Use of High Energy Photons Does Not Compromise Pathologic Response Rate in Treatment of Non-Small Cell Lung Cancer

Purpose/Objective: Most cooperative group trials involving radiation for lung cancer require treatment of the primary tumor with photon energies 6MV. When treating tumors of the lung with higher energy photons most planning systems are unable to accurately determine the contribution of scatter at the interface of the low density lung and the higher density tumor, potentially leading to decreased target coverage and poorer local control. At The University of Maryland our standard approach has involved the use of higher energy photons ( 15MV) in the neoadjuvant setting because the better dose homogeneity obtained decreases hot spots in the surgical bed potentially leading to decreased postoperative mortality and morbidity. The purpose of this study is to examine the pathologic complete response rate of primary tumors in patients with stage IIB-IIIB NSCLC treated with concurrent chemoradiation at our institution to determine if our use of high energy photons has led to a lower than expected complete response rates. Published cooperative group trimodality experiences have reported complete response rates of 18–21%.