LBA 06 - Clinical Effectiveness of Single Course Low-Dose Radiation Therapy in Knee Osteoarthritis: Short-term Results from the Randomized, Sham-Controlled Trial
Presenter(s)
B. H. Kim1, D. H. Ro2, J. H. Wang3, D. H. Lee3, K. Shin4, M. J. Kim4, T. W. Kim5, M. J. Chang5, D. H. Kim6, M. Han7, J. H. Lee8, J. H. Kang9, J. Y. Kim10, E. H. Hong10, S. J. Cho10, H. S. Han2, H. J. Kim11, and W. Park12; 1Department of Radiation Oncology, Seoul National University College of Medicine, SMG-SNU Boramae Medical Center, Seoul, Korea, Republic of (South), 2Department of Orthopaedic Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea, Republic of (South), 3Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of (South), 4Division of Rheumatology, Department of Internal Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea, Republic of (South), 5Department of Orthopedic Surgery, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea, Republic of (South), 6Department of Radiology, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, Korea, Republic of (South), 7Medical Research Collaborating Center, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, Korea, Republic of (South), 8Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of (South), 9Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea, Republic of (South), 10Radiation Effects Research Section, Radiation Health Institute, Korea Hydro & Nuclear Power, Seoul, Korea, Republic of (South), 11Department of Radiation Oncology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea, Republic of (South), 12Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of (South)
Purpose/Objective(s):
Low-dose radiation therapy (LDRT) has been historically used as a non-pharmacologic option for osteoarthritis (OA), but solid evidence from randomized trials is still limited.Materials/Methods: In this multicenter, randomized, sham-controlled trial, 114 patients with knee OA were allocated to receive sham irradiation, total 0.3 Gy/6 fractions, or total 3 Gy/6 fractions. The main inclusion criteria are primary knee OA classified as Kellgren-Lawrence grade 2–3 and a baseline walking pain score of 50–90/100. Use of concomitant analgesics, except for rescue drug, was restricted during the first 4 months. Re-irradiation was not allowed. The primary endpoint was the OMERACT-OARSI response rate at 4 months.
Results: All participants completed the treatment with perfect adherence. In the full analysis set, the responder rate at 4 months was significantly higher in the 3 Gy group (70.3%) than in the sham group (41.7%, p=0.014), whereas the 0.3 Gy group showed no significant difference compared to sham (58.3%, p=0.157). Similar results were observed in the per-protocol set. Clinically meaningful improvement (=16) in WOMAC total score at 4 months was observed more frequently in the 3 Gy group (56.8%) compared to sham (30.6%, p=0.024). However, there were no significant differences in the mean changes from baseline in other secondary outcomes, including VAS, PGA, serum inflammatory markers, and the amount of rescue drug use. No treatment-related toxicity was reported.
Conclusion:
A single course of 3 Gy LDRT led to significant improvement in clinical outcomes for patients with mild-to-moderate knee OA. These findings support its potential as a conservative treatment option. Long-term and imaging-based follow-up is ongoing.