Radio-frequency ablation is a technique that is being increasingly used for the treatment of isolated liver metastases in patients with colorectal cancer. It involves the placement of metal probes into the liver under radiological guidance and delivering heat directly to the tumour. Following treatment patients need to be followed up carefully because sometimes the tumour can regrow and, if caught at an early stage, these recurrences can be re-treated. Normal scans (like CT or ultrasound) are not always very accurate in diagnosing recurrence of cancer. Positron Emission Tomography (PET) can be a useful technique to differentiate between scar tissue and viable cancer cells. It works by injecting patients with glucose that has been labelled with a radio-active tag. Cancer cells take up glucose quicker than most normal cells in the body, and so scans can highlight ‘hot spots’ which represent areas of cancer in the body.

At the Society of Nuclear Medicine and Molecular Imaging in Vancouver earlier this month, a team from Georgia Regents University in Augusta presented findings from their study into using PET scanning to pick up early signs of recurrence following radio-frequency ablation. In the 79 patients that they studied, almost all recurrences occurred with 12 months of the procedure. They found that PET was a very accurate way of picking up these early recurrences and so may prove very important in the management of patients with liver metastases.

Society of Nuclear Medicine and Molecular Imaging 2013 Annual Meeting: Abstract 67. Presented June 9, 2013.