Guide to Stereotactic Radiotherapy Brain Tumors
Learn about stereotactic radiotherapy for brain tumors, including how it works, benefits, and what patients can expect from this precise treatment.
Written by Dr. Mohammed Kamran
Reviewed by Dr. Shaik Abdul Kalam MD (Physician)
Last updated on 8th Oct, 2025
Introduction
Receiving a diagnosis of a brain tumour is a life-changing moment, filled with complex medical terms and daunting decisions. For many patients, the word "surgery" brings to mind invasive procedures and long recovery times. But what if there was a way to treat a brain tumour with extreme precision, without a single incision? This is the promise of stereotactic radiotherapy, a revolutionary approach that has transformed neuro-oncology. This guide will demystify this advanced treatment, explaining how it works, who it can help, and what you can expect from the process. We'll break down the technology, from Gamma Knife to CyberKnife, and explore the significant benefits it offers over traditional methods. Our goal is to empower you with clear, understandable information, so you can have informed discussions with your healthcare team about the best path forward for your brain health.
What is Stereotactic Radiotherapy? Beyond the Scalpel
Stereotactic radiotherapy is a highly precise form of radiation therapy that delivers targeted, high-dose radiation to a well-defined tumour or lesion within the brain, while minimising exposure to the surrounding healthy tissue. Think of it like using a magnifying glass to focus sunlight on a single leaf, leaving the rest of the plant untouched. The term "stereotactic" refers to the use of a three-dimensional coordinate system to locate the target with sub-millimetre accuracy.
This precision is what sets it apart. Unlike conventional radiation, which might treat a larger area of the brain, stereotactic techniques are so accurate that they can effectively destroy tumour cells with a margin of error less than the width of a grain of rice.
Stereotactic Radiosurgery (SRS) vs. Stereotactic Radiotherapy (SRT)
These two terms are often used interchangeably, but there's a subtle yet important distinction:
- Stereotactic Radiosurgery (SRS): Typically involves delivering a high dose of radiation in a single session. Despite its name, no actual surgery is performed. It's best for smaller, well-defined tumours.
- Stereotactic Radiotherapy (SRT): Involves delivering the high dose of radiation over multiple sessions (called fractions).
This approach, known as fractionation, can be safer for tumours located near critical structures (like the optic nerve) or
for larger tumours, as it allows healthy cells time to recover between treatments.
The Core Principle: Pinpoint Accuracy
The entire process hinges on accuracy. It combines advanced imaging like MRI and CT scans with sophisticated
computer software to create a detailed 3D map of the brain and the tumour. During treatment, the patient's head is held
perfectly still using a customised mask or a lightweight frame. This ensures the radiation beams hit the exact target planned by the radiation oncologist and neurosurgeon, making the treatment both highly effective and remarkably safe.
Is Stereotactic Radiotherapy Right for You? Conditions We Treat
Stereotactic radiotherapy is a versatile tool used to manage a wide range of conditions affecting the brain. It is often the preferred treatment when a tumour is inoperable due to its location or when a patient is not a good candidate for traditional open surgery.
Treating Malignant Brain Tumours
- Metastatic Brain Tumours: These are cancers that have spread to the brain from other parts of the body (e.g., lung, breast, melanoma). SRS is exceptionally effective at treating a limited number of these metastases, often in a single session, and is considered a standard of care. Studies show that stereotactic radiosurgery can achieve local tumour control rates exceeding 80-90% for many metastatic brain tumours.
- Gliomas (including Glioblastoma): For some types of primary brain tumours, SRS or SRT may be used as a "boost" after conventional radiation or to treat recurrent tumours.
Managing Benign Tumours and Other Conditions
- Meningioma: These are typically slow-growing, non-cancerous tumours. SRS can effectively stop their growth or cause them to shrink, avoiding the risks of surgery.
- Acoustic Neuroma (Vestibular Schwannoma): A benign tumour on the nerve connecting the ear to the brain. SRS is
highly successful at controlling its growth while striving to preserve hearing and facial nerve function. - Arteriovenous Malformations (AVMs): These are tangles of abnormal blood vessels. Focused radiation causes the
AVM to thicken and close off over time, reducing the risk of bleeding. - Trigeminal Neuralgia: For this severe facial pain condition, SRS can target the nerve root to disrupt pain signals.
