New York State Medicare also provide benefits for care at MSK.

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