Efficacy And Prognostic Factors Analysis Of Hypofractionated Radiotherapy For Oligometastatic Non-Small Cell Lung Cancer

BackgroundLocal therapy(including surgery,radiation therapy,or radiofrequency ablation)is becoming an important part of oligometastatic non-small cell lung cancer(OMNSCLC).Hypofractionated radiation therapy(HFRT)can appropriately adjust the single dose and the number of fractions according to the location and size of the metastatic tumor and the adjacent normal tissue,so as to reduce the radiation dose to organs at risk and reduce the toxicity.The literature on the use of HFRT in the treatment of OM-NSCLC patients in the new treatment context is limited.This study retrospectively analyzed the clinical data of OM-NSCLC patients receiving HFRT to explore the therapeutic efficacy and safety of HFRT in OM-NSCLC patients.Materials and MethodsA retrospective analysis of OM-NSCLC patients who received HFRT in the Department of Oncology and Radiotherapy of the First Affiliated Hospital of Bengbu Medical College from January 2018 to December 2021.Locations of metastases include brain,lung,liver,bone,adrenal gland,and lymph nodes.The dose of HFRT was 25.0-60.0Gy,2.5-8.0Gy/fraction;the median bioequivalent dose was 65.2±12.6Gy,and 9patients with brain metastases received HFRT combined with whole brain radiation therapy(whole brain radiation therapy,WBRT),the dose of WBRT is 30.0-40.0Gy,2.0-3.0Gy/fraction.The dose fractionation scheme was appropriately adjusted according to the location and size of the lesion.The treatment effect was evaluated according to the RECIST1.1 standard,and the radiotherapy-related adverse reactions were evaluated according to the RTOG/EORTC toxicity standard.In this study,SPSS 25.0 software was used for statistical analysis,Kaplan-Meier method for survival analysis,Cox regression model for univariate and multivariate analysis,and univariate analysis for local control(LC)of lesions.P<0.05 considered the difference to be statistically significant.Results1.According to the inclusion and exclusion criteria,62 eligible patients were enrolled.Patients were followed up for a median of 28.0 months(range,5.0-36.0months),and a median age of 62 years(range,38-86 years).The median progressionfree survival(PFS)and median overall survival(OS)were 12.0 months and 23.0months,respectively.1-year and 2-year PFS were 54.8% and 19.4% respectively;1-year and 2-year OS were 83.9% and 45.2% respectively;12-month and 18-month LC were78.2% and 33.3% respectively.2.Univariate analysis showed pathological type(P<0.001),whether the primary tumor received local treatment(P=0.013),T stage(P=0.003),N stage(P=0.003),number of metastatic organs(P=0.009)and number of metastatic lesions(P=0.006)was significantly associated with PFS in OM-NSCLC patients.The results of multivariate analysis showed that the pathological type(P<0.001)and whether the primary tumor received local treatment(P=0.004)were still significantly related to the PFS of the patients.3.Univariate analysis showed ECOG score(P=0.041),pathological type(P<0.001),metastatic status(P=0.029),whether the primary tumor received local treatment(P=0.024),mutation type(P=0.039),T stage(P=0.002),N stage(P=0.001),number of metastatic organs(P=0.019)and number of metastases(P=0.010)were significantly correlated with OS of OM-NSCLC patients.The results of multivariate analysis showed that ECOG score(P=0.029),pathological type(P=0.005),metastasis status(P=0.022),and whether the primary tumor received local treatment(P=0.020)were still significantly related to the OS of patients.4.Univariate analysis of 78 HFRT metastatic lesions showed that lesion gross tumor volume(GTV)(P=0.013)and radiotherapy dose(P=0.012)were significantly correlated with LC in OM-NSCLC patients.Conclusions1.HFRT for the metastatic lesions of selected eligible OM-NSCLC patients can obtain good PFS,OS and LC,and is a safe and effective treatment.2.The pathological type and whether the primary tumor received local treatment are important prognostic factors for PFS in patients with OM-NSCLC.ECOG score,pathological type,whether the primary tumor received local treatment,and metastatic status were important prognostic factors for OS in patients with OM-NSCLC.The GTV volume of the lesion and the dose of radiotherapy are independent prognostic factors for LC.