Glossary
Radiation Therapist Terms & Vocabulary
15 essential radiation therapist terms with plain-English definitions: the vocabulary you’ll hear in training and on day one.
Key radiation therapist vocabulary
These 15 terms come up constantly in radiation therapist training, on the job and in interviews. Knowing them helps you follow instructions, document accurately and sound prepared.
- ARRT
- American Registry of Radiologic Technologists.
- Brachytherapy
- Internal radiation.
- Dosimetrist
- Plans radiation dose.
- Fraction
- One daily treatment.
- Gray (Gy)
- Unit of radiation dose.
- IGRT
- Image-guided radiation therapy.
- Immobilization
- Keeping the patient still.
- IMRT
- Intensity-modulated radiation therapy.
- Isocenter
- Treatment target point.
- Linear accelerator
- Machine that delivers radiation.
- Quality assurance
- Checks of machine accuracy.
- Radiation oncologist
- Physician directing treatment.
- Simulation
- Planning scan for treatment.
- Skin reaction
- Side effect on treated skin.
- Tattoo marks
- Tiny dots for alignment.
Practice these terms
Test yourself with the free Radiation Therapist practice test: it includes vocabulary questions built from this list. For a complete course, see Radiation Therapist training.
Browse terms from every career in our career glossary.