What is the depth of Dmax for a 60Co beam in a 10x10 cm field?

The depth of Dmax, or the maximum dose depth, refers to the point in tissue where the dose delivered by a radiation beam is at its highest, before it begins to decrease with deeper penetration. For a 60Co beam, which operates at a lower energy level compared to higher energy linear accelerators, the Dmax is generally shallow due to its interaction characteristics with biological tissue.

In the case of a 60Co beam in a 10x10 cm field, the Dmax is typically around 0.5 cm. This value is grounded in the dosimetric principles related to cobalt-60, which emit gamma radiation with a specific energy profile that allows for significant dose deposition very close to the surface. Therefore, the Dmax depth for a 60Co beam is characteristic of its energy level and the resulting dose distribution, making 0.5 cm the correct answer.

Understanding Dmax is crucial in radiation therapy planning, as it influences treatment strategies, the choice of energy for the beam, and the measurement of dose distribution within the patient. In clinical practice, knowing that the maximum dose is achieved at this depth helps dosimetrists ensure that the tumor receives sufficient dose while minimizing exposure to surrounding healthy tissues.