May 11, 2011 (London, United Kingdom) — In a worst-case scenario, radiotherapy for primary liver cancer or for liver metastases can result in death, as there is a critical volume of liver function that needs to be preserved for the patient to survive. If radiotherapy destroys too much of the remaining healthy tissue, the result can be fatal liver failure. "It is rare, but it does happen — it has happened in my department," says Morten Hoyer MD, PhD, consultant and professor of oncology at Aarhus University Hospital, Denmark.
To reduce the risk for such a catastrophe, Dr. Hoyer and his team have developed a method for detecting liver function in 3-dimensional images (using 18-fluro-deoxy-galactose as a radiotracer on positron emission tomography and computed tomography scans) and are using these images to guide stereotactic radiotherapy for liver metastases.
The research was presented yesterday here at the European Society for Therapeutic Radiology and Oncology (ESTRO) 11th Biennial Conference and was highlighted as one of the best abstracts from the meeting during a press conference.
This is a good example of image-guided and intensity-modulated radiotherapy, commented Dirk Verellen, PhD, from the Universitair Ziekenhuis, Brussels, Belgium, who moderated the press conference. "We cannot bend the beams of radiation so that they turn corners and avoid healthy organs," he said, "but we can change the intensity of the beam, so that it delivers a much lower dose to healthy tissue and a much higher dose to the tumor."
"By functional radiotherapy planning, the radiation is directed to the tumor based on information from a galactose [positron emission tomography and computed tomography scan] in a way where the beams follow corridors of liver with low function," Dr. Hoyer explained. "This method will spare the best functioning liver tissue."
So far, the team has treated 9 patients with the new method. "We have spared up to 50% of the best liver tissue in some patients, but less in other patients," Dr. Hoyer told Medscape Medical News. However, he said he was optimistic that the technique could spare more than 50% of the best functioning tissue in some patients.
Increasing the volume of health liver tissue left intact will improve the patients' chances of survival, he explained in an interview. There is a crucial volume of 700 cm3 of healthy tissue needed, and if less than this is left, the patient may not survive. So far, the patients treated have had cancer in healthy livers, but the new technique will be even more valuable in patients with hepatitis or cirrhosis, as they have little functioning liver tissue to begin with, he added.
Stereotactic radiotherapy has already had an effect on the treatment of liver cancer, as it "allows a shift from an invasive approach, by surgery, towards a noninvasive approach, by irradiation," commented Johan Bussink MD, from the Department of Radiation Oncology, Radboud University Nijmegen Medical Center in the Netherlands. "Even when metastases are present, median survival has increased from 6 months to more than 2 years," Dr. Bussink commented in an ESTRO press release highlighting this research.
European Society for Therapeutic Radiology and Oncology (ESTRO) 11th Biennial Conference: Abstract 172. Presented May 9, 2011.
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Cite this: Image-Guided Radiotherapy for Liver Metastases Spares Healthy Liver - Medscape - May 11, 2011.