Total hip arthroplasty (THA) is a well-established procedure to cure different pathologies of the hip joint with an increasing incidence [1]. The presence of hip implants (and most notably its massive femoral stem) can decrease diagnostic accuracy in Computed Tomography (CT) and severely impair radiotherapy of the pelvis. As information on the used material can be difficult to obtain, non-invasive material characterization is of major interest to optimize radiation planning if treatment beam has…