In radiation therapy, what does the term "isodose" refer to?

Isodose refers to a line of constant radiation dose, meaning it represents areas within the treatment field where the radiation dose delivered to the tissue is the same. Isodose contours are essential in radiation therapy planning because they help clinicians visualize and analyze the distribution of the radiation dose throughout the target volume and surrounding tissues. By employing isodose lines, radiation oncologists can ensure that the prescribed dose adequately covers the tumor while minimizing exposure to healthy tissues, which is crucial for maximizing treatment effectiveness and reducing side effects.

The concept of isodose curves assists in treatment planning by allowing practitioners to adjust beam angles, intensities, and modulation to achieve the desired dose distribution. This is vital for conformal radiation therapy and intensity-modulated radiation therapy (IMRT), where precision in dose delivery is necessary.

The other options, while related to radiation therapy, do not define isodose. Shielding and protective garments relate to safety measures in the context of radiation exposure rather than dose distribution, and patient positioning techniques focus on how the patient is oriented during treatment instead of the dose itself.