Comparison of imbolization accuracy between styrofoam and breast carrier in intensity-modulated radiotherapy after breast conservative surgery for breast cancer patients / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the difference of styrofoam and breast carrier in postposition fixation of intensity-modulated radiotherapy after breast conservative surgery for breast cancer patients.Methods From February 2018 to August 2018,tweenty-four patients with breast cancer in Sun Yet-Sen Memorial Hospital of Sun Yet-sen University were selected for this study,who underwent hypofactionationed radiotherapy after breast conservative surgery with total dose 42.56 Gy/16Fractions.They were randomized into styrofoam test group and breastcarrier control group.Cone beam CT as used to record the positioning error under the directions of left and right (x),head and foot (y),abdomen and back (y) within two groups at the first,third,fifth,seventh,eleventh time before irradiation.Furthermore,the PTV extension margin was calculated and the positioning time of two groups was recorded.Two sets of pendulum errors were analyzed by independent sample T-test,and the outspread value of inter-fractional set up error of the PTV was calculated.Results The errors of the test group and the control group in the direction of x,y,z were as follows(2.36±1.89) and (2.56±2.05) mm (P=0.49),(1.76± 1.78) and (3.28±2.79) mm (P＜0.05),(1.47± 1.49) and (1.73± 1.81) mm (P=0.28).The extension values of inter-fractional set up error of CTV to PTV were 2.97,2.92,2.21 mm and 3.41,4.09,2.59 mm respectively.The time of single positioning was (3.4± 1.1) and (5.5 ± 3.1) min respectively (P=0.01).Conclusion Styrofoam has better positioning accuracy and efficiency compared with breast carrier.