Application Of Respiratory Control Technology In Radiotherapy After Radical Mastectomy For Left Breast Cancer

Objectives:To explore whether patients undergoing radiation therapy after radical mastectomy can be combined with deep inspiration breath hold technique(DIBH)to reduce the risk of organ damage.Method:Fourteen patients who underwent radical mastectomy for left breast cancer and received radiotherapy after left breast surgery in our hospital were selected as subjects to improve the preparation of respiratory training,and to obtain a calm breathing state and a deep inhalation breath state during CT positioning scan.Under the CT image,each patient was given a VMAT plan,and the dose parameters of the target area(PCTV all)and related dangerous organs were compared and analyzed.Result:PCTV all,whole lung MLD and left lung V20 satisfy the normal distribution and are analyzed by paired t-test.As shown in Table 1,the results are as follows:1.PCTV all(cm3)results:752.082±39.481 cm3 in FB mode and 749.644±43.855cm3 in DIBH mode.It can be seen from paired t-test that there is no statistically significant difference in PCTV all under different respiratory states(t=0.643,P=0.532).2.The average dose of MLD(Gy)in the whole lung was 7.438±0.776Gy in FB mode and 7.079±0.789Gy in DIBH mode,and FB was significantly higher than DIBH.From the paired t-test analysis,the difference of mean lung mean MLD in different respiratory states was statistically significant(t=3.713,P=0.003).3.Left lung V20(%)results:24.704±1.652%in FB mode and 22.589±2.214%in DIBH mode,FB is significantly higher than DIBH.From the paired t-test analysis,the difference of left lung V20 in different respiratory states was statistically significant(t=3.457,P=0.004).The normality test found that the data of heart V30,cardiac Dmean and whole lung V20 did not satisfy the normal distribution(P<0.05),analyzed by Wilcoxon Signed Ranks Test,As shown in Table 2:4.Cardiac V30(%)results:The median in FB mode is 1.230%,and in DIBH mode is 1.005%,FB is significantly higher than DIBH,indicating that DIBH is lower than FB and heart V30(%),by paired rank sum test Available,the difference of heart V30(%)under different respiratory conditions was statistically significant(Z=-2.012,P=0.044).5.Cardiac Dmean(Gy)results:the median was 5.426Gy in FB mode and 5.292Gy in DIBH mode,FB was significantly higher than DIBH,indicating that compared with FB,the average dose of heart combined with DIBH decreased,by paired rank sum test Available,the difference of Dmean(Gy)in the heart was statistically significant(Z=-1.977,P=0.048).6.Total lung V20(%)results:The median of FB mode was 11.235%,10.245%in DIBH mode,FB was higher than DIBH,indicating that DIBH is lower than FB,whole lung V20(%),by paired rank sum The test showed that the difference of V20(%)in the whole lung under different respiratory conditions was statistically significant(Z=-3.296,P=0.001).Conclusion:For patients undergoing radiation therapy after radical mastectomy,combined with deep inhalation breath holding technology can reduce the dose of heart and lung,reduce the occurrence of cardiopulmonary adverse reactions,and minimize the vital organs while ensuring the target dose.Irradiated dose.In clinical practice,if patients with radical mastectomy are treated,it is recommended to combine deep inhalation breath holding technique with radiotherapy.