What is a common form of immobilization used in radiation therapy?

Vacuum cushions are indeed a common form of immobilization used in radiation therapy. They are designed to conform to the patient's body shape and position, providing stable support during treatment. This helps to minimize movement, which is crucial for delivering precise radiation to the targeted area while sparing surrounding healthy tissues.

When patients are positioned in these cushions, air is removed, allowing the material to closely mold around them. This technique enhances comfort and allows for reproducible positioning across treatment sessions, which is essential for the effectiveness of radiation therapy.

Other forms of immobilization like pillows may provide some support, but they do not offer the same level of precision and adaptability that vacuum cushions do. Tissue compensators and thermoplastic masks serve different purposes in treatment planning and delivery; they are geared towards shaping the radiation field and securing the patient's position in a more rigid manner, but they do not provide the same flexible and conforming capabilities as vacuum cushions.