ABSTRACT
Objective@#To preliminarily investigate the difference of position fixation accuracy between polyurethane styrofoam and vacuum negative pressure pad in intensity-modulated radiation therapy (IMRT) after radical mastectomy for breast cancer.@*Methods@#Forty breast cancer patients, who received breast-conserving surgery followed by hyper-fractionated IMRT of the whole breast (42.56 Gy for 16 times) in our hospital between 2017 and 2018 were recruited and randomly divided into the polyurethane styrofoam group and vacuum negative pressure pad group. Before IMRT treatment, the anterior and lateral films of patients were taken with kilovoltage digital radiographs (KVDRs) by Varian Trilogy machine-borne OBI KV image verification system. The KVDRs images were matched with the DRR images reconstructed by the planned system to obtain the setup errors in the left and right, head and foot, and ventral and back directions between two groups. Each patient was verified for 10 times to obtain 400 sets of data. The independent sample t-test was adopted to analyze the setup errors between two groups. The external expansion value of graded setup errors from clinical target volume (CTV) and planned target volume (PTV) was calculated.@*Results@#The setup errors in the left and right, head and foot, ventral and back directions between the styrofoam fixation and vacuum pad groups were (1.63±1.29) mm and (1.83 ±1.61) mm (P=0.18), (1.46±1.51) mm and (2.26±2.03) mm (P=0.00), and (1.30±1.35) mm and (1.91±1.67) mm (P=0.00), respectively. The external expansion values of setup errors from CTV to PTV were 2.19 mm, 2.51 mm, 1.57 mm and 2.40 mm, 3.97 mm and 2.63 mm, respectively.@*Conclusion@#Both two fixation methods meet the clinical requirements. However, the setup accuracy and reproducibility in the polyurethane styrofoam group are better than those in the vacuum negative pressure pad group.
ABSTRACT
Objective To preliminarily investigate the difference of position fixation accuracy between polyurethane styrofoam and vacuum negative pressure pad in intensity-modulated radiation therapy (IMRT) after radical mastectomy for breast cancer.Methods Forty breast cancer patients,who received breast-conserving surgery followed by hyper-fractionated IMRT of the whole breast (42.56 Gy for 16 times) in our hospital between 2017 and 2018 were recruited and randomly divided into the polyurethane styrofoam group and vacuum negative pressure pad group.Before IMRT treatment,the anterior and lateral films of patients were taken with kilovoltage digital radiographs (KVDRs) by Varian Trilogy machine-borne OBI KV image verification system.The KVDRs images were matched with the DRR images reconstructed by the planned system to obtain the setup errors in the left and right,head and foot,and ventral and back directions between two groups.Each patient was verified for 10 times to obtain 400 sets of data.The independent sample t-test was adopted to analyze the setup errors between two groups.The external expansion value of graded setup errors from clinical target volume (CTV) and planned target volume (PTV) was calculated.Results The setup errors in the left and right,head and foot,ventral and back directions between the styrofoam fixation and vacuum pad groups were (1.63± 1.29) mm and (1.83 ± 1.61) mm (P=0.18),(1.46t1.51) mm and (2.26±2.03) mm (P=0.00),and (1.30±1.35) mm and (1.91±1.67) mm (P=0.00),respectively.The external expansion values of setup errors from CTV to PTV were 2.19 mm,2.51 mm,1.57 mm and 2.40 mm,3.97 mm and 2.63 mm,respectively.Conclusion Both two fixation methods meet the clinical requirements.However,the setup accuracy and reproducibility in the polyurethane styrofoam group are better than those in the vacuum negative pressure pad group.
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.