**13. Survival**

confounded by haemorrhage, necrosis resulting in size enlargement, peripheral thin rim of granulation tissue mimicking metastasis, fibrosis, peritumoural ischemia or hepatitis [1]. Therefore, the evaluation of treatment response includes not only the changes in the lesionsize,

Morphologic radiologic features, including changes in tumour heterogeneity and internal structure, enhancement and margins, can indicate favourable tumour response to treatment [138]. On CT, CRC metastases in the liver have heterogeneous structure and ill-defined margins. Responding lesions obtain homogeneous structure and outlined margins [17]. The morphologic response on CT correlates with pathologic response and with the survival [138]. PET-CT characterises the metabolic activity in the lesions [1], suggesting pathogenetically substantiated accurate estimate of tumour response. However, the sensitivity of PET decreases after chemotherapy [17]. Clinically importantly, PET can identify lack of chemotherapy

Preceding treatment can induce not only tumour shrinkage but also liver parenchymal damage. By CT, steatosis that affects more than 30% of parenchyma can be diagnosed by the liver attenuation index characterising the difference in the attenuation between liver and spleen. By MRI, the analysis of water and fat proton signals is possible, leading to more accurate estimates of steatosis than by CT and US [1, 140]. Sinusoid obstructive syndrome can be caused by oxaliplatin-based chemotherapy. It is characterised by sinusoidal injury that may lead to

Complete radiologic response can be obtained in 5–38% of patients. The frequency of complete radiologic response depends on the efficacy of preoperative treatment and on the quality and completeness of radiologic investigation. Metastasis can become difficult to observe on CT if the size decreases and/or the surrounding liver tissue develops steatosis. MRI can be used to identify the residual lesions. The MRI-documented disappearance of the metastasis is sugges‐

The correlation between radiologic and pathologic complete response ranges 20–100% in different studies. Thus, at present, all sites of disease should be resected surgically. A fraction of lesions (up to 24% of patients with complete response on CT) can be grossly identified during the operation. Full mobilisation of liver and palpation, followed by intraoperative conven‐ tional and contrast-enhanced US, are the subsequent options rising the yield to 45% of patients. Contrast-enhanced US identifies additional 10–15% of nodules, compared with palpation and conventional ultrasonography technique. The intraoperative yield is lower in patients who have had preoperative MRI, suggesting that MRI is the method of choice to identify true small

If the radiologically regressed metastases are not resected, they tend to recur. The frequency of durable clinical response, usually defined as disease-free period for 1 year, correlates with

fibrosis or veno-occlusive disease. The radiologic findings are nonspecific [1].

but also its morphology and functional status [17].

efficacy just after 1 cycle [139].

188 Recent Advances in Liver Diseases and Surgery

**12. Complete radiologic response**

tive of true complete histologic response.

residual metastases that are missed by less sensitive CT [17].

The median survival of patients affected by metastatic colorectal cancer has increased signif‐ icantly, e.g., from 27.3 months in 1994 to 39.4 months in 2007 [13]. Analogous increase in the survival is reported also by other authors [14]. The 5-year and 10-year survival can reach even 58% and 36%, correspondingly [15]. Lower 5-year survival after surgical treatment has been reported earlier, e.g., 25–40% [78, 110, 141–144], contrasting with the 5-year survival of 15% in patients with unresectable metastases [33, 145, 146]. The 10-year survival of 25–26% has been described [123, 147, 148]. Better survival is observed in case of delayed metastases [14].
