Study on the relationship between physical condition and positioning error in breast cancer patients undergoing postoperative intensity modulated radiation therapy

JIANG Yuling; CHENG Jun; ZHOU Chun

doi:10.3969/j.issn.1674-4136.2024.03.012

Abstract：Objective To explore the relationship between body mass index(BMI),chest circumference,breast volume and positioning error in breast cancer patients undergoing postoperative intensity modulated radiation therapy.Methods Sixty-three patients with breast cancer who received IMRT in Nantong Third People Hospital from January 2019 to October 2022 were selected to compare the positioning error differences of patients with different BMI,chest circumference,breast volume,etc.Results In 63 patients with breast cancer,the Left and right(X axis)positioning error was(2.61±0.72)mm,the Head and foot direction(Y axis)positioning error was(2.84±0.80)mm,and the Front and rear direction(Z axis)positioning error was(2.89±0.78)mm.With the increase of BMI,the positioning errors of X axis,Y axis and Z axis increased(P＜0.05),among which the positioning errors of X axis,Y axis and Z axis in patients with BMI≥24.0 kg/m2were(3.13±0.53)mm,(3.60±0.63)mm and(3.88±0.66)mm,respectively,which were significantly higher than those in patients with BMI＜18.5 kg/m2 and 18.5-23.9 kg/m2(P＜0.05).The positioning errors of X axis and Y axis in patients with chest circumference≥89 cm were(2.84±0.52)mm and(3.07±0.56)mm,respectively,which were significantly higher than those in patients with chest circumference＜89 cm.With the increase of breast volume,the positioning error of X axis increased(P＜0.05),in which the positioning error of X axis in patients with breast volume＞800 cm3 was(3.16±0.68)mm,which was significantly higher than that in patients with breast volume＜500 cm3 and 500-800 cm3(P＜0.05).There was no significant difference in positioning errors of X axis,Y axis and Z axis among patients of different ages(P＞0.05).Conclusions The positioning error of intensity modulated radiation therapy for breast cancer is affected by the BMI,chest circumference and breast volume of the patient,and has no significant relationship with the patient's age.