Lack of beneficial effects of low-dose radiation therapy on hand osteoarthritis symptoms and inflammation: a randomised, blinded, sham-controlled trial

Summary Objectives Low-dose radiation therapy (LDRT) is widely used as treatment for osteoarthritis (OA) in some countries, while relatively unknown in others. Systematic literature review displayed a lack of high-level evidence for beneficial effects in clinical practice. The aim was to assess the efficacy of LDRT on symptoms and inflammation in hand OA patients in a randomised, blinded, sham-controlled trial, using validated outcome measures. Design Hand OA patients, ≥50 years, with pain ≥5 (scale 0–10) and non-responding to conservative therapy were included and randomised 1:1 to receive LDRT (6 × 1 Gy in 2 weeks) or sham (6 × 0 Gy in 2 weeks). Primary outcome was the proportion of OMERACT-OARSI responders, 3 months post-intervention. Secondary outcomes were pain and functioning (Australian/Canadian Hand Osteoarthritis Index; AUSCAN), quality of life (Short Form Health Survey; SF36) and inflammatory outcomes: erythrocyte sedimentation rate and C-reactive protein serum levels, effusion, synovial thickening and power Doppler signal on ultrasound (range 0–3). Results Fifty-six patients were included. After 3 months, no significant difference in responders was observed between groups (LDRT: 8 (29%); sham: 10 (36%); difference −7% (95%CI −31–17%)). Also, differences in clinical and inflammatory outcomes between groups were small and not significant. Conclusions We were unable to demonstrate a substantial beneficial effect of LDRT on symptoms and inflammation in patients with hand OA, compared to sham treatment. Although a small effect can not be excluded, a treatment effect exceeding 20% is very unlikely, given the confidence interval. Therefore, in the absence of other high-level evidence, we advise against the use LDRT as treatment for patients with hand OA. Clinical trial registration number NTR4574 (Dutch Trial Register).