In the surgery of the skull base, what procedure is typically done to the lesion, is it a radical or definitive approach?

Surgical Approach for Skull Base Lesions

In skull base surgery, the definitive approach is the recommended treatment for lesions, aiming for complete resection with microscopically negative margins (R0) when feasible, or microscopically positive margins (R1) when R0 is not achievable. 1, 2

Surgical Management Principles

Primary Surgical Goal

• The quality of surgical margins is the most important prognostic factor for skull base tumors 2
• En bloc R0 resection is the standard treatment when feasible and when sequelae are acceptable to the patient 2
• For skull base and upper cervical tract lesions (particularly chordomas), complete R0 resection is rarely achievable, and R1 resection (microscopically positive margins) should be the goal of surgery 2

Approach Selection

• Tumor location is the most important variable to define the primary treatment approach 2
• The surgical approach must be carefully selected to maximize exposure while minimizing brain retraction and injury to vital structures 3
• Common approaches include:
  • Pterional approach
  • Frontolateral approach
  • Transsphenoidal approach
  • Suboccipital lateral approach 3

Specific Considerations for Skull Base Chordomas

• For skull base chordomas, preoperative biopsy is not recommended if the tumor cannot be reached easily or safely, or if there is high risk of tumor cell seeding 2
• When biopsy is performed, the biopsy track needs to be included in the surgical resection 2
• If en bloc R0 resection is not feasible, definitive radiation therapy alone should be considered as a valid alternative 2

Adjuvant Therapy

• Adjuvant radiation therapy should always be considered for skull base and cervical spine tumors, particularly when R1 resection margins are achieved 2
• Particle therapy (high-dose protons or carbon ions) provides better local control and survival compared to conventional radiation 2
• Due to the relative radiation resistance of chordomas, high doses (at least 74 GyE) are required 2

Potential Complications and Management

• Major complications include:
  • Cerebrospinal fluid leakage (9.5%)
  • Infections (5.4%)
  • Neural injuries (4.1%)
  • Vascular injuries (2.7%) 4
• Skull base reconstruction is critical to prevent these complications, often using multilayered closure techniques 4
• Local recurrence has extremely poor survival rates and local control is rarely achievable 2

Treatment Center Considerations

• Due to the complexity and rarity of skull base lesions, management should be carried out at specialized centers with multidisciplinary teams including:
  • Expert pathologists and radiologists
  • Surgeons familiar with skull base surgery
  • Radiation oncologists with access to particle therapy
  • Medical oncologists
  • Palliative care team 2, 1

The definitive approach to skull base lesions must balance maximal tumor removal with preservation of neurological function and quality of life. When complete resection is not possible, a combined approach with surgery and adjuvant radiation therapy offers the best chance for long-term disease control and survival.