ArthroRad 3 & 12 month follow up research: Pioneering single-blinded research trials in low dose radiotherapy for Osteoarthritis.

IORBC are pleased to share this summary on the ArthroRad trial for low-dose radiotherapy for osteoarthritis (OA) which was conducted by Niewald et al, a team from DEGRO (German Society for Radiation Oncology). The trial reports focus on 3 & 12 month follow ups and mark an important contribution to OA treatment research, opening new avenues for pain management and highlighting the necessity for continued investigation in this field.

The bicentric, prospective, and randomised single blinded trial compared the effectiveness of a standard dose versus a very-low-dose regime of radiotherapy in patients with OA of the hand and knee joints. The patient profile included OA patients with symptoms persisting for over 3 months, over 40 years old, and in general good health. Those with prior local radiotherapy, trauma, rheumatoid arthritis, or vascular diseases were excluded. The mean duration of the pain prior to radiotherapy was 56.2 months.

It is important to note that the DEGRO team openly acknowledged the limitations of the trial which were largely caused by slow patient recruitment meaning that the trial had to be closed prematurely.  This recruitment issue is likely to have had a significant impact on the study data and will perhaps cause some concerns about the representativeness of the patient population.

The treatment protocols for the standard arm were a total dose of 3.0 Gy, in fractions of 0.5 Gy twice weekly. The experimental arm received a total dose of 0.3 Gy, in fractions of 0.05 Gy twice weekly (every joint region was randomized separately) and patients were unaware of their dosage. Key findings were as follows:

Pain Response: After 3 & 12 month periods, both the 3.0 Gy and 0.3 Gy doses provided good pain relief without significant differences between them. No side effects were recorded.

Quality of Life: Improvement in quality of life was noted, aligning with pain relief, but without significant differences between the groups.

Prognostic Factors: The only significant factor influencing treatment outcome was the initial pain level before radiotherapy so that patients with a higher VAS score at the beginning of radiotherapy responded more favorably than those with lower VAS score.

Second Course of Radiotherapy: In patients with insufficient initial response, a second course did not provide significant additional benefits.

The main discussion point arising from these trials is the comparison of the analgesic effect of both the standard and very low doses which were similar – challenging the notion that higher doses are more effective for pain relief in OA. The findings align with previous studies showing the effectiveness of low-dose radiotherapy in pain management for OA.

In conclusion, whilst the trial did not find a difference in the analgesic effect of a standard dose compared to a very low one, it did find that low dose radiotherapy can offer a viable option for pain relief in OA, with minimal side effects. The study made  recommendations for further research to explore the optimal radiotherapy dose and compare it against placebo treatments. 

In further discussion with, the IORBC posed the following questions to Prof. Niewald:

Question 1: If you were to do a similar study what would you improve based on your results? Would you change the type of the study design and participants?

Answer: In my opinion, it would be most important to perform a dose-finding-trial in which one arm should receive a sham dose. Blinding as performed by the colleagues Minten and Mahler would be advantageous. The aim of such a trial would be to repeat (or not repeat) the Dutch results. From our local point of view I cannot recommend changing the diagnoses. A further improvement would be to record the use of analgesics during one year after RT.

Question 2: What is your opinion about the placebo effect on the OA, is it possible that this effect is like the effect of the 0.05Gy?

Answer: I cannot exclude a placebo effect whereas our radiobiologist (Claudia E.Rübe) states that there are definite effects after the application of very low doses like 0.05Gy.

Question 3: In your opinion what is the most positive achievement of the ArthroRad Study?

Answer: In my opinion, the most positive effect is to see the effect of very low doses.

Our thanks to Prof. Dr. M.Niewald for sharing his thoughts and feedback on his paper with the IORBC. To read the Original Articles, please follow the links below..

Read the full articles here:

Niewald – Arthrorad hand,knee OA 3Gy vs 0.3Gy – 3 month

Niewald – Arthrorad 12m results

Source:

Prof. Marcus Niewald et al. ArthroRad trial: multicentric prospective and randomized single-blinded trial on the effect of low-dose radiotherapy for painful osteoarthritis depending on the dose.Published October 12, 2023 (12 month follow-up).