Radiosurgery, also known as stereotactic radiosurgery (SRS), is a non-invasive treatment method that utilizes precisely focused radiation beams to address tumors and other conditions affecting the brain and spine. Unlike traditional surgery, no incision is made during radiosurgery. Instead, it employs advanced 3D imaging techniques to deliver high doses of radiation directly to the targeted area, minimizing the impact on surrounding healthy tissues. This article aims to provide an in-depth understanding of radiosurgery, its mechanism of action, different types, conditions treated, potential side effects, and the technology behind it.
What is Radiosurgery or Stereotactic Radiosurgery?
Radiosurgery, specifically stereotactic radiosurgery (SRS), involves the use of multiple precisely focused radiation beams to treat tumors and other conditions in the brain and spine. It is a non-invasive procedure that does not require traditional surgical incisions. By utilizing advanced 3D imaging, SRS delivers high doses of radiation to the affected area while minimizing damage to surrounding healthy tissues. In many cases, stereotactic radiosurgery for brain and spine conditions can be completed in a single session, providing convenience and efficiency for patients.
How does Stereotactic Radiosurgery work?
Similar to other forms of radiation therapy, stereotactic radiosurgery works by damaging the DNA of the targeted tumor cells. This damage prevents the cells from reproducing, ultimately causing the tumors to shrink. The high dose of radiation delivered during stereotactic radiosurgery not only induces tumor shrinkage but also leads to the closure of blood vessels over time, effectively cutting off the tumor’s blood supply.
Different Types of SRS Techniques:
Stereotactic radiosurgery techniques may vary slightly depending on the specific machine used to deliver the treatment. Several radiotherapy machines are employed for SRS treatment, including:
- Linear Accelerator: A linear accelerator produces high-energy X-rays to target and treat tumors with precision. It is one of the most commonly used machines for SRS.
- Helical Tomotherapy: Helical Tomotherapy combines intensity-modulated radiation therapy (IMRT) with computed tomography (CT) imaging capabilities. This allows for highly precise and individualized treatment planning and delivery.
- CyberKnife: The CyberKnife system employs robotic technology to deliver highly accurate radiation beams to the tumor. It uses real-time imaging to track and adjust for any patient movement during treatment.
- Proton Beam Therapy: Proton beam therapy utilizes protons, rather than X-rays, to deliver radiation to the tumor. It offers unique advantages in targeting tumors while minimizing radiation exposure to surrounding healthy tissues.
- Gamma Knife: Gamma Knife radiosurgery is a specialized technique that focuses multiple beams of gamma radiation on the target area. It is commonly used to treat conditions in the brain.
Conditions Treated with SRS:
Stereotactic radiosurgery is effective in treating various cancerous and non-cancerous brain and spine conditions, including:
- Brain Tumors: SRS is utilized to treat both benign and malignant brain tumors, such as meningioma, paraganglioma, hemangioblastoma, and craniopharyngioma. It is also employed to treat brain metastases, which are cancers that have spread to the brain from other parts of the body.
- Arteriovenous Malformation (AVM): AVM refers to an abnormal tangle of arteries and veins in the brain that disrupts the normal blood flow. SRS can destroy the AVM and induce the closure of affected blood vessels over time, reducing the risk of bleeding or stroke.
- Trigeminal Neuralgia: Trigeminal neuralgia is a chronic pain disorder affecting the trigeminal nerves, causing extreme facial pain. SRS can target the nerve root responsible for transmitting pain signals, providing relief from symptoms.
- Acoustic Neuroma: Acoustic neuroma, also known as vestibular schwannoma, is a non-cancerous tumor that develops along the balance and hearing nerve leading from the inner ear to the brain. SRS can slow down tumor growth and minimize nerve damage.
- Pituitary Tumors: Tumors in the pituitary gland can disrupt hormone regulation. Radiosurgery can be used to shrink these tumors and restore pituitary gland function.
- Tremors: SRS may also be employed to treat tremors associated with functional neurological disorders like Parkinson’s disease and essential tremor.
Side Effects of SRS:
Stereotactic radiosurgery is generally a safe procedure with minimal risks compared to traditional surgery. Since no surgical incisions are involved, complications related to anesthesia, bleeding, and infection are significantly reduced. However, there are some potential side effects to be aware of:
- Early Complications: These are usually temporary and may include fatigue, swelling in the brain (causing symptoms like headache, nausea, and vomiting), and scalp or hair issues near the treatment sites. Hair loss is typically minimal and temporary.
- Late Side Effects: In rare cases, individuals may experience late side effects months after treatment. These side effects can include other brain or neurological problems. It is important to note that the occurrence of these late side effects is infrequent.
Conclusion
Radiosurgery, particularly stereotactic radiosurgery (SRS), offers a non-invasive and highly precise treatment option for various brain and spine conditions. By leveraging advanced imaging technologies and radiation delivery techniques, SRS delivers high doses of radiation directly to the targeted area, leading to tumor shrinkage and minimal impact on healthy tissues. With different types of SRS machines available, treatment can be tailored to the specific needs of each patient. Although there may be some temporary side effects, the overall risk profile of SRS is lower compared to traditional surgery. Stereotactic radiosurgery continues to revolutionize the field of neurosurgery, providing patients with effective and convenient treatment options.
Dr. Animesh Saha Senior Consultant- Clinical Oncology -Apollo Cancer Centre,Kolkata