title: Once Daily High-dose Radiation (≥60 Gy) Treatment in Limited Stage Small Cell Lung Cancer.
abstract: BACKGROUND
  To investigate outcomes and prognostic factors in patients treated with once daily high-dose (≥60 Gy) radiation therapy (HDRT) and concurrent platinum-based chemotherapy in limited stage small cell lung cancer (LS-SCLC). While we await current phase III trials to determine optimal radiation dose fractionation schemes in LS-SCLC, we report our experience in LS-SCLC with once daily HDRT. We hypothesized that HDRT would achieve similar efficacy and tolerability as twice daily therapy.
  
  
  METHODS
  We conducted a single institution retrospective review of all patients with LS-SCLC who underwent curative intent treatment from 2005-2013. Patients treated with HDRT (≥60 Gy) and concurrent chemotherapy (cisplatin or carboplatin and etoposide) were included in our analysis. Clinicopathologic variables assessed include gender, performance status, time to treatment, response to treatment, toxicity, volumetric tumor response at 3 months, and use of prophylactic cranial irradiation (PCI).
  
  
  RESULTS
  42 patients with LS-SCLC who initiated concurrent chemoradiation from 2005 to 2013 were included in the analysis. 38 patients (90%) completed definitive treatment to the lung; 16 (38%) also completed PCI. Median failure free survival (FFS) and overall survival (OS) were 11.9 and 23.1 months, respectively. Two-year and 5-year OS rates were 47% (CI=30-62%) and 21% (CI=7-38%), respectively. On univariate analysis, PCI was associated with improved FFS but this was not significant (p=0.18). Gender was the only co-variate significantly associated with statistical differences in FFS (p=0.03) and OS (p=0.02). Grade 3 and 4 esophagitis were 10.5% and 2.6%, respectively. Pre-HDRT tumor volume and 3-month post-treatment tumor volume were both associated with FFS (p<0.01) but not OS.
  
  
  CONCLUSIONS
  In this single institution series, daily HDRT demonstrated a 2-year OS of 47% in LS-SCLC. This compares well to the historical survival of daily fractionation (47%) from INT 0096 reported by Turrisiet. al. Male gender was predictive of significantly worse FFS and OS. Once daily HDRT has similar OS to twice-daily radiation schemes; however, further studies assessing once daily HDRT for LS-SCLC are warranted.
authors.affiliation: University of Iowa Hospitals & Clinics, Iowa City, IA.
authors.forename: Amir
authors.initials: A
authors.lastname: Zahra
authors.affiliation: University of Iowa Hospitals & Clinics, Iowa City, IA.
authors.forename: Tangel
authors.initials: T
authors.lastname: Chang
authors.affiliation: University of Iowa Hospitals & Clinics, Iowa City, IA.
authors.forename: Taher Abu
authors.initials: TA
authors.lastname: Hejleh
authors.affiliation: University of Iowa Hospitals & Clinics, Iowa City, IA.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Furqan
authors.affiliation: University of Iowa Hospitals & Clinics, Iowa City, IA.
authors.forename: Gerald H
authors.initials: GH
authors.lastname: Clamon
authors.affiliation: Albany Stratton VA Medical Center, Albany, NY.
authors.forename: Sudershan K
authors.initials: SK
authors.lastname: Bhatia
authors.affiliation: University of Iowa Hospitals & Clinics, Iowa City, IA.
authors.forename: John M
authors.initials: JM
authors.lastname: Watkins
authors.affiliation: University of Iowa, Holden Comprehensive Cancer Center, Iowa City, IA.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Mott
authors.affiliation: University of Iowa Hospitals & Clinics, Iowa City, IA.
authors.forename: Logan L
authors.initials: LL
authors.lastname: Ahmann
authors.affiliation: University of Iowa Hospitals & Clinics, Iowa City, IA.
authors.forename: Kellie L
authors.initials: KL
authors.lastname: Bodeker
authors.affiliation: University of Iowa Hospitals & Clinics, Iowa City, IA.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Spitz
authors.affiliation: University of Iowa Hospitals & Clinics, Iowa City, IA.
authors.forename: John M
authors.initials: JM
authors.lastname: Buatti
authors.affiliation: University of Iowa Hospitals & Clinics, Iowa City, IA.
authors.forename: Bryan G
authors.initials: BG
authors.lastname: Allen
keywords: Daily High-Dose Radiation Therapy; Limited Stage Small cell Lung Cancer; Radiation Dose Fractionation