Chapter 84 CNS Tumors In Children Flashcards
(225 cards)
1
Q
What percentage of childhood malignancies known with genetic predisposition?
A
2-5%
2
Q
What are the genetic predisposition in childhood malignancies?
A
- Neurofibromatosis types 1(NF-1) and 2 (NF-2)
- Tuberous Sclerosis
- Nevoid basal cell(Gorlin’s) syndrome
- Familial adenomatous polyposis
- Li-Fraumeni syndrome
3
Q
What is the main predisposing factor of childhood malignancies?
A
Majority remains with no predisposing factors
4
Q
Radiotherapy causes disrupted neuro Genesis and cortical atrophy. Patient failed to acquire new knowledge and skills at age-appropriate rate and show progressive decline in IQ over time. The magnitude of deficit depends on?
A
- Age at treatment
- Tumor location
- Treatment factors(RT volume, dose and use of chemotherapy)
5
Q
What intervention could be used for helping patients with RT induced deficits?
A
The following can be start soon after treatment for best results
- Cognitive or behavioral therapy
- Pharmacotherapy
- Exercise
6
Q
Endocrine deficit are very common after RT. Which harmone deficiency is primarily responsible that correlates with dose of RT?
A
Growth harmone
7
Q
Which harmone deficiency is primarily responsible that is seen after CSI?
A
Thyroid harmone
8
Q
What percentage of CNS malignancies occurs in childhood?
A
20-25%
9
Q
What strategies could be used to avoid or minimize long term effects of treatment for pediatric brain tumor?
A
- Avoidance of RT altogether
- Delay of RT for age 3-8 years by chemotherapy
- Use of daily anesthesia, improved immobilization, daily pretreatment image verification
- Use of new RT modalities eg Proton
- Use of reduced RT target volume eg in medulloblastoma
- Reduce RT dose eg in medulloblastoma
- Use of small fraction size in radiosensitive tumor eg germinoma 1.5Gy/Fx
- HFRT eg current Europian studies in Medulloblastoma
10
Q
During patient positioning and immobilization in CSI, what maneuver will help avoid dentition in exit dose from superior aspect of spinal field?
A
Neck extension with careful selection of level for junction of brain and spinal fields
11
Q
Lower border of thecal sac can be as high as L5 and as low as S3. In the interest of CTV coverage and normal tissue sparing, how do we individualize lower border of spine field in CSI?
A
MRI findings
12
Q
During CSI, what percentage of variation of dose along spinal axis will require use of dose compensation and how can we achieve that?
A
> 10%
Using MLC
13
Q
What are possible solutions for field matching over cervical spine/risk of over- or under dosage?
A
- Angle brain fields
- Use half beam blocks for brain fields
- Use couch rotation or match line wedge
14
Q
What are possible solutions for irradiation of normal tissue thyroid gland?
A
Care of level of junction
15
Q
Most common CNS tumor in pediatric age group?
A
Medulloblastoma
16
Q
Most common CNS tumors in adult group?
A
High grade glioma
17
Q
WHO classification of Astrocytic tumors Grade I Grade II Grade III Grade IV
A
Grade I - Pilocytic Astrocytoma
Pilomyxoid Astrocytoma - aggressive behavior, may include leptomeningeal seeding
Grade II - Diffuse Astrocytoma
Fibrillary Astrocytoma
Gemistocytic Astrocytoma
Protoplasmic Astrocytoma
Grade III - Anaplastic Astrocytoma
Grade IV - Glioblastoma Multiforme
Giant Cell Glioblastoma
Gliosarcoma
Subependymal Giant Cell Astrocytoma - Rare
Pleomorphic Xanthoastrocytoma - Rare
Gliomatosis cerebri
18
Q
What are low grade glioma?
What is the overall survival rates at 10 and 15 years
A
Grade I/II
80-100%
19
Q
Group LGGs according to an anatomic locations
A
Cerebellar Astrocytoma
Hemispheric Astrocytoma
Midline Supratentorial tumors
Corpus Callosum
Lateral and third ventricle
Hypothalamus
Thalamus
Optic pathway tumors
Brainstem LGAs
LGAs of Spinal Cord
20
Q
What is most common Astrocytoma in pediatric age group?
