Binkley, Michael S.Koenig, Julie L.Kashyap, MehrXiang, MichaelLiu, YufeiSodji, QuaoviMaxim, Peter G.Diehn, MaximilianLoo, Billy W., Jr.Gensheimer, Michael F.2020-07-302020-07-302020-05-19Binkley, M. S., Koenig, J. L., Kashyap, M., Xiang, M., Liu, Y., Sodji, Q., Maxim, P. G., Diehn, M., Loo, B. W., Jr, & Gensheimer, M. F. (2020). Predicting per-lesion local recurrence in locally advanced non-small cell lung cancer following definitive radiation therapy using pre- and mid-treatment metabolic tumor volume. Radiation oncology (London, England), 15(1), 114. https://doi.org/10.1186/s13014-020-01546-yhttps://hdl.handle.net/1805/23454Background: We evaluated whether pre- and mid-treatment metabolic tumor volume (MTV) predicts per lesion local recurrence (LR) in patients treated with definitive radiation therapy (RT, dose≥60 Gy) for locally advanced non-small cell lung cancer (NSCLC). Methods: We retrospectively reviewed records of patients with stage III NSCLC treated from 2006 to 2018 with pre- and mid-RT PET-CT. We measured the MTV of treated lesions on the pre-RT (MTVpre) and mid-RT (MTVmid) PET-CT. LR was defined per lesion as recurrence within the planning target volume. Receiver operating characteristic (ROC) curves, cumulative incidence rates, and uni- and multivariable (MVA) competing risk regressions were used to evaluate the association between MTV and LR. Results: We identified 111 patients with 387 lesions (112 lung tumors and 275 lymph nodes). Median age was 68 years, 69.4% were male, 46.8% had adenocarcinoma, 39.6% had squamous cell carcinoma, and 95.5% received concurrent chemotherapy. Median follow-up was 38.7 months. 3-year overall survival was 42.3%. 3-year cumulative incidence of LR was 26.8% per patient and 11.9% per lesion. Both MTVpre and MTVmid were predictive of LR by ROC (AUC = 0.71 and 0.76, respectively) and were significantly associated with LR on MVA (P = 0.004 and P = 7.1e-5, respectively). Among lesions at lower risk of LR based on MTVpre, higher MTVmid was associated with LR (P = 0.001). Conclusion: Per-lesion, larger MTVpre and MTVmid predicted for increased risk of LR. MTVmid was more highly predictive of LR than MTVpre and if validated may allow for further discrimination of high-risk lesions at mid-RT informing dose painting strategies.en-USAttribution 4.0 InternationalFDG-PETMetabolic tumor volumeLung cancerArticle