A special kind of targeted radiotherapy that uses high energy neutrons instead of protons or electrons to kill cancer cells is unlikely to significantly improve outcomes for patients with mesothelioma. That word comes from a top radiation oncologist at one of the few cancer centers in the United States where “fast neutron” radiotherapy is available.
Because high-energy neutrons can do more serious damage to the DNA of cancer cells than other types of radiotherapy, fast neutron radiotherapy is sometimes considered more effective for certain types of cancer, particularly if the cancer is inoperable as is often the case with mesothelioma. This type of treatment can also produce more serious side effects than standard radiation therapy. It is considered one of the best approaches for cancer of the salivary gland.
To test the effectiveness of fast neutron radiotherapy for pleural mesothelioma, a team of researchers led by Dr. Shilpen Patel of the University of Washington School of Medicine and the Seattle Cancer Care Alliance performed a retrospective chart review of mesothelioma patients who received the treatment between 1980 and 2012.
A total of 30 mesothelioma patients, ranging in age from 46 to 72, received fast neutron radiotherapy as part of their treatment regimen. For more than half of these patients, the therapy was part of a tri-modal treatment plan that also included surgery and chemotherapy.
The median overall survival of mesothelioma patients in the study was 20.3 months – not significantly better or worse than standard therapy. One patients died during treatment and another one was unable to tolerate the side effects and stopped treatment early. Not surprisingly, the patients who had the best outcomes were those whose mesothelioma was in an early stage.
Dr. Shilpen and his colleagues conclude that, while fast neutron radiotherapy can be used to help treat mesothelioma patients, it is far from a cure. “Treatment with fast neutron radiotherapy did not significantly improve outcomes, even when used in a trimodality regimen,” reports Dr. Patel.
Each year, about 2,500 Americans are diagnosed with mesothelioma, a treatment-resistant malignancy of the membranes that surround internal organs. All types of mesothelioma are closely associated with exposure to asbestos.
Patel, SA et al, “Fast neutron radiotherapy in the treatment of malignant pleural mesothelioma”, February 2015, American Journal of Clinical Oncology, pp. 47-50.