Comparison Of Recent Efficacy And Prognosis Analysis Of Different Dose And Fractionated Radiation Therapy For Patients With Unresectable Pancreatic Cancer

Objective: To evaluate the objective efficiency and safety of radiotherapy for unresectable pancreatic cancer under different fractionated dose modes,and to analyze the relevant prognostic factors,in order to establish optimal radiotherapy regimen and provide more options for the patients with pancreatic cancer.Materials and Methods: All patients with PDAC who received radiotherapy between September 2017 and September 2020 were retrospectively reviewed.The effects of the patients treated with hypofractionated radiothrapy and conventional radiotherapy regimens were compared.The differences in recent efficacy,adverse events,overall survival,1-year and2-year survival rate in the patients after radiotherapy were assessed,which sought to determine the prognostic factors affecting survival.Results: Among the 64 patients who received radiotherapy,44(68.75%)cases received hypofractionated radiothrapy,20(31.25%)cases received conventional fractionated externalbeam radiation,and 32(50%)cases received chemoradiotherapy.The patients who received hypofractionated radiothrapy were more likely to have survival benefit(median OS: 16.46 vs.12.77 months,P = 0.040),with 1-year survival rate of 66% and 49% and 2-year survival rate of 24% and 12%,respectively,while there was no difference in recent response rate(P = 0.532)or adverse event between the two groups(P > 0.05).Univariate analysis shows that the distant metastasis(χ2 = 5.823,P = 0.016),radiation dose(χ2 = 11.348,P = 0.001),chemotherapy(χ2= 9.658,P = 0.002),neoadjuvant chemotherapy(χ2 = 4.342,P = 0.037)and sequential chemotherapy(χ2 = 4.412,P = 0.036)have an impact on survival in the patients.In a multivariate Cox proportional hazards analysis,the statistical outcomes suggested that distant metastasis(P = 0.021),radiation dose(P = 0.001),chemotherapy(P = 0.003),neoadjuvant chemotherapy(P = 0.048),and sequential chemotherapy(P = 0.044)were independent prognostic factors for the patients.Conclusions:(1)Hypofractionated radiothrapy was an effective treatment for pancreatic cancer,showing better advantages in median overall survival than conventional fractionated radiotherapy.(2)Distant metastasis,radiation dose,chemotherapy,neoadjuvant chemotherapy,and sequential chemotherapy have potential influence on the survival in the patients.Multivariate Cox proportional risk regression model were created to identify prognostic factors associated with PDAC.Statistical outcomes concluded that distant metastasis,radiation dose,chemotherapy,neoadjuvant chemotherapy,and sequential chemotherapy were independent prognostic factors.