Effects of preoperative breast magnetic resonance imaging examination and postoperative three dimensional conformal radiotherapy in breast cancer patients receiving breast conserving surgery

doi:10.3969/j.issn.1002-7386.2018.13.002

Abstract：Objective To investigate the effects of preoperative breast magnetic resonance imaging ( MRI ) examination and postoperative three dimensional conformal radiotherapy in breast cancer patients receiving breast conserving surgery. Methods The data about 116 patients with early breast cancer who were treated in our hospital were enrolled in the study. These patients were divided into different groups according to different variables including patient's age, tumor size, tumor location and pathological features,then the detection ability by breast MRI for additional lesions of patients was analyzed and compared with that by conventional detection means. Meanwhile 16 patients who were consistent with the condition of three dimensional radiotherapy and were treated in our hospital from August 2012 to May 2015 were also enrolled in the study. The differences among radiation doses of heart and lung, distribution of volumes and doses in every patient were analyzed, moreover, the indication and dosage dominance of three dimensional radiotherapy were compared with those of conventional radiotherapy. Results The MRI detected additional finding lesions in 40 patients (34. 4% ),moreover, the additional findings were confirmed to be malignant in 25 patients (21. 6% ),which led to the changes of treatment means. MRI had a higher resolving power for soft tissues than that by molybdenum target mammography and B ultrasound examination. Moreover the lesions less than 1cm were detected in 27 patients. The breast size percentage in 16 patients treated by three dimensional conformal radiotherapy who received 50% prescription dosage was two times as high as that of patients who received 100% prescription dosage,and the percentage of PTV occupying breast size in the same side was almost the same as 95% isodose line. Conclusion Before breast conserving surgery,MRI can make up for the deficiencies of molybdenum target mammography and B ultrasound examination,which can find out additional lesions,providing a more accurate and comprehensive reference for surgery. After breast-conserving surgery, the three dimensional conformal radiotherapy has better homogeneity, which can effectively avoid radiation damage on surrounding normal tissues and reduce radiation doses on critical organs when increasing radiation doses on tumor tissues.