Pediatrics Flashcards
Ddx for posterior fossa mass
Brainstem glioma
Medulloblastoma
Ependymoma
Astrocytoma (JPA)
ATRT
Hemangioblastoma
Mets
Lymphoma
DDx of suprasellar mass
Craniopharyngioma
Optic glioma
Pituitary adenoma
Germ cell tumor
Abcess
Meningioma
Ependymoma
Small round blue cell tumors
- LEARN MR
- Lymphoma
- Ewings
- ALL
- RMS
- Neuroblastoma
- Medulloblastoma
- Retinoblastoma
What is one way to avoid scoliosis
Don’t irradiate just part of vertebral body
Parinaud Syndrome
Impaired upward gaze
Pseudo-Argyll Robertson pupil (accomodates but does not react)
Convergence nystamus
What lesions associated with Parinaud syndrome
Pineal glad tumor or dorsal midbrain lesion
What is the most important management thing to state for pediatric patients?
Treat kid on protocol if available
For pediatric CNS workup, how to approach diagnosis of PF lesion
Do not biopsy as this risks herniation –> go for maximal safe resection
How to approach mgmt of PF mass if surgery not immediately available?
Shunt
ONLY if surgery not immediately available
Other workup of CNS lesions?
Neuro exam (CN, motor, sensory, cerebellar, Parinaud syndrome, fundoscopic exam)
CT and MRI of the brain and spine (through S4)
When should postop brain be done
Within 48 hours of surgery
When should LP be done if not prior to surgery
14 days post op
Treatment of HGG
Put on protocol
- Maximally safe resection
- If <3: chemo alone (vincristine, cyclophosphamide)
- If >3: RT
- If anaplastic oligo, consider adjuvant PCV
- If GBM, consider concurrent and adjuvant TMZ
- If unresectable: chemoRT
what is HGG RT dose
59.4 in 33 fractions
How does TMZ compare for kids vs adults
TMZ data not as good for kids
Contouring for pediatric HGG
- CTV1 is contrast enhancing + T2 flair + 1.5 cm expansion –> 46 Gy
- CTV2 is T1post + 1.5 cm –> 60 Gy
Where do pediatric ependymomas form
posterior fossa (60%)
Suprtentorial (30%)
Spinal cord (10%)
What is the treatment of anaplastic ependymoma
- Maximal safe resection
- Adjuvant RT to tumor bed alone
- No chemo
- Consider CSI if +LP or +MRI
Dose of RT for ependymoma
- Tumor bed
- 59.4 if age >3
- 54 for children 1-3 years of age
- Spinal cord
- 36 Gy CSI for children > 3
- Consider focal boosts to 45 Gy if gross disease
Most important prognostic factor for ependymoma
extent of resection
Contouring for ependymoma
- GTV is surgical target and residual disease
- CTV is GTV + 1 cm
- PTV is CTV + 0.5 cm
- Treat to 59.4 Gy
Typical age range of ATRT
<3 years old
Treatment of ATRT
Maximal safe resection
Chemotherapy (vincristine, MTX, cis, etop, cyclophosphamide x2 then carbo/thiotepa x3)
Adjuvant RTto 54 Gy
What staging/workup should occur for all pediatric brain pts
MRI brain, MRI spine (either preop or within 2 weeks)
LP (either preop or 14d postop)
Send kids with CNS tumors for what testing
- Neurocog/IQ testing
- Audiology
- Genetics if syndromic tumor
- Endocrine consult
- Fundoscopic and eye exam with VF testing
Mgmt of LGG
Principally maximall safe resection
RT for recurrence
When should RT be used for pediatric LGG
If recurrent after resection
If bx or STR and patient asymptomatic
Dose of RT for LGG
54 Gy in 30
Contouring of LGG
GTV= FLAIR residual disease
CTV= GTV+0.5 cm
PTV=5 mm
Describe JPA
Large cystic mass of cerebellum, hypothalamus, brainstem, usually benign and slow growing
JPA is associated with what syndrome
NF1
What is path hallmark of JPA
rosenthal fibers
Treatment of JPA
- Surgery is preferred
- If GTR –> no RT
- If STR –> can consider RT or obs
- If unresectable
- 3rd ventriculostomy for hydrocephalus
- Chemo (vincristine/carbo) preferred
- Consider RT if symptomatic, not responding, recurrent
Dose of RT for JPA
50.4 Gy in 28 fractions
Contouring for JPA
Get kid on trial!
