ArthroRad trial: multicentric prospective and randomized single-blinded trial on the effect of low-dose radiotherapy for painful osteoarthritis depending on the dose—results after 3 months’ follow-up

Abstract

Purpose Randomized comparison of the effect of radiotherapy on painful osteoarthritis (OA) applying a standard-dose vs. a very-low-dose regime Patients and methods Patients with OA of the hand and knee joints were included. Further inclusion criteria: symptoms for more than 3 months, favorable general health status, age above 40 years. Patients with prior local radiotherapy, trauma, rheumatoid arthritis, or vascular diseases were excluded. After randomization (every joint was randomized separately), the following protocols were applied: standard arm: total dose 3.0 Gy, single fractions of 0.5 Gy twice weekly; experimental arm: total dose 0.3 Gy, single fractions of 0.05 Gy twice weekly. The dosage was not known to the patients. The patients were examined 3 and 12 months after radiotherapy. Scores like VAS (visual analogue scale), KOOS-SF (the knee injugy and osteoarthritis outcome score), SF-SACRAH (short form score for the assessment and quantification of chronic rheumatic affections of the hands), and SF-12 (short form 12) were used. Results A total of 64 knees and 172 hands were randomized. 3.0 Gy was applied to 87 hands and 34 knees, 0.3 Gy was given to 85 hands and 30 knees. After 3 months, we observed good pain relief after 3 Gy and after 0.3 Gy, there was no statistically significant difference. Side effects were not recorded. The trial was closed prematurely due to slow recruitment. Conclusion We found favorable pain relief and a limited response in the functional and quality of life scores in both arms. The effect of low doses such as 0.3 Gy on pain is widely unknown. Further trials are necessary to compare a conventional dose to placebo and to further explore the effect of low doses on inflammatory disorders.

Low-dose RaDiation therapy for patients with KNee osteoArthritis (LoRD-KNeA): a protocol for a sham-controlled randomised trial

“…For sample size calculation, a randomised, comparative, parallel, three-arm design is used with 80% power and a two-sided alpha of 0.025 considering the comparison of the control group to each of the two types of experimental groups; a total of two tests are planned, and Bonferroni correction is performed. According to the ArthroRad trial, when doses of 0.05 Gy and 0.5 Gy per fraction (similar to this trial) were applied to degenerative arthritis of the hand and knee, the combined response rate of ‘markedly improved’ and ‘improved’ was around 60% 15. In addition, when the results of several retrospective studies were combined, clinical symptom improvement was observed in 63%–90% of cases after LDRT 2.…”

“…In the recent ArthroRad trial, the use of analgesics during the trial was also not limited despite patients having undergone surgical interventions or injections to the involved joint after LDRT were excluded as soon as this therapy became known. 15 They commented that limiting the intake of oral analgesics was unrealistic. In our study, we may be able to test whether inhibiting of concomitant analgesics is practically feasible through our study.…”

“…As a result, unspecified analgesics were used by approximately half of the patients (56% in the LDRT group and 43% in the sham group) for 3 months, and this uncontrolled part may have resulted in a study with bias. In the recent ArthroRad trial, the use of analgesics during the trial was also not limited despite patients having undergone surgical interventions or injections to the involved joint after LDRT were excluded as soon as this therapy became known 15. They commented that limiting the intake of oral analgesics was unrealistic.…”

“…According to the ArthroRad trial, when doses of 0.05 Gy and 0.5 Gy per fraction (similar to this trial) were applied to degenerative arthritis of the hand and knee, the combined response rate of ‘markedly improved’ and ‘improved’ was around 60%. 15 In addition, when the results of several retrospective studies were combined, clinical symptom improvement was observed in 63%–90% of cases after LDRT. 2 Therefore, the number of samples for this study may be determined by the following hypothesis test: assuming that the proportion of responders is 65% in the experimental groups and 30% in the control group, when the power is 80% and the alpha error is 5%, 34 patients are needed in each group.…”

Non-Oncological Radiotherapy: A Review of Modern Approaches

“…The study showed no statistically difference in pain control between the two schemes. Further studies need to be performed because there’s no evidence about the effect of low doses such as 0.3 Gy in the literature [ 54 ].…”