The role of stereotactic radiosurgery for treatment of intracranial lesions is well established.Its use for the treatment of spinal lesions has been limited by the availability of effective target-immobilizing devices. Conventional external beam radiotherapy lacks the precsion to allow delivery of large doses of radiation near radiosensitive structures such as spinal cord
The Cyberknife is an image-guided frameless stereotactic radiosurgery system that allows for the radiosurgical treatment of spinal lesions. This study evaulted the feasibility and effectiveness of spinal lesions with Cyberknife.
In this prospective cohort evaluation of a spine radiosurgery technique,24 spinal lesions in 21 consecutive patients were treated with radiosurgery technique ( 7 cervical,11 thoracic,4 lumber,and 2 sacral). There were 6 benign tumors and 18 malignant lesions. All does plans were calculated on the basis of computed tomographic images acquired from 1.25-mm slices with inverse treatment planning technique. Radiosurgical circular cones ranging in diameter from 5 to 40 mm were used.
Tumor dose was maintained at 12 to 39Gy to 80% isdose line (mean,24Gy) and 1 to 5 fractioned. Canal volume receiving more than 8 Gy ranged from 0.0~1.23 cm3 (mean,0.2cm3). No acute radiation toxicity or new neurological deficits occurred during the follow-up period ( range,3~6mo;mean,4.3 mo.).Axial and radical pain fully improved in 11 of 13 patient and 2 partial improved than before treatment.
Conclusions: The major potential benefits of radiosurgical ablation of spinal lesions are short treatment time in an outpatient setting with rapid recovery and symptomatic response. This technique offers a successful therapeutic modality for the treatment of a variety of spinal lesions as a primary treatment or for lesions not amenable to open surgical techniques, in medically inoperable patients,in lesions located in previously irradiated sites, or as an adjunct to surgery.