GTV= residual T1post and T2 flair changes
CTV=GTV + 5mm
PTV = 3-5 mm
What is outcome for JPA
5 year OS > 90%
How to describe low grade ependymoma
Calcs and cysts are common as well as descent through the foramen magnum (tongue of tumor)
What is G1 ependymoma
subependymoma
myxopapillary
What is G2 ependymoma
classic ependymoma
what is path hallmark of low grade ependymoma
perivascular pseudorosettes
Most important prognostic factor for ependymoma
extent of resection
Mgmt of intracranial ependymoma
- Maximal safe resection
- STR - neoadjuvant chemo –> second look surgery
- Grade I/GTR - maybe ok to observe (but high rate of recurrence)
- Grade II/III GTR - adjuvant RT
- Check for spine disease
- If CSF+: 36
- If gross diease: boost to 45
- If <3 yo, chemo
Dose of RT for ependymoma
If GI/GII: 54 Gy
If GIII: 59.4 Gy
For CSI: 36 Gy boost gross disease to 45
Mgmt of spinal ependymoma
- Gross total resection
- Obs for GTR and maybe myxopapillary
- Adjuvant RT for other situations
- 45 Gy to 2 vert bodies above and below
- Boost gross disease to 50.4 if cord, 59.4 if conus or cauda
Contouring for ependymoma
GTV = gross disease and tumor bed
CTV = GTV + 1.5
PTV = 3-5 mm
Most common location for brainstem glioma
pons (70%)
Most common form of brainstem glioma
DIPG - diffuse intrinsic pontine glioma
Mutation a/w brainstem glioma
H3 K27M
How to diagnose a DIPG
Typically a radiographic diagnosis but more recently a push to do biopsies to see if that can guide molecularly targeted therapies
What has been the only thing shown to improve OS for brainstem glioma
RT
Dose for DIPG
54 Gy in 30 fractions
Use photons as no advantage to protons
What chemo is used for DIPG
Nothing routine
There are trial testing various agents
Dose of reRT for DIPG
Consider additional 36-45 Gy
Median survival for DIPG
6-12 mos
What is the contouring for DIPG?
CTV = GTV + 1 cm
PTV = CTV+3 mm
Treat to 54 Gy
Workup for optic glioma
- H&P
- CT or MRI
- Labs including HCG, AFP, endocrine labs
- Ophthalmologic exam
- Genetics referral
Should bx be performed of optic glioma
Only if diagnosis uncertain
Management of optic gliomas
- Surgery - organ preservation if possible and maximally safe debulking
- Chemo (carboplatin and vincristine)
- RT - effective local control and prevents worsening of vision loss and deficits from POD
Which optic glioma patients should get chemo alone
- Children <3
- Children with NF1 due to 2nd malig risk
Dose of RT for optic glioma
54 Gy
Target for optic glioma
Optic nerve, chiasm, optic tracts
Median age for medulloblastoma
Median age 5-6
20% occur before 2 year
What are the path features which should be considered for medullo?
Anaplasia
Histologic subtype
Molecular group
Workup for medulloblastoma
- MRI brain
- MRI spine if possible
- Labs - CBC, CMP, endocrine labs
- Baseline neurocog testing
- Audiology
- Ophthalmology with VF testing
DO NOT DO UPFRONT CSF DUE TO RISK OF HYDRO
Management of medulloblastoma
- Start steroids
- Consider maximally safe resection (if not possible or unsafe, proceed to VP shunt placement)
- Post op MRI in 48 hrs
- CSF and MRI spine 10-14 days later
- Determine if standard risk or high risk
- RT with weekly vincristine
- Possibly adjuvant chemo
When should medullo RT start after surgery
23-30 days post op
Total treatment duration for medulloblastoma
55 weeks
What is best prognosis molecular subtype of medulloblastoma
WNT, followed by SHH
What is poorest prognosis medulloblastoma subtype
Group 3 (frequently M+, Myc+)
How is medulloblastoma staged?
