ASTRO: Low-Dose Radiotherapy Shows Potential in Early Knee Osteoarthritis

THURSDAY, Oct. 8, 2026 (HealthDay News) — Low-dose radiotherapy (LDRT) offers multiple benefits in early knee osteoarthritis (OA), according to a study presented at the annual meeting of the American Society for Radiation Oncology, held from Sept. 26 to 30 in Boston.

Maria Makarova, M.D., Ph.D., from the Northern State Medical University in Arkhangelsk, Russia, and colleagues presented an integrated analysis of a complete randomized trial to examine the effect of LDRT in early knee OA. A total of 292 patients with symptomatic Kellgren-Lawrence (KL) grade 0 to 2 knee OA were randomly assigned to symptomatic slow-acting drugs for OA (SYSADOA) alone or SYSADOA plus orthovoltage LDRT (4.5 Gy in 10 fractions; 146 individuals in each group).

The researchers observed greater and more durable improvements in pain, physical function, and quality of life with LDRT than SYSADOA alone. Significantly less structural progression was demonstrated on magnetic resonance imaging, including a reduction in the overall Whole-Organ Magnetic Resonance Imaging Score at 12 and 36 months; there was also less cartilage deterioration and bone marrow edema progression. LDRT reduced disability during long-term follow-up (adjusted hazard ratio, 0.33). There was a reduction in total knee arthroplasty in the LDRT group (hazard ratio, 0.51). The greatest benefit was seen for patients with baseline KL2 disease, with reductions in both disability and total knee arthroplasty (hazard ratios, 0.37 and 0.32, respectively).

“The combination of less disability and fewer knee replacements in these patients is particularly encouraging,” coauthor Bobby (Nagendra) Koneru, M.D., from Loyola University in Maywood, Illinois, said in a statement. “It suggests an opportunity to study whether treating inflammation earlier can change the longer course of the disease.”

Several authors disclosed ties to the biotechnology, medical technology, and medical device industries.

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