Low-Dose Radiotherapy for Osteoarthritis: Current Evidence, Practical Recommendations and Future Perspectives

Osteoarthritis (OA) is a widespread degenerative joint disease with increasing prevalence in aging populations. While conservative management such as physiotherapy, NSAIDs, and intraarticular injections form the mainstay of treatment, a significant proportion of patients, particularly elderly individuals or those unfit for surgery, remain symptomatic. Low-dose radiotherapy (LDRT) has re-emerged as a potential noninvasive therapeutic option based on its anti-inflammatory effects and favorable safety profile. This narrative review summarizes current clinical evidence, practical recommendations, and future directions for the use of LDRT in OA. Although some randomized controlled trials have reported no additional benefit of LDRT over sham treatment, these studies have been criticized for limited sample size, short follow-up duration, suboptimal patient selection, and deviation from standard LDRT protocols. Nevertheless, other randomized trials as well as large retrospective studies suggest clinically meaningful benefits in selected patients. Standard dosing regimens typically consist of 3.0-6.0 Gy delivered in 0.5-1.0 Gy fractions over 2-3 weeks, with a second course recommended in nonresponders. Practical considerations including patient selection, joint-specific dose planning, and patient education are essential to optimize outcomes. While the absolute risk of radiation-induced malignancy is considered negligible in elderly populations, safety measures such as shielding and cumulative dose monitoring are advised. Further large-scale, placebo-controlled studies are needed to clarify optimal dose, timing, and synergistic effects with pharmacological therapies to strengthen the role of LDRT in OA management.