Self-shielding, Gyroscopic Stereotactic Radiosurgery for Tumors of the Spine

Introduction: The ZAP-X ® Gyroscopic Radiosurgery System is a new advancement in stereotactic radiosurgery, which is unique regarding its self-shielding component. Here, we report our initial experience using the Zap-X Gyroscopic Radiosurgery system to treat spinal tumors at Jersey Shore University Medical Center.

Methods: 3 patients with spinal tumors were treated using the ZapX system from December 2023 to June 2024. Data was extracted for patient demographics and symptoms, tumor characteristics and diagnosis, dosimetry, and postoperative outcomes. Patient 1 was a 39 year old female with a C2/C3 schwannoma who presented with tingling and weakness of the left face and arm. Patient 2 was an 83 year old female with a C1 meningioma who presented with dizziness, tremors, speech change, focal weakness, and gait instability complicated by history of transient ischemic attacks. Patient 3 was a 59 year old male with prostate cancer metastasis at C1/C2.

Results: The treated tumor volumes were 0.61 , 3.00, and 6.29 cc for Patients 1, 2, and 3, respectively. Patient 1 had five fractions of treatment with 16 isocenters with a dosage of 30 Gy. Patient 2 had three fractions of treatment with 8 isocenters at a dosage of 24 Gy. Patient 3 had five fractions of treatment with 13 isocenters at a dosage of 30 Gy. The mean treatment time was 50 minutes. Patient 1 had complete resolution of her symptoms, while patient 3 tolerated the treatment well with no complications. Patient 2 tolerated her radiosurgery well but died from diabetic ketoacidosis and lung cancer.

Conclusion : Our case series shows the successful treatment of 3 patients with no complications. This research can inform the current literature surrounding this novel technology and its usefulness in treating tumors of the spine.