Surveying the Contralateral Breast Dose during the Primary Breast Irradiation of Mastectomized Patients in Three Hospitals in Tehran

Contralateral breast dose from primary breast irradiation has been implicated in the risk of second breast malignancies. In the radiotherapy departments of Iran, based on oncologist’s and physicist’s viewpoint, a special technique and set-up may be used for treatment of chest wall in mastectomized patient. The present study compared three different breast treatment techniques and set-up used in three different hospitals H1, H2 and H3 in Tehran by measuring radiation dose to the contralateral breast. In this study, total number of 69 patients with ages ranged from 25 to 75 years were investigated. Dose measurements were made using thermoluminescent dosimeters(TLD) chips. The technique used in the hospitals showed the highest contralateral breast dose in H2 and the lowest in H3. In all techniques, contralateral breast dose showed a direct relationship with A-P and lateral chest wall diameters as well as target volume. Also, with normalization of dose to target volume and entrance dose, H2 has the highest and H3 the lowest contralateral breast dose. This study showed that the patient set-up is the most important factor in increasing contralateral breast dose in these three hospitals. Therefore, patient set-up used in H3 is suggested as a better method.