Sacral metastases

The most common sacral tumor.

Sacral metastases are often diagnosed late when they have already extended beyond the osseous margins around the sacral nerves and other surrounding organs.

Patients commonly present with pain due to sacral nerve root compression and pathological fractures.

Zeng et al. retrospectively reviewed a prospective spine SBRT database for cervical spine metastases and sacral metastases. Patients were followed at 2- to 3-mo intervals with a clinical visit and full spine magnetic resonance imaging (MRI) and they report overall survival (OS), vertebral compression fracture (VCF), and MR imaging-based local control (LC) rates.

Fifty-two patients and 93 treated spinal segments were identified. Fifty-six segments were within the cervical spine and 37 within the sacrum, the median follow-up was 14.4 and 19.5 mo, and the median total dose/number of fractions was 24 Gy/2, respectively. Cumulative LC at 1 and 2 yr were 94.5% and 92.7% for the cervical cohort, and 86.5% and 78.7% in the sacral cohort, respectively. Lack of posterior spinal element involvement in the cervical spine (P < .0001) and absence of epidural disease (hazard ratio 0.275, 95% confidence interval 0.076-0.989, P = .048) in the sacral cohort predicted LC. Median OS was 16.3 and 28.5 mo in the cervical spine and sacrum cohorts, respectively. Two cases of sacral VCF, 1 brachial plexopathy, and 1 lumbar-sacral plexopathy were observed.

Although high rates of LC were observed, strategies specific to the sacrum may require further optimization ¹⁾.