Chang staging, focusing on M
M0 medulloblastoma
No CSF or hematogeneous mets
M1 medulloblastoma
Microscopic disease in CSF
M2 medulloblastoma
Gross nodular cranial seeding beyond the primary site
M3 medulloblastoma
Gross nodular SPINAL seeding
M4 medulloblastoma
Mets outside CNS (bone)
What are the clinical categories of medulloblastoma
standard risk (2/3)
high risk (1/3)
How is average risk defined
GTR or < 1.5 cm2 residual
Age >3
M0
No anaplasia on path
Treatment approach for average risk medulloblastoma
- CSI to 23.4 in 13 fractions of 1.8 Gy
- Involved field boost to 54 Gy in 30 fractions
- Weekly vincristine
- Adjuvant chemotherapy with 6-8 cycles of cisplatin backbone chemotherapy
How to define high risk medulloblastoma
- STR or >1.5 cm2 residual
- Age <3 months
- M+
- Anaplastic histology
Treatment of high risk medulloblastoma
- CSI to 36 Gy in 20 fractions
- Boost to entire posterior fossa to total dose of 55.8 Gy in 31 fractions
- Weekly vincristine
- Other scenarios
- Boost additional brain disease to 55.8
- If focal spine disease, boost to 45 if above conus, 50.4 if below conus
- If diffuse spinal disease 39.6 Gy
- Consolidation with 6-8 cycles of cis based chemo
Dose for medullo diffuse spinal disease
39.6 (1.8.x 22)
5 year EFS for standard risk medullo
80%
5 year EFS for high risk medullo
65%
What is the youngest patient eligible for CSI?
age 3+
(catastrophic neurocognitive changes and patients can’t live independently if getting CSI before that age)
Strategy to try to bridge time to CSI for young children
Chemotherapy to help reserve RT for salvage
Posterior fossa syndrome
- Child awakes from surgery fine
- 1-4 days post op develops
- Hypotonia
- Ataxia
- Mutism
- Emotional lability
- Irritability
How many children get PF syndrome
30%
What share of kids with posterior fossa syndrome get better?
20%
What is the treatment for posterior fossa syndrome
No specific treatment
Do not stop RT
Diseases which require CSI
- Medulloblastoma
- Pineoblastoma/ependymoblastoma
- ATRT
- M+ ependymoma
- M+ germ cell (germinoma)
- NGGCT
- Supratentorial PNET
Contouring medullo tumor bed boost
GTV= tumor bed (T1post) + residual disease
CTV = GTV + 1.5 cm (respecting tentorium and bone)
PTV= 3-5 mm
What structure should be spared for medulloblastoma boost
cochlea
Cochlea constraint for kids
Dmax < 35
V30 < 50%
Pituitary constraint for kids
V35 < 50%
Most common locations for CNS germ cell tumors
Suprasellar
Pineal
What is the most common subtype of germ cell tumor?
