CORONARY ARTERIES EXPOSURE IN LEFT SIDED BREAST CANCER RADIOTHERAPY : DOSIMETRIC STUDY

Purpose :The cardiac toxicities are especially important in left-sided breast cancer radiotherapy(RT) compared to the right-sidedcancers.Our study aims to perform a dosimetric analysis to evaluate the effect of RT on coronary arteries and heart in breast-conserving surgery. Methods : Through a dosimetric studywe randomly selected a total of 36 patients with early stage right and left-sided breast carcinomas (T1/T2 +N0) .All patients underwent breast-conserving surgery .Whole Breast Adjuvant Radiotherapy was delivered with tumor beds boost using 3D conformal radiotherapy (3D-CRT) and computed tomography based planning .The doses for coronary arteries and heart were recorded and median values compared between groups. Results :The highest mean of radiation dose in patients with left-sided breast cancer was to LAD 2402.48 ± 838.39 cGy, while the highest mean dose in right-sided breast cancer patientswas to RV 130.18 ± 24.92. The highest maximumdose of radiotherapy was applied to heart at left-sided breast cancer patients as well as at right-sides prients. Themean V5 of the LV was 18.68% (6.89–31.69), mean V25 of the LV was 5.22% (0.45–16.54), mean V5 in bilateral ventricleswas 23.73% (2.56–26.89), and mean V25 in bilateral ventricles 6.78% (0.63–13.63).