Clinical Study Of Hematological Factors Predicting Radiation Lung Injury (RILI) After Intensity Modulated Radiation Therapy In Thoracic Tumor Patients

Purpose: This study focuses on Intensity modulated radiation therapy for patients with thoracic tumor.The relationship between clinical hematological factors(neutrophil(N),neutrophil/lymphocyte(NLR),monocyte/lymphocyte(MLR))and the occurrence of radiation induced lung injury(RILI)before and after IMRT,and the predictive value of RILI.To provide a theoretical basis for the prevention and avoidance of severe RILI and the optimal selection of radiotherapy plan for further clinical guidance.Methods:Forty thoracic cancer patients who received conformal intensity modulated radiation therapy(IMRT)in the Department of Tumor General,The First Affiliated Hospital of Jiamusi University from October 2017 to September 2022 were selected as the research objects.All patients had complete clinical data and were diagnosed by histopathology or puncture cytology.Dosage: 95%PTV 50-66 Gy,2.0Gy/time,5times/week,and corresponding organs at risk were protected.After treatment,patients were followed up for the prescribed duration of hospitalization.Follow-up included blood routine,physical examination,interrogation,auscultation,and chest CT examination combined with imaging until 1 year after radiotherapy.The patients were divided into two groups(grade 2): no RILI group and RILI group(Grade 2),using the classification standard of lung function injury with radioactive substances of the American Cancer Radiotherapy Collaboration Group and the European Cancer Therapy Collaboration Group(RTOG).1 week before radiotherapy and the time point of daily adjustment of radiotherapy plan were 95%PTV 50Gy/25 f.The values of peripheral blood neutrophils(N),neutrophils/lymphocytes(NLR),monocytes/lymphocytes(MLR)and clinical symptoms of patients before and after radiotherapy were changed.In addition,the dose volume histogram was collected to obtain V5 and V20,the clinical data of patients,and the corresponding ROC curve was drawn in combination with clinical hematologicalinflammatory response indicators,so as to analyze the relationship between radiation lung injury and them and determine the optimal threshold value.When P<0.05,the difference was statistically significant,and when P<0.01,the difference was significant.Results: All the data were statistically processed and analyzed.1.In this study,the incidence rate of ≥Grade 2 RILI was 27.50%(11/40),among which grade 2 RILI occurred in 8 cases and grade 3 RILI in 3 cases,and no grade 4 or grade 5radiation lung injury occurred.2.Univariate analysis shows that: In thoracic tumor patients receiving IMRT,the incidence of RILI was higher in those with higher changes in blood routine indexes of neutrophil(N),neutrophil/lymphocyte(NLR)and monocyte/lymphocyte(MLR)than before radiotherapy.Was a risk factor for RILI ≥ grade 2,and the differences were statistically significant(P<0.05).3.ROC curve analysis and X2 test showed that when neutrophil number(N)≥3.290×109/L,neutrophil/lymphocyte(NLR)≥2.687×109/L,monocyte/lymphocyte(MLR)≥0.406×109/L,the incidence of Grade ≥2 RILI was significantly increased(P<0.05).4.Multivariate analysis showed that neutrophil(N),neutrophil/lymphocyte(NLR),and monocyte/lymphocyte(MLR)were independent risk factors for ≥ grade 2 RILI.Conclusions: The following conclusions can be drawn:1.Patients with radioactive lung injury often present with abnormal chest CT findings,and most of the changes in chest CT are reversible after treatment.2.For thoracic cancer patients receiving radiotherapy,when the total dose of radiotherapy reaches 50 Gy,blood cell analysis is detected and neutrophil(N),neutrophil/lymphocyte(NLR)and monocyte/lymphocyte(MLR)are higher than before radiotherapy,we should give patients individualized treatment in time and actively review chest CT.Reduce the exposure volume and adjust the radiation dose according to the demand to avoid the formation of very serious RILI.3.Neutrophils(N),neutrophils/lymphocytes(NLR),monocytes/lymphocytes(MLR)were risk predictors of grade 2 RILI.4.The risk of grade 2 RILI was reduced when neutrophil count(N)<3.290×109/L,neutrophil/lymphocyte(NLR)<2.687×109/L,monocyte/lymphocyte(MLR)<0.406×109/L.