Frequently Asked Questions

Usually, yes. Medicare and most major commercial insurance plans cover LDRT for osteoarthritis, though you should still expect the typical co-pay or deductible that applies to any outpatient procedure on your plan.

Some insurers require prior authorization before treatment, so it's worth asking the radiation oncology office to verify your specific benefits before you start. Most centers that offer LDRT have financial counselors who can do this for you.

It depends on your insurance plan. Many plans allow you to schedule directly with a radiation oncology department, especially once a diagnosis of osteoarthritis is documented. Others require a referral from your primary care doctor, orthopedist, or rheumatologist first.

Either way, the simplest first step is usually a conversation with the doctor who already manages your joint pain. Ask if they can refer you, or ask the radiation oncology office directly whether a referral is required.

The strongest recent evidence is a multicenter, randomized, sham-controlled trial led by investigators at Seoul National University and presented at the American Society for Radiation Oncology (ASTRO) 2025 Annual Meeting.^[1] A sham-controlled design is especially important because placebo responses in osteoarthritis trials can be substantial.^[2] In the trial, 114 patients with knee osteoarthritis were assigned to 3 Gy in six fractions, 0.3 Gy in six fractions, or sham treatment. At four months, 70.3% of patients in the 3 Gy group met the study's response criteria, compared with 41.7% in the sham group (p=0.014). The 0.3 Gy group was not significantly different from sham, and no treatment-related toxicity was reported.^[1]

Other recent findings are encouraging but need to be interpreted according to their study designs. The ongoing US MOBILE study is a prospective observational study rather than a randomized trial. Its 2025 interim analysis included 108 patients and 150 treated joint sites. Among the 76 sites with six-month follow-up, the mean pain score decreased from 7.6 before treatment to 3.4, and 84% of patients reported some pain improvement.^[3] The German ArthroRad trial randomized patients to 3 Gy or 0.3 Gy. Both groups reported pain relief, but there was no statistically significant difference between the two doses at 12 months. Because ArthroRad did not include a sham group, it could not determine how much of the improvement was caused by radiation rather than placebo or other effects.^[4]

Not all of the evidence is positive. A 2025 systematic review and meta-analysis pooled 12 studies involving about 1,750 patients and found no statistically significant benefit of LDRT over sham treatment for pain or physical function. Most adverse events were similar between groups, although mild nail reactions were more frequent with LDRT.^[5] A 2019 Dutch randomized, double-blinded, sham-controlled trial also found no substantial benefit for knee osteoarthritis symptoms or inflammatory signs.^[6] Differences in dose, patient selection, outcome measures, and follow-up may contribute to the conflicting results, but that explanation has not yet been proven.

So where does that leave things? The 2025 Korean sham-controlled trial provides important positive evidence for a standard 3 Gy course, while the MOBILE study provides encouraging real-world interim results.^[1][3] At the same time, ArthroRad, the 2025 meta-analysis, and the Dutch sham-controlled trial show why the evidence should not be described as settled.^[4][5][6] A radiation oncologist can help interpret how these findings apply to a particular patient, joint, and treatment protocol.

References:
1. 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
2. Zhang W, Robertson J, Jones AC, Dieppe PA, Doherty M. The placebo effect and its determinants in osteoarthritis: meta-analysis of randomised controlled trials. Annals of the Rheumatic Diseases. 2008;67:1716-1723. PubMed
3. Byrd HF, et al. Interim Analysis of Mitigating Osteoarthritis by Intervention with Low-Dose Irradiation to Extremities (MOBILE). ASTRO 2025 Annual Meeting, Abstract 249. Abstract
4. 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;200:134-142. PubMed
5. 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
6. 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;78:83-90. PubMed

Not new, though it can feel that way in the US. LDRT for osteoarthritis has been used in parts of Europe, especially Germany, for decades under established dose and treatment protocols. It's a growing option at US hospitals and radiation oncology practices, with Medicare and most major commercial insurance plans already covering it, which isn't typically the case for something considered experimental.

That said, "not experimental" and "settled science" aren't the same thing. As the previous question covers, the evidence includes strong recent positive trials alongside studies that found no significant benefit over sham treatment. The treatment itself and the way it's delivered are well-established; how consistently it works, and for whom, is still an active area of research.

Some observational studies and treatment centers report that relief may last many months and, in some responders, longer. The exact duration is uncertain, and stronger placebo-controlled long-term data are still limited. Some programs consider retreatment if symptoms return, but policies vary.

A typical LDRT course uses about 3 Gy divided over six treatments. This is substantially lower than the total dose commonly used in cancer treatment, although dose alone does not determine risk. Age, treatment location, the amount of normal tissue exposed, and individual health history also matter.

