What factors most influence the skin dose during x-ray therapy?

The skin dose during x-ray therapy is significantly influenced by beam quality and filtration. Beam quality refers to the energy of the x-rays generated by the machine and essentially impacts how deeply the x-rays can penetrate tissue. Higher energy beams can generate a higher dose to deeper tissues while reducing the skin dose due to increased attenuation effects.

Filtration is critical as it removes low-energy x-rays from the beam that do not contribute to the therapeutic effect and would primarily be absorbed by the skin. This ensures that the patient receives a more uniform dose distribution, minimizing unnecessary skin exposure.

Together, beam quality and filtration play a pivotal role in both maximizing the effectiveness of the treatment and optimizing safety for the skin, thus making them the primary factors influencing skin dose during x-ray therapy.