A
Pilocytic Astrocytoma
21
Q
Name the sites accounting for almost all of LGAs, Pilocytic
A
Cerebellum
Anterior Optic Pathway
22
Q
Describe macroscopic features of Pilocytic Astrocytoma
A
Well circumscribed, associated cystic component.
23
Q
Describe microscopic features of Pilocytic Astrocytoma
A
Biphasic pattern
- Varying proportion of compacted bipolar cells with Rosenthal fibers
- Loosely textured multipolar cells with microcysts and granular bodies
24
Q
Features compatible with Pilocytic Astrocytoma but not a sign of malignancy
A
Rare mitosis
Occasional hyperchromatic nuclei
Micro vascular proliferation
Infiltration of meninges
25
Large proportion of diffuse astrocytoma arise from?
Intrinsic pontine tumors
| Cerebral hemisphere
26
Describe macroscopic features of diffuse astrocytoma
Infiltration rather than destruction of anatomic structure
| Usually not well circumscribed
27
Describe microscopic features of diffuse astrocytoma
1. Well differentiated fibrillary or gemistocytic neoplastic astrocytoma on a background of loosely structured often microcystic tumor matrix
2. Presence of nuclear atypia is diagnostic criterion
3. Mitotic activity, necrosis, microvascular proliferation are absent
28
Symptoms relate to location of tumors
1. Hemispheric tumor
2. Hypothalamic tumor
3. Diencephalic syndrome
1. Focal motor deficit
2. Neuro endocrine deficit
3. Emaciation with loss of subcutaneous fat despite normal or increased appetite , alert appearance, increased vigor and euphoria, pallor without anemia, nystagmoid movement of eyes.
29
Name LGAs who may not require any tumor specific treatment. Initial approach of surveillance with active intervention will be taken only at the time of progressive disease that is symptomatic
1. NF-1 with optic pathway tumor
| 2. LGAs with tectal lesion with hydrocephalus without localizing brain stem signs.
30
What percentage of complete resection is achieved in cerebral, cerebellar, spinal cord tumors?
What percentage of complete resection is achieved in diencephalic tumor?
>80%
50%
31
In joint CCG-POG study, subtotal resection without adjuvant treatment, what is 8 years progression free survival and overall survival rates?
PFS with 1.5 cm3 residual 45%
| OS with 1.5cm3 residual 90%
32
What is the role of post-operative radiotherapy in less than complete tumor resection?
It results in improved disease free survival without benefit in overall survival
33
What is the period for risk of disease progression after incomplete tumor resection?
Initial 3 years after incomplete tumor resection
34
When does second surgery be considered?
When does other treatment be reserved like RT and Chemotherapy?
At tumor progression and operable
At tumor progression and inoperable
35
What is the indication of adjuvant chemotherapy particularly in infant and young children and patient of all ages with NF-1?
Patient are greatest risk of developing neuro cognitive, vaso-occlusive and neuroendocrine sequelae of RT treatment.
36
What is the overall response rate in terms of stable disease to chemotherapy as adjuvant therapy in LGAs?
70-100%
37
How long can chemotherapy permit delay of RT?
2 to 4+ years
38
What age group benefit delay of RT by using chemotherapy?
5-8 years
39
CTV margin for pilocytic astrocytoma?
0-1 cm around GTV in T1 weighted gadolinium enhanced images
40
CTV margin for infiltrative diffuse fibrillary astrocytoma?
1-1.5 cm around GTV seen in T2 weighted or Flair images
41
What is standard dose of LGAs?
50-54Gy
42
What are radioactive solutions used in recurrent LGAs after RT where symptoms relate more to cyst wall than solid component of tumor?
32P
90Y
198Au
186Re
43
Post RT MRI in initial months shows no change in tumor volume or rather increase in size..what should you do next?
Tumor regression in LGAs is slow..post RT imaging, tumor may remain stable or increase in size..close follow up with repeat imaging is best approach.
44
What percentage of high grade astrocytoma accounts for all CNS tumors in pediatric age group?
5%
45
What comprises of HGAs?
Grade III Anaplastic Astrocytoma(AA)
| Grade IV GBM
46
Describe 6 histopathologic features of HGAs
```
Nuclear atypia
Cellular pleomorphism
Mitotic activity
Vascular thrombosis
Microvascular proliferation
Necrosis
```
47
HGAs is common in what age group?
Older adolescent
48
What are the common sites of HGAs?
