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

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.

Efficacy and Safety of Gemcitabine Plus Cisplatin as Potential Preoperative Chemotherapy in Locally Advanced Intrahepatic, Perihilar, and Mid-Cholangiocarcinoma: A Retrospective Cohort Study.

BACKGROUND: In this retrospective cohort study, the potential of gemcitabine (gem)/cisplatin (cis) chemotherapy as future preoperative therapy for patients with unresectable locally advanced or borderline resectable intrahepatic, perihilar, and mid-cholangiocarcinoma was investigated. METHODS: All patients with intrahepatic, perihilar, and mid-cholangiocarcinoma presented at Amsterdam UMC between January 2016 and October 2019 were included. The radiologic response after 3 and/or 6 cycles of gem/cis chemotherapy in patients with unresectable locally advanced or borderline resectable disease was derived from the original radiologic reports and subsequently re-evaluated for surgical exploration by consensus reading of 2 HPB surgeons and 1 radiologist. RESULTS: Overall, 65 of 364 patients had a locally advanced or borderline resectable disease. Twenty-eight patients were treated with palliative chemotherapy, including 25 (89.3%) patients who received more than 3 cycles. Twenty-two patients (88.0%) and 13 patients (46.4%) showed RECIST stable disease or partial response after 3 and 6 cycles of chemotherapy, respectively. Three patients experienced grade 3 adverse events. Consensus reading concluded that exploration could have been reconsidered in 7 of 28 patients (25.0%). CONCLUSION: Gem/cis may be a safe and feasible preoperative treatment in initially unresectable locally advanced or borderline resectable cholangiocarcinoma. In addition, the findings of this study support to always rediscuss patients with stable or responsive disease in multidisciplinary team meetings to reconsider resection. Besides, prospective studies are needed to investigate this effect further and, based on these preliminary data, seem feasible in this setting.

A prospective study comparing water only with positive oral contrast in patients undergoing abdominal CT scan.

Consecutive adults scheduled to undergo abdominal CT with oral contrast were asked to choose between 1000 ml water only or positive oral contrast (50 ml Télébrix-Gastro diluted in 950 ml water). Two abdominal radiologists independently reviewed each scan for image quality of the abdomen, the diagnostic confidence per system (gastrointestinalsystem/organs/peritoneum/retroperitoneum/lymph nodes) and overall diagnostic confidence to address the clinical question (not able/partial able/fully able). Radiation exposure was extracted from dose reports. Differences between both groups were evaluated by Student's t-test, Mann-Whitney-U-test or chi-square-test. Of the 320participants, 233chose water only. All baseline characteristics, image quality of the abdomen and the diagnostic confidence of the organs were comparable between groups and both observers. Diagnostic confidence in the water only group was more commonly scored as less than good by observer1. The results were as follows: the gastrointestinal system(18/233vs1/87; p = 0.031), peritoneum (21/233vs1/87; p = 0.012), retroperitoneum (11/233vs0/87; p = 0.040) and lymph nodes (11/233vs0/87; p = 0.040). These structures were scored as comparable between both groups by observer2. The diagnostic confidence to address the clinical question could be partially addressed in 6/233 vs 0/87 patients (p = 0.259). The water only group showed a tendency towards less radiation exposure. In summary, most scan ratings were comparable between positive contrast and water only, but slightly favored positive oral contrast for one reader for some abdominal structures. Therefore, water only can replace positive oral contrast in the majority of the outpatients scheduled to undergo an abdominal CT.