The role of stereotactic radiosurgery in the treatment of intramedullary spinal cord neoplasms: a systematic literature review

Advances in imaging technology and microsurgical techniques have made microsurgical resection the treatment of choice in cases of symptomatic intramedullary tumors. The use of stereotactic radiosurgery (SRS) for spinal tumors is a recent development, and its application to intramedullary lesions is debated. We conducted a literature search through PubMed’s MeSH system, compiling information regarding intramedullary neoplasms treated by SRS. We compiled histology, tumor location and size, treatment modality, radiation dose, fractionation, radiation-induced complications, follow-up, and survival. Ten papers reporting on 52 patients with 70 tumors were identified. Metastatic lesions accounted for 33 %, while 67 % were primary ones. Tumor location was predominantly cervical (53 %), followed by thoracic (33 %). Mean volume was 0.55 cm³ (95 % confidence interval (CI), 0.26–0.83). Preferred treatment modality was CyberKnife® (87 %), followed by Novalis® (7 %) and linear particle accelerator (LINAC) (6 %). Mean radiation dose was 22.14 Gy (95 % CI, 20.75–23.53), with mean fractionation of 4 (95 % CI, 3–5). Three hemangioblastomas showed cyst enlargement. Symptom improvement or stabilization was seen in all but two cases. Radionecrotic spots adjacent to treated areas were seen at autopsy in four lesions, without clinical manifestations. Overall, clinical and radiological outcomes were favorable. Although surgery remains the treatment of choice for symptomatic intramedullary lesions, SRS can be a safe and effective option in selected cases. While this review suggests the overall safety and efficacy of SRS in the management of intramedullary tumors, future studies need randomized, homogeneous patient populations followed over a longer period to provide more robust evidence in its favor.