The evolving role of imaging in colorectal liver metastasis treatment planning and prognostication

While a plethora of new imaging techniques are being investigated as adjuncts or improvement to existing imaging tests, most of these novel techniques take many years before they are validated for clinical use. The aims of this thesis, which is focused on patients with colorectal liver metastases, were three-folds: (1) to evaluate whether the use of liver specific contrast enhanced MRI with diffusion-weighted MRI improves the surgical management of these patients compared with conventional CT, (2) to evaluate whether imaging tests used in routine clinical practice, such as 18-Flurodeoxyglucode (FDG) PET/CT and diffusion-weighted MRI (DW-MRI), yield predictive and prognostic information in this clinical setting and (3) to evaluate the use of conventional MRI and DW-MRI in identifying the effects of malignancy on the adjacent liver parenchyma and also treatment-related complications of the hepatic parenchyma. The studies undertaken showed that although the use of liver specific contrast enhanced MRI with DW-MRI has a higher diagnostic sensitivity compared with CT, its use did not significantly alter management in the majority. When assessing colorectal liver metastases using DW-MRI, the pre-treatment lesion ADC values may predict response to treatment although this requires further validation. Using FDG PET-CT imaging, we showed that higher pre-treatment standardized uptake value (SUV) predicted for shorter patient progression free survival. Using a combination of diffusion-weighted MR imaging and T1-weighted MRI, we described a novel MRI diagnostic sign of hepatic injury from malignant biliary obstruction, which was corroborated with serum alanine transferase (ALT) derangements. In a separate evaluation, we found that although the sign of sinusoidal obstruction syndrome (SOS) on gadoxetic acid enhanced MRI was frequently observed in patients receiving oxaliplatin chemotherapy, it was infrequently associated with significant long term hepatic veno-occlusive disease.As FDG-PET/CT and diffusion-weighted MRI are becoming more main-stream in clinical practice, these techniques will play an increasingly role in the management of colorectal liver metastases.Open Acces