2925 - Low-Dose Radiotherapy for Refractory Post-Traumatic Chronic Osteomyelitis: A Retrospective Case Series

Purpose/Objective(s):

Chronic post-traumatic osteomyelitis remains a significant therapeutic challenge, particularly in patients with refractory disease after severe contamination, delayed surgical management, and prolonged antibiotic exposure. Low-dose radiotherapy (LDRT) has recognized anti-inflammatory and immunomodulatory effects but is rarely applied to chronic bone infection. We hypothesized that LDRT induces a measurable anti-inflammatory treatment response in refractory post-traumatic chronic osteomyelitis. The primary objective was to quantify radiotherapy-associated reductions in pain, sinus tract (fistula) activity, and inflammatory burden using clinical and imaging-based endpoints.

Materials/Methods:

Five patients (median age 45 years) with radiologically and microbiologically confirmed refractory chronic post-traumatic osteomyelitis of the lower extremities were treated following failure of surgical debridement and prolonged antibiotic therapy. LDRT was delivered using a cobalt-60 unit (1.25 MeV) with 2D conformal planning, employing one or two opposing fields, at a dose of 0.5 Gy twice weekly to a total dose of 3.0 Gy, with escalation to 6.0 Gy in cases of persistent inflammatory activity. Study endpoints included pain intensity assessed by the visual analog scale (VAS), sinus tract status, inflammatory changes on imaging assessed by conventional radiography, CT or MRI as clinically indicated, with scintigraphy performed selectively in equivocal cases, and treatment-related toxicity graded according to CTCAE v5.0. The median follow-up duration was 4 months.

Results:

All patients demonstrated clinical improvement following LDRT. Mean VAS pain score decreased from 7 to 1 (p<0.05). Two patients achieved inflammatory control after 3.0 Gy, while three required dose escalation to 6.0 Gy. Sinus tract closure occurred in four patients during or shortly after treatment. In one patient with a tibial bone defect, inflammatory stabilization was achieved 1.5 months after completion of LDRT, enabling successful reconstructive bone autografting without evidence of active infection. No acute toxicity = grade 2 was observed.

Conclusion:

Low-dose radiotherapy provides clinically meaningful inflammatory control in refractory chronic post-traumatic osteomyelitis, resulting in pain reduction and sinus tract resolution. LDRT may function either as a definitive anti-inflammatory treatment or as a bridge to reconstructive bone autografting within a multidisciplinary care pathway. These findings support the necessity for further prospective studies evaluating low-dose radiotherapy (LDRT) in non-malignant chronic inflammatory bone diseases.