Pre-treatment FDG-PET predicts the site of in-field progression following concurrent chemoradiotherapy for stage III non-small cell lung cancer

Lung Cancer. 2015 Jan;87(1):23-7. doi: 10.1016/j.lungcan.2014.10.016. Epub 2014 Nov 6.

Abstract

Purpose: 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).

Conclusion: 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.

Keywords: Chemoradiotherapy; FDG-PET; Metabolic tumor volume; Non-small cell lung cancer; Patterns of Failure; SUV.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Carcinoma, Non-Small-Cell Lung / diagnosis*
  • Carcinoma, Non-Small-Cell Lung / mortality
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Carcinoma, Non-Small-Cell Lung / therapy*
  • Chemoradiotherapy
  • Disease Progression
  • Female
  • Fluorodeoxyglucose F18*
  • Follow-Up Studies
  • Humans
  • Lung Neoplasms / diagnosis*
  • Lung Neoplasms / mortality
  • Lung Neoplasms / pathology
  • Lung Neoplasms / therapy*
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Positron-Emission Tomography*
  • ROC Curve
  • Radiotherapy Dosage
  • Tomography, X-Ray Computed
  • Treatment Outcome

Substances

  • Fluorodeoxyglucose F18