LDRT for Osteoarthritis: A Guide for Physicians

This page is for clinicians who see patients with osteoarthritis: primary care physicians, orthopedic surgeons, rheumatologists, and radiation oncologists. Patients increasingly ask about low-dose radiation therapy (LDRT) after reading about it online. Here is a short, sourced summary of where it fits, who may benefit, what the evidence does and does not show, and how to connect a patient with a program.

LDRT at a Glance

• Dose: the regimen supported by the 2026 American Radium Society (ARS) guideline is 0.5 Gy per fraction for 6 fractions, 3 Gy total. Some programs use 1 Gy per fraction (6 Gy total)^[1][2].
• Schedule: six short outpatient visits, two to three times a week over about two to three weeks, after a planning visit. A second course is sometimes offered months later if the response is incomplete or pain returns^[1].
• Delivery: external beam, usually on the same kind of linear accelerator used for cancer treatment. No anesthesia, no needles, and the patient is not radioactive afterward.
• Dose context: a 3 Gy course is a small fraction of typical cancer doses, which are often 40 to 80 Gy.

Where It Fits in Osteoarthritis Care

The ARS Appropriate Use Criteria, the first U.S. consensus guideline on LDRT for osteoarthritis, came from a panel of radiation oncologists, rheumatologists, orthopedic surgeons, and a patient advocate. It describes LDRT as an appropriate option for patients with symptomatic osteoarthritis who^[1]:

• Have persistent pain and functional limitation
• Have not had adequate relief from conservative care such as exercise, physical therapy, weight management, NSAIDs, topical agents, bracing, or injections
• Are poor surgical candidates, or prefer to delay or avoid surgery
• Understand both the potential benefit and the current limits of the evidence

The guideline does not recommend LDRT as first-line treatment. It notes that patients with mild to moderate osteoarthritis are the most likely to benefit, and it encourages shared decision-making and collaboration across specialties rather than routine use for every patient with osteoarthritis^[1].

Patient Selection

Patients who tend to fit:

• Osteoarthritis confirmed by exam and imaging, most often in the knee, hand, hip, shoulder, ankle, or foot. The evidence is most direct for the knee.
• Pain that has lasted months and limits walking, sleep, work, or daily tasks
• An inadequate or short-lived response to conservative care
• Able to attend six short visits over two to three weeks

Situations that need a closer look:

• Inflammatory arthritis. LDRT is generally not used for rheumatoid, psoriatic, or other autoimmune arthritis.
• Younger patients. Many programs are cautious, since radiation-related risk has more years to develop.
• Advanced structural damage. LDRT does not regrow cartilage, and the strongest sham-controlled data involve mild to moderate knee osteoarthritis.
• Pregnancy, prior radiation to the same area, or connective tissue disease such as scleroderma or lupus.
• Referred pain. Hip pain from the lumbar spine or shoulder pain from the cervical spine should be ruled out first.

What the Evidence Shows

The ARS panel reviewed 52 studies and found overall response rates of 60% to 90%, with improvements in pain, mobility, and quality of life. It also noted that much of this experience comes from Europe, study quality varies, and more randomized, sham-controlled trials are needed^[1].

The sham-controlled trials are mixed:

• Korea, knee, 2025 (114 patients): at four months, 70.3% of the 3 Gy group met response criteria versus 41.7% with sham. A 0.3 Gy arm was no better than sham. Results so far are short-term^[3].
• Netherlands, knee, 2019 (55 patients): 6 Gy showed no difference from sham in pain or function^[4].
• Netherlands, hand, 2018 (56 patients): no difference from sham at three months^[5].
• Germany, ArthroRad, 2024 (229 patients): 3 Gy and 0.3 Gy gave similar improvement at 12 months. With no sham arm, a placebo effect cannot be excluded^[6].

Why the trials disagree is still debated. Differences in dose, patient selection, and sample size are the usual explanations. Our Research and Evidence page has more detail and links to each study.

Safety

Acute side effects are uncommon and usually mild, such as temporary skin irritation near the treated joint. A 2025 meta-analysis of 12 studies with about 1,750 patients did find more adverse events overall with LDRT than with comparison treatments, mainly nail reactions^[7].