Long-term clinical experience has not identified a clear signal of increased radiation-induced cancer after LDRT for osteoarthritis. However, available studies are not large enough to rule out a very small risk completely. No dose of ionizing radiation is considered entirely risk-free, and the radiation oncologist should discuss how the expected benefit and potential risk apply to the individual patient.

No. LDRT for osteoarthritis is delivered by external beam, the same basic type of machine used for diagnostic X-rays and most cancer radiation therapy. The machine produces radiation only while it's switched on and aimed at the treatment area. It doesn't linger in or on the body afterward, so patients are not radioactive once a session ends and don't need to limit contact with family, including children or someone who is pregnant.

This is different from a smaller number of treatments in other areas of medicine, like radioactive iodine for certain thyroid conditions or some brachytherapy implants, where the patient does carry radioactive material for a period and does need to follow specific precautions. LDRT for osteoarthritis is not one of those treatments.

Hair loss is not a side effect reported with LDRT for osteoarthritis. It's generally associated with radiation passing through hair-bearing skin at meaningfully higher doses, most familiar from whole-brain radiation therapy for brain tumors. LDRT targets joints such as the knee, hip, hand, shoulder, elbow, ankle, or foot at a small fraction of that dose, so it isn't expected to affect hair anywhere on the body, including at the treatment site.

Many patients report few immediate side effects and can return to usual activity after treatment. Temporary skin irritation, fatigue, or other local effects are possible, depending on the body area treated. Serious short-term side effects appear uncommon in published studies, but the radiation oncologist should review both short- and long-term risks before treatment.

Programs generally consider adults with osteoarthritis or degenerative joint pain, most often in the knees, hips, hands, shoulders, elbows, ankles, or feet, who have not gotten enough relief from medications, injections, physical therapy, or other conservative treatments and want to discuss a non-surgical option. Evidence is not equally strong for every joint.

Many programs are cautious about using LDRT in younger adults because radiation-related risk has more time to develop. Age requirements vary by program, and the radiation oncologist considers age together with the joint being treated, prior care, imaging, and overall health.

People who may be better candidates generally have persistent, function-limiting pain in at least the moderate range (roughly 4 out of 10 or higher). This is not a universal cutoff, and each radiation oncology program may use different criteria.

The strongest recent sham-controlled evidence involved patients with mild-to-moderate knee osteoarthritis. Patients with advanced structural damage may be less likely to improve because LDRT cannot regrow cartilage or restore a severely damaged joint.^[1]

LDRT is generally not used for rheumatoid, psoriatic, or other autoimmune forms of arthritis. Those are managed differently, and a rheumatologist is the right first call for those conditions.

Reference: 1. 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

Steroid injections are quick and can help short-term, but relief is often measured in weeks to a few months and repeated injections carry their own risks. Joint replacement surgery can be very effective but is a major procedure with recovery time, and isn't right for everyone or every stage of disease.

LDRT sits between these: it's non-invasive and outpatient like an injection, but centers report relief that, when it works, tends to last longer than a typical injection, without the recovery time of surgery. As with the effectiveness question above, how it compares head-to-head in rigorous trials is still being studied.

Usually, yes. Most patients can be positioned for treatment even with limited mobility, and radiation therapy staff routinely accommodate wheelchairs, walkers, and other assistive equipment. Positioning may take extra time or extra help from the therapy team for a joint that's hard to hold still, but that's a logistics question for the treatment center, not typically a reason to rule LDRT out.

Severe, unusual positioning limitations are best discussed directly with the radiation oncology department before scheduling, so they can plan accordingly.

The full process has a few stages: a consultation first, then a CT scan (called a simulation) to map out your treatment plan. After the CT, expect to wait one to two weeks while your radiation oncologist and physics team build your treatment plan before your first actual treatment session. Then come the six treatment sessions themselves, given two to three times a week over about two to three weeks. Each treatment visit takes roughly 10 to 15 minutes, most of which is lying on the treatment couch while you're positioned. The actual radiation exposure itself lasts well under a minute. Once a week during your treatment course, you'll typically have a short check-in with your care team. There's no needle, no sedation, and no recovery period. You can drive yourself home or go about your day afterward.

For a fuller walk-through of each stage, see our What to Expect page, and consider bringing our printable question checklist to your first appointment.

LDRT is delivered using the same general category of equipment used for other radiation therapy: most often a linear accelerator (linac), the standard machine found in nearly every radiation oncology department, though some programs use smaller office-based orthovoltage units instead. Which machine your treatment center uses depends on their equipment and the joint being treated, not on you as a patient.

Either way, the visit itself looks the same: you're positioned on a treatment table, the machine delivers the dose from outside the body, and you go home afterward.

Our location directory lists confirmed programs across the country with an interactive map. If you don't see one near you, it's still worth asking your local radiation oncology department directly. Some offer it without listing it prominently online.