title: Pre-treatment FDG-PET predicts the site of in-field progression following concurrent chemoradiotherapy for stage III non-small cell lung cancer.
abstract: OBJECTIVE
  Locoregional progression following definitive chemoradiotherapy (CRT) for locally advanced non-small cell lung cancer (NSCLC) is common. In this study, we explore the utility of pre-treatment PET for predicting sites of disease progression following CRT.
  
  
  METHODS
  We identified patients treated at our institution with definitive, concurrent CRT for stage III NSCLC in the years 2007-2010 who underwent staging FDG-PET/CT. Using a semiautomatic gradient-based tool, visible thoracic hypermetabolic lesions were contoured on each patient's pre-treatment PET. Post-treatment imaging was reviewed to identify specific locations of disease progression. Patients' maximum SUV (SUVmax_pat) and metabolic tumor volume (MTV_pat) were evaluated as predictors of clinical outcomes using logrank testing. Competing risks analysis was performed to examine the relationship between lesion (tumor or lymph node) MTV (MTV_les) and the risk of local disease progression. Patient death and progression in other sites were treated as competing risks.
  
  
  RESULTS
  28 patients with 82 hypermetabolic lesions (27 pulmonary tumors, 55 lymph nodes) met inclusion criteria. Median follow-up was 39.0 months for living patients. Median progression-free survival (PFS) was 12.4 months, and median overall survival (OS) was 31.8 months. Low MTV_pat was associated with improved PFS (median 14.3 months for MTV<60 cc vs. 9.7 months for MTV>60 cc, p=0.039). MTV_les was strongly associated with the risk of local disease progression. The 2-year cumulative incidence rate (CIR) for progression in lesions larger than 25 cc was 45%, compared to 5% for lesions under 25 cc (p<0.001).
  
  
  CONCLUSIONS
  Pre-treatment PET can be used to identify specific lesions at high risk for treatment failure following definitive CRT for locally advanced NSCLC. Selective treatment intensification to high-risk lesions should be studied as a strategy to improve clinical outcomes in this patient population.
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th Street, Bronx, NY 10467, United States. Electronic address: ohri.nitin@gmail.com.
authors.forename: Nitin
authors.initials: N
authors.lastname: Ohri
authors.affiliation: Department of Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th Street, Bronx, NY 10467, United States. Electronic address: bpiperdi@montefiore.org.
authors.forename: Bilal
authors.initials: B
authors.lastname: Piperdi
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th Street, Bronx, NY 10467, United States. Electronic address: mgarg@montefiore.org.
authors.forename: Madhur K
authors.initials: MK
authors.lastname: Garg
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th Street, Bronx, NY 10467, United States. Electronic address: wbodner@montefiore.org.
authors.forename: William R
authors.initials: WR
authors.lastname: Bodner
authors.affiliation: Department of Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th Street, Bronx, NY 10467, United States. Electronic address: rgucalp@montefiore.org.
authors.forename: Rasim
authors.initials: R
authors.lastname: Gucalp
authors.affiliation: Department of Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th Street, Bronx, NY 10467, United States. Electronic address: rperezso@montefiore.org.
authors.forename: Roman
authors.initials: R
authors.lastname: Perez-Soler
authors.affiliation: Department of Cardiothoracic Surgery, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th Street, Bronx, NY 10467-2490, United States. Electronic address: skeller@montefiore.org.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Keller
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th Street, Bronx, NY 10467, United States. Electronic address: cguha@montefiore.org.
authors.forename: Chandan
authors.initials: C
authors.lastname: Guha
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D012372:ROC Curve; D011879:Radiotherapy Dosage; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Chemoradiotherapy; FDG-PET; Metabolic tumor volume; Non-small cell lung cancer; Patterns of Failure; SUV