Revisiting Radiotherapy: Low-Dose Radiation Therapy for Refractory Osteoarthritis

Osteoarthritis (OA) is a highly prevalent musculoskeletal disorder causing chronic pain and disability. As many patients fail conservative therapy or are unsuitable for surgery, effective non-invasive options are needed. Low-dose radiation therapy (LDRT) has re-emerged as a treatment targeting OA-related inflammation and providing symptom relief. This narrative review summarises the epidemiology and pathophysiology of OA, the radiobiological rationale for LDRT, patient selection criteria, clinical outcomes, and safety considerations. Evidence from randomised controlled trials, observational studies, and international guidelines — particularly German Society for Radiation Oncology (DEGRO) — was also reviewed. At low doses (0.5–1.0 Gy per fraction; total 3 Gy), LDRT exerts anti-inflammatory effects that translate into significant pain relief and functional improvement in OA of affected joints. Evidence from randomised and observational studies showed good tolerance, mild to no toxicity, and an extremely low theoretical risk of secondary malignancy. DEGRO guidelines endorse LDRT as an adjunctive treatment for selected patients with painful OA who have failed conservative therapy or are unsuitable for surgery. LDRT is a safe, evidence-based, non-invasive option that provides effective pain relief and functional improvement in selected patients with osteoarthritis. By addressing chronic joint inflammation, it offers a practical therapeutic “middle ground” between conservative management and surgery. Further research is warranted to optimise patient selection, timing, and predictive biomarkers of response.