2. Low grade glioma
o Slow growing tumours
◦ Divided as
◦ Pilocytic
Astrocytoma (grade I)
DNET (Dysembryoplastic Neuroepithelial Tumor)
◦ Non pilocytic
Fibrillary Astrocytoma
Diffuse Infilterating astrocytoma
Oligodendroglioma
3. WHO grade Histology Imaging Outcome
I
(usually
paediatric)
Low
proliferation
Discrete Possibility of cure
after surgery
80% 10 year survival
II
Mostly in adults
Often present
with seizures
Nuclear atypia
Infiltrative few
mitoses
Non-enhancing
Hyperdense on T2
FLAIR Infiltrative, ?
oedema
Median survival 5-10
years
Can transform to
high grade
5. Facts
50% to 75% of WHO grade II gliomas transform to high
grade glioma within 6 to 7 years of diagnosis
LGGs are primarily reported in the frontal lobes (44%),
followed by the temporal (28%) and parietal (14%)
domains
Interestingly, LGGs originating in the cerebellar region are
associated with a better prognosis than those originating
supratentorially
6. Molecular markers
TP53 mutations
Common in diffuse Astrocytomas and are mutually
exclusive from 1p/19q co-deletions
1p/19q Deletions
50-70% Oligodendroglial tumors
Loss of 1p or both 1p/19q may predict chemosensitivity
and predicts prolonged survival
7. IDH 1 mutations
60-90% of LGG
Associated with improved survival
May help differentiate:
gliosis vs tumor or
pilocytic tumors vs grade II astrocytoma
Molecular markers
9. Updated WHO
classification(2016)
o For grade II and Grade III glioma
Diffuse astrocytoma
• IDH-mutant
• gemistocytic astrocytoma IDH mutant
• IDH-wildtype
• NOS
•Oligoastrocytoma NOS
•Oligodendroglioma
• IDH-mutant, 1p19q co-deleted
• oligodendroglioma NOS
10.
11. Initial management
Seizures:
◦ levitiracetam, lacosamide, topirimate, lamotrigine
Edema:
◦ Steroids, dexamethasone 10 mg stat then 8 mg BD
Obstructive Hydrocephalus:
◦ may require surgery and perhaps placement of a
“shunt” to bypass the blockage and lower the
pressure
13. Prognostic factors (Pignati etal
EORTC 22844 and 22845)
1. Age >40
2. Symptomatic (not just seizure activity)
3. Enhancement
4. >6cm
5. Crossing the midline
6. Astrocytic (IDH wt and TERT mutated particularly poor)
>2 factors MS = 3.2 years
≤2 factors MS = 7.7 years
• If >2 of above, definitely consider doing something
14. What is the post-op
status?
Oligodendroglioma Astrocytoma
Age < 40
yrs and
GTR
Follow up
Yes No
Post op RT
50.4Gy/30# or
54Gy/30#
6 cycles of
adjuvant PCV
Watch and
wait
16. Principals of Surgery
Greater extent of resection improves OS and
seizure control
Gross total resection
Maximal safe resection
Maximizing tumour resection recommended over
simple debulking
Stereotactic biopsy
uncommon, it remains a reliable first step for
cases in which the diagnosis is uncertain
25. Progression after RT
o Resurgery (If resectable)
o Chemotherapy (Unresectable disease)
o Reirradiation with SRS/FSRT (Small recurrences)
o Newer targeted agents under trial
28. Radiotherapy dose
RTOG Ph-III randomized study
Necrosis more with higher RT dose
211 pts from 1986-1994
Median follow-up: 76 months
Age >18 years with biopsy
proven supratentorial lesions
Histology (WHO Grade I and II)
Excluded: pilocytic
astrocytoma with gross total
resection
RT- 50.4 Gy vs 64.8 Gy
ShawJCO2002; 20:2267-2276
30. Karim IJROBP 1996; 36: 549-56
EORTC 22844: Ph-III study
379 pts
Median follow-up:74m
Age 16-65 years with biopsy
proven supratentorial lesions
Histology (WHO Grade I and II):
QOL worse with higher RT dose
31. EORTC 22845
Randomized phase III
RT Dose (54Gy/30#) Immediate RT vs RT at
Progression
Improved median progression free survival (5.3 yrs vs
3.4 yrs)
Better seizure control rates No difference in Median
survival (7.4yrs vs 7.2 yrs)
No difference in rate of malignant transformation.
35. High dose per fraction
EORTC 22844 & 22845
At 6 yr follow up:
1.8-2 Gy/fr RT: No impact on cognitive function
>2 Gy/fr: Higher decline in memory domain
At 12 yr follow up:
Cognitive function decline in both 1.8-2 Gy/fr & >2Gy/fr RT
However, impact of High dose per fraction on cognitive function
reduced
Van den Bent Lancet 2005
36. Progression to high grade
EORTC 22845
issue At 12 yr follow up:
Progression to high grade:
RT arm: 50%
No RT arm:51%
No different is progression to high grade with & without RT
Van den Bent Lancet 2005
38. RTOG 9802
Buckner et al
Adjuvant chemotherapy
Grade 2 glioma (any subtype)
High risk > 40 years
54Gy in 30 fractions +/- 6 x PCV q8 weekly
Improved overall survival with addition of PCV
Median: 13.3 vs 7.8 years
10 year OS: 60% vs 40%, HR 0.59, p=0.003
Improved progression free survival with PCV
10 year PFS: 21% vs 51%
Largest benefit in oligodendroglioma NEJM April 2016
39. Progression & transformation
LGG may progress without transformation:
Increase in tumour size without transformation to
High grade
- No contrast enhancing
- Low perfusion
- MR spectro: No Choline peak
- Need to treat as low grade glioma
40. LGG may progress with
transformation:
Increase tumour size &
transformation to high grade
- Contrast enhancing (Patchy)
- Higher perfusion
- MR spectro: Choline peak
- Need to treat as High grade
glioma
Progression & transformation