Low-dose radiation therapy (LDRT) is effective in treating knee osteoarthritis, suggest findings presented September 28 at the American Society for Radiation Oncology (ASTRO) annual meeting in San Francisco.
In his talk, Byoung Hyuck Kim, MD, PhD, from Seoul National University College of Medicine, Boramae Medical Center in South Korea presented the study results showing that a single course of LDRT relieved pain in patients with mild to moderate knee osteoarthritis. It also improved physical function in the four months after treatment, the team found.
“Our trial could provide objective evidence for the efficacy of LDRT and suggest that it’s a nonpharmacologic, scalable option that merits larger trials,” Kim said.
Initial treatment for osteoarthritis includes pain medicine and lifestyle adjustments. Surgery is considered when symptoms become worse. While European practices are more open to LDRT as an alternative treatment, low awareness among practices in other countries limits its use, Kim said. He added that high-quality, randomized evidence against placebo cohorts has been limited.
Kim and colleagues studied the efficacy of LDRT in a multicenter, randomized, sham-controlled trial. The study included 114 patients with knee osteoarthritis who received sham irradiation, total 0.3 Gy/6 fractions, or total 3 Gy/6 fractions. The patients were grouped in a 1:1:1 ratio for each cohort. The patients had their osteoarthritis classified as Kellgren-Lawrence grade 2 to 3 (mild to moderate) and a baseline walking pain score of 50 to 90 out of 100 (moderate to severe pain).
The team used the Western Ontario and McMaster Universities Arthritis Index (WOMAC) to evaluate osteoarthritis. It considered a pain score change of 16 or greater as clinically meaningful improvement.
All participants completed the treatment and adhered to study guidelines. The researchers reported the following findings:
The team also reported no significant differences in the average changes from baseline in other secondary outcomes. These included the visual analog scale, patient global assessment, serum inflammatory markers, and the amount of rescue drug use. The team also observed no treatment-related toxicity.
Kim said the findings support the potential of LDRT as a conservative treatment option.
He added that the team is working on 12-month follow-up to assess how durable the benefits are and how symptom relief correlates with imaging-based measures. Future studies will also include larger trials to evaluate outcomes in specific subgroups and economic analyses comparing LDRT with pain medicine-based regimens.
Kim said the results from future trials may help growth in adoption of this treatment method and become a more attractive option for patients.
“We need more evidence and a lot of experience to make that possible,” Kim told AuntMinnie.com.
In an accompanying expert perspective, Kristina Mirabeau-Beale, MD, from GenesisCare said the findings show the benefits of radiation in treating osteoarthritis, including being a safe option.
“This shows that with this lower dose and no adverse effects, it [LDRT] a safe option for our patients,” she said. “We look forward to the long-term follow-up of this well-done study.”