Dosimetric comparison of the effect of BREATH-holding technique on organ doses at risk in left breast cancer radiotherapy

In breast cancer radiotherapy (RT), it is important to protect the organs at risk (OAR) as well as to provide a good dose distribution at the target volume. Therefore, we aimed to reduce RT doses by removing the OAR from the target volume in RT to be performed with the breath-hold [Breath-Hold (BH)] technique. 10 patients with a diagnosis of left breast cancer who had previously received RT and completed their treatment were included in the study. Different computed tomography (CT) images taken with both [Free Breathing (FB)] and BH techniques were transferred to the treatment planning system (TPS), and a treatment plan was made for each patient with 2 separate VMAT techniques. In the plans made, doses of target volume, heart, LAD, ipsilateral lung, contralateral lung, whole lung, contralateral breast, brachial plexus, thyroid and esophagus were compared using dose volume histogram (DVH). As a result of the dosimetric comparison of the treatment plans made with the FB and BH techniques, it was seen that the reduction in the heart, LAD and ipsilateral lung doses in the treatment plans made with the BH technique was statistically significant (p<0.05). The V5 value of the contralateral lung was found to be statistically lower (p=0.043) in the FB technique. Dmax, Dmean, V10 values of the whole lung were found to be statistically lower (p<0.05). There was no statistical difference in the plans made with the BH technique for the contralateral breast, thyroid, brachial plexus and esophagus. In both planning techniques, the planned target volume (PTV) was adequately surrounded by the reference isodose. It has been seen that the doses taken by the heart, LAD, ipsilateral lung can be reduced and it is a feasible method without compromising the desired dose for the target volume with the BH technique in patients with RT indication due to the diagnosis of left breast cancer.