Robotic image-guided radiosurgery for the treatment of neoplastic vertebral pain

Pantaleo Romanelli, MD
IRCCS Neuromed IRCCS, Via Atinense 18, 86077 Pozzilli, Italy

Abstract

Metastatic spinal lesions are common in cancer patients. Spinal metastases usually involve the vertebral bodies and are characterized by severe pain. Surgical treatment, as a consequence of its high invasiveness, is rarely offered to patients with metastatic disease and expected limited life span. Spinal radiosurgery provides high rates of pain and local growth control with limited risk of neurological complications. The use of radiosurgery to treat spinal lesions has been strongly facilitated by the development of image-guided robotic radiosurgery, a technique able to deliver stereotactic irradiation to intra- and extra-cranial targets.....

INTRODUCTION

.... Three image-guided linear accelerator (LINAC)-based devices are currently used to deliver spinal radiosurgery : the Novalis Tx...TomoTherapy® Hi-Art® ...and the CyberKnife...

Radiosurgery

Several studies have demonstrated that radiosurgery is feasible and effective for palliation of spinal metastases. Cyberknife radiosurgery has been used and reported much more than other modalities of spinal radiosurgery, due to the intrinsic ability of the system to provide accurate single stage irradiation to the spine. A limited number of studies reporting the outcome of spinal radiosurgery using the Novalis and the Hi-Art systems will be discussed first....

Future Perspectives

Although spinal radiosurgery remains in its infancy, the data reported in the literature clearly show an effective role for it in the treatment of spinal metastases. Stereotactic delivery of radiation to metastatic lesions near the spinal cord can result in good tumor control, rapid and durable pain relief, and in some cases recovery of neurologic function, with little evidence of radiation-related side effects or radiation necrosis. The largest studies of spinal radiosurgery have consistently shown excellent clinical outcomes without complications using single-fraction approaches. Gerszten et al. presented outcome of a 115-patient study including 108 metastatic lesions (14). They treated all patients with a mean single-fraction dose of 14 Gy (12-20 Gy) prescribed to the 80% isodose line. No acute radiation toxicity or new neurological deficits occurred during the follow-up period (median, 18 months). Axial and radicular pain improved in 74 of 79 patients. In the large-scale study from the same group, not a single instance of radiation-induced neurological complications was observed.

Taken along with the current findings, pain control and local control after single-fraction or hypofractionated radiosurgery are equivalent. This is consistent with results of randomized studies that have failed to show significant difference in pain control between single- and multifraction regimens for external-beam radiation therapy. We can conclude that single-fraction radiosurgery is effective in most cases of spinal lesions, and that hypofractionated radiosurgery should be reserved for treatment of special cases (e.g., larger tumors). The efficacy and safety of highly conformal radiation therapy against metastatic spinal lesions appears to be well established based on the data in the literature....


Conclusions

Spinal radiosurgery is a fast, non-invasive treatment used with good results in a growing number of patients with vertebral metastatic pain. In particular, radiosurgery is rapidly becoming the main treatment option for patients with stable vertebral disease, offering high rates of pain and tumor growth control and low incidence of neurological complications.