Efficacy of Low-Dose Radiotherapy for Pain Control in Elderly Patients With Advanced Knee Osteoarthritis: A Prospective Single-Arm Study From India

Background Osteoarthritis is one of the commonly occurring causes of disability and pain in the elderly Indian population. Low-dose radiotherapy (LDRT) has been used in Europe and the US for symptomatic management. Objectives To evaluate the efficacy of LDRT in achieving clinically significant pain reduction (≥30% improvement in Visual Analogue Scale (VAS)), its durability over 12 months, and its safety in elderly patients with advanced knee osteoarthritis who were unsuitable for or declined surgical intervention. Methods and materials One hundred and six patients aged >50 years with Kellgren-Lawrence grade III-IV knee osteoarthritis (OA) received LDRT using cobalt-60, delivering 3 Gy in six fractions (0.5 Gy/fraction, two times a week). Pain was assessed using VAS at baseline and at four weeks, four months, eight months, and 12 months. Inflammatory biomarkers (erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)) and treatment-related toxicity were also evaluated. Results LDRT produced a significant reduction in pain compared with baseline, with mean VAS decreasing from 7.9±0.6 to 3.5±1.2 at 4 weeks and remaining significantly improved through 12 months (4.0±0.9; all P<0.001). Overall, 88 subjects out of 90 (97.8% of evaluable subjects) achieved at least a 30% reduction in pain. CRP and ESR levels both decreased significantly after treatment (P=0.002 and 0.006, respectively). No grade ≥3 adverse events, radiation-induced tissue injury, or unexpected toxicities were observed. Conclusions LDRT was safe, well tolerated, and provided reasonable pain relief for up to 12 months in elderly patients with advanced knee OA, subject to limitations of this study. These findings support further randomized sham-controlled trials incorporating functional outcomes, quality-of-life measures, and translational biomarkers to define the role of LDRT in contemporary osteoarthritis management.