The Effect of Breast Reconstruction Prosthesis on Photon Dose Distribution in Breast Cancer Radiotherapy Running Tittle: Prosthesis Effect on Photon Dose Distribution

Introduction: Silicone prosthetic implants are commonly utilized for tissue replacement and breast augmentation after mastectomy. On the other hand, some patients require adjuvant radiotherapy in order to prevent local-regional recurrence and increment of the overall survival. In case of recurrence, the radiation oncologist might have to irradiate the prosthesis. The aim of this study was to evaluate the effect of silicone prosthesis on photon dose distribution in breast radiotherapy.Materials and Methods: The experimental dosimetry was performed using the prosthetic breast phantom and the female-equivalent mathematical chest phantom. A Computerized Tomography based treatment planning was performed using a phantom and by Core Plan Treatment Planning System (TPS). For measuring the absorbed dose, thermoluminescent dosimeter (TLD) chips (GR-207A) were used. Multiple irradiations were completed for all the TLD positions, and the dose absorbed by the TLDs was read by a light telemetry (LTM) reader.Results: Statistical comparisons were performed between the absorbed doses assessed by the TLDs and the TPS calculations for the same sites. Our initial results demonstrated an acceptable agreement (P=0.064) between the treatment planning data and the measurements. The mean difference between the TPS and TLD results was 1.99%.The obtained findings showed that radiotherapy is compatible with silicone gel prosthesis.Conclusion: It could be concluded that the silicon breast prosthesis has no clinically significant effect on distribution of a 6 MV photon beam for reconstructed breasts.

کلیدواژه ها:

Radiation Therapy ، Breast Implant ، Phantom ، Silicon