Patterns of locoregional failure in locally advanced non-small cell lung cancer treated with definitive conformal radiotherapy: Results from the Gating 2006 trial

Radiother Oncol. 2018 Feb;126(2):291-299. doi: 10.1016/j.radonc.2017.11.002. Epub 2017 Dec 1.


Purpose: To determine the patterns of locoregional failure (LRF) in patients with locally advanced non-small cell lung cancer treated with definitive radiotherapy (RT).

Patients and methods: One hundred and fifty-four patients from the Gating 2006 prospective randomized trial were treated with conformal RT with or without respiratory motion management. For patients with a LRF as first event, treatment planning with simulation CT, pre-treatment 18FDG PET-CT and post-treatment images demonstrating recurrence were registered and analyzed. Measurable LRF was contoured (rGTV) and classified as in-field, marginal, or out-of-field.

Results: Median follow-up was 27.8 months. Forty-eight patients presented with LRF. One-year and 2-year locoregional disease-free survival rates were 77% (95% CI 70-83) and 72% (95% CI 64-79) respectively. 79% of the patients with LRF as first event relapsed within the RT field (55% isolated), 30% had marginal LRF component. Isolated out-of-field failure occurred in only 3% of all patients. The regions of highest FDG-uptake on pre-treatment PET-CT were located within the recurrence in 91% of patients with in-field LRF.

Conclusion: In-field failure was the most common pattern of failure. Escalated dose RT with high-dose fractions guided by PET parameters warrants further investigation.

Keywords: 18FDG PET-CT; Conformal radiotherapy; Dosimetric analysis; Locoregional failure; Lung cancer.

Publication types

  • Clinical Trial, Phase III
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Carcinoma, Non-Small-Cell Lung / diagnostic imaging
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Carcinoma, Non-Small-Cell Lung / radiotherapy*
  • Disease-Free Survival
  • Female
  • Fluorodeoxyglucose F18
  • Humans
  • Lung Neoplasms / diagnostic imaging
  • Lung Neoplasms / pathology
  • Lung Neoplasms / radiotherapy*
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / pathology
  • Positron Emission Tomography Computed Tomography / methods
  • Prospective Studies
  • Radiopharmaceuticals
  • Radiotherapy Planning, Computer-Assisted
  • Radiotherapy, Conformal


  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18