A Prospective Phase II Clinical Study of Simultaneous Integrated Boost Radiotherapy on Stage III Local-advanced Non-Small Cell Lung Cancer Patients.

Abstract

PURPOSE/OBJECTIVE(S)\nIn consideration of the results of the RTOG0617 study, researchers began to adopt a prudent policy to high-dose radiotherapy. Based on the assume that radiation dose escalation to the primary tumor can improve local control and therefore producing survival benefits under the condition of limiting the dose to the organ at risk (OAR), we launched the study to evaluate the effect of simultaneous Integrated boost (SIB) radiotherapy implemented on the stage III local-advanced non-small cell lung cancer (LA-NSCLC) patients.\n\n\nMATERIALS/METHODS\n42 Patients with stage III LA-NSCLC who were eligible for definite concurrent chemoradiotherapy were prospectively given the radiation regimen of single dose of 2.0Gy for PTV, 2.2Gy for CTV, and 2.4 -2.8Gy for GTV with 25 fractions. Other stage III LA-NSCLC patients retrospectively collected with routinely radiotherapy were matched through PSM. 2 Cycles of platinum based concurrent chemotherapy were carried on patients in both groups. The primary endpoints were progression-free survival (PFS), toxic effects and dose for normal tissues, with the secondary end point of overall survival (OS). The Kaplan-Meier method was used to evaluate PFS and OS, and the Mann-Whitney U test for toxic effects and the dose for normal tissues.\n\n\nRESULTS\nThe median PFS time was 20.6 vs 9.0 months (P\u202f=\u202f0.01), and the median OS was 40.0 vs 24.5 months (P\u202f=\u202f0.02) in the SIB group and the control group respectively, all were obviously longer in the SIB group. No significant differences of radiation-related pneumonitis (P\u202f=\u202f0.95) and myelosuppression (P\u202f=\u202f0.40) have been observed between the two groups, as well as nausea, vomiting, esophagitis and dyspnea. The dose and the radiation-effected volume to the surrounding normal tissues also did not show the tendency of increasement in the SIB group.\n\n\nCONCLUSION\nThe results of our research has revealed that the dose escalation did improve the PFS and OS while not increased the dose to the surrounding normal tissues and the occurrence of toxic effects. Simultaneous integrated boost radiotherapy to the primary tumor might be a safe and feasible regimen to improve survival benefit for the stage III LA-NSCLC patients eligible for definite concurrent chemoradiotherapy in the future.