Investigation of the Effect of the Temporary Tissue Expander Used for Breast Reconstruction on Dose Distribution of Chest Wall Radiation
Tarih
2018Yazar
Cibiceli, S.
Çatlı Dinç, S.
Erpolat, Ö. P.
Akyol, O.
Meriç, N.
Karahacioğlu, E.
Üst veri
Tüm öğe kaydını gösterÖzet
The rate of breast reconstruction after mastectomy is increasing in women with breast cancer. At the breast reconstruction, silicone implants or temporary tissue expanders (TTEs) are placed instead of breast tissue taken during mastectomy. It is unclear how TTEs which contain metallic structures and filled with saline, affect dose distribution during RT. For this reason, so that optimum RT planning can be performed, the effect of metallic port in the Mentor TTE of dose distribution has been examined in our study.
MOSFET, NanoDot OSLD and EBT3 film dosimetric methods were used in the measurements. As a result of single frontal irradiation with metallic port made of samarium cobalt magnet and stainless steel, removed from the TTE, the maximum dose reduction rate at the bottom of the metallic port is 29.65% with NanoDot OSLD. The maximum dose increase rate over the metallic port is 6.25% with NanoDot OSLD. At the results obtained with measurements of 6 MV photon energy on rando phantom using TTE and silicone implant; for 3DCRT and IMRT treatment techniques, dose increase of less than 5% was observed on the over, right and left side of the metallic port with all dosimetric methods and the planning data. Under the metallic port, the rate of dose changes determined below 4% for these two treatment techniques. While using 9 MeV and 12 MeV electron energy, each dosimetric method and the data obtained from the treatment plans are evaluated in measurements dose increments of 12.63% with 9 MeV electrons and 10.66% with 12 MeV electrons were observed on the over, right and left side of the metallic port.
While examining the measurements, due to scattering caused by metallic port while there were doses increasing over the metallic port, there were doses decreasing under the metallic port. But according to the changes in dose at the doses prescribed by international dosimetric protocols (±%5) at our study the change in dose observed with 3DCRT and IMRT techniques at 6 MV photon energy appears to be not large enough to affect tumor treatment provided that the metallic port is introduced into TPS. At the 9 MeV and 12 MeV incision scar electron boost treatments, the metallic port significantly increased the skin dose even though it was introduced to TPS.