Low-Dose Radiotherapy (LDRT)

Clinical Information for Patients and Referrers

Targeting persistent osteoarthritis joint pain and other inflammatory musculoskeletal conditions

Discover more about LDRT

Low-dose radiotherapy (LDRT) is a structured outpatient treatment delivered within established radiotherapy facilities for selected benign musculoskeletal conditions, most commonly osteoarthritis.

LDRT is considered following appropriate conservative management and specialist assessment.

Safe, effective,
non-invasive
treatment

Most patients feel little to no side effects from treatment

Low risk with no recovery time

Short treatment course

Typically, six outpatient sessions (~10 mins each) over 2-3 weeks

Minimise disruption in your life

Compatible with other treatments

No impact on future procedures, including joint replacement surgery

Fits in with current care

Minimal side effects

Effective & precise

No wait-list

Immediate consultation

LDRT for Osteoarthritis

What is Low-Dose Radiotherapy (LDRT)?

Low-dose radiotherapy involves delivering very small doses of targeted radiation to a symptomatic joint or soft tissue.

The doses of radiotherapy used are substantially lower than those used in cancer treatment (~5% of the total dose), and typically delivered over six short outpatient sessions over a couple of weeks.

Treatment is delivered using the same precision planning systems and quality assurance processes used in modern radiotherapy departments.

How does LDRT work?

At low doses, radiation is thought to exert anti-inflammatory and immune-modulatory effects within treated tissues.

Laboratory and clinical research suggest that low-dose radiation may:

• Modulate inflammatory signalling pathways
• Influence immune cell activity within affected tissue
• Alter local pain-related pathways

These biological effects are believed to contribute to symptom improvement in some patients.

Not all patients experience benefit, and response cannot be predicted with certainty.

What does the evidence tell us?

Efficacy

LDRT has been used for decades in parts of Europe and is gaining attention throughout the world including the UK, the USA and more recently in Australia.

There are multiple cohort studies predominantly from Europe, and recently from the USA using a contemporary treatment protocol – which combined suggest efficacy particularly in early to moderate stages (Kellgren-Lawrence Grade 1-3).  

Recent presentation of the LoRD-KNeA Randomised Controlled Trial at ASTRO 2025 demonstrated efficacy beyond sham. 

10-year follow up of a Russian Randomised Controlled Trial has demonstrated improved pain and function scores, along with reduced arthroplasty rates in the LDRT arm compared with the sham group. In addition, there appears to be a significant joint preservation effect demonstrated on both MRI and x-ray imaging on prolonged follow up, raising the question as to whether LDRT could potentially be disease modifying rather than just symptom modifying. 

While these recent results are encouraging, there have been mixed reports previously. We await the results of further multi-centre randomised controlled trials.

Safety

Low toxicity observed across decades of use in Europe, with recent systematic reviews confirming favourable risk-benefit.

Acute Side Effects may include a mild transient pain flare, erythema/dry skin (Grade 1), or rare fatigue with an incidence ~5% in modern series, resolving within weeks without intervention.

With any radiation exposure there is always a risk of developing a secondary cancer. For the very low doses used in LDRT, theoretical excess absolute risk is suggested to be very low at ~0.01-0.05% per Gy (minimal bone marrow exposure at knee); no excess cancers observed in multiple large European series with long term follow up. Risk is age-dependent and likely negligible over age 50.

LDRT is included as standard management in German and Spanish guidelines. In the USA, UK and Australia, LDRT is still considered an investigational modality.

An expert team
with you at every step

Pinpoint Radiotherapy | Arthritis & Pain Clinic

Mulitple sites across Melbourne

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