What is the treatment for infra and supratentorial enhancing lesions?

Treatment for Infratentorial and Supratentorial Enhancing Lesions

The treatment approach depends critically on establishing a definitive histological diagnosis first, followed by multimodal therapy tailored to the specific pathology—surgical resection is the cornerstone for most lesions, with adjuvant radiation and/or chemotherapy determined by tumor type, grade, and extent of resection.

Initial Diagnostic Workup

Before initiating treatment, tissue diagnosis is essential for enhancing lesions:

• For patients without known primary malignancy: Perform systematic workup including chest CT, abdominal/pelvic CT, and consider FDG-PET if multiple brain lesions are present 1
• Stereotactic or open biopsy is indicated when no readily accessible tumor exists elsewhere or when diagnosis is uncertain 1
• MRI with gadolinium is the preferred imaging modality for characterizing lesions and planning treatment 1
• Spinal MRI and lumbar puncture should be considered for infratentorial tumors to assess for CSF dissemination 1

Management of Acute Complications

Hydrocephalus Management

For patients presenting with obstructive hydrocephalus:

• External ventricular drain via frontal trajectory for acute intracranial hypertension requiring immediate ICP stabilization 1
• Endoscopic third ventriculostomy (ETV) is preferred in centers with neuroendoscopic expertise, as tumor biopsy can be performed simultaneously with lower complication rates compared to shunting 1
• CSF shunting remains reliable for insidious hydrocephalus, particularly in limited-resource settings 1
• Ventriculoperitoneal shunt for persistent hydrocephalus in medulloblastoma and primitive neuroectodermal tumors 1

Treatment by Tumor Type

Pineal Region Tumors (Infratentorial/Supratentorial Interface)

Surgical approach selection is critically informed by: (1) relationship to deep venous network, (2) angle of straight sinus, (3) tumor height along vertical axis 1

Surgical corridor options include:

• Midline infratentorial supracerebellar: For mildly sloped/straight sinus with low-lying tumor 1
• Lateral supracerebellar: For most pineal lesions, especially those extending laterally into thalamus 1
• Occipital transtentorial: For large tumors occupying both supra- and infratentorial spaces 1
• Interhemispheric transcallosal: For tumors high along splenial-fourth ventricle axis 1

Treatment by histology:

• Pineocytoma: Gross total resection is usually the only treatment required 1
• Pineoblastoma: Maximal safe resection followed by risk-adapted craniospinal irradiation (23.4-36 Gy) plus chemotherapy 1

Medulloblastoma and Supratentorial PNETs

Surgical resection should be routine initial treatment to establish diagnosis, relieve symptoms, and maximize local control—complete resection achieved in 50% of patients and associated with improved survival 1

Adjuvant radiation therapy after surgery is standard of care:

• Conventional dose: 30-36 Gy craniospinal irradiation with boost to 55.8 Gy to primary site 1
• Reduced dose: 23.4 Gy craniospinal combined with chemotherapy for average-risk patients, though one randomized trial found increased relapse risk with dose reduction 1

Systemic chemotherapy: Postirradiation chemotherapy increasingly common, especially for children, to allow radiation dose reduction 1

Pleomorphic Xanthoastrocytoma (Supratentorial)

Optimal surgical resection should be undertaken in all patients as primary treatment 1, 2

Postoperative management:

• Grade 2 (typical PXA) with complete resection: Simple clinical follow-up with serial MRI 1, 2
• Grade 3 (anaplastic features): Postoperative external-beam radiotherapy mandatory, irrespective of resection extent 1, 2
• Incomplete resection or progression: Consider surgery, radiotherapy, and/or chemotherapy (though optimal regimens uncertain) 1, 2

Ependymoma (Infratentorial or Supratentorial)

Localized lesions:

• Surgery is standard treatment with complete resection confirmed by early postoperative MRI being a good prognostic factor 1
• Localized radiotherapy (not craniospinal) should be used if radiotherapy is administered 1

Grade 2 with complete resection: No complementary treatment necessary 1

Grade 3 or incomplete resection: Localized postoperative radiotherapy should be offered 1

Metastatic lesions: Craniospinal radiotherapy should be offered, with poor prognosis 1

Brain Metastases (1-3 Limited Lesions)

For patients with limited systemic disease or reasonable systemic treatment options:

Surgical candidates with single lesion:

• Surgical resection plus postoperative WBRT (Category 1 recommendation) 1
• SRS plus WBRT (Category 1 recommendation) 1
• SRS alone or after resection are reasonable options 1

Unresectable tumors: WBRT and/or radiosurgery 1

WBRT dosing: 30-45 Gy in 1.8-3.0 Gy fractions depending on performance status 1

Progressive extracranial disease with survival <3 months: WBRT alone, though surgery may be considered for symptom relief 1

Glioblastoma (Supratentorial)

Initial treatment: Maximal safe surgical resection followed by focal radiotherapy (60 Gy/30 fractions) with concomitant temozolomide (75 mg/m² daily during RT for 42 days, maximum 49 days) 3

Maintenance therapy: 6 cycles of temozolomide (150-200 mg/m² on Days 1-5 of every 28-day cycle) starting 4 weeks after RT completion 3

PCP prophylaxis required during temozolomide plus RT regardless of lymphocyte count 3

Recurrent disease:

• Local recurrence: Repeat resection if possible, followed by systemic chemotherapy if performance status favorable 1
• Reirradiation is Category 2B option if prior radiation produced good/durable response 1
• Alternating electric field therapy may be considered for glioblastoma (Category 2B) 1

Follow-Up Protocol

Serial MRI surveillance:

• 2-6 weeks post-RT, then every 2-4 months for 2-3 years, then less frequently 1
• Early scans allow appropriate corticosteroid titration, as scans may appear worse during first 3 months after RT completion (pseudoprogression) 1
• MR spectroscopy, MR perfusion, or PET can be considered to rule out radiation-induced necrosis or pseudoprogression 1

For esthesioneuroblastoma: Neurological assessment and neuroimaging at 3-month intervals 4

Common Pitfalls to Avoid

• Do not assume all enhancing lesions are malignant: Enhancement >3 months should raise suspicion for sarcoidosis, vascular abnormality (developmental venous anomaly, capillary telangiectasia), or other non-neoplastic pathology 1
• Confirm enhancement with pre-contrast images: Spontaneous T1 hyperintensity from lipid/iron-laden macrophages can mimic enhancement 1
• Do not perform WBRT twice: Patients previously treated with WBRT should not undergo repeat WBRT at recurrence due to neurotoxicity concerns 1
• Avoid inappropriate grouping: Esthesioneuroblastoma has significantly better prognosis (5-year survival ~90%) than other sinonasal malignancies and should not be treated identically 4