Guang Li, PhD

Guang Li, PhD

Pictured: Guang Li, PhD

I am an attending physicist in the Department of Medical Physics. My clinical research explores ways to improve how we deliver radiation treatment to MSK patients. When we use the most precise methods possible, we kill cancer cells while keeping nearby healthy tissue safe.

My research is about using image guidance systems to track how a body’s motion can affect treatment planning and delivery. Patient motion refers to people moving as we’re getting them ready for treatment, and during treatment. When you breathe, for example, your body moves a little, and so does your organs or a tumor. That motion can affect treatment.

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I’m most interested in combining 3D and 4D optical surface imaging (OSI) with internal imaging methods. Examples of these methods include CT, MRI, and PET scans. We think using these imaging methods together can improve treatment. It may be a better way for us to set up daily treatment for a patient. It also can be a better way to monitor their motion during treatment.

We developed a new way to assess motion from breathing (multi-breath target motion assessment). This new approach combines 2 methods: optical surface imaging spirometry and a time-resolved 4D MRI method. We’re using deep learning tools that let us study and adjust for movement in tumors and organs. This motion is caused by breathing during radiation therapy.

MSK has 32 optical surface imaging (OSI) systems at 8 of our locations. These systems include 26 AlignRT Advance, 2 AlignRT inBore, and 4 AlignRT offline systems. I’m in charge of the clinical aspects of purchasing, installing, commissioning, operating, and new procedure development for these OSI systems.

At MSK, we only use the latest imaging methods. Surface-guided radiotherapy (SGRT) is a new approach for getting ready for treatment and monitoring during treatment. SGRT is far more accurate than the usual way of setting up for treatment using body tattoos and markers. Our patients are more comfortable because treatment set-up is faster. Treatment also is more precise.

So far, we’re developing frameless brain stereotactic radiosurgery (SRS) and radiotherapy (SRT) procedures, and breast SGRT procedures with no tattoos.

I’m responsible for developing clinical procedures for making 3D-printing bolus. A bolus is a device used in radiotherapy, and ideally sits on the skin with no air gaps. I’m also responsible for the clinical procedures for making 3D-milling immobilization devices, which keep people from moving during treatment. Finally, I track and resolve any clinical issues that come up between treatment planning and the machine shop. I keep our clinical workflow running smoothly.

I have certification from the American Board of Radiology and a license from the state of New York.


Doctors and faculty members often work with pharmaceutical, device, biotechnology, and life sciences companies, and other organizations outside of MSK, to find safe and effective cancer treatments, to improve patient care, and to educate the health care community.

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Guang Li discloses the following relationships and financial interests:

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This page and data include information for a specific MSK annual disclosure period (January 1, 2022 through disclosure submission in spring 2023). This data reflects interests that may or may not still exist. This data is updated annually.

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