AbstractID: 8985 Title: Evaluation of the Skin Dose for Breast Patients
Radiation dose to the patient’s skin is one of the major issues when treating breast or chest wall after breast reconstruction. The goal is
usually to deliver the prescription dose at some shallow depths, keeping the skin dose at an adequate level at the same time. Therefore,
it is very important to evaluate the skin dose for different treatment techniques. In the present study the skin dose for various treatment
techniques are measured using 0.15 mm thick TLD chips (lateral dimensions). The study is conducted using an acrylic breast
phantom. It is essential to use the same phantom when trying to compare different techniques, because the skin dose is highly
dependent on the geometry of the irradiated breast. The phantom was irradiated with 6 MV, 10 MV (with and without beam spoiler
providing additional electron contamination) tangential photon beams (using conventional wedges and IMRT) and energy modulated
electron beams from a Primus linear accelerator (Siemens Medical Systems). The results show that for 6 MV beams the dose to the
skin was 45% to 60% of the prescription dose depending on the location. For 10 MV beams the dose to the skin was similar to that for
the 6 MV beams when using a spoiler and about 5% less than that without a spoiler. The skin dose for electrons is between 85% and
100%, which indicates that the use of photon tangential beams in combination with modulated electron beams may have a great
potential.