Radio- KO Radiotherapy for Knee Osteoarthritis Clinical Trial

The Randomized Clinical Trial of Low-Dose Radiotherapy for Knee Osteoarthritis

The primary aim of this study is to investigate whether low-dose radiotherapy is an effective treatment to reduce the pain of knee osteoarthritis. A secondary aim is to determine whether patients experience any more measurable side effects than those receiving sham treatments.

Study Overview

• Status: Recruiting
• Conditions: Osteoarthritis, Knee
• Intervention / Treatment: Radiation: Low dose radiotherapy; Other: Sham comparator

Detailed Description

This single center, single-blinded, sham-controlled randomized controlled trial will compare low dose radiation therapy and sham radiation therapy for knee osteoarthritis. Participants with symptomatic knee OA based on clinical and radiographic criteria will be randomized 1:1 to receive 0.5 Gy LDRT over 2 weeks ideally on a Monday-Wednesday-Friday three times each week for two weeks treatment course for a total of 3 Gray or identical sham treatment (an identical procedure without the radiation). Non-responders to the initial Low-Dose Radiotherapy (LDRT)/sham treatment will receive a second treatment course of 0.5 Gy Low-Dose Radiotherapy (LDRT) or sham repeat treatment course over 2 weeks x 6 depending on their randomization (treatment arm participants receiving a second treatment course and sham arm participants receiving a second course of identical sham treatments without radiation). Intermittent and Constant Osteoarthritis Pain (ICOAP) outcome scales will be emailed to all participants for completion at baseline and weekly for six months. The study will thus terminate after all participants have completed 6 months of time in the study.

• Study Type: Interventional
• Enrollment (Estimated): 128
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Family Medicine Research Study Coordinators; Phone Number: 507-422-6823; Email: RSTFMSC@mayo.edu

Study Locations

• United States
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Recruiting
      • Mayo Clinic
      • Contact: Family Medicine Research Study Coordinators; Phone Number: 507-422-6823; Email: RSTFMSC@mayo.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• age 50-85 years

  • ICOAP pain scale A1 at least moderate intensity or B6 at least moderate intensity
  • diagnosed with primary knee OA ICD-10 codes M17.x
  • history of morning stiffness in knees that lasts less than 30 minutes
  • history of crepitus without a history of warmth, redness or sudden onset of swelling
  • physical exam findings of medial or lateral joint line tenderness on palpation that is in the same location as the knee pain for which their primary care provider has ordered an intraarticular steroid injection into the same knee.
  • absence of primary knee pain in the pes anserine or hamstring or gastrocnemius tendons
  • radiographic Kellgren-Lawrence grade 2-3 on 4-view knee x-rays taken within the last year
  • ability to complete surveys in English

Exclusion Criteria:

• Kellgren-Lawrence grade 1 or 4

  • pregnancy or women 54 years and younger with potential for pregnancy (if they or their partner have not had tubal ligation, hysterectomy, or vasectomy)
  • history of ipsilateral intraarticular knee surgery
  • use of injected corticosteroids within 3 months or hyaluronans within 6 months or within 1 month if there was no sustained improvement post-injection of either corticosteroid or hyaluronan.
  • history of trauma to this knee in the last year that clearly caused the pain now present
  • history of RA, gout, pseudogout, hemarthroses (eg, hemophilic arthropathy) or other inflammatory arthritis involving this knee
  • history of symptomatic hip OA
  • history of psychosis, personality disorder, uncontrolled affective disorder
  • history of fibromyalgia
  • malignancy requiring active treatment
  • current regular use of opiate analgesics, PRP, or acupuncture for the knees

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Low dose radiotherapy; Low dose radiation therapy for knee osteoarthritis	Radiation: Low dose radiotherapy; Participants will receive low dose radiotherapy (0.5 Gy) 3 times per week, for two weeks delivered via the X-Strahl Orthovoltage device.
Sham Comparator: Placebo; No radiation therapy	Other: Sham comparator; Participants will receive identical treatment 3 times per week, for two weeks delivered via the X-Strahl Orthovoltage device, without radiation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Area Under the Curve (AUC) of ICOAP Scores	Change in the Intermittent and Constant Osteoarthritis Pain (ICOAP) outcome scale weekly for six months after intervention analyzed as area under the curve of patients with Kellgren-Lawrence grade 2-3 knee OA.	Baseline, 6 months
Analgesic use frequency in treatment vs. sham participants	Differences in the rate of improvement between the 2 groups with analysis to include time points of 2 months and 4 months after intervention.	6 months

Collaborators and Investigators

• Sponsor: Mayo Clinic
• Investigators: Principal Investigator: Stephen P. Merry, M.D., Mayo Clinic; Principal Investigator: Paul D. Brown, M.D., Mayo Clinic

Study record dates

Study Major Dates

• Study Start (Actual): June 4, 2025
• Primary Completion (Estimated): June 28, 2026
• Study Completion (Estimated): June 29, 2026

Study Registration Dates

• First Submitted: March 7, 2025
• First Submitted That Met QC Criteria: March 14, 2025
• First Posted (Actual): March 20, 2025

Study Record Updates

• Last Update Posted (Actual): June 22, 2025
• Last Update Submitted That Met QC Criteria: June 18, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Osteoarthritis, Knee
• Other Study ID Numbers: 24-006759

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No