Accuracy of Multislice Liver CT and MRI for Preoperative Assessment of Colorectal Liver Metastases after Neoadjuvant Chemotherapy

Abstract

Introduction: To determine the best imaging modality for preoperative detection, characterization and measurement of colorectal liver metastases (CRLM) after neoadjuvant chemotherapy (NAC). Methods: A total of 79 lesions in 15 patients with CRLM were included. Following NAC, all patients received multislice liver CT (MSCT) and magnetic resonance imaging (MRI) that were scored by two observers for lesion number, type, diameter (mm) and segmental location. Intraoperative findings, histopathology and follow-up imaging were used as reference standard for surgically treated patients; non-surgical candidates underwent follow-up imaging. Results: Lesion detection rate was similar for MSCT and MRI (76 and 80%, respectively, p = 0.648). Lesion characterization was significantly superior (p = 0.021) at MRI (89%, ĸ 0.747, p = 0.001) compared to MSCT (77%, ĸ 0.235, p = 0.005). Interobserver variability for diameter measurement was not significant at MRI (p = 0.909 [95% CI –1.245 to 1.395]), but significant at MSCT (p = 0.028 [95% CI –3.349 to –2.007]). Differences in diameter measurement were independent of observer (p = 0.131), and no statistical effect from imaging modality on diameter measurement was observed (p = 0.095). Conclusion: MRI is superior to MSCT in preoperative characterization and measurement of CRLM after NAC. Lesion detection rates for both modalities are comparable.

Gadoxetic acid-enhanced MRI and diffusion-weighted imaging for the detection of colorectal liver metastases after neoadjuvant chemotherapy

“…with 18 years of experience in interpreting abdominal CT and MRI), additional three lesions (0.5 cm, 0.6 cm and 1.6 cm in diameter) in three patients were also observed to be liver metastases. These lesions showed typical imaging findings of metastasis on MRI [14,24], and interval growth in the longest axial diameter of at least 20 % was seen on post-operative follow-up contrastenhanced CT and MR examinations (mean follow-up interval, 6.7 months; range, 1-11 months). Two lesions were considered as false-negative lesions on initial preoperative image interpretation as a result of their small size.…”

“…This has also been shown to have a clear influence on the staging accuracy of preoperative imaging modalities for CRLMs [11][12][13][14]. In a recent metaanalysis study by van Kessel et al [15], CT, FDG-PET and FDG-PET/CT showed lower diagnostic performances for the evaluation of CRLMs in patients treated with chemotherapy compared to chemonaive patients, whereas MRI showed a high pooled sensitivity of 85.7 % in patients who underwent chemotherapy.…”

Impact of the Time Interval Between MDCT Imaging and Surgery on the Accuracy of Identifying Metastatic Disease in Patients With Pancreatic Cancer

“…Moreover, other imaging modalities (i.e., PET/CT and MRI) are not routinely used for preoperative evaluation of pancreatic cancer at our institution. It is, again, highly likely that these modalities would have identified lesions not visible at laparoscopy or laparotomy and potentially would have increased the rate of decline in MDCT accuracy over time [19–21]. …”

Response assessment of colorectal liver metastases with contrast enhanced CT/18F-FDG PET

“…Therefore follow up imaging has been used to confirm the presence of liver disease in the nonoperable patients by assessing lesion growth over time [27,28].…”