乳腺癌改良根治术后放疗胸骨剂量参数与急性血液学毒性的关系

Relationship Between Irradiated Dosimetric Parameters of Sternal and Acute Hematological Toxicity in Radiotherapy for Breast Cancer Patients After Modified Radical Mastectomy

[目的]研究乳腺癌改良根治术后放疗胸骨剂量学参数与急性血液学毒性的关系。[方法]回顾性分析2015年12月至2019年5月于河北省人民医院行乳腺癌改良根治术后放疗的56例患者的临床资料,在剂量体积直方图(dose-volume histogram,DVH)上记录胸骨的V5、V10、V20、V30、V40、Dmean、Dmax、D20、D40、D60、D80,记录患者血液学指标,并进行血液学毒性分级,评价患者胸骨剂量参数与急性血液学毒性的关系。[结果]胸骨的V20、V30与≥2级的急性血液学毒性发生相关;胸骨V10、V20、V30、V40、D60、D80与≥2级白细胞毒性发生相关。胸骨V30是≥2级急性血液学毒性发生的独立危险因素(P=0.037);胸骨V40、D80是≥2级白细胞毒性发生的独立危险因素(P=0.039,P=0.033)。当胸骨V30≥24.38cm3时,≥2级急性血液学毒性发生率明显升高(52%vs 8%,P=0.001),当胸骨V40≥6.48cm3时,≥2级白细胞毒性发生率明显升高(61%vs 32%,P=0.035)。此外,ki-67阳性率越高、化疗—放疗时间间隔越小越容易发生≥2级中性粒细胞毒性(P=0.016,P=0.038)。进一步研究影响胸骨剂量的因素得出体重指数(body mass index,BMI)、胸廓比与胸骨V40剂量呈负性相关。[结论]对于乳腺癌改良根治术后行辅助放疗的患者,降低胸骨受照剂量可减少2级及以上急性血液学毒性的发生。某些临床因素也会影响急性血液学毒性,要引起足够的重视。

[Purpose]To investigate the relationship between irradiated dosimetric parameters of sternum and acute hematologic toxicities(HT)in breast cancer after radical mastectomy.[Methods]The clinical data of 56 patients treated with radiotherapy after radical mastectomy in Hebei General Hospital from December 2015 to May 2019 were analyzed retrospectively,The parameters V5,V10,V20,V30,V40,Dmean,Dmax,D20,D40,D60 and D80 of the sternum were recorded on dose-volume histogram(DVH).Hematological indexes were recorded and HT was graded to evaluate the relationship between sternal dose parameters and acute HT.[Results]Sternum V20,V30 were associated with increased risk of grade≥2 acute HT;sternum V10,V20,V30,V40,D60,D80 were associated with increased risk of grade≥2 leukopenia.Sternum V30 was the independent risk factor of grade≥2 acute HT(P=0.037),and V40,D80 were independent risk factors of grade≥2 leukopenia(P=0.039,P=0.033).The cut-off point of V30 exposed to the sternum was 24.38 cm3,and the cut-off point of V40 exposed to the sternum was 6.48 cm3.In addition,higher ki-67 and higher chemotherapy-radiotherapy time interval were more likely to cause grade≥2 neutrophil toxicity(P=0.016,P=0.038).Further study of the factors affecting sternal dose indicated that the body mass index(BMI)and thoracic ratio were negatively correlated with sternum V40.[Conclusion]Reducing the irradiated dosage of sternum may decrease the risk of grade≥2 acute HT in breast cancer after radical mastectomy.In addition,some clinical factors might affect HT,which should be paid more attention to.