A Retrospective Study of GTV Additive Accelerated Hyperfractionation Radiotherapy Combined with Concurrent Chemotherapy in Stage II-IIIa Non-Small Cell Lung Cancer

Abstract

Background Among patients with inoperable or declined surgery for stage I-IIIa NSCLC, radiation therapy is the dominant treatment method. When SBRT is used, the outcome is comparable to surgery for stage I NSCLC. Increasing the cure rate and reducing radiation damage by modifying the dose-fraction-time pattern of radiation therapy for stage II-IIIa NSCLC is currently a top priority. In this study, we evaluated gross tumor volume (GTV) plus accelerated hyperfractionation radiotherapy and concurrent chemotherapy for stage II-IIIa NSCLC patients in a retrospective manner. Methods Retrospective analysis of 168 cases with pathologically or cytologically confirmed stage II-IIIa (T1-4N0-2M0) who received accelerated hyperfractionated radiotherapy with wild-center field GTV plus (two different target areas, two different doses) (planned target volume (PTV): PTV 45Gy/25f, GTV 25Gy/25f after 6 hours, 5 days/week, 2 times/day, end of 5-6 weeks) and synchronized chemotherapy (platinum-containing double agent combination chemotherapy or oral etoposide capsules and vincristine capsules) in patients with NSCLC at our hospital from 2002.12-2017.12. Four to six weeks after treatment, the efficacy was evaluated according to Response Evaluation Criteria In Solid Tumours (RECIST), and toxic reactions during the treatment were observed. Survival analysis was performed using the Kaplan-Meier method to calculate patients' local control rates (LC), overall survival rates (OS), and progression-free survival rates (PFS) at 1, 3, and 5 years. Multi-factor prognostic analysis was performed by the Logrank test, and univariate prognostic analysis and Cox model. Results: The complete response rates (CR)were30.4%, partial response rates (PR) were 58.9% and stable disease rates (SD) were 7.7%. The LC rates at 1, 3 and 5 years were 95.8%, 85.1% and 79.8%, respectively; the OS rates were 91.1%, 66.1% and 50.0%, and the PFS rates were 70.2%, 54.2% and 45.2%. All indicators were better than those of the standard conventional fractionated 60Gy/30F concurrent chemotherapy regimen. Since the second daily radiotherapy only irradiated GTV, the doses received by organs at risk (OAR) such as the lung, esophagus and heart could be controlled within the standard range, except for the high incidence of bone marrow suppression due to radiotherapy, the incidence of grade 2-3 lung radiation injury and esophageal radiation injury was ≤7%. Multivariate analysis revealed that clinical stage, platinum-containing chemotherapy regimens and type of pathology were independent risk factors for prognosis (P<0.05). Conclusion GTV additive accelerated hyperfractionation radiotherapy and concurrent chemotherapy in patients with stage II-IIIa NSCLC has an encouraging efficacy profile with tolerable toxicity.