14 High-grade Glioma: Surgical Treatment

Case 14 High-grade Glioma: Surgical Treatment

Ramaz Malak and Robert Moumdjian

Fig. 14.1 T1-weighted magnetic resonance images (MRIs) of the head with contrast enhancement, axial (A) and coronal (C) sections. (B) Computed tomography (CT) scan of the head with contrast enhancement.

Clinical Presentation

A 52-year-old woman presents with a de novo tonic–clonic seizure.

She is otherwise neurologically intact.

Computed tomography (CT) and magnetic resonance imaging (MRI) scans of her brain are obtained (Fig. 14.1).

Questions

Describe the CT and MRI scans.

Provide a differential diagnosis of this ring-enhancing lesion.

What are the prognostic factors for glioblastoma multiforme (GBM)?

Describe perioperative technologies that enhance the rate of total resection.

Describe the relation between extent of resection and survival.

What factors hinder a complete resection?

The patient has a recurrence of symptoms after 10 months. An MRI shows an enhancing lesion at the site of resection (Fig. 14.2).
What are your differential diagnoses and investigations?
Provide indications for reoperation and describe complications of a reoperation.

Fig. 14.2 T1-weighted magnetic resonance image (MRI) of the head with contrast enhancement, axial section, 10 months postresection.

Answers

Describe the CT and MRI scans.

The scans show a nonhomogeneously enhancing lesion with a necrotic center in the right frontal lobe invading the corpus callosum.

Provide a differential diagnosis of this ring-enhancing lesion.

Malignant astrocytoma, metastases, abscess including toxoplasmosis, lymphomas, resolving hematoma, cysticercosis cyst, trauma, infarction

What are the prognostic factors for GBM?

Age (the younger the better)

Karnofsky performance score (KPS; >70 associated with better survival)

General and medical conditions

Cystic component (suggestive of necrosis)

Completeness of the resection (>90% resection associated with better survival)

Adjuvant therapy (standard of care conferring best survival rates remains a combination of surgery, radiation, and chemotherapy)1
Describe perioperative technologies that enhance the rate of total resection.
- Table 14.1^2–5
- Other modalities include
  - Cortical mapping
  - Awake craniotomy⁶
  - Robotics
Describe the relation between extent of resection and survival.
- Table 14.2^7–9
What factors hinder a complete resection?
- Tumor location in a functionally eloquent brain region
- Deep structures and brainstem invasion of the tumor
- Invasion of vascular structures
- Multiloculated GBM
What are your differential diagnoses and investigations?
- differential diagnosis
  - Tumor recurrence
  - Distinct tumor de novo (genetic predisposition)
  - Nonneoplastic lesion: abscess, radiation necrosis, inflammation, pseudotumor
- Investigation
  - In addition to basic imaging (CT/ MRI with and without contrast) and basic laboratory panel. Investigations also include those described below.
  - The main two diagnoses to diff erentiate remaining tumor recurrence versus radiation necrosis
  - See Table 14.3¹⁰ for comparison of some studies
  - MRI with gadolinium: Both tumor recurrence and radiation necrosis show enhancement.
  - MR spectroscopy: In specimens with mixed necrosis and neoplasm, the spectral patterns are less definitive.
  - Cerebral blood volume (CBV) mapping: Lesions with relative CBV greater than 2.6 mL blood/g of tissue were indicative of tumor recurrence, and relative CBV of less than 0.6 was consistent with radiation necrosis. However, there was significant overlap between the groups.
  - Positron emission tomography (PET) scan: Metabolic activity (glucose uptake) is increased in tumor and decreased in radiation necrosis.
  - Biopsy: may ultimately be necessary to distinguish tumor recurrence, radiation necrosis, and abscess.
Provide indications for reoperation and describe complications of a reoperation.
- Indications for reoperation
  - Favorable location: possibility of total or subtotal resection (≥ 90%)
  - KPS more than 70
  - Long disease-free interval
  - Good general condition: hematologic reserve, immunity, coagulation profile
  - Variable depending on previous treatment: surgery, irradiation, chemotherapy, steroids
  - In highly selected patients with GBM recurrence, average overall survival after maximal tumor resection is 30 weeks.¹¹
  - Table 14.4¹¹
- Complications of reoperation
- Death in 17%, edema, infection, bleeding, seizure, neurologic deterioration, cerebrospinal fluid fistula, functional deterioration (decreased KPS), wound dehiscence