Radiosurgery for benign tumors of the spine using the Synergy S: Clinical experience and future trendsPeter Gerszten1, Mubina Quader2, Josef Novotny3, John C. Flickinger, MD41Pittsburgh, United States 2Department of Radiation Oncology, University of Pittsburgh Medical Center 3Prague, Czech Republic 4Department of Radiation Oncology, University of Pittsburgh Keywords: spinal radiosurgery, spinal cord, radiosurgery, spine tumors, outcome
In distinction to the development of the clinical indications for intracranial radiosurgery, spine radiosurgery’s initial primary focus was and still remains the treatment of malignant disease. The role of stereotactic radiosurgery for the treatment of intracranial benign tumors has been well established. However, there is much less experience and much more controversy regarding the use of radiosurgery for the treatment of benign tumors of the spine.
This study presents the clinical experience and current trends of radiosurgery in the treatment paradigm of benign tumors of the spine as part of a dedicated spine radiosurgery program.
Radiosurgery was used as the primary treatment in 22 cases (55%) and for recurrence after open surgical resection in 18 cases (45%).
Forty benign spine tumors were treated using the Synergy S system; 13 cervical, 9 thoracic, 11 lumbar, and 7 sacral. Thirty-four cases (85%) were intradural. The most common histologies were schwannoma (15), neurofibroma (7), and meningioma (8). Eighteen cases (45%) had previously undergone open surgical resection. This cohort was compared to our prior institutional experience of 73 benign spine tumors treated using the CybeKnife.
No subacute or long term toxicity occurred (median 26 months). The mean prescribed dose to the gross tumor volume (GTV) was 14 Gy (range 11 to 17) delivered in a single fraction in 35 cases. In 5 cases in which the tumor was found to be intimately associated with the spinal cord, the prescribed dose was 18 to 21 Gy delivered in 3 fractions. No evidence of tumor growth was seen on serial imaging in any case. Compared to the prior cohort, there was a trend towards increased patient age, GTV, and use of radiosurgery in the post-surgical setting, as well as a simultaneous decrease in the prescription dose.
This was a retrospective study.
Radiosurgery is a safe and clinically effective treatment alternative for benign spinal neoplasms. While surgical extirpation is currently considered to be the best initial treatment option for most benign spinal tumors, spine radiosurgery has been demonstrated to have long-term benefit for such lesions. In a similar manner to which radiosurgery has become a primary treatment option for a variety of intracranial benign tumors, radiosurgery may become the most favorable treatment alternative for similar histologies when found in the spine.
The application of radiosurgery for non-neoplastic spine disease also deserves future investigation. Project Roles:
P. Gerszten (), M. Quader (), J. Novotny (), J. Flickinger ()