Post-chemoradiotherapy FDG PET with qualitative interpretation criteria for outcome stratification in esophageal squamous cell carcinoma

PLoS One. 2019 Jan 7;14(1):e0210055. doi: 10.1371/journal.pone.0210055. eCollection 2019.

Abstract

Objectives: Post-chemoradiotherapy (CRT) FDG PET is a useful prognosticator of esophageal cancer. However, debate on the diverse criteria of previous publications preclude worldwide multicenter comparisons, and even a universal practice guide. We aimed to validate a simple qualitative interpretation criterion of post-CRT FDG PET for outcome stratification and compare it with other criteria.

Methods: The post-CRT FDG PET of 114 patients with esophageal squamous cell carcinoma (ESCC) were independently interpreted using a qualitative 4-point scale (Qual4PS) that identified focal esophageal FDG uptake greater than liver uptake as residual tumor. Cohen's κ coefficient (κ) was used to measure interobserver agreement of Qual4PS. The Kaplan-Meier method and Cox proportional hazards regression analyses were used for survival analysis. Other criteria included a different qualitative approach (QualBK), maximal standardized uptake values (SUVmax3.4, SUVmax2.5), relative change of SUVmax between pre- and post-CRT FDG PET (ΔSUVmax), mean standardized uptake values (SUVmean), metabolic volume (MV) and total lesion glycolysis (TLG).

Results: Overall interobserver agreement on the Qual4PS criterion was excellent (κ: 0.95). Except the QualBK, SUVmax2.5, and TLG, all the other criteria were significant predictors for overall survival (OS). Multivariable analysis showed only Qual4PS (HR: 15.41; P = 0.005) and AJCC stage (HR: 2.47; P = 0.007) were significant independent variables. The 2-year OS rates of Qual4PS(‒) patients undergoing CRT alone (68.4%) and patients undergoing trimodality therapy (62.5%) were not significant different, but the 2-year OS rates of Qual4PS(+) patients undergoing CRT alone (10.0%) were significantly lower than in patients undergoing trimodality therapy (42.1%).

Conclusions: The Qual4PS criterion is reproducible for assessing the response of ESCC to CRT, and valuable for predicting survival. It may add value to response-adapted treatment for ESCC patients, and help to decide whether surgery is warranted after CRT.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Carcinoma, Squamous Cell / diagnostic imaging
  • Carcinoma, Squamous Cell / therapy*
  • Chemoradiotherapy
  • Esophageal Neoplasms / diagnostic imaging
  • Esophageal Neoplasms / therapy*
  • Female
  • Fluorodeoxyglucose F18*
  • Humans
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Outcome Assessment, Health Care / methods
  • Outcome Assessment, Health Care / statistics & numerical data
  • Positron Emission Tomography Computed Tomography / methods*
  • Proportional Hazards Models
  • Retrospective Studies
  • Tomography, X-Ray Computed

Substances

  • Fluorodeoxyglucose F18

Grants and funding

This study was supported by research grant [CMRPG8F0681] from the Chang Gung Memorial Hospital in Kaohsiung. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.