Meet the Team: Therapy Medical Physicist

Radiation therapy is a powerful tool in the fight against cancer, but delivering it safely and accurately requires more than just technology—it demands deep scientific expertise. That’s where medical physicists come in. Often working behind the scenes, these professionals are critical to ensuring that every patient receives precisely the right dose of radiation, every time.

So, who are medical physicists and what do they do?
A medical physicist is a scientist with specialized training in the use of radiation in medicine, particularly in radiation oncology. Their primary responsibility is to guarantee the safety, quality, and accuracy of radiation treatments. They are the experts who make sure that the high-powered machines used to treat cancer—linear accelerators (linacs)—are calibrated correctly, operating safely, and delivering the prescribed radiation dose as intended.

Medical physicists work closely with radiation oncologists, dosimetrists, and radiation therapists as part of the patient care team. While they don’t often interact directly with patients, their work has a direct and vital impact on treatment outcomes.

The process begins after a treatment plan has been developed by the dosimetrist and approved by the radiation oncologist. The medical physicist then steps in to perform a rigorous review of the plan, checking that it meets all safety and quality standards. They run tests using sophisticated software and sometimes physical phantoms (simulated tissue models) to verify that the dose distributions are accurate and that the equipment will deliver radiation to the exact intended areas.

One of their key duties is quality assurance (QA). Medical physicists perform regular checks on all treatment machines, imaging systems, and planning software. This includes daily, monthly, and annual testing to ensure that equipment is functioning properly and within tight tolerances. Any deviation could affect patient safety or treatment effectiveness, so their attention to detail is critical.
Medical physicists also play a leading role in commissioning new equipment, integrating new technologies, and developing protocols for advanced treatments like stereotactic body radiation therapy (SBRT) or stereotactic radiosurgery (SRS). Their expertise bridges the gap between the complex science of radiation and the clinical goal of curing cancer while minimizing side effects.

With the rise of remote technologies and automation, some aspects of medical physics can now be performed remotely, but many tasks—including machine QA and certain types of treatments—still require a hands-on presence in the clinic. As such, medical physicists often divide their time between office-based analysis and on-site technical work in the treatment facility.

Medical physics is a dynamic and intellectually challenging field that blends science, engineering, and clinical care. For those with a strong background in physics or engineering and a passion for healthcare, it offers a deeply meaningful career with a direct impact on patient lives.

To learn more about becoming a medical physicist, visit:
• https://www.aapm.org/
• https://www.campep.org/