• most common primary intra-axial brain tumour, common in 4-6th decades
Astrocytoma Grading System
Clinical Features
sites: cerebral hemispheres >> cerebellum, brainstem, spinal cord
symptoms: recent onset of new/worsening H/A, N/V, seizure, ± focal deficits or symptoms of increased ICP
Investigations
CT/MRI /w contrast: variable appearance depending on grade (see Table - Astrocytoma Grading System)
tissue biopsy: WHO grade and histology correlates with prognosis, but 25% chance of sampling error due to tumour heterogeneity
High grade astrocytoma on CT
Heterogenous contrast enhancement
Ill-defined borders (infiltrative)
Peritumoural edema
Central necrosis
Compression of ventricles, midline shift
Treatment
low grade diffuse astrocytoma
close follow-up, radiation, chemotherapy, surgery all valid options
surgery: not curative, trend towards better outcomes
radiotherapy alone or post-op prolongs survival (retrospective evidence)
chemotherapy: usually reserved for tumour progression
high grade astrocytomas (anaplastic astrocytoma and GBM)
surgery
gross total resection: maximal safe resection + fractionated radiation with 2 cm margin + concomitant and adjuvant temozolomide
except: extensive dominant lobe GBM, significant bilateral involvement, end of life near, extensive brainstem involvement
stereotactic biopsy if resection not possible, followed by fractioned radiation with 2 cm margin
expectant (based on functional impairment - Karnofsky score <70; patient’s/family’s wishes)
aim to prolong "quality" survival
chemotherapy: ~20% response rate, temozolomide (agent of choice); better response to temozolomide predicted by MGMT gene hypermethylation
multiple gliomas: WBRT ± chemotherapy