Introduction: The incidence of renal cell carcinoma continues to rise, and the spinal column is the most common site for bony metastases. Radiation therapy is one treatment option for spinal renal metastases. In particular, stereotactic body radiotherapy (SBRT) is a newer treatment that reportedly has benefits over conventional external beam radiation. The objective of this study is to systematically review the current literature on SBRT for metastatic renal cell carcinoma to the spine.
Methods: A web-based search of Pubmed, Embase, and Scopus was conducted in accordance to the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines. Clinical articles that evaluated SBRT for renal cell metastases were identified. After inclusion and exclusion criteria were applied, the search resulted in 9 articles. Data including: pain outcomes, local control, survival outcomes, vertebral compression fracture (VCF), and toxicity were extracted and evaluated.
Results: The studies analyzed demonstrated an improvement in pain in 41%-95% of patients. The local control rates after SBRT ranged from 71.2%-85.7% at a 1-year interval, a significant improvement when compared to conventional external beam radiotherapy (cEBRT). The rate of vertebral compression fracture after treatment with SBRT ranged from 16% to 27.5%, with single-fraction therapy being a risk factor for increased incidence. The overall toxicity rates demonstrated a range from 23%-38.5%, with only 3 cases of grade three toxicity (nausea) and no cases of radiation myelitis.
Conclusions: The use of SBRT for spinal metastases from renal cell carcinoma resulted in significant local control and pain outcomes. There is a risk of vertebral compression fracture with stereotactic body radiotherapy; however, the treatment appears well tolerated with few serious side effects. There is a continued need for long term prospective studies investigating the optimal role of SBRT in the treatment algorithm of RCC spinal metastases.
Patient Care: By understanding the application of stereotactic radiosurgery for renal cell metastases to the spine and the associated clinical outcomes, the neurosurgeon can make a more evidence-based decisions/treatment plan for these patients.
Learning Objectives: By the conclusion of this session, participants should be able to:
1. Understand the role of radiosurgery in treatment of renal cell metastases to the spine
2. Identify the clinical outcomes for renal cell metastases to the spine treated with radiosurgery