Risk of vertebral compression fracture specific to osteolytic renal cell carcinoma spinal metastases after stereotactic body radiotherapy: A multi-institutional study

Isabelle Thibault; Eshetu G Atenafu; Eric Chang; Sam Chao; Al-Omair Ameen; Stephanie Zhou; Nicholas Boehling; Ehsan H Balagamwala; Marcelo Cunha; John Cho; Lilyana Angelov; Paul D Brown; John Suh; Laurence D Rhines; Michael G Fehlings; Arjun Sahgal

Risk of vertebral compression fracture specific to osteolytic renal cell carcinoma spinal metastases after stereotactic body radiotherapy: A multi-institutional study

J Radiosurg SBRT. 2015;3(4):297-305.

Authors

Isabelle Thibault¹, Eshetu G Atenafu², Eric Chang³, Sam Chao⁴, Al-Omair Ameen^{1

5}, Stephanie Zhou¹, Nicholas Boehling⁶, Ehsan H Balagamwala⁴, Marcelo Cunha¹, John Cho⁵, Lilyana Angelov⁷, Paul D Brown⁶, John Suh⁴, Laurence D Rhines⁸, Michael G Fehlings⁹, Arjun Sahgal^{1

5}

Affiliations

¹ Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave, Toronto, Ontario, M4N 3M5, Canada.
² Department of Biostatistics, University Health Network, University of Toronto, 610 University Ave, Toronto, Ontario, M5T 2M9, Canada.
³ Department of Radiation Oncology, University of Southern California, Los Angeles, California, USA, 930033.
⁴ Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio, 44195, USA.
⁵ Department of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, 610 University Ave, Toronto, Ontario, M5T 2M9, Canada.
⁶ Department of Radiation Oncology, M.D. Anderson Cancer Center, The University of Texas, Houston, Texas, USA, 77030.
⁷ Department of Neurosurgery, Cleveland Clinic, Cleveland, Ohio, 44195, USA.
⁸ Department of Neurosurgery, M.D. Anderson Cancer Center, The University of Texas, Houston, Texas, 77030, USA.
⁹ Department of Neurosurgery and Spinal Program, Toronto Western Hospital, University of Toronto, 399 Bathurst St, Toronto, Ontario, M5T 2S8, Canada.

PMID: 29296412
PMCID: PMC5675497

Abstract

Purpose: Determine the risk of vertebral compression fracture (VCF) following stereotactic body radiotherapy (SBRT), specific to osteolytic renal cell carcinoma (RCC) spinal metastases, and associated predictive factors.

Methods: 187 RCC osteolytic spinal tumor segments in 116 patients obtained from a multi-institutional pooled database were reviewed. Each segment was evaluated according to the Spinal Instability Neoplastic Score (SINS).

Results: The median follow-up was 8.0 months. 34 VCF (34/187, 18%) were observed and median time to VCF was 2.4 months. VCF was observed in 43% (10/23), 24% (4/17) and 14% (20/147) of segments treated with 24Gy/fraction (fx), 20-23Gy/fx and ≤19Gy/fx, respectively. Multivariate analysis identified dose per fx (p=0.005), baseline VCF (p<0.001) and spinal misalignment (p=0.002) as predictors of VCF. Prior conventional radiotherapy (p=0.029) was found to be protective.

Conclusions: 18% of osteolytic RCC spinal metastases fractured post-SBRT. The presence of a baseline fracture, spinal mal-alignment and treatment with ≥20Gy/fx predicted for VCF.

Keywords: intensity-modulated radiation therapy; lytic bone metastases; radiotherapy; renal cell carcinoma; robotic radiosurgery; side effects; spine instability neoplastic score; spine metastases; spine stereotactic body radiotherapy; spine stereotactic radiosurgery; vertebral compression fracture.