Ablative therapy for liver tumours

Abstract

Established ablative therapies for the treatment of primary and secondary liver tumours, including percutaneous ethanol injection, cryotherapy, and radiofrequency ablation, are discussed. Newer techniques such as magnetic resonance imaging guided laser interstitial thermal therapy of liver tumours has produced a median survival rate of 40.8 months after treatment. The merits of this newly emerging technique are discussed, together with future developments, such as focused ultrasound therapy, which holds the promise of non-invasive thermoablation treatment on an outpatient basis.

Figure 1

Vertically orientated double magnet configuration (0.5 T) with a 56 cm gap for the operator to gain access to the patient. A liquid crystal monitor within the bore displays the current magnetic resonance image to the operator.

Figure 2

(Top left to bottom right) Near real time colour thermal map acquired during laser interstitial thermal therapy of colorectal carcinoma metastasis. Images are acquired in the sagittal plane and regularly updated as necrosis develops. The colour scale ranges from blue to green to yellow to red. Once a persistent green colour develops, irreversible necrosis has occurred.

Figure 3

Axial T₁ weighted gadolinium enhanced magnetic resonance imaging of the liver in a patient with colorectal carcinoma metastasis four weeks after (top row) the first thermal ablation and four weeks after (bottom row) a second thermal ablation. After the first ablation, low signal non-enhancement in the centre of the metastasis represents necrosis but some enhancing tumour remains around the periphery. After the second ablation no enhancement is seen, and there is uniform low signal representing complete necrosis of the metastasis.