Study On The Prognosis Of Brain Metastases Based On Dosimetry,Imaging Features And NLR

Objectives1.Brain metastases are the most common intracranial malignant tumors,among which lung cancer has the highest risk of metastasis.this study analyzed the dosimetric advantages of Volumetric Modulated Arc Therapy(VMAT)in whole brain plus simultaneous integrated boost radiotherapy for brain metastases from lung cancer.2.To observe the short-term efficacy,long-term survival rate and prognostic factors of VMAT whole brain plus simultaneous integrated boost in the treatment of brain metastases from lung cancer.3.To analyze the changes of apparent diffusion coefficient(ADC)in VMAT before and after radiotherapy and to predict and evaluate the short-term efficacy of VMAT in the treatment of brain metastases.4.To analyze the changes of neutrophil to lymphocyte ratio(NLR)in VMAT before and after radiotherapy and to predict and evaluate the short-term efficacy of VMAT in the treatment of brain metastasesMethods1.The clinical data of 40 patients with brain metastasis of lung cancer who received VMAT radiotherapy in my hospital from January 1,2016 to April 30,2018 were analyzed retrospectively.2.Ten patients were randomly selected and make IMRT 9-field simultaneous integrated boost(SIB)plan respectively,and the advantages and disadvantages were compared with the VMAT plan.The dose of whole brain was 30 Gy per time,and the GTV of was simultaneous integrated to 40 Gy per time,1-3 metastatic tumors in 5 cases and 4-7 metastatic tumors in 5 metastatic tumors.Evaluation indicators:conform index(CI)and homogeneity index(HI)of PGTV and PTV.3.The imaging examinations(CT,MRI)of 40 patients before and after radiotherapy were taken from the His system,and the short-term efficacy of the patients was evaluated according to the response assessment in neuro-oncology(RANO).4.Forty patients with brain metastasis of lung cancer were followed up,including regular reexamination and telephone follow-up.intracranial progression-free survival(IPFS)and overall survival(OS)were calculated by Kaplan-Meier method,and univariate analysis and Cox regression model multivariate analysis were performed..5.Among the 40 patients with brain metastases,20 patients underwent MRI examination before and 1 month after radiotherapy.A total of 60 brain metastatic lesions were evaluated according to RANO criteria.The 60 lesions were divided into radiation sensitive group(CR+PR)38(63.3%)and insensitive group(SD+PD)22(36.7%).The Receiver operating characteristic curve(ROC)method was used to analyze the value of ADC value in predicting and evaluating the efficacy of VMAT radiotherapy in patients with lung cancer with brain metastases.6.The counts of neutrophils and lymphocytes in the blood routine of the patients were recorded before and after radiotherapy,and NLR was calculated.the curative effect of radiotherapy was evaluated according to RANO criteria.40 patients were divided into radiotherapy sensitive group(CR+PR,n=19)and non-sensitive group(SD+PD,n=21).The ROC method was used to analyze the value of NLR in predicting and evaluating the efficacy of VMAT radiotherapy in patients with lung cancer with brain metastasis.Results1.VMAT is superior to IMRT(in CI and HI of the target area of brain metastases and CI in the target area of whole brain.With the increase of the number of brain metastases,the advantage of VMAT plan is more obvious.2.The 1-year IPFS was 52.3%,the median intracranial progression-free survival time was 28 months,the 1-year and 2-year OS were 56.8%and 36.7%,respectively,and the median survival time was 15 months.3.Univariate analysis showed that targeted therapy(P=0.043),KPS(P=0.0002)and RPA grade(P=0.006)were associated with IPFS,while targeted therapy(P=0.039),KPS(P=0.021),RPA grade(P=0.037),GPA score(P=0.045),NLR(P=0.043)and single dose of PGTV(P=0.008)were associated with OS.4.Multivariate analysis showed that targeted therapy(P=0.033)was an independent influencing factor of IPFS and targeted therapy(P=0.014),KPS(P=0.046)were independent prognostic factors of OS.5.Of the 60 lesions in 20 patients,the ADC value of 35 lesions(58.3%)increased after VMAT radiotherapy compared with that before radiotherapy,and the difference was statistically significant(P=0.015).The ADC value of sensitive group after radiotherapy was higher than that before radiotherapy(P=0.012).There was no significant difference in ADC value of insensitive group before and after radiotherapy(P=0.645).The diagnostic threshold of ADC value before radiotherapy is 0.878 ×10-3mm2/s,at this time,the sensitivity of evaluating whether the lesion is sensitive or not is 71.05%,the specificity is 59.09%;after radiotherapy,the diagnostic threshold of ADC value is 0.679 × 10-3mm2/s,the sensitivity is 28.95%,the specificity is 86.36%,the diagnostic threshold of ADC change value is 0.247 × 10-3mm2/s,the sensitivity is 39.47%,and the specificity is 90.91%.6.The total NLR of 40 patients after radiotherapy had no significant difference compared with that before radiotherapy,but the NLR of sensitive group after radiotherapy was higher than that of non-sensitive group(P=0.013),and the NLR of insensitive group had no significant difference before and after radiotherapy(P=0.247).The NLR value of sensitive group before radiotherapy was lower than that of insensitive group(P=0.027).there was no significant difference in NLR between sensitive group and insensitive group after radiotherapy(P=0.628),but there was no significant difference in NLR between sensitive group and insensitive group after radiotherapy.Before radiotherapy,the diagnostic threshold of NLR was 8.63,the sensitivity was 100%,and the specificity was 40.91%;after radiotherapy,the diagnostic threshold of NLR was 2.66,the sensitivity was 81.58%,and the specificity was 54.55%.ConclusionThe larger number of brain metastases,the more significant the dosimetric advantage of VMAT is;the patients with high KPS score,high GPA score,low RPA grade and low NLR value had a better prognosis;targeted therapy was an independent factor affecting IPFS and OS;the ADC value of lesions after radiotherapy was higher than that before radiotherapy(P=0.015);the difference of NLR value between sensitive group and non-sensitive group before radiotherapy was statistically significant,which has a certain diagnostic value in evaluating the short-term efficacy of VMAT radiotherapy for brain metastases.