Tolerance of autologous and allogeneic bone grafts to therapeutic radiation in humans

Abstract

Purpose: To examine the effect of perioperative irradiation on bone graft healing and functional integrity. Methods and Materials: Fifty-five bone grafts (10 autologus and 45 allogeneic) performed between 1978 and 1995 were evaluated retrospectively. Sixteen received preoperative radiation, 11 received postoperative, and 13 were treated with a combination of pre- and postoperative radiation. Fifteen nonirradiated grafts were randomly selected to serve as controls. Twenty-three of the grafts were placed in patients who received chemotherapy in the perioperative period. Functional graft survival and radiographic healing quality were evaluated. Results: Overall rates of graft survival at 1 year were 89% for autografts and 79% for allografts. Graft survival rates were 86% and 68% at 1 and 5 years for the irradiated group, and 67% and 58% for the control group. No significant difference was seen in the Kaplan-Meier graft survival curves of the two groups. There was a nonsignificant trend toward improved radiographic healing quality in the control group. No significant differences in outcome based on treatment chronology were found with survival rates of 88% for preoperative treatment and 100% for postoperative treatment. No relation between outcome and bone dose (preoperative + postoperative dose), graft dose (postoperative dose), or mean dose/day was found. There was a trend ( p = 0.0525) toward worse outcome seen in the Kaplan-Meier curves of patients who received chemotherapy. This difference, however, was not seen in the 1-year survival rates or healing quality. Tobacco use tended toward predicting failure, with 63% graft survival compared to 85% in nonsmokers ( p = 0.09). Healing quality was significantly lower in the smoking group. Conclusion: The low failure rate of grafts in irradiated sites, overall and compared to controls from this study and relevant literature, as well as the lack of dose and time effects, does not support significant deviation from the indicated treatment regimen for patients who have received or are expected to receive a graft. The trend toward decreased quality of radiographic bone healing, and data published in relevant literature indicating improved healing when radiation is withheld until 3–4 weeks postoperatively suggest this delay should be attempted when not expected to otherwise compromise patient outcome. A nonsignificant trend only for the effect of chemotherapy on bone grafts was seen, thus we do not recommend changes in its use as appropriate for disease management other than a preference against use during the immediate perioperative period.