Which method of correcting for obliquity adjusts for discrepancies in surface angles during treatment?

The isodose shift method is utilized to correct for discrepancies in surface angles during treatment, particularly in scenarios where the treatment area is not perpendicular to the radiation beam. When the surface of the treatment area is oblique, the depth of tumor or critical structures can vary from what is assumed in a standard plan. The isodose shift method allows for a more accurate representation of how the radiation dose is distributed within the body by adjusting the isodose curves to account for these changes in surface angle.

This is crucial for ensuring that the prescribed dose effectively covers the target volume while minimizing exposure to surrounding healthy tissues. By applying this method, dosimetrists can confirm that the intended dose is delivered accurately even when the surface contour is irregular or at an angle. Thus, the isodose shift method effectively compensates for the complexities introduced by obliquity, ensuring improved treatment planning and outcomes.