Low-Dose External Beam Radiation Therapy and Painful Hip Due to Coxarthrosis and Greater Trochanteric Pain Syndrome: Predictive Impact of Diagnosis, Target Volume Definition, and Season of Treatment.

Abstract

Coxarthrosis and greater trochanteric pain syndrome (GTPS) are common etiologies of hip pain. In this retrospective study, we analyzed the treatment response within the 3 to 12 months of low-dose external beam radiation therapy (LD-EBRT) for coxarthrosis and GTPS along with potential predictive factors. We evaluated data from patients who were treated with radiation therapy for GTPS or coxarthrosis at our radiation centers between 2014 and 2024. In addition, all planning computed tomography scans were analyzed according to the Kellgren-Lawrence score. Subsequent univariate and multivariate analyses of the data were performed. The clinical response rate (overall response rate [ORR]) was approximately 64% in GTPS and 58% in coxarthrosis. Approximately 20% of the patients received a second series of LD-EBRT, and approximately 5% a third. In multivariate regression analyses of coxarthrosis, factors negatively correlated with ORR were an initial increase in pain, age ≥ 70 years, and body mass index (BMI) ≥ 25 kg/m². The outcome was independent of symptom duration, LD-EBRT season, and planning target volume. In GTPS, symptom duration >12 months, initial pain increase, and prior hip prosthesis were negatively correlated with ORR. No dependence on the LD-EBRT season or on the definition of the planning target volume was observed. LD-EBRT may be an effective treatment option for GTPS and coxarthrosis. Early application of this therapy option appears to alleviate symptoms, regardless of season or planning target volume.