The depth of maximum absorbed dose (D-Max) along the beam central axis is primarily used for what purpose?

The depth of maximum absorbed dose (D-Max) is critical in radiation therapy because it indicates the point along the beam central axis where the dose delivered to the tissue is highest. This information is essential for monitor unit calculations and determining the appropriate treatment time for patients.

Understanding D-Max allows dosimetrists to accurately calculate how many monitor units (MUs) are needed to deliver a specific dose to the target volume while minimizing exposure to surrounding healthy tissues. In practice, it helps ensure that the prescribed dose to the tumor is delivered effectively and safely, which is essential for successful treatment outcomes.

In contrast, while defining margins for planning, measuring skin response, and calculating lateral margins are important aspects of treatment planning, they focus on different components of the treatment process that do not directly utilize the concept of D-Max in the same way monitor unit calculations do.