Safety and Efficacy of Balloon-Assisted Kyphoplasty Followed by Stereotactic Body Radiation Therapy for Pathological Fractures.

Background and objectives: In patients experiencing pain secondary to pathological compression fractures, balloon-assisted kyphoplasty and subsequent stereotactic body radiation therapy (SBRT) may allow for restoration of vertebral height and irradiation of the underlying malignancy to control local disease progression. The aim of this study was to evaluate the safety and efficacy of kyphoplasty treatment before SBRT in patients with spinal metastases and benign tumors.

Methods: An analysis of a prospectively collected database of 70 patients and 75 metastatic and benign spinal lesions that underwent kyphoplasty before SBRT at a single institution (2002-2023) was conducted. Patient characteristics were recorded, including treatment history, dosimetry and fractionation schedule, pain outcomes, local control (LC), and overall survival. The Bilsky score and Spinal Instability Neoplastic Score were calculated to assess epidural involvement and spinal stability, respectively.

Results: The median time from kyphoplasty to SBRT was 29 days (range: 2-159). Seventy-two lesions (96%) were managed with single-fraction SBRT and 3 lesions (4%) with a multifraction regimen. The median single-fraction prescription dose was 20 Gy (range: 12-25) delivered to a median tumor volume of 35.1 cc (range: 2.2-160). After a median follow-up period of 9 months (range: 1-201), 6 lesions (8%) locally progressed. Pain was reported to improve or remain stable for most patients (88%). The LC rate was 88% at 6 months, 1 year, and 2 years. No prognostic factors were significantly associated with LC. The median overall survival was 11 months (range: 1-201) after radiosurgery. There were no reports of cement extravasation or radiation-induced neurological deficit. Two acute pain flares (3%) were reported 1 and 3 months after radiosurgery.

Conclusion: The combined kyphoplasty and SBRT treatment paradigm can be used to treat patients with painful pathological compression fractures. Long-term LC and patient-reported improvement in pain were observed without the morbidity associated with open surgery.