Low-Dose Radiation Linked to Lasting Improvement in Knee Osteoarthritis Symptoms: Study - Video

Low-dose radiation therapy may provide more than pain relief for early knee osteoarthritis, with a long-term study suggesting it could also slow disease progression.

The findings, to be presented at the American Society for Radiation Oncology (ASTRO) Annual Meeting, come from an integrated analysis of a randomised trial involving 292 patients in Russia. Participants were followed for a median of 11.9 years.

Patients had symptomatic knee osteoarthritis at Kellgren-Lawrence grades 0, 1 or 2, meaning they had early or mild disease. They were randomly assigned to receive medication alone or medication combined with low-dose radiation therapy. The radiation treatment delivered a total dose of 4.5 Gy over 10 sessions.

Both groups initially reported less pain. However, improvements in pain, physical function and quality of life were more sustained among patients who received radiation therapy.

MRI scans followed for three years also showed less structural deterioration in the radiation therapy group. At 12 months, MRI scores showed slight improvement compared with worsening in the medication-only group, with the difference remaining significant during follow-up.

Researchers also examined longer-term outcomes using regional health records. Across the study population, low-dose radiation therapy was associated with a 67% lower adjusted hazard of government-certified disability related to knee osteoarthritis.

The greatest apparent benefit was seen among 78 patients with grade 2 disease. Disability occurred in 31% of patients who received radiation therapy compared with 61% of those receiving medication alone. Knee replacement was performed in 14% and 36%, respectively.

Researchers suggested that grade 2 disease may represent a stage when inflammation and joint damage are established but substantial structural damage has not yet occurred.

However, the findings do not establish that low-dose radiation is disease-modifying. The trial was conducted at a single centre, participants knew their treatment, and the control group did not receive simulated radiation Larger multicentre randomised trials with simulated radiation controls and long-term follow-up are needed to confirm the findings.

REFERENCE: Bobby (Nagendra) Koneru, et al.; Randomized Trial of Low-Dose Radiotherapy for Knee Osteoarthritis: Patient-Reported, Structural and Long-Term Clinical Endpoints; American Society for Radiation Oncology (ASTRO) Annual Meeting