The risk factors and the relationship between radiation dose and complications and prosthetic reconstruction failure in patients with post-mastectomy breast implant reconstruction: a retrospective cohort study.

Background: The risk factors for breast implant reconstruction complications and prosthetic reconstruction failure are currently inconclusive. Besides, there is a lack of studies regarding the relationship between radiation dose distribution and complications. This study explored the risk factors for breast implant reconstruction complications and analyzed the influence of radiation dose distribution on complications. Methods: Patients undergoing breast prosthesis reconstruction between January 2012 and June 2020 were retrospectively reviewed. Patient demographics, treatments, and perioperative factors were recorded, as well as complications and prosthetic reconstruction failures. Multivariable logistic regression models were used to explore the risk factors of reconstruction complications and prosthesis reconstruction failure. The radiation dose distribution was obtained by examining the dose-volume histogram and compared among patients with and without complications. Results: Two hundred and sixteen patients (221 reconstructions) were not irradiated, whereas 59 (59 reconstructions) received radiotherapy (RT). The median follow-up period was 47.7 months. Multivariate regression analysis showed that RT [odds ratio (OR) =2.000; 95% confidence interval (CI): 1.065-3.754; P=0.031] and chemotherapy (OR =2.226; 95% CI: 1.032-4.799; P=0.041) were independent risk factors for overall reconstruction complications; and hypertension (HT) (OR =8.222; 95% CI: 1.056-64.034; P=0.044) or RT (OR =2.442; 95% CI: 1.009-5.908; P=0.048) were risk factors for prosthetic reconstruction failure. There was a statistically significant difference in the radiation dose distribution between patients with and those without complications. Patients with complications had a significantly higher mean dose of 5 or 10 cc around the maximum radiation dose in the planning target volume (PTV) (P=0.045 and P=0.034, respectively), irradiation volume with a dose of 107% of prescription dose (P=0.027), and proportion of irradiation volume with doses of 105% and 107% of prescription dose to the total PTV (P=0.019 and P=0.042, respectively). Conclusions: RT can increase implant reconstruction complications and prosthetic reconstruction failure, but remains an acceptable option in a multidisciplinary setting. In addition to RT, chemotherapy is a risk factor for overall complications of breast implant reconstruction. HT is a risk factor for prosthetic reconstruction failure, so the patient's blood pressure should be actively monitored and controlled during the perioperative period. The radiation dose level and the volume with high-dose radiation should be limited to reduce complications.