8 JUNE 2025IN MY OPINIONINTRODUCTION TO RADIATION THERAPYX-ray was first discovered by Wilhelm Roentgen on November 8, 1895. About two and half months later, on January 29, 1896, an X-ray was used to treat breast cancer patients. Fast forward over 100 years, clinicians are using various types of radiation (e.g., x-ray, electrons, protons, carbons, and others) to treat not only oncological diseases but also non-oncological diseases like heterotopic ossification, arterial venous malformation and trigeminal neuralgia. Radiation therapy uses highly energetic radiation (ionizing radiation) to induce DNA damage to the cancer cells while minimizing radiation damage to the normal tissue. Radiation can be used for curative intent and palliative purposes depending on the stage of the disease and location. There has been a long history of evidence based clinical trials and clinical experiences to show that radiation is highly effective at treating cancer with a highly favorable survival rate. Recently, there has been tremendous increase use of imaging modalities to better target cancers before, during and after treatment for the purpose of radiation treatment planning, target localization, and treatment outcome evaluation.COMPUTED TOMOGRAPHY (CT)Computed tomography is an imaging system that utilizes ionizing radiation to generate volumetric images that are anatomically accurate. In radiation oncology, CT has become a standard imaging modality to capture three-dimensional images of the patient's anatomy to identify the location of the tumor and surrounding critical structures. From it, physicians can digitally contour the tumor(s) and critical structures. Using this information, clinical staff can create a radiation treatment plan that is customized to the patient's anatomy and tumor geometry and location. In addition to providing the patient's anatomy, CT images are also used to simulate radiation treatment and calculate Imaging Application in Radiation TherapyBy Heeteak Chung, Ph.D., MBA, Director of Medical Physics, Baylor Scott and White Health
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