2/3 cerebral hemisphere
| Remaining : deep midline structures thalamus, basal ganglia, cerebellum
49
What is the predominant failure pattern in HGAs?
Local
50
What is the percentage of leptomeningeal spread in HGAs?
10-30%
51
Describe the basic principle of treatment in HGAs
Surgery followed by RT
Complete resection shows survival advantage
Maximal surgical resection compatible with good neurological outcome
Second surgical procedure if significant residual tumor after first
52
Describe target delineation in HGAs
GTV of tumor bed, residual enhancing or non enhancing residual tumor plus abnormality seen in T2 weighted MRI with CTV margin of 1.5cm
53
What is dose prescription in HGAs?
54-60 Gy standard dose
50-54Gy if dose tolerance of normal organ like optic chiasm exceeds its dose constrain
54
What chemotherapy can be used in adult HGAs ?
Temozolamide
55
What is median time of progression and overall survival at 5 years of HGAs in children
Median time of progression 10-11 months
Overall survival 20%
56
In HGAs, by location which has good and bad prognosis?
Good prognosis cerebral hemisphere
| Bad prognosis thalamic lesion
57
In HGAs, by age which has good and bad prognosis?
Good prognosis younger than age 3
| Bad prognosis older children more than 3 years
58
p53 over expression and MIB-1 labeling index has good or bad prognosis?
Bad prognosis
59
What is the age group of optic pathway glioma?
2-6 years
| 75% are younger than 10 years
60
1/3rd of optic pathway glioma is associated with what genetic predisposing factor?
Bilateral optic nerve involvement is pathognomonic of?
NF-1
61
Name 3 clinicopathologic entities of optic pathway glioma
1. Tumor confined to optic nerve
2. Anterior tumor : tumor confined to optic chiasm
3. Posterior or chiasmatic/hypothalamic tumor(70%) : tumor involve hypothalamus or adjacent structure
62
Describe general principle of treatment of optic pathway glioma
Surgical resection if no useful vision
Chemotherapy for infants and age up to 5 years if useful vision
Radiotherapy for older children
63
What is the long term tumor control rate with chemotherapy or radiotherapy in optic pathway glioma?
100%
64
Describe general principle of chiasmatic glioma
1. Surgery is NO option
2. NF-1 and younger than 5 years : Surveillance is appropriate initial management or Chemotherapy
3. Without NF-1 and older children : radiotherapy is reserved for salvage after chemotherapy
65
Long term progression free survival and overall survival in chiasmatic glioma
Long term progression free survival 60-90%
| Overall survival 90-100%
66
What are early and late findings of posterior or chiasmatic/hypothalamic glioma?
Early findings : nystagmus, impaired visual acuity, visual field defects
Late findings : increased head circumference, signs and symptoms of increased ICP
67
Describe general principles of posterior or chiasmatic/hypothalamic glioma
1. CSF diversion and surgical resection
2. Chemotherapy NF-1 with younger than 5 years
3. Radiotherapy without NF-1 with older children, disease progression with chemotherapy, disease progression at diagnosis or after surgery.
68
What is dose prescription of posterior or chiasmatic/hypothalamic glioma
45-50 Gy younger children
| 50-54 Gy older children above 5 years
69
What is the local tumor control with RT in posterior or chiasmatic/hypothalamic glioma?
70-80%
70
What is the long term survival in posterior or chiasmatic/hypothalamic glioma?
50-80%
71
Patient of posterior or chiasmatic/hypothalamic glioma with NF-1, how do we do follow up?
MR angiography as part of regular follow up imaging protocol and intervene surgically if necessary to avoid CVA
72
Why do we need MR angiography for follow up of patient with posterior or chiasmatic/hypothalamic glioma?
With NF-1 they are at greatest risk of moyamoya syndrome, a progressive vasocclusive process involving circle of willis
73
What percentage of brainstem glioma comprises of all CNS tumors in pediatric age group?
10-15%
74
Name favorable groups of brainstem glioma
Low grade focal
Dorsal exophytic
Cervicomedullary tumors
75
Name more aggressive brainstem glioma
Diffuse intrinsic pontine glioma
76
Describe features of low grade focal brainstem glioma
Well circumscribed, cystic, without evidence of infiltration, without edema
77
Describe general principle of treatment of low grade focal brainstem glioma
Surgery in experienced hands for well selected cases
| Standard RT of 54Gy over 6 weeks with CTV margin of 0.5cm
78
What are the factors that depends on outcome of conventional RT in low grade focal brainstem glioma?
