Patients with plantar fasciitis experienced significantly less pain and improved quality of life following a standard dose of external beam radiation therapy (RT), according to a study published online July 25 in the International Journal of Radiation Oncology*Biology*Physics.
Approximately 8 to 10 percent of the population has severe bone heel spurs, with the most common treatments for alleviating the pain being ice, heat and various anti-inflammatory agents. Steroids and local anesthetics can be injected, and oral analgesic medications may be prescribed, but most of these methods have only provided short-term pain relief.
The results of this study demonstrated that up to 80 percent of standard dose patients experienced complete pain relief, and pain relief remained constant or even improved for up to 64 percent of the study participants during the follow-up period of 48 weeks post-treatment.
RT has been used in this setting for more than 60 years because it provides an anti-inflammatory effect. However, its mechanism of action is unknown, and the possibility of a placebo effect has been raised.
Marcus Niewald, MD, PhD, a radiation oncologist at Saarland University Medical Center in Homburg/Saar, Germany, devised a prospective, randomized trial to compare the effect of standard dose RT with low-dose RT among patients with plantar fasciitis.
A total of 66 patients enrolled in the study and were evaluated every six weeks until 12-months post treatment. Four patients were secondarily excluded after the trial began; 29 patients received a standard regimen, and the remaining 33 patients received a low dose of radiation therapy. The standard-dose patients were treated with a 6 Gy dose, applied in six single fractions of 1 Gy twice weekly on non-consecutive days. The low-dose arm received 0.6 Gy, applied in six single fractions of 0.1 Gy twice weekly on non-consecutive days.
Primary endpoints included patient- and physician-reported health survey scores, Calcaneodynia score (CS, which measures heel pain symptoms) and visual analogue scale (VAS).
“After treatment of these 62 patients the difference between the effects of radiation therapy in the two arms became very clear in the clinical impressions, this urged us to perform an interim analysis, and finally, led to the decision to prematurely close the trial,” wrote Niewald et al.
After three months of follow up, VAS score was -20 in the low-dose group and -43.39 in the standard-dose group, and the researchers reported similar results in CS. After 48 weeks, 21 of 33 patients in the low-dose group required re-irradiation. These patients showed results comparable to standard-dose patients who were not re-irradiated.
A total of five of 29 patients in the standard-dose group were re-treated, which improved results. The researchers did not observe acute side effects or long-term toxicity.
Niewald and colleagues explained there were several limitations to the study. The low-dose treatment could not be categorized as placebo; neither physicians nor patients were blinded to the dose group; statistical power may have been limited due to the early close of the trial and use of oral analgesics was not restricted, which may have confounded results.
“Radiation therapy yields important pain relief in patients with painful heel spur (plantar fasciitis) compared with very low doses, and this could be proven at a high level of evidence for the first time,” concluded Niewald et al.