This paper discusses a new Implant Safety Tool, used to assess the safety of patients with metal implants exposed to radio-frequency (RF) fields. This specialist tool is discussed on the example of pectus patients with titanium bar-implant inserted during the minimally invasive Nuss procedure. The authors created a 3D realistic model of a 34-year-old male patient with a Nuss bar-implant. A numerical analysis based on the finite-difference time-domain (FDTD) method was performed for a far field source in the form of a plane wave with the frequency of 64 MHz, which corresponds to the RF exposure generated by MRI devices at 1.5 T. The obtained results allow concluding that the concave Nuss bar-implant poses no risk during environmental and occupational RF field exposures.