100P - A new PET-CT score for locally-advanced inoperable NSCLC stage III patients treated with chemoradiotherapy

Date 05 April 2019
Event European Lung Cancer Congress 2019
Topics Imaging
Presenter Olarn Roengvoraphoj
Citation Annals of Oncology (2019) 30 (suppl_2): ii31-ii37. 10.1093/annonc/mdz067
Authors O. Roengvoraphoj1, C. Eze1, J. Taugner1, A. Gjika1, A. Tufman2, L. Käsmann1, I. Hadi1, E. Mille3, C. Belka1, F. Manapov1
  • 1Radiation Oncology, LMU Klinikum der Universität München, 81377 - München/DE
  • 2LMU Klinikum der Universität München, 80336 - Munich/DE
  • 3Nuclear Medicine, LMU Klinikum der Universität München, 81377 - München/DE

Abstract

Background

FDG-PET/CT is an integral part of staging and radiation treatment planning for patients with stage III non-small cell lung cancer (NSCLC). In this study, we analysed the correlation between different PET parameters and survival in NSCLC patients treated with chemoradiotherapy (CRT).

Methods

Ninety-nine consecutive patients with NSCLC stage IIIA-B and good performance status, who underwent FDG-PET-CT before the start of CRT were analysed. Maximum standardized uptake value of primary tumor (SUVmax_PT) and range between the two most distant PET-positive (SUV≥3) lymph nodes in two directions (cranio-caudal and transversal) were analysed for their correlation with patient survival. The cranio-caudal distance was defined as A- and the transversal as B-line. The area under the ROC curve (AUC) as well as the cut-off SUVmax, A- and B-lines were calculated.

Results

Median survival for the entire cohort was 20.8 months (95% CI: 15.3-26.3). Patients with SUVmax_PT ≥ 8 had poor overall survival (OS) (19 vs. 40 months in patients with SUVmax ≥ 8 and <8, p < 0.0001). A-line was not associated with OS, whereas B-line < 3.7 cm improved OS significantly (30 vs. 16 months in patients with B-line < 3.7 and ≥3.7cm, p = 0.001). The sum of A- and B-lines with the cut-off at 6.7cm correlated with overall survival significantly (29 vs. 18 months in patients with sum < 6.7 and ≥6.7cm, p = 0.04). The PET-CT score was generated on the basis of PET parameters correlated with OS in univariate analysis. The patients were divided into 4 subgroups. The low-risk subgroup (0 points) included patients with SUVmax_PT< 8, B-line < 3.7 cm and the sum of A- and B-lines < 6.7 cm (n = 20, 21.3%). Twenty-eight patients (29.5%) had 1 point (intermediate risk), 20 (21.3%) had 2 points (high) and 26 patients (27.7%) had 3 points (very high risk). Median OS in terms of low/intermediate/high and very high risk subgroups was 40 (95% CI: 0-83)/27 (95% CI: 15-39)/26 (95% CI: 15-37) and 14 months (95% CI: 13-14), (p = 0.0001).

Conclusions

A new PET-CT score was developed for patients with inoperable stage III NSCLC treated with definitive CRT. Initial SUVmax_PT < 8, B-line < 3.7 cm and PET-CT score were predictors of patient long-term outcome.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.