Stereotactic body radiation therapy for benign spine tumors: is dose de-escalation appropriate?

Restricted access


Akin to the nonoperative management of benign intracranial tumors, stereotactic body radiation therapy (SBRT) has emerged as a nonoperative treatment option for noninfiltrative primary spine tumors such as meningioma and schwannoma. The majority of initial series used higher doses of 16–24 Gy in 1–3 fractions. The authors hypothesized that lower doses (such as 12–13 Gy in 1 fraction) might provide an efficacy similar to that found with the dose de-escalation commonly used for intracranial radiosurgery to treat acoustic neuroma or meningioma and with a lower risk of toxicity.


The authors identified 38 patients in a prospectively maintained institutional radiosurgery database who were treated with definitive SBRT for a total of 47 benign primary spine tumors between 2004 and 2016. SBRT consisted of 9–21 Gy in 1–3 fractions using the CyberKnife (n = 11 [23%]), Synergy S (n = 21 [45%]), or TrueBeam (n = 15 [32%]) radiosurgery platform. For a comparison of SBRT doses, patients were dichotomized into 1 of 2 groups (low-dose or high-dose SBRT) using a cutoff biologically effective dose (BED10Gy) of 30 Gy. Tumor control was calculated from the date of SBRT to the last follow-up using Kaplan-Meier survival analysis, with comparisons between groups completed using a log-rank method. To account for potential indication bias, a propensity score analysis was completed based on the conditional probabilities of SBRT dose selection. Toxicity was graded using Common Terminology Criteria for Adverse Events version 4.0 with a focus on grade 3+ toxicity and the incidence of pain flare.


For the 38 patients, the most common histological findings were meningioma (15 patients), schwannoma (13 patients), and hemangioblastoma (7 patients). The median age at SBRT was 58 years (range 25–91 years). The 47 treated lesions were located in the cervical (n = 18), thoracic (n = 19), or lumbosacral (n = 10) spine. Five (11%) lesions were lost to follow-up after SBRT. The median follow-up duration for the remaining 42 lesions was 54 months (range 1.2–133 months). Six (16%) patients (with a total of 8 lesions) experienced pain flare after SBRT; no significant predictor of pain flare was identified. No grade 3+ acute- or late-onset complication was noted. The 5-year local control rate was 76% (95% CI 61%–91%). No significant difference in local control according to dose, fractionation, previous radiation, surgery, tumor histology, age, treatment platform, planning target volume, or spine level treated was found. The 5-year local control rates for low- and high-dose treatments were 73% (95% CI 53%–93%) and 83% (95% CI 61%–100%) (p = 0.52). In propensity score–adjusted multivariable analysis, no difference in local control was identified (HR 0.30, 95% CI 0.02–5.40; p = 0.41).


Long-term follow-up of patients treated with SBRT for benign spinal lesions revealed no significant difference between low-dose (BED10Gy ≤ 30) and high-dose SBRT in local control, pain-flare rate, or long-term toxicity.

ABBREVIATIONS BED10Gy = biologically effective dose; SBRT = stereotactic body radiation therapy; SRS = stereotactic radiosurgery.

Article Information

Correspondence John A. Vargo: West Virginia University, Morgantown, WV.

INCLUDE WHEN CITING Published online May 25, 2018; DOI: 10.3171/2017.12.SPINE17920.

Disclosures Dr. Vargo receives speaking honoraria from Brainlab.

© AANS, except where prohibited by US copyright law.



  • View in gallery

    Local control of benign spinal lesions treated with SBRT.

  • View in gallery

    Local control of benign spinal tumors treated with low-dose (BED10Gy ≤ 30 Gy) or high-dose (BED10Gy > 30 Gy) SBRT.



