A Prospective Study of the Effect of Different Palliative Radiotherapy Fractionation Schedules on Tumor Response and Toxicity in Advanced Non-Small Cell Lung Cancer (NSCLC) Patients

Abstract

Background: The optimal dose of palliative radiotherapy (RT) in symptomatic advanced lung cancer is unclear. Patients and methods: Patients with advanced NSCLC who were indicated for thoracic palliative RT with age up to 65 y and Performance Status (PS) 0 - 2 and no significant cardiac or lung co-morbidities were randomized into two fractionation arms: arm A: 30 Gy/10 over 2 weeks and arm B: 27 Gy/6 over 3 weeks (2 fractions per week) using 2 anterior posterior (AP-PA) fields in both arms. Primary end points were symptomatic and radiological tumor response, respiratory functions assessment. Secondary end point was toxicity. Results: From December 2014 to October 2015, 40 patients were randomized, 20 patients in each arm. There was statistically insignificant higher symptomatic improvement in arm B. Four weeks after treatment, 12 out of 40 patients (30%), 6 patients in each arm, had radiological Partial Response (PR) of the primary thoracic lesion without significant difference between the two arms. There was a tendency for improvement in the post treatment mean Forced Vital Capacity (FVC) and Forced Expiratory Volume in one second (FEV1) in each arm without statistical significance. There were no reported skin reaction s or esophagitis in both arms up to 4 weeks after treatment. Eleven out of the 40 patients (27.5%), 6 in arm B and 5 in arm A, had radiological signs of radiation pneumonitis without significant difference between both arms. Conclusion: The two RT fractionation schedules showed equal efficacy in terms of symptoms relief, radiological response of the primary thoracic tumor, respiratory functions and toxicity. Thus the 27 Gy/6 fractionation arm appears preferable compared to 30 Gy/10 arm to minimize the patients ’ visits and load on the machines.