If you have been diagnosed with any of these conditions, consulting a specialist on a platform like Apollo24|7 can help you understand if stereotactic radiotherapy is a suitable option for your specific case.
Consult a Radiation Oncologist for the best advice
The Technology Behind the Treatment
Several advanced systems can deliver stereotactic radiotherapy. The choice depends on the tumour's characteristics and the medical center's equipment.
Frame-Based Systems: The Gold Standard Gamma Knife
- The Gamma Knife® is one of the oldest and most established technologies. It uses 192 or 201 focused beams of cobalt-60 radiation that converge with pinpoint accuracy on the target.
- Procedure: A lightweight, rigid frame is attached to the patient's skull under local anaesthesia. This frame ensures
absolute immobility and serves as a reference for targeting.
Best for: Single-session SRS for small to medium-sized tumours and AVMs.
Frameless Systems: The Flexibility of CyberKnife and Linear Accelerators
- CyberKnife®: This is a robotic system that mounts a compact linear accelerator on a flexible robotic arm. It moves
around the patient, delivering radiation from hundreds of different angles. Its key feature is real-time tumour tracking, which adjusts for minor patient movements without needing a rigid head frame. This makes the CyberKnife treatment experience more comfortable for many. - Linear Accelerators (Linacs): Modified standard radiation machines, like Novalis Tx® or TrueBeam®, can also
perform stereotactic procedures. They use advanced imaging guidance to verify position before and during treatment. They are highly versatile and can deliver both single-session SRS and multi-session SRT.
What to Expect: Your Stereotactic Radiotherapy Journey
Understanding the process can alleviate much of the anxiety associated with treatment.
Step 1: Consultation and Precise Treatment Planning (Simulation)
This is the most crucial phase. You will meet with a multidisciplinary team, including a radiation oncologist and neurosurgeon. If you proceed, a custom-fit, soft plastic mask will be created to hold your head gently in place. You will then undergo a high-resolution MRI or CT scan while wearing this mask. This imaging data is fed into planning software to create a custom stereotactic radiotherapy plan, which can take several hours or days to perfect.
Step 2: Treatment Day - What Actually Happens?
The treatment itself is painless and silent, much like getting an X-ray.
- You will lie on a treatment couch, and your personalised mask will be secured.
- The team will use the onboard imaging system to ensure you are positioned with millimetre accuracy.
- You will be alone in the room but in constant audio and visual contact with the therapists.
- The machine will move around you, delivering radiation according to the plan. You won't feel anything. A typical
session lasts from 30 minutes to over an hour. - For a single-session SRS, you will usually go home the same day. For multi-session SRT, you will return daily for
several days.
Step 3: Recovery and Follow-up Care
One of the biggest advantages is the short recovery time after a gamma knife or similar procedures. Most people resume normal activities within a day or two. Side effects are usually mild (see below). Your team will schedule regular follow-up MRI scans to monitor the tumour's response, which may show shrinkage or a loss of blood supply (indicating successful treatment).
Weighing the Pros and Cons: Benefits and Potential Side Effects
Before starting any treatment or medication, it’s important to understand both its advantages and risks.
The Significant Advantages of Stereotactic Precision
- Non-invasive: No incisions, no blood loss, and no risk of surgical infection.
- Minimal Recovery Time: Patients can quickly return to their daily lives.
- Precision: Protects healthy brain tissue, preserving neurological function.
- Effectiveness: High rates of tumour control, often in a single session.
- Option for Inoperable Tumours: Treats lesions deep within the brain that are too risky for surgery.
Understanding the Short-term and Long-term Risks
While generally safe, potential side effects of stereotactic radiosurgery can occur:
- Short-term: Fatigue, scalp redness or irritation where the mask was fitted, temporary hair loss in the treatment area, and
headache are common but usually resolve quickly. - Long-term: There is a small risk of swelling (edema) in the treated area, which can be managed with medication. In
rare cases, damage to nearby healthy tissue can occur, or new neurological symptoms may develop. The risk of long-
term effects is significantly lower than with whole-brain radiation.
Stereotactic vs. Whole-Brain Radiation Therapy: A Key Difference
It's crucial to distinguish these two approaches. Whole-brain radiation therapy (WBRT) treats the entire brain and was once common for metastatic cancer. However, it often leads to significant cognitive side effects, like memory loss, because it affects healthy brain tissue. Stereotactic radiotherapy, by sharply focusing the dose, avoids this widespread impact, offering effective tumour control with a much better quality of life. Today, for a limited number of brain metastases, stereotactic approaches are strongly favored over WBRT.
