Why is immobilization critical in head and neck radiation therapy?

Immobilization is crucial in head and neck radiation therapy primarily because it significantly reduces movements to about 5 mm. This precise immobilization is essential for several reasons. In this specific treatment area, even slight movements can lead to fluctuations in the position of the tumor relative to critical structures such as the spinal cord, optic nerves, and healthy tissues. Maintaining such a narrow margin of movement is vital to ensure accurate targeting of the tumor while minimizing exposure to surrounding healthy tissues, thereby increasing the effectiveness of the treatment and reducing the risk of side effects.

Achieving immobilization with good reproducibility ensures that the treatment fields are consistently aligned with the planned radiation dose distribution. This uniformity is particularly important in head and neck cases due to the complex anatomy and the need to deliver high doses of radiation precisely. Enhanced accuracy from immobilization leads to better treatment outcomes and reduced complications, emphasizing the importance of minimizing movement during therapy sessions.