Long-term cancer risk is the question most physicians ask. No dose of radiation is considered risk-free. In a German series of 4,699 patients treated for musculoskeletal conditions, 3 solid cancers developed within previously treated areas (0.064%), and blood cancer rates were slightly higher when the field was near marrow-rich bone^[8]. The ARS guideline estimates the lifetime risk of a fatal radiation-induced cancer from a 6 Gy knee course at about 0.7 in 1,000 at age 50 and 0.3 in 1,000 at age 70^[2]. Risk is lowest for peripheral joints such as knees, hands, and feet, and higher near the trunk and pelvis. See Can LDRT Cause Cancer? for the full discussion.

Notes by Specialty

• Primary care. You are often the first to hear the question. A referral to radiation oncology is a consultation, not a commitment to treat. Recent imaging and a list of prior treatments make that first visit more useful.
• Orthopedic surgery. LDRT may suit patients who are poor surgical candidates or who want to delay arthroplasty. It is not a substitute for surgery when surgery is clearly indicated, and it does not change joint structure.
• Rheumatology. LDRT is an option for osteoarthritis, not for inflammatory arthritis. Confirming the diagnosis matters, and rheumatologists helped write the ARS guideline.
• Radiation oncology. The ARS guideline and its full document cover dose, technique, shielding, and patient selection in detail^[1][2]. If your practice offers LDRT for osteoarthritis and is not in our directory, or a listing needs correcting, please contact us and choose "Hospital / location update."

How to Refer a Patient

• Find a program. Our directory lists hospitals and radiation oncology practices across the U.S. that offer LDRT for osteoarthritis, with phone numbers, and a map. Some listings are confirmed and some are still being verified, so patients should call Radiation Oncology to confirm.
• Send what helps. Recent X-ray or MRI reports, the treatments tried and how long each helped, current medicines, and any history of radiation therapy.
• Coverage. Original Medicare covers outpatient radiation therapy under Part B^[9]. Commercial plans vary, and some require prior authorization or a referral. The radiation oncology office can usually verify benefits.

For patients, these pages explain the same ground in plain language: Am I a Candidate?, What to Expect, LDRT Side Effects, and How to Talk to Your Doctor About LDRT.

References:
1. Dove A, et al. American Radium Society (ARS) Appropriate Use Criteria (AUC) for Low-Dose Radiotherapy for Treatment of Osteoarthritis. American Journal of Clinical Oncology. Published online May 25, 2026, ahead of print. PubMed
2. American Radium Society Appropriate Use Criteria for Use of Radiotherapy for Treatment of Osteoarthritis. Expert Panel for Use of Radiotherapy in the Treatment of Arthritis. 2026. Full guideline document. Full document (PDF)
3. Kim BH, et al. Clinical Effectiveness of Single Course Low-Dose Radiation Therapy in Knee Osteoarthritis: Short-term Results from the Randomized, Sham-Controlled Trial. ASTRO 67th Annual Meeting Late-Breaking Abstract LBA 06. 2025. Abstract
4. Mahler EAM, et al. Effectiveness of low-dose radiation therapy on symptoms in patients with knee osteoarthritis: a randomised, double-blinded, sham-controlled trial. Annals of the Rheumatic Diseases. 2019. PubMed
5. Minten MJM, et al. Lack of beneficial effects of low-dose radiation therapy on hand osteoarthritis symptoms and inflammation: a randomised, blinded, sham-controlled trial. Osteoarthritis and Cartilage. 2018;26:1283-1290. PubMed
6. Niewald M, et al. ArthroRad trial: randomized multicenter single-blinded trial on the effect of low-dose radiotherapy for painful osteoarthritis: final results after 12-month follow-up. Strahlentherapie und Onkologie. 2024. PubMed
7. Hammadeh BM, et al. Efficacy, safety, and pain management of low-dose radiation therapy in osteoarthritis: a comprehensive systematic review and meta-analysis. Rheumatology International. 2025;45:210. PubMed
8. Risk of radiation-induced malignancy after low-dose radiotherapy for non-malignant musculoskeletal disorders: A long-term retrospective analysis of n=4699 patients. International Journal of Radiation Oncology, Biology, Physics. 2026. Red Journal abstract
9. Radiation therapy coverage. Medicare.gov. Medicare.gov