A new study of a high-dose radiation treatment option known as hemithoracic radiation therapy brings hope of increased survival rates for mesothelioma patients.

The small study, involving 45 patients, yielded encouraging results for a rare cancer that is historically ineffective towards most treatment options.

Mesothelioma is a cancer of the lining of the lungs that affects an estimated 3,000 Americans per year. The only known cause is asbestos exposure.

Common treatments for this disease include chemotherapy, surgery and radiation therapy.

This newly tested hemithoracic radiation treatment may put the odds back in the doctors’ and patients’ favor.

“Our experience provided clear evidence that radiation is arguably the most effective single agent for mesothelioma and new technology, including intensity-modulated radiotherapy, allow high doses to be delivered safely,” said Malcolm Feigen, M.D., of the Austin Health Radiation Oncology Center in Melbourne, Australia.

Hopeful Results

Of the 45 patients who were studied, the overall median survival rate was 12.4 months from the time of treatment. This method utilized a technique known as intensity-modulated radiation therapy (IMRT). The estimated one-year survival rate reached 50 percent.

According to Feigen, the results of the study contradict the idea that mesothelioma is insensitive to radiation. His comments were made at the European Lung Cancer Conference (ELCC).

“I stood before [the ELCC] 2 years ago to present the first 14 patients we had analyzed and asked whether there was a role for high-dose hemithoracic radiotherapy in unpneumonectomized mesothelioma patients.”

“I think now that the answer to that question is ‘absolutely.'”

Feigen and his colleagues began experimenting with 3-D conformal radiation and IMRT in 2003 and were able to find the more beneficial option. As the IMRT method yielded the 12.4 month survival rate, the 3-D conformal method only resulted in 7.9 months.

Recommendation of Caution

During the doctor’s presentation at the ELCC, however, he did receive a response from Paul Baas, MD, PhD of the Netherlands Cancer Institute in Amsterdam, who offered caution on Feigen’s assessment.

Baas suggested the unselected subject group didn’t represent a controlled clinical study. He further added concern about the lack of safety within the tested group.

“I think your group is very lucky not to have had fatal pneumonitis because I think this is one of the risks,” said Baas.

“We also use drugs that do interact very dangerously with radiotherapy.”

Baas raised additional concerns regarding the hazard of radiation toxicity. He stated that the despite the method used, healthy tissue will be exposed to radiation.

“I think IMRT in mesothelioma is possible but you have to be aware of the risks.”

“Toxicity should be part of any trial to study this. We have some evidence that a combination of 3-D conformal and IMRT might limit the risk.”