Radiation therapy is delivered by a specialized team of professionals, not a single doctor. The group typically includes a radiation oncologist, radiation therapists, a medical physicist, a dosimetrist, and an oncology nurse. Each person handles a distinct part of your treatment, from the initial plan through your final session.
The Radiation Oncologist
The radiation oncologist is the physician who leads your care. This is the doctor who evaluates whether radiation is the right approach for your cancer, selects the type of radiation best suited to your situation, and designs your treatment plan. That plan includes the precise radiation dose needed to destroy cancerous cells while limiting damage to surrounding healthy tissue.
Beyond planning, the radiation oncologist oversees every treatment session and manages side effects as they come up. You’ll typically see this doctor once a week during treatment for a check-in visit, where they assess how your body is responding and adjust the plan if needed. Radiation oncologists complete four years of medical school followed by five years of specialized training, and most are board-certified by the American Board of Radiology.
The Radiation Therapist
The radiation therapist is the person you’ll see most often. While the oncologist designs the plan, the radiation therapist carries it out, positioning you on the treatment table each day, pinpointing the exact area to be treated, and operating the radiation machine. A typical course of radiation runs five days a week for several weeks, so you’ll interact with your radiation therapist on a daily basis throughout that stretch.
Radiation therapists also monitor you for any unusual reactions during treatment and keep daily records of each session. They check the treatment machines regularly to confirm everything is functioning correctly. Most have completed a two- to four-year educational program and hold certification from the American Registry of Radiologic Technologists.
Because of the frequency of contact, radiation therapists often become a key source of day-to-day support. Skin changes and other side effects can shift noticeably between your weekly doctor visits, and therapists are often the first to notice something that needs attention.
The Medical Physicist
A medical physicist works behind the scenes to ensure your treatment is safe and accurate. They collaborate directly with the radiation oncologist during planning, verifying that the complex calculations behind your treatment will deliver the right dose to the right place. They are also responsible for the quality assurance programs that keep every piece of equipment in the department calibrated and functioning properly.
Medical physicists are experts in the software and machine models that generate treatment plans. They review plans for safety, check dose calculations, and troubleshoot technical problems. Most hold a doctoral or master’s degree in physics and complete one to two additional years of clinical training before becoming board-certified.
The Dosimetrist
The dosimetrist is the specialist who builds the initial treatment plan based on the radiation oncologist’s instructions. Using imaging data from your simulation scan, the dosimetrist maps out how radiation beams will be shaped and angled to cover the tumor while sparing normal tissue. They generate a continuous stream of detailed treatment plans, often working through complex cases that require careful balancing of dose and safety.
Many dosimetrists start their careers as radiation therapists and transition into planning after intensive additional training. Others graduate from dedicated one- to two-year dosimetry programs. Once the dosimetrist completes a plan, the medical physicist reviews it for quality and accuracy before the oncologist gives final approval.
The Oncology Nurse
The radiation oncology nurse handles patient education, symptom management, and advocacy. Before treatment starts, the nurse walks you through what to expect, including potential side effects and how to manage them at home. During treatment, they assess how you’re doing at your weekly visits, monitor for complications, and coordinate with the rest of the team if your care plan needs to change.
Nurses are often the first person you’ll call with questions between appointments. They bridge the gap between the technical side of treatment and your everyday experience of it.
Other Support Staff
Depending on the facility, your team may also include a social worker and a dietitian. Social workers help with the logistical and emotional challenges that come with cancer treatment, from navigating insurance to connecting you with counseling. Dietitians address the nutritional side effects that radiation can cause, especially for cancers of the head, neck, or abdomen, where eating and digestion are directly affected.
How the Team Works Together
Your treatment begins with a consultation where the radiation oncologist evaluates your case and discusses options. If radiation is recommended, you’ll go through a simulation appointment, essentially a planning session where imaging scans map your anatomy. The radiation therapist helps position you during this visit and sets up a schedule for your treatment sessions.
Over the next few days to weeks, the dosimetrist builds a treatment plan based on the oncologist’s directives. The medical physicist reviews it for safety. The oncologist gives final approval. Only then does daily treatment begin, with the radiation therapist delivering each session and the oncologist checking in weekly. The nurse stays in contact throughout, watching for side effects and keeping your experience as manageable as possible.
Accreditation standards from the American College of Radiology require that every radiation oncology department maintain qualified staff across these roles. A board-certified or board-eligible radiation oncologist, certified radiation therapists, and a qualified medical physicist are the minimum for safe operation.