Radiation-induced capsule tissue reactions around textured breast implants in a rat model

SummaryCapsule fibrosis and other complications around various filled breast implants were evaluated in a rat radiation model after 12 months of implantation.Model implants, one per rat, were implanted subcutaneously. One month after subcutaneous implantation, high voltage radiation followed one half each group.A higher rate of capsule fibrosis occurred in radiated animals. Malignant tumors at the implantation site developed in 40% of radiated and 24% of non-radiated animals, with a much higher rate of mitosis in the radiated group (Mann–Whitney, P=0.008P=0.008). The presence of an implant is a cofactor for tumor development in rats (χ2χ2-test, χ2=6.927χ2=6.927; P=0.008P=0.008) as well as radiation, since none of the control animals developed tumors.Applied to humans, capsule contracture (fibrosis) is a common complication of radiation, while development of radiation-induced sarcoma is a rare complication after postoperative radiotherapy by all account. Still further long-term follow-up human studies are necessary.