Low-Dose Radiotherapy for Painful Knee Osteoarthritis
Key facts
- Where
- Fuenlabrada, Granada, and Valencia, SpainSee the 4 sites
Where in Spain
- Hospital Universitario de FuenlabradaFuenlabrada, SpainContact: Dolores Bedmar, MD, PhDNo longer taking part
- Hospital Universitario Clínico San CecilioGranada, SpainContact: Vanessa Jerviz, MDNo longer taking part
- Hospital Ascires ValenciaValencia, SpainContact: Jorge Pastor, MDNo longer taking part
- Hospital General Universitario de ValenciaValencia, SpainContact: Dolores López, MDNo longer taking part
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorTrial details
- Who runs it
- Universidad Rey Juan Carlos
- Trial code
- NCT07886697
- Record updated
- 21 October 2026
- Original description
Knee osteoarthritis is a common cause of chronic pain and difficulty with everyday activities, particularly in older adults. Some patients continue to experience clinically relevant knee pain despite medication, therapeutic exercise, physiotherapy, or other conservative treatments.Read full original descriptionShow less
Low-Dose Radiotherapy for Painful Knee Osteoarthritis: A Multicenter, Interdisciplinary, Prospective Single-Arm Study
Knee osteoarthritis is a common cause of chronic pain and difficulty with everyday activities, particularly in older adults. Some patients continue to experience clinically relevant knee pain despite medication, therapeutic exercise, physiotherapy, or other conservative treatments.
This prospective, multicenter study will evaluate changes in pain, physical function, health-related quality of life, and safety after low-dose radiotherapy (LDRT) in adults aged 60 years or older with painful primary knee osteoarthritis. All participants will receive the same treatment, and there will be no control or sham-treatment group.
Participants will receive one course of low-dose radiotherapy to the study knee, consisting of six fractions of 0.5 Gy, for a total dose of 3.0 Gy, administered twice weekly on nonconsecutive days over approximately 3 weeks.
Clinical assessments will be performed before treatment and approximately 45 and 90 days after the last radiotherapy fraction. The main outcome is the change from baseline to Day 90 in average knee pain during the previous 7 days, measured on a 0-to-10 Numerical Rating Scale. The study hypothesis is that average knee pain will be lower at Day 90 than before treatment. Other outcomes include physical function, health-related quality of life, the participant's overall assessment of the affected knee, pain response, analgesic use, treatment completion, additional knee treatments, and adverse events.
Inclusion: Age 60 years or older; Clinical and radiographic diagnosis of primary knee osteoarthritis; Kellgren-Lawrence grade II or III osteoarthritis in the index knee; Pain in the index knee for at least 6 months; Baseline average index-knee pain intensity greater than 4 on a 0-to-10; Numerical Rating Scale (NRS), referring to the previous 7 days; Persistent clinically relevant knee pain despite documented prior conservative management. Conservative management must include pharmacological treatment appropriate to the participant's clinical profile and therapeutic exercise and/or physiotherapy. If any of these measures were not undertaken because of contraindication, intolerance, or clinical inability, the reason must be documented; Radiograph of the index knee performed within 6 months before inclusion and adequate to confirm the diagnosis and Kellgren-Lawrence grade. A new radiograph will be obtained if no valid recent examination is available; Ability to understand the study procedures and reliably complete the required clinical assessments and questionnaires; Written informed consent to participate in the study.
Exclusion: Previous radiotherapy involving the treatment region; Intra-articular corticosteroid injection, intra-articular hyaluronic acid injection, or radiofrequency procedure involving the index knee within the 2 months before inclusion; Active connective tissue disease with clinically relevant skin or soft-tissue involvement in the treatment region, including active systemic lupus erythematosus or rheumatoid arthritis when considered clinically relevant for radiotherapy; Fibromyalgia or a psychiatric disorder that, in the investigator's judgment, would substantially compromise reliable assessment of pain or patient-reported outcomes; Kellgren-Lawrence grade 0, I, or IV in the index knee; Knee prosthesis in the index knee; Body mass index greater than 39 kg/m²; Inability to provide informed consent or to reliably complete the required study assessments.