What are the current surgical approaches to brain tumor resection

Surgical resection is often a key component in the treatment of brain tumors, aiming to remove as much of the tumor as safely as possible while preserving neurological function. Advances in technology and surgical techniques have improved the precision and safety of these procedures. Here are the current surgical approaches to brain tumor resection:

1. Craniotomy

• Overview:

  • The most common surgical approach for brain tumor resection.
  • Involves removing a section of the skull (bone flap) to access the brain, perform the tumor resection, and then replacing the bone flap at the end of the surgery.

• Procedure:

  • The patient’s head is secured in a fixed position.
  • A scalp incision is made, and the bone flap is temporarily removed to expose the brain.
  • The tumor is then resected using microsurgical techniques, with care taken to avoid damage to surrounding healthy brain tissue.
  • After the tumor is removed, the bone flap is replaced and secured with plates and screws, and the scalp is sutured.

• Intraoperative Tools:

  • Intraoperative MRI/CT: Used to update imaging during surgery, helping to assess the extent of tumor resection in real-time.
  • Intraoperative Ultrasound: Provides real-time images of the brain, aiding in tumor localization and assessment of resection margins.
  • Neuronavigation Systems: Advanced GPS-like systems that guide the surgeon to the precise location of the tumor using preoperative imaging data.
  • Neuroendoscopy: A minimally invasive technique using an endoscope for visualization and resection of the tumor, often used in deep-seated or ventricular tumors.

2. Awake Craniotomy

• Overview:

  • A specialized form of craniotomy where the patient is awake during part of the surgery to allow real-time monitoring of brain function.
  • Particularly useful for tumors located near or within eloquent brain areas responsible for critical functions like speech, motor control, and sensory processing.

• Procedure:

  • The patient is anesthetized for the initial steps (scalp incision and craniotomy), but then awakened for the tumor resection phase.
  • During resection, the patient is asked to perform specific tasks (e.g., speaking, moving limbs) to help the surgical team avoid damaging essential brain regions.
  • Once the tumor resection is complete, the patient is re-anesthetized for the closure of the skull and scalp.

• Applications:

  • Commonly used for tumors in the language and motor cortex, and other critical brain regions.

3. Endoscopic Surgery

• Overview:

  • A minimally invasive technique using an endoscope—a thin, flexible tube with a camera and instruments—to access and remove tumors.

• Types of Endoscopic Approaches:

  • Endoscopic Endonasal Approach (EEA): Accesses tumors through the nasal passages and sphenoid sinus, commonly used for pituitary tumors, craniopharyngiomas, and other midline skull base tumors.
  • Intraventricular Endoscopy: Used to resect tumors within the brain's ventricles, such as colloid cysts or intraventricular gliomas.
  • Endoscopic-Assisted Craniotomy: Combines traditional craniotomy with endoscopy to enhance visualization and access during tumor resection.

• Benefits:

  • Reduced trauma to surrounding brain tissue, faster recovery, and shorter hospital stays.

4. Laser Interstitial Thermal Therapy (LITT)

• Overview:

  • A minimally invasive technique that uses laser energy to heat and destroy tumor tissue.
  • Also known as laser ablation.

• Procedure:

  • A small burr hole is drilled into the skull, and a laser fiber is inserted into the tumor under MRI guidance.
  • The laser energy heats and ablates the tumor tissue, while the surrounding area is cooled to protect healthy brain tissue.

• Applications:

  • Suitable for small, deep-seated, or recurrent tumors, especially in patients who are not candidates for traditional surgery.

5. Stereotactic Radiosurgery (SRS)

• Overview:

  • A non-invasive method that delivers highly focused beams of radiation to the tumor, sparing surrounding healthy tissue.
  • While not a traditional surgery, it is often considered a "surgical" approach due to its precision and effectiveness in treating brain tumors.

• Types of SRS:

  • Gamma Knife: Uses multiple gamma rays to target the tumor with high precision.
  • CyberKnife: A robotic system that delivers radiation from multiple angles, allowing for treatment of tumors in various locations.
  • Linear Accelerator (LINAC) Based Systems: Delivers radiation using a movable linear accelerator, often used for larger or irregularly shaped tumors.

• Applications:

  • Often used for small or inaccessible tumors, metastases, or as a follow-up treatment after conventional surgery.

6. Laser Ablation with MRI-Guided Focused Ultrasound (MRgFUS)

• Overview:

  • A novel approach that uses MRI to guide focused ultrasound waves to ablate brain tumor tissue.
  • It is non-invasive and does not require an incision.

• Procedure:

  • The patient is placed in an MRI scanner, and focused ultrasound waves are directed at the tumor.
  • The MRI provides real-time feedback, allowing precise targeting and monitoring of the treatment.

• Applications:

  • Currently under investigation for certain types of brain tumors and conditions like essential tremor and Parkinson’s disease.

7. Neuroendoscopic-Assisted Minimally Invasive Craniotomy

• Overview:

  • Combines the benefits of craniotomy with endoscopy to achieve minimally invasive tumor resection.
  • Allows for smaller incisions and reduced disruption to brain tissue.

• Procedure:

  • Similar to a traditional craniotomy, but with the addition of an endoscope to enhance visualization and access.
  • Particularly useful for deep-seated or complex tumors.

8. Intraoperative Neuromonitoring

• Overview:

  • While not a standalone surgical approach, intraoperative neuromonitoring is a critical adjunct used in many brain tumor surgeries.
  • Monitors the function of the brain, spinal cord, and peripheral nerves during surgery to avoid injury.

• Techniques:

  • Electrocorticography (ECoG): Records electrical activity from the brain’s surface to map critical areas.
  • Somatosensory Evoked Potentials (SSEPs): Monitors sensory pathways.
  • Motor Evoked Potentials (MEPs): Monitors motor pathways.
  • Electromyography (EMG): Records muscle activity to detect nerve function.

Conclusion

The surgical approaches to brain tumor resection have evolved significantly, offering a range of techniques tailored to the tumor's location, type, and the patient’s overall condition. These include traditional craniotomy, awake craniotomy for tumors near critical brain areas, minimally invasive endoscopic approaches, laser-based therapies, and non-invasive radiosurgery. The choice of approach is highly individualized, aiming to maximize tumor removal while preserving neurological function and minimizing risks.