Experience counts in radiation therapy for mesothelioma patients
Researchers at the Duke University Medical Center say a five-year review of case records reveals more evidence that high-dose radiation therapy can extend the lives of patients with pleural mesothelioma.
Until recently, radiation therapy was considered most effective in early-stage mesothelioma as part of a tri-modal regime that also involves surgery and chemotherapy. Earlier studies have suggested that in more advanced cases, it is difficult to target the radiation in doses adequate to kill cancer cells without simultaneously damaging healthy tissue and nearby organs.
But Duke oncology experts say that the more experience clinicians have with intensity-modulated radiation therapy, a computer-controlled technique that precisely targets cancer cells, the better the outcomes of their patients.
The researchers examined the records of 30 mesothelioma patients who received intensity-modulated radiation therapy, or IMRT, following extrapleural pneumonectomy, an aggressive surgery that involves removing all or parts of the lung, chest lining and diaphragm. Recent studies have found that more than 40 percent of surgical patients cannot complete their tri-modal regiment because of major complications or death; those who relapse following surgery usually die within 3 months.
Although median survival of the Duke cohort was similarly disappointing — just 23.2 months — 50 percent of patients had survived two years after treatment and 47 percent had achieved local control of the cancer. More than a third of the patients were disease free after two years.
The findings showed that patients who were treated by Duke doctors with longer experience using IMRT did better and suffered fewer side effects than those who were treated with the same technology in earlier years.
In addition to measuring the patients’ responses to IMRT, the duke researchers studied the toxicity of the therapy to the other, healthy lung and adjacent tissue. In 15 earlier cases, lung toxicity developed in four patients, versus none in the last 15 patients treated.
The study, published online this week, will appear in the May 2012 issue of the International Journal of Radiation Oncology, Biology and Physics