Conclusion
Stereotactic radiotherapy represents a monumental leap forward in the care of patients with brain tumours. By marrying cutting-edge technology with medical expertise, it offers a powerful, precise, and patient-friendly alternative to traditional treatments. Its ability to target disease with unparalleled accuracy means better outcomes, fewer side effects, and a faster return to normal life. If you or a loved one is facing a brain tumour diagnosis, it is essential to seek a consultation at a center that offers this advanced modality. A thorough evaluation by a skilled radiation oncologist and neurosurgeon is the first step in determining if this innovative approach is the right weapon for your fight. Remember, an informed patient is an empowered partner in their own healthcare journey. If you have further questions or need to discuss a diagnosis, consider booking an online consultation with a neuro-oncology specialist through Apollo24|7 to explore your options.
Consult a Radiation Oncologist for the best advice
Consult a Radiation Oncologist for the best advice
Dr. Rupam Manna
Radiation Specialist Oncologist
4 Years • MBBS MD(RADIO THERAPY)
Barasat
Diab-Eat-Ease, Barasat
Dr. Naman Utreja
Radiation Specialist Oncologist
11 Years • MBBS, MD Radiotherapy
Noida
Shanvi Heart and Cancer Care Clinic, Noida
(50+ Patients)
Dr. Satyesh Nadella
Radiation Specialist Oncologist
10 Years • MBBS, MD
Hyderabad
Apollo Hospitals Jubilee Hills, Hyderabad
Dr. Jayasree Kuna
Radiation Specialist Oncologist
4 Years • MD
Chinagadila
Apollo Hospitals Health City Unit, Chinagadila
Dr. Shilpa Reddy K
Radiation Specialist Oncologist
10 Years • MBBS,DNB Radiation oncology,
Hyderabad
Apollo Hospitals Jubilee Hills, Hyderabad
Consult a Radiation Oncologist for the best advice
Dr. Rupam Manna
Radiation Specialist Oncologist
4 Years • MBBS MD(RADIO THERAPY)
Barasat
Diab-Eat-Ease, Barasat
Dr. Naman Utreja
Radiation Specialist Oncologist
11 Years • MBBS, MD Radiotherapy
Noida
Shanvi Heart and Cancer Care Clinic, Noida
(50+ Patients)
Dr. Satyesh Nadella
Radiation Specialist Oncologist
10 Years • MBBS, MD
Hyderabad
Apollo Hospitals Jubilee Hills, Hyderabad
Dr. Jayasree Kuna
Radiation Specialist Oncologist
4 Years • MD
Chinagadila
Apollo Hospitals Health City Unit, Chinagadila
Dr. Shilpa Reddy K
Radiation Specialist Oncologist
10 Years • MBBS,DNB Radiation oncology,
Hyderabad
Apollo Hospitals Jubilee Hills, Hyderabad
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Frequently Asked Questions
1. Is stereotactic radiotherapy painful?
No, the treatment itself is completely painless. You will not feel the radiation. The only minor discomfort may come from wearing the custom mask, which can feel snug, or from having to lie still for the duration of the session.
2. How long does it take for a brain tumour to shrink after radiosurgery?
The response varies by tumour type. Benign tumours like meningiomas may not shrink significantly but stop growing. Malignant tumours often show shrinkage on follow-up MRI scans over several weeks to months. The primary goal is to destroy the tumour's ability to grow.
3. What is the success rate of SRS for metastatic brain tumours?
Success rates are very high. Stereotactic radiosurgery typically achieves local control, meaning the treated tumour stops growing in over 80-90% of cases. The overall prognosis depends on the control of the primary cancer elsewhere in the body.
4. Will I lose my hair?
Hair loss is usually limited to the small area where the radiation beams enter the scalp. It is often temporary, but in some cases, it can be permanent. Your care team can show you the exact spots where this might occur.
5. Can stereotactic radiotherapy be repeated if a tumour comes back?
In many cases, yes. If a new tumour appears or a previously treated tumour recurs in a different location, repeat stereotactic radiotherapy may be a feasible and effective option. This decision is made by your medical team based on the new tumour's size and location.