1. location - pons vs others
2. Imaging appearance - tumor volume, density on CT, enhancement pattern)
3. Histology - malignant vs benign
79
Describe radiological findings of dorsal exophytic brainstem glioma
MRI sharply delineated from surrounding tissue
Hypointense on T1
Hyperintense on T2
Enhance uniformly and brightly after gadolinium
80
What is most common histology of tumor in dorsal exophytic brainstem glioma
Pilocytic astrocytoma
81
What is the treatment of choice for dorsal exophytic brainstem glioma
Surgery
82
What is the indication of RT in dorsal exophytic brainstem glioma
Routine postoperative RT NOT indicated
Should be considered for
High grade lesion
Disease progression in early
83
Treatment strategy for tumor recurrence in dorsal exophytic brainstem glioma
Further surgery and RT
84
How is the overall prognosis of dorsal exophytic brainstem glioma
Excellent
85
What is the treatment choice for cervicomedullary brainstem glioma
Surgery
86
What is the gross total resection rate of cervicomedullary brainstem glioma
70-80%
87
What is the indication of RT in cervicomedullary brainstem glioma?
NO indication of RT
88
What is the common histology of tumor in diffuse intrinsic pontine brainstem glioma
Fibrillary Astrocytoma
89
Name cranial nerves commonly involved in diffuse intrinsic pontine tumors
CN VI and VII
90
Describe radiologic feature of diffuse intrinsic pontine brainstem glioma
Best seen in T2 or FLAIR
| Ring enhancement suggestive of high grade histology
91
What is the indication of surgery in diffuse intrinsic pontine brainstem glioma
Surgery has NO role
92
What is the progression free survival, survival rate at 2 years in DIPG?
Progression free survival median
93
Current standard of treatment for DIPGs
Semi urgent basis treatment
54Gy in 30 fnx over 6 weeks
CTV margin of 1-1.5 cm
94
What is the percentage of intramedullary spinal cord tumor of all CNS tumor in pediatric age group?
3-6%
95
What are the majority of intramedullary spinal cord tumor type?
60% are LGAs
30% ependymoma
Remainder are ganglioganglioma, teratoma, lipoma, dermis and epidermis cyst
96
Describe imaging finding of Astrocytoma of spinal cord
Solid component with one or more cysts, enhance heterogenously with use of contrast
97
What percentage of children with Pilocytic Astrocytoma can undergo complete or subtotal resection with routine use of surgical adjunct such as ultrasonic aspiration , intra operative ultrasound, sensory and motor evoked potential monitoring?
80%
98
What is long term progression free survival after surgery in LGAs of spinal cord?
70-90%
99
What is the treatment option if total or subtotal resection is not possible?
Second surgery
| Close follow up with second surgery and RT at time of progression
100
What is the treatment option for LGAs Spinal cord for young children?
Chemotherapy
101
What is treatment option for HGAs spinal cord ?
Biopsy followed by RT
| Role of surgery is less clear
102
Describe target delineation for LGAs spinal cord
50.4Gy in 28 fnx over 6 weeks
| CTV 1-1.5 cm
103
Describe target delineation for HGAs spinal cord
50.4Gy in 28 fnx over 6 weeks
| CTV atleast 1.5cm or one vertebral body
104
Describe WHO classification of ependymoma tumors of spinal cord
Grade I Myxopapillary Ependymoma
Grade II Ependymoma
Grade III Anaplastic Ependymoma
105
Myxopapillary Ependymoma is almost always located in what part of spinal cord?
Conus filum terminale
106
Myxopapillary Ependymoma, what should be the initial imaging work up and why?
MRI whole spine and brain
| Because leptomeningeal metastasis is not uncommon
107
What is treatment of choice in Myxopapillary Ependymoma?
Surgery
108
With local recurrence or leptomeningeal mets, what is treatment options for Myxopapillary Ependymoma?
Further surgery and RT
109
Leptomeningeal spread at diagnosis or relapse after surgery without RT, treatment option for Myxopapillary Ependymoma spinal cord
CSI followed by boost to primary site
110
Describe RT for tumor recurrence in Myxopapillary Ependymoma spinal cord?
