Proton beam therapy has a significant advantage over intensity modulated radiation therapy (IMRT) when it comes to improving disease-free survival and tumor control in patients with head and neck cancers, according to a study by Mayo Clinic radiation oncologists.
Their research, published in Lancet Oncology, involved a systematic review of the literature on outcomes of proton beam therapy compared to IMRT. The analysis included studies of patients who had no previous treatment, as well as patients who had recurrent disease. They collected data on overall survival, disease-free survival, and tumor control at five years and at the patient's longest follow-up.
They found disease-free survival to be significantly higher at five years for patients receiving proton beam therapy (72 percent) compared to those receiving IMRT (50 percent). The rates on tumor control didn't differ between the two groups at five years, but was significantly higher for patients receiving proton beam therapy (81 percent) than those undergoing IMRT (64 percent) at the longer follow-up period.
The use of proton beam therapy has been somewhat controversial because of the expense involved in constructing treatment centers and the decision by several insurers not to cover it because of a lack of outcomes evidence.
Supporters of proton beam therapy have argued that it is safer and more effective than conventional radiotherapy treatments--particularly in cases of head and neck cancer--because it's precision makes it possible to reach tumors at the base of the skull and along the spinal cord.
The problem has been a paucity of research confirming that proton beam therapy results in better outcomes for these patients. Now, however, according to lead study author Robert Foote, a radiation oncologist at Mayo Clinic, the findings "suggest that the theoretical advantages of proton beam therapy may in fact be real."