Facts About Spinal Tumors
About 90% of all spine tumors (cord + vertebral) are metastatic resulting from the spread of cancer cells from the initial tumor to another part of the body. This is a common problem affecting more than 200,000 patients a year in the United States. Spinal metastasis is a vague term which can be variably taken to refer to metastatic disease to any of the following:
- Vertebral bone metastases
- Intradural extra medullary metastases
- Intramedullary metastases within the spinal cord
Presentation can be highly variable, however, the most common initial symptom is localized pain due to involvement of the vertebrae by the tumor. The pain usually is present for days or months before other symptoms appear. It is worsened by movement and by coughing or sneezing. In contrast with the pain from herniated disc disease, it worsens when the patient is lying down. A tingling or electric sensation down the back or in the upper and lower limbs upon flexion of the neck is an early sign of cord compression. Loss of bowel or bladder control may be the presenting symptom but usually occurs late. Abnormal sensations typically tingling or pricking (“pins and needles”), and numbness of the extremities or trunk can also be seen.
The diagnostic imaging study of choice is MRI of the spine. An MRI can show parts of the vertebrae compromised by the tumor as well as help display intraspinal extradural masses compressing the spinal cord.
The mechanism of metastatic spread of malignant tumors to the region is variable and includes:
Hematogenous: via the blood stream, arterial or venous
Direct invasion: from a tumor nearby
Breast cancer, lung cancer and melanoma are common sources of spine metastases. Renal tumors, prostate cancer, multiple myeloma and lymphoma are other primaries that can metastasize to the spine. It is estimated that every year over 200,000 patients will develop vertebral metastasis, of which 10% can have epidural spinal extension with cord compression. This progression of the cancer is considered an emergency and if left untreated can rapidly progress to paralysis. Spinal cord compression frequently requires prompt multi-modality management with medical, surgical and radiation interventions. For many years, conventional radiation therapy has been the most common treatment for patients with metastatic spinal tumors.
Spinal Surgery without Surgery – Spinal Radiosurgery
Beyond the convenience of a shorter duration of treatment, spinal radiosurgery provides greater dosage of radiation to a lesion compared to conventional radiotherapy. This translates into a high-rate of tumor control and faster pain-relief for the patients. The minimally invasive nature of this approach is consistent with recent trends in open spinal surgery and helps to maintain or improve a patient’s quality of life. Spinal radiosurgery has expanded the neurosurgical treatment options for patients with spinal and paraspinal metastasis, as well as the primary tumors.
Spinal and paraspinal metastases are common complications of advanced cancer. The incidence of spinal metastasis is increasing because patients are living longer due to recent advances in systemic therapy. Corticosteroids, pain management, radiation therapy, and surgical resection with possible fusion have been the mainstays of treatment for these patients.
Varian Edge™ Technology
By definition, Radiosurgery (SRS / SBRT) is delivered in 1 to 5 fractions using a modern linear accelerator (LINAC), such as the Varian Edge™. The Edge™ unit was specially designed to deliver body radiosurgery treatments of cancer and some benign tumors. This unit has multiple technical advantages, such as more precise methods for localization and delivery of the radiation with high dose rates guided by an advanced digital computer in less treatment times than other systems. This treatment scheme has been highly successful in the management of benign and malignant tumors of the spine.