50.4Gy
| CTV margin 1.5cm or one vertebral body
111
3rd most common CNS tumor in children
Ependymoma
112
What is the age group in children who acquire Ependymoma?
Half of all cases younger than 5 years
113
Most common site of Ependymoma in ventricular system or spinal cord
2/3rd cases in Ependymoma lining of 4th ventricle
114
Most common presentation of Ependymoma
Symptoms and sign of increased intracranial pressure
115
Describe imaging features of Ependymoma
Tumor is usually large
Well circumscribed
Displacement rather than invasion of adjacent structures
116
Describe mode of spread of Ependymoma
Primarily local
| 5-10% have leptomeningeal spread at diagnosis
117
Essential work up of Ependymoma
MRI whole CNS and CSF cytology
118
What percentage of complete surgical resection can be achieved in Supratentorial Ependymoma?
70-90%
119
Describe general principle of Ependymoma
Complete resection followed by post-operative RT for all children older than 12 months
120
What is the standard of care for infratentorial ependymoma?
Local RT since there is no evidence that use of CSI affects outcome
121
Describe target delineation for Ependymoma
GTV = tumor bed + any extension caudal to foramen magnum + any anatomic shift due to surgery+ any residual tumor
CTV = 0.5cm(COG) - 1cm(St. Jude prospective study)
122
What is standard of dose for supra- and infra-tentorial ependymoma ?
54Gy
123
What is the dose recommendation of spinal ependymoma?
45-50Gy
124
Role of chemotherapy in Ependymoma
Unclear
| COG baby study showed prolonged use of chemotherapy and delay of RT more than 1 year associated with worse survival
125
Describe histologic features of anaplastic ependymoma
High Mitotic index
Microvascular proliferation
Pseudopalisading necrosis
126
Describe general principle of treatment of anaplastic ependymoma
Maximal surgical resection followed by RT in all patients
127
What is the dose prescription for anaplastic ependymoma
54-60Gy
128
Describe target delineation for anaplastic ependymoma
Tumor bed with any macroscopic residual disease with CTV margin of 1 cm
129
What is event free survival and overall survival for anaplastic ependymoma?
St. Jude series
Event free survival at 7 years is 61.3%
Overall survival 71.8%
130
WHO classification of choroid plexus tumor
Grade I Choroid Plexus Papilloma
Grade II Atypical Choroid Plexus Papilloma
Grade III Choroid Plexus Carcinoma
131
What is the percentage of Choroid Plexus tumor of all brain tumors in children
2-4%
132
Which is the common type of Choroid Plexus tumor?
Choroid Plexus Papilloma accounts more than half of tumor type
133
Choroid plexus tumor arise from mostly which part of ventricle?
Lateral ventricle
134
What should be the initial imaging work up and why in choroid plexus tumors?
Gadolinium enhanced MRI spinal axis and CSF cytology
| Because even papilloma seed into CSF space
135
Describe general principle of treatment for choroid plexus papilloma
Surgery with complete resection
Follow up without adjuvant treatment
Further surgery if feasible after incomplete resection
136
What is the indication of RT in choroid plexus papilloma?
Tumor progression despite tumor resection
137
What is the percentage of tumor recurrence and overall survival in CPP?
Tumor recurrence 10%
| Overall survival 100%
138
Describe general principle of treatment in Choroid Plexus Carcinoma
Surgery if feasible but often difficult
Postoperative RT appears to be useful
Chemotherapy can be used to delay RT until 3 years old
When both are used, RT is delivered early after 2 cycles of Chemo
139
What RT approach can be used with atypical CPP or CPC
CSI with leptomeningeal spread
140
Name 2 mixed neuronal-glial tumor type where RT is indicated
Ganglioglioma and Anaplastic ganglioglioma
| Central Neurocytoma
141
What is the common location of Ganglioglioma or Atypical ganglioglioma?
Temporal region
142
What is the common presentation of Ganglioglioma or Atypical Ganglioglioma?
Seizure
143
What is treatment of choice for Ganglioglioma or Atypical Ganglioglioma?
Surgery
144
What is the role of RT in mixed neuronal-glial tumors?
Anaplastic Ganglioglioma and central Neurocytoma with incomplete resection only
145
What is the dose prescription if RT is indicated in central neurocytoma?
