EFFECT OF BREAST AUGMENTATION AFTER BREAST-CONSERVING SURGERY FOR BREAST CANCER ON RADIATION DOSE -SILICONE PROSTHESIS AND CHANGES IN RLADIATION DOSE

「Abstract」The results of a study simulating postoperative radiation therapy of remaining breast tissue with a silicone bag prosthesis implanted to examine the effects of the prosthesis on radiation dosage and surrounding tissue are reported. The evaluation was conducted in two stages: 1) a water phantom was used to evaluate scattering effects of a prosthesis installed inside the phantom using GRD set around the prosthesis. Measurements were conducted on both entrance and rear sides of the prosthesis. 2) a Rand phantom was used to measure radiatien doses around the prosthesis. The first evaluation resulted in a less than 5.4% reduction in dose at the rear side of the prosthesis whereas the second evaluation, for opposing portal irradiation used with breast-conserving surgical treatment, showed the effects of the prosthesis on radiation dosage being within ±2%, the permitted treatment range. In conclusion, for treating breast cancer, combining surgical treatment of the cancer with implanting of prosthesis for breast reconstruction followed by radiation treatment appears feasible as no effects on dosage were observed on treatment effectiveness.