Dose attenuation through a titanium alloy hip prosthesis.

The problem of dose perturbation due to hip prostheses during pelvic irradiation can be significant. Dose attenuation by a commonly used titanium alloy hip prosthesis was measured. Depending on the energy of the radiation beam and the thickness along the prosthesis, the attenuation was between 32% and 64%. This attenuation effect should be considered in treatment planning, especially in a patient with bilateral hip prostheses and when undergoing treatment for prostate cancer where the tumor typically lies between prostheses.