Interobserver Variability in CT-based Morphologic Tumor Response Assessment of Colorectal Liver Metastases

Nina J Wesdorp*, Ruby Kemna, Karen Bolhuis, Jan H T M van Waesberghe, Irene M G C Nota, Femke Struik, Ikrame Oulad Abdennabi, Saffire S K S Phoa, Susan van Dieren, Martinus J van Amerongen, Thiery Chapelle, Cornelis H C Dejong, Marc R W Engelbrecht, Michael F Gerhards, Dirk Grünhagen, Thomas M van Gulik, John J Hermans, Koert P de Jong, Joost M Klaase, Mike S L LiemKrijn P van Lienden, I Quintus Molenaar, Gijs A Patijn, Arjen M Rijken, Theo M Ruers, Cornelis Verhoef, Johannes H W de Wilt, Rutger-Jan Swijnenburg, Cornelis J A Punt, Joost Huiskens, Jaap Stoker, Geert Kazemier, Dutch Colorectal Liver Expert Panel

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Purpose To evaluate interobserver variability in the morphologic tumor response assessment of colorectal liver metastases (CRLM) managed with systemic therapy and to assess the relation of morphologic response with gene mutation status, targeted therapy, and Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 measurements. Materials and Methods Participants with initially unresectable CRLM receiving different systemic therapy regimens from the randomized, controlled CAIRO5 trial (NCT02162563) were included in this prospective imaging study. Three radiologists independently assessed morphologic tumor response on baseline and first follow-up CT scans according to previously published criteria. Two additional radiologists evaluated disagreement cases. Interobserver agreement was calculated by using Fleiss κ. On the basis of the majority of individual radiologic assessments, the final morphologic tumor response was determined. Finally, the relation of morphologic tumor response and clinical prognostic parameters was assessed. Results In total, 153 participants (median age, 63 years [IQR, 56-71]; 101 men) with 306 CT scans comprising 2192 CRLM were included. Morphologic assessment performed by the three radiologists yielded 86 (56%) agreement cases and 67 (44%) disagreement cases (including four major disagreement cases). Overall interobserver agreement between the panel radiologists on morphology groups and morphologic response categories was moderate (κ = 0.53, 95% CI: 0.48, 0.58 and κ = 0.54, 95% CI: 0.47, 0.60). Optimal morphologic response was particularly observed in patients treated with bevacizumab (P = .001) and in patients with RAS/BRAF mutation (P = .04). No evidence of a relationship between RECIST 1.1 and morphologic response was found (P = .61). Conclusion Morphologic tumor response assessment following systemic therapy in participants with CRLM demonstrated considerable interobserver variability. Keywords: Tumor Response, Observer Performance, CT, Liver, Metastases, Oncology, Abdomen/Gastrointestinal Clinical trial registration no. NCT02162563 Supplemental material is available for this article. © RSNA, 2022.

Original languageEnglish
Article numbere210105
Number of pages11
JournalRadiology. Imaging cancer
Volume4
Issue number3
DOIs
Publication statusPublished - May 2022

Keywords

  • Colorectal Neoplasms/diagnostic imaging
  • Female
  • Humans
  • Liver Neoplasms/diagnostic imaging
  • Male
  • Middle Aged
  • Observer Variation
  • Prospective Studies
  • Tomography, X-Ray Computed/methods

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