Dosimetric comparison of 3 dimensional radiotherapy and intensity modulated radiation therapy planning techniques in breast cancer

Objective:To detect the superior radiotherapy technique in patients with breast cancer in terms of the target volumes and the organ at risk (OAR). Method: In this study, we included 20 breast cancer patients who were applied modified radical mastectomy. Two different treatment plans (IMRT and 3DCRT) were prepared for each patient. Chest wall, supraclavicular, axillary and/or mammaria interna lymphatic regions were contoured as clinical target volüme (CTV). For planning target volüme (PTV), 0,5 cm was added to CTV (post margin; 0,3 cm). The doses of the target volumes and the OAR volumes (contralateral breast, heart, ipsilateral lung), the homogeneity index (HI) were compared. For the heart, the contralateral breast, the ipsilateral lung, Dmean and V25, Dmean and Dmax, D5 and D20 were evaluated, respectively. In addition, D2, D98, D95 ve Dmean were investigated for the PTV. Mann Whitney test was used for statistical analysis and p <0.05 was considered significant. Results:IMRT technique was superior to the 3DCRT in terms of the PTV, the OAR volumes and the HI. However, irradiated contralateral breast volume was less in the 3DCRT technique. Conclusion:The optimal treatment planning of the patient should be decided by considering the advantages and disadvantages of the plan