germinoma (60%)
Serum marker profile of germinoma
mild elevation in hcg ok
normal AFP
DDx for a suprasellar or pineal mass
Germinoma or NGGCT
Pinealblastoma
Ependymoma
Craniopharyngioma
LGG
Hamartoma
Teratoma
LCH
Workup for germ cell tumor
- H&P with evals from neuro, ophtho
- MRI brain
- Labs
- CBC, CMP
- AFP, bHCG, LDH (both serum/CSF)
- TSH, GnRH, ADH, CRH
- Biopsy if necessary
- Referrals to audiology, neurocog testing, VF
- Rule out testicular GCT - PEx and scrotal US
- CSF and MRI spine 2 weeks post op (if not preop)
What is the surgical plan for germ cell tumors
If uncertain, bx is ok to confirm pure germinoma
Germinomas do not need resection
NGGCT will need resection
Treatment options for germinoma
- NO SURGERY unless NGGCT
- Combined modality therapy
- Induction chemo of 2-4 cycles carbo-etop
- If CR: whole ventricle to 21 Gy + boost to 9 Gy
- If PR: second look surgery or WV
- Induction chemo of 2-4 cycles carbo-etop
- RT alone
- Whole ventricle RT to 24 Gy
- Boost to 45 Gy
RT approach if CR after induction chemo for Germinoma
- Whole ventricle to 21 Gy in 1.5 Gy fractions (14 fractions)
- Primary site boost to 9 Gy
RT approach if PR after induction chemo for Germinoma
- Consider second look surgery to see if mature component
- Whole ventricle to 24 Gy in 1.5 Gy fractions (16)
- Primary site boost to 12 Gy (8)
RT approach if no induction chemo for Germinoma
- No surgery
- Whole ventricle to 24 Gy in 1.5 Gy fractions
- Tumor boost to 45 Gy in 1.5 Gy fractions
What is a bifocal germ cell tumor
Tumor in suprasellar and pineal regions synchronously
Treatment approach for bifocal germ cell tumor
DO NOT NEED CSI
Whole ventricle to 24 Gy
Boost both sites to 45 Gy
Trilateral germ cell tumor
Retinoblastoma
Pineal
Suprasellar
5 year OS for germinoma
>90%
Whole ventricle contouring
Lateral ventricles, 3rd vent, 4th vent and pre-pontine cistern expanded by 1 cm for CTV
Contouring for tumor boost germ cell tumor
Fuse T1post and T2 MRI
contour pre-chemo disease and do 1.5 cm expansion
Markers for choriocarcinoma
Very high hcg
Markers for yolk sac tumor
elevated AFP
What is important prognostic consideration for NGGCT
extent of resection, though not always possible given anatomy
Treatment strategy for NGGCT
- Maximally safe resection
- Chemotherapy
- carbo/etop alternating with ifos/etop for 4-6 cycles
- Second look surgery if not in CR
- RT
What is the RT approach for NGGCT
CSI + primary boost
RT strategy for NGGCT
CSI to 36 Gy (20 fractions)
Primary site boost to 54 Gy (tumor + 1 cm)
Location of prepontine cistern
Where does craniopharyngioma arise?
Rathke pouch
Radiographic hallmarks of craniopharyngioma
Distinct due to cysts and califications
What is the workup for craniopharyngioma
- H&P with full neuro and visual exam
- Labs: CBC, CMP, bHCG, AFP, LDH, endocrine panel
- MRI of brain with sellar protocol
- MRI spine if able and CSF if able prior to surgery, if not 10-14d postop
- Neurocog testing, audiology, VF, IQ
Initial management of craniopharyngioma
- Maximal safe resection via transsphenoidal approach
Next step if TSS for craniopharyngioma is GTR
Observation
Next step if TSS for craniopharyngioma is STR or bx
Radiation to dose of 54 Gy in 30 fractions of 1.8 Gy
UNLESS CHILD IS LESS THAN 3
What is recurrence of subtotally resected craniopharyngioma
50%
Contouring for craniopharyngioma
- GTV = residual disease including cysts
- CTV = GTV + 1 cm (respecting anatomic boundaries)
- PTV = CTV + 3 mm with daily CBCT
What is control rate of GTR for craniopharyngioma
70-85% but associated with significant morbidity
Outcomes of STR + RT for craniopharyngioma
85-90%
What is a practical RT consideration for treating craniopharyngiomas with RT?
Cyst or tumor swelling during RT can threaten coverage and result in chiasmal compression
Thus should obtain WEEKLY MRIs to confirm target volumes and consider cyst fenestration if target gets too big
Late effects of RT to suprasellar region
- DI (increased sodium and AMS)
- Growth hormone dysfunction
- Visual complications
- Moya Moya syndrome with occlusion of carotid arteries
- Hypothalamic dysfunction
Symptoms of hypothalamic dysfunction
Sleep disturbances
Weight gain
Memory impairment
Appearance of optic glioma
What percentage of RB patients are hereditary?
40% due to germline mutations in RB gene
What share of retinoblastomas are bilateral
20-30%