Chamberlain MCTredway TL: Adult primary intradural spinal cord tumors: a review. Curr Neurol Neurosci Rep 11:3203282011


Chang SDMurphy MGeis PMartin DPHancock SLDoty JR: Clinical experience with image-guided robotic radiosurgery (the Cyberknife) in the treatment of brain and spinal cord tumors. Neurol Med Chir (Tokyo) 38:7807831998 (Tokyo)


Chang UKRhee CHYoun SMLee DHPark SQ: Radiosurgery using the Cyberknife for benign spinal tumors: Korea Cancer Center Hospital experience. J Neurooncol 101:91992011


De Salles AAPedroso AGMedin PAgazaryan NSolberg TCabatan-Awang C: Spinal lesions treated with Novalis shaped beam intensity-modulated radiosurgery and stereotactic radiotherapy. J Neurosurg 101 (Suppl 3):4354402004


Dodd RLRyu MRKamnerdsupaphon PGibbs ICChang SD JrAdler JR Jr: CyberKnife radiosurgery for benign intradural extramedullary spinal tumors. Neurosurgery 58:6746852006


Flickinger JCKondziolka DLunsford LD: Dose and diameter relationships for facial, trigeminal, and acoustic neuropathies following acoustic neuroma radiosurgery. Radiother Oncol 41:2152191996


Gagnon GJNasr NMLiao JJMolzahn IMarsh DMcRae D: Treatment of spinal tumors using cyberknife fractionated stereotactic radiosurgery: pain and quality-of-life assessment after treatment in 200 patients. Neurosurgery 64:2973072009


Gerszten PCBurton SAOzhasoglu CMcCue KJQuinn AE: Radiosurgery for benign intradural spinal tumors. Neurosurgery 62:8878962008


Gerszten PCChen SQuader MXu YNovotny J JrFlickinger JC: Radiosurgery for benign tumors of the spine using the Synergy S with cone-beam computed tomography image guidance. J Neurosurg 117 (Suppl):1972022012


Gerszten PCQuader MNovotny J JrFlickinger JC: Radiosurgery for benign tumors of the spine: clinical experience and current trends. Technol Cancer Res Treat 11:1331392012


Kondziolka DNiranjan ALunsford LDFlickinger JC: Stereotactic radiosurgery for meningiomas. Neurosurg Clin N Am 10:3173251999


Marchetti MDe Martin EMilanesi IFariselli L: Intradural extramedullary benign spinal lesions radiosurgery. Medium- to long-term results from a single institution experience. Acta Neurochir (Wien) 155:121512222013


Monserrate AZussman BOzpinar ANiranjan AFlickinger JCGerszten PC: Stereotactic radiosurgery for intradural spine tumors using cone-beam CT image guidance. Neurosurg Focus 42(1):E112017


Niranjan ALunsford LDFlickinger JCMaitz AKondziolka D: Dose reduction improves hearing preservation rates after intracanalicular acoustic tumor radiosurgery. Neurosurgery 45:7537651999


Purvis TEGoodwin CRLubelski DLaufer ISciubba DM: Review of stereotactic radiosurgery for intradural spine tumors. CNS Oncol 6:1311382017


Ryu SIChang SDKim DHMurphy MJLe QTMartin DP: Image-guided hypo-fractionated stereotactic radiosurgery to spinal lesions. Neurosurgery 49:8388462001


Sachdev SDodd RLChang SDSoltys SGAdler JRLuxton G: Stereotactic radiosurgery yields long-term control for benign intradural, extramedullary spinal tumors. Neurosurgery 69:5335392011


Sahgal AChou DAmes CMa LLamborn KHuang K: Image-guided robotic stereotactic body radiotherapy for benign spinal tumors: the University of California San Francisco preliminary experience. Technol Cancer Res Treat 6:5956042007


Saraceni CAshman JBHarrop JS: Extracranial radiosurgery—applications in the management of benign intradural spinal neoplasms. Neurosurg Rev 32:1331412009




All Time Past Year Past 30 Days
Abstract Views 168 168 38
Full Text Views 192 192 37
PDF Downloads 215 215 19
EPUB Downloads 0 0 0


Google Scholar