Evaluation for local failure by 18F-FDG PET/CT in comparison with CT findings after stereotactic body radiotherapy (SBRT) for localized non-small-cell lung cancer

Atsuya Takeda, Etsuo Kunieda, Hirofumi Fujii, Noriko Yokosuka, Yousuke Aoki, Yoshikazu Oooka, Yohei Oku, Toshio Ohashi, Naoko Sanuki, Tomikazu Mizuno, Yukihiko Ozawa

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

Purpose: Stereotactic body radiotherapy (SBRT) is the standard care for medically inoperable early non-small-cell lung cancer (NSCLC). However, it can be difficult to differentiate local recurrence from non-recurrence radiation-induced lung opacity. We retrospectively assessed 18F-FDG PET/CT to detect local recurrence after SBRT for NSCLC. Methods: Between 2005 and 2011, 273 NSCLCs in 257 patients were treated with SBRT. Prescribed doses were 50Gy and 40Gy per 5 fractions for peripheral and central lesions, respectively. Tri-monthly follow-up CT scans were acquired. 18F-FDG PET/CT scans were scheduled for screening at one year after SBRT or when recurrence was highly suspected. The dual-time-point maximum standardized uptake values (SUVmaxs) and their retention indexes (RIs) were obtained. Results: A total of 214 18F-FDG PET/CT scans were obtained for 164 localized NSCLC tumors in 154 patients. The median follow-up period was 24.9 months (range: 6.3-72.1). Among these, 21 scans of 17 tumors were diagnosed as local recurrence. The median SUVmaxs on early and late images of recurrence and their RI were 5.0 (range: 3.2-10.7), 6.3 (range: 4.2-13.4), and 0.20 (range; 0-0.41), respectively. These were significantly higher than the respective values of non-recurrence images of 1.8 (range: 0.5-4.6), 1.7 (range: 0.5-6.1), and 0.00 (range: -0.37-0.41) (all p<0.05). For SUVmaxs on early and late images, optimal thresholds were identified as 3.2 and 4.2. Using each threshold, the sensitivity and specificity were 100% and 96-98%, respectively. CT findings were classified into ground-glass opacity (N=9), scar or fibrotic change (N=96), consolidation with air-bronchogram (N=34), consolidation only (N=22), and nodule (N=17); the respective numbers of recurrence were 0, 0, 1, 3, and 17. Conclusion: SUVmaxs of 18F-FDG PET/CT could detect local recurrence after SBRT for localized NSCLC. In contrast, CT scan results had a limited ability to diagnose local recurrence.

Original languageEnglish
Pages (from-to)248-253
Number of pages6
JournalLung Cancer
Volume79
Issue number3
DOIs
Publication statusPublished - 2013 Mar 1

Keywords

  • Detection of local recurrence
  • F-FDG PET/CT
  • Non-small-cell lung cancer
  • Stereotactic body radiotherapy (SBRT)

ASJC Scopus subject areas

  • Oncology
  • Pulmonary and Respiratory Medicine
  • Cancer Research

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