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How does radiation therapy preserve an organ’s structure and function?

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linear accelerator; external beam radiation therapy — radiation therapy External beam radiation therapy (also known as external beam teletherapy, or long-distance therapy) being delivered using a machine known as a linear accelerator.

Radiation therapy preserves an organ’s structure and function by delivering precise doses of ionizing radiation to a tumor while minimizing exposure to surrounding healthy tissues.12

Techniques to achieve this include:

Conformal and Intensity-Modulated Radiation Therapy (IMRT): These methods use multiple beams or specialized collimators to shape the radiation field to the tumor's exact dimensions, sparing adjacent normal structures.1
Beam Direction and Depth: By focusing beams from multiple directions or using high-energy sources like linear accelerators, physicians can deposit energy deep within the body while reducing the dose delivered to superficial or surrounding healthy organs.23
Brachytherapy: Placing radioactive sources directly into or near a tumor allows for high-dose treatment with minimal impact on distant, healthy tissues.23
Fractionation: Administering radiation in repeated, smaller doses allows healthy cells—which are often better at recovering from radiation damage than rapidly proliferating cancer cells—to repair themselves between sessions.3

By carefully planning the dose distribution and utilizing image guidance to account for organ motion, clinicians can effectively target disease while maintaining the integrity of vital organs.13