Study on the influence of volume change of tumor bed on radiotherapy dose volume distribution after breast conserving surgery for early breast cancer

Objective To study the influence of volume change of tumor bed on radiotherapy dose volume distribution after breast conserving surgery for early breast cancer. Methods 13 early breast cancer patients received breast-conserving surgery were selected. For all 3 CT scanning in patients with tumors, row delineation of tumor and normal tissue target positioning, the tumor bed after volume as well as the planned radiation dose volume were compared in three times of scans. Results 13 cases of three CT scans of patients with tumor bed volume point to (32.85±9.30)cm3, (24.50±4.71)cm3, (16.48±4.46)cm3, there were statistically significant differences before and after(t=2.888, 5.723, 4.458, all P<0.05); 3 planned radiation dose in patients with volume was stepped down, and the differences were statistically significant (F=20.28, 96.32, 14.21, 16.75, 26.29, all P<0.001). Conclusion Earlier the tumor bed following breast surgery volume decreased rapidly, tumor volume change will affect the target area of the bed covers and the exposure of normal tissue dose-volume. Key words: Breast neoplasms; Radiotherapy