What is the Prognostic Value of a Discordant Radiologic and Pathologic Response in Patients Undergoing Resection of Colorectal Liver Metastases After Preoperative Chemotherapy?

BACKGROUND: The clinical significance of discordant radiological and pathological response to preoperative chemotherapy of colorectal liver metastases (CLM) is unknown. METHODS: From 2011 to 2016, all eligible patients undergoing resection for CLM after preoperative chemotherapy were included at two centres. Patients were categorized according to radiologic response using RECIST as Rad-responders (complete/partial response) or Rad-non responders (stable disease) and according to Blazer et al. pathologic response grade as Path-responders (complete/major response) or Path-non responders (minor response). Survival outcome was analysed according to radiologic and pathologic response. RESULTS: Among 413 patients undergoing resection of CLM, 119 fulfilled the inclusion criteria. Among these, 52 (44%) had discordant radiologic and pathologic response including 27 Rad-non responders/path responders and 25 Rad-responders/Path-non responders. Rad-non responders/path responders and Rad-responders/Path-non responders had similar characteristics except for the proportion receiving more than 6 cycles of preoperative chemotherapy (7/27 vs 16/25; P = 0.017). Median disease-free survival was not different in patients with or without discordant radiologic and pathologic responses (P = 0.195) but the type of discordance had an impact on oncologic outcome as median disease-free survival was 13.9 months (95% CI 5.7-22.2 months) in Rad-non responders/Path responders and 8.6 (6.2 - 10.9 months) in Rad-responders/Path-non responders (P = 0.034). Univariate and multivariate analysis showed that major pathologic response was associated with improved disease-free survival (OR 0.583, 95% CI 0.36-0.95, P = 0.031). CONCLUSION: A discordant radiologic and pathologic response is common after preoperative chemotherapy for CLM. In these patients, pathologic response drives oncologic outcome.

Comparison of semi-automated and manual methods to measure the volume of liver tumours on MDCT images.

OBJECTIVE: To retrospectively compare semi-automated and manual volume measurements of malignant liver tumours and inter- and intra-observer variability using commercially available software. METHODS: This study was performed on 60 consecutive patients with untreated liver metastases (30) and HCCs (30), i.e. 92 lesions (49 metastases, 43 HCCs) using hepatic MDCT. Lesion volumes were manually measured independently by two radiologists and semi-automatically by the same two radiologists and a technician. Those measurements were repeated on 20 patients (10 metastases and 10 HCCs) a week later. An independent operator timed all the measurements. Using the Spearman correlation coefficient and Bland-Altman plots, statistical analyses were performed. RESULTS: Liver lesion volumes obtained with semi-automated and manual methods were well correlated (Spearman, r = 0.98 and 0.91). Their agreement was high for intra-observer measurements with the semi-automated method (Spearman, r = 0.91 and 0.94). The agreement was lower for inter-observer measurements with both methods (Spearman, r = 0.87 for semi-automated and 0.91 for manual). The semi-automated method significantly reduced the post-processing duration (23s ± 19s vs. 33s ± 11s, p value <0.0001). CONCLUSION: In our study, semi-automated volume analysis of malignant liver tumours correlated well with the manual method. Furthermore, the semi-automated volume analysis was significantly quicker.