Clinical characteristics of patients with non-small cell lung cancer eligible for biology-guided radiotherapy.

Abstract

e20523 Background: Biology-guided radiotherapy (BgRT) is a novel radiotherapy modality that uses real-time positron emission tomography (PET) to guide radiotherapy beamlets. BgRT recently received FDA clearance for clinical use using the 18F FDG radiotracer for the treatment of tumors in lung and bone. We sought to identify non-small cell lung cancer (NSCLC) patients who may be candidates for BgRT based on diagnostic FDG PET/CT imaging. Methods: We conducted an IRB-approved retrospective assessment of NSCLC patients diagnosed between 01/01/2006 and 12/31/2013 at a tertiary care center in the United States. Patient and tumor characteristics were verified by an institutional data repository team and through electronic medical record review. Patients were excluded from analysis when documentation of clinical/ imaging findings was insufficient. Frequency of characteristics were interpreted with and without tumor diameter and maximum standardized uptake value (SUVMax) parameters, to confirm eligibility for BgRT on this novel radiotherapy device. Results: Of the 686 patients eligible for analysis, 523 presented with tumor SUVMax of ≥6 on diagnostic PET imaging and 360 presented with tumor diameters of at least 2 cm and below 5 cm. Of the 277 patients who met both SUVMax and size parameters, respectively, 75 (27.1%), 145 (52.3%), and 57 (20.6%) presented with squamous, adenocarcinoma, or other/unknown histology, and 77 (27.9%), 29 (10.5%), 92 (33.3%), and 78 (28.3%) presented with stage I, II, III, or IV tumors (AJCC 7th edition). Conclusions: Theoretical applicability of biology-guided radiotherapy was observed in our NSCLC patient cohort. Therefore, despite current limitations of radiotracer uptake thresholds and tumor size restrictions, there is broad potential applicability of this treatment modality, either as a single modality treatment or in conjunction with active systemic therapy. [Table: see text]