Typical Neurocytoma 50Gy
| Atypical Neurocytoma 54Gy
146
What is the percentage of pineal region tumors in children?
2-8%
147
What is the common tumor type in pineal gland?
Approximately half of the pineal gland tumor are germ cell tumors
148
WHO classification of pineal parenchymal tumors
Pineocytoma Grade I
Pineal parenchymal tumor of intermediate differentiation Grade II/III
Pineoblastoma Grade IV
149
Which is the common tumor type in pineal parenchymal tumors?
Approximately half are Pineocytoma
150
What is the MRI finding of Pineocytoma?
Spherical
Well circumscribed
Hypointense on T1, Hyperintense on T2
Homogenous contrast enhancement
151
Describe general principle of treatment of Pineocytoma
Surgical resection via occipital transtentorial approach or infratentorial supracerebellar approach with functional MRI
Postoperative RT
152
What is percentage of progression free survival after complete or subtotal resection in Pineocytoma?
90-100%
153
Describe target delineation and dose prescription in Pineocytoma
CTV margin 1 cm
| Dose 50-55Gy
154
Describe histologic features of pineoblastoma
Patternless sheets of densely packed small cells with round to irregular nuclei and scanty cytoplasm
155
Define age group of pineoblastoma
Infants and very young children
156
Describe MRI findings in pineoblastoma
Multilobulated
Heterogenously enhancing
Area of necrosis and/or hemorrhage
Infiltrative
157
What percentage of pineoblastoma shows leptomeningeal spread?
50%
158
Describe general principle of treatment of pineoblastoma
Surgery followed by RT(CSI) and chemotherapy in children older than 3 years
159
What is the period of tumor recurrence in children treated with chemotherapy without RT?
Within first 11 months - POG
| Within first 1.2 years - CCG
160
What is trilateral retinoblastoma?
Bilateral retinoblastoma with Pineoblastoma
161
What is the second most common CNS tumor in pediatric age group?
Embryonal tumors like Medullobalstoma, Supratentorial PNET
162
What is the percentage of Medulloblastoma of all CNS tumors in children?
15-20%
163
Where is the common origin of medulloblastoma?
Cerebellar vermis
164
What is the percentage of leptomeningeal spread in medulloblastoma?
30-35%
165
What post operative period can lumbar puncture be performed to avoid false positives?
After 2 weeks
166
Medullobalstoma can spread extracranially to which sites?
Lymph nodes and bone
167
What are the factors that correlate with outcome of medulloblastoma?
Age at diagnosis
Presence or absence of leptomeningeal spread at diagnosis
Completeness of surgical resection
168
# Define standard risk medulloblastoma
Which histologic cell type is consider to have standard risk for recurrence in medulloblastoma ?
Tumor residual
169
# Define high risk medulloblastoma
Which histologic cell type has unfavorable features to consider high risk for recurrence in medulloblastoma ?
Tumor residual >1.5cm3
With evidence of CSF dissemination
Large Cell or Anaplastic
170
What is the percentage of complete or near complete resection in medulloblastoma
80%
171
Standard of care for children older than 3 years with standard risk medulloblastoma
1. CSI to 35-36Gy+Posterior fossa boost to 54-55.8Gy
| 2. Reduced dose CSI(23.4Gy) + PFB to 54-55.8Gy followed by systemic chemotherapy
172
Chemotherapy used in standard risk medulloblastoma
```
CCG pilot study
Weekly vincristine followed by adjuvant systemic chemo
Vincristine 1.5mg/m2
CCNU 75mg/m2
Cisplatinum 75mg/m2
```
173
Standard of care for children older than 3 years with High risk medulloblastoma
CSI to 35-36Gy+Posterior fossa boost to 54-55.8Gy and post-RT Chemotherapy
174
What percentage of medulloblastoma accounts for CNS tumors in infants?
20-40%
175
Describe M-stage in medulloblastoma
| M0-M4
M0 - No evidence of metastasis
M1 - Tumor cells are found in CSF by lumber puncture or cell cytology
M2 - Tumor beyond primary site but still in brain
M3 - Tumor deposits in spine area that are easily seen in MRI
M4 - Tumor spreads to areas outside CNS
176
Prognosis in infants is worst compared to older children in medulloblastoma because?
Tumor biology