Low-Dose Radiation Therapy for Osteoarthritis: A Retrospective Single-Institution Analysis of 69 Patients and 168 Joints.

Purpose: This retrospective study evaluated the analgesic effects of low-dose radiation therapy (LDRT) for painful osteoarthritis.

Methods and materials: We analyzed 69 patients who underwent LDRT for osteoarthritis between January and December 2023, treating 168 joints. Pain intensity was measured using a numeric rating scale for the total score (0-100) and the relevant score (0-10). Each phase of treatment was delivered as 3 Gy in 6 fractions (0.5 Gy per fraction) over 2 to 3 weeks. Assessments were conducted pretreatment ("pre-RT"), at the end of treatment (EOT), and at a 10-week follow-up (FU). The von Pannewitz score measured patient-assessed improvement.

Results: The mean pre-RT total pain score was 40.4, with a relevant pain score of 6.3. At EOT, scores decreased significantly to 26.0 and 4.0, respectively (p < .05 and p < .01). At FU, scores remained significantly low at 25.8 and 4.0, respectively (p < .05 and p < 0.1 compared with pre-RT). Eighty percent of joints showed significant pain improvement (von Pannewitz score 0-2) at EOT, with 72% maintaining this at FU. Thirty-three percent of joints received a second LDRT phase, demonstrating further pain reduction. Pain score improvements did not significantly differ across joint types (p = .29).

Conclusions: This modern American case series demonstrates significant and sustained pain relief with LDRT for osteoarthritis across various joint types. The findings suggest that LDRT is a promising noninvasive treatment option, with potential benefits of repeated courses in select patients. Further randomized controlled trials are needed to validate these observations.