Management of Recurrent Skull Base Meningiomas

The management of recurrent meningiomas requires a multi-disciplinary team that involves a neurosurgery, radiation oncology for adjuvant radiation, and neuro-oncology for medical/chemotherapy options. Surgery and radiation are the two primary treatments for recurrent meningiomas. Repeat surgery for recurrent skull base meningiomas, while complex and with relatively high complication rates, remains a mainstay of treatment, particularly when the patient has neurological deficits from the recurrent tumor. Important preoperative considerations include tumor location, planned extent of resection, consideration of the role of surgical adjuncts such as custom cranioplasties when there is extensive bone involvement, and somatostatin-PET based imaging to reveal tumor extent through scar tissue. Radiation therapy, including stereotactic radiosurgery, fully fractionated radiotherapy, and brachytherapy are integral in managing recurrent skull base meningiomas, although careful consideration of prior treatments and potential complications is essential for optimal patient outcomes. Brachytherapy is a viable option for recurrent meningiomas, particularly in cases where prior treatments have been exhausted and small volumes of residual tumor are adjacent to critical structures that cannot be safely resected. Effective chemotherapy remains an unmet need for meningiomas, but some drugs may offer moderate benefit or stabilization for recurrent meningiomas, although this remains primarily experimental/off-label. There is no proven highly effective chemotherapy for meningioma. Drugs often used to treat recurrent meningiomas with limited success include somatostatin analogs, often in combination with mTOR inhibition, immunotherapy, and alkylating agents. VEGF antibodies have also shown some benefit and can be helpful when symptomatic cerebral edema is present. Somatostatin analogs coupled to radioactive Lutetium are also under investigation, along with cell cycle and hedgehog pathway inhibitors. In conclusion, treatment of recurrent skull base meningiomas is a complex problem, with repeat surgery, radiation and medical options all playing a role, although there is a significant need for improved medical therapies. Thus, clinical trials exploring novel treatments with biomarker guided targeted molecular therapies are necessary to improve outcomes for patients with recurrent skull base meningiomas.