Stereotaxic radiation therapy

Stereotaxic Radiation Therapy

Stereotaxic radiation therapy, also known as stereotactic radiotherapy, is a form of external beam radiation therapy that precisely delivers a high dose of radiation to a targeted area, often a tumor, while minimizing exposure to surrounding healthy tissues. This technique is commonly used in the treatment of brain tumors, lung cancer, liver cancer, and other localized malignancies.

History

The development of stereotaxic radiation therapy can be traced back to the mid-20th century with the invention of the stereotactic frame by Lars Leksell, a Swedish neurosurgeon. The technique was initially used for stereotactic radiosurgery (SRS) in the treatment of brain disorders. Over time, advancements in imaging and radiation delivery technologies have expanded its application to other parts of the body.

Principles

Stereotaxic radiation therapy relies on precise imaging techniques, such as CT scans, MRI, and PET scans, to accurately locate the tumor. The patient is immobilized using a stereotactic frame or a body mold to ensure that the radiation is delivered to the exact location. The radiation beams are then shaped and directed from multiple angles to converge at the tumor site, delivering a high dose of radiation while sparing adjacent healthy tissue.

Techniques

There are several techniques used in stereotaxic radiation therapy, including:

• Stereotactic Radiosurgery (SRS): A single high-dose radiation treatment, often used for small brain tumors or arteriovenous malformations.
• Stereotactic Body Radiotherapy (SBRT): Also known as stereotactic ablative radiotherapy (SABR), this involves delivering a few high-dose treatments to tumors outside the brain, such as in the lung or liver.

Applications

Stereotaxic radiation therapy is used to treat a variety of conditions, including:

• Brain Tumors: Both benign and malignant tumors, such as glioblastoma and meningioma.
• Lung Cancer: Particularly early-stage non-small cell lung cancer (NSCLC).
• Liver Cancer: Including hepatocellular carcinoma and metastatic liver lesions.
• Spinal Tumors: Both primary and metastatic tumors affecting the spine.

Advantages

The main advantages of stereotaxic radiation therapy include:

• Precision: High accuracy in targeting the tumor, reducing damage to surrounding healthy tissue.
• Efficacy: High doses of radiation can be delivered, potentially leading to better tumor control.
• Non-Invasive: Unlike surgery, this therapy does not require incisions or anesthesia.

Limitations

Despite its advantages, stereotaxic radiation therapy has some limitations:

• Not Suitable for All Tumors: It is most effective for small, well-defined tumors.
• Potential Side Effects: Can include fatigue, skin irritation, and, in some cases, damage to nearby organs.

Also see

• Radiation therapy
• Stereotactic surgery
• CyberKnife
• Gamma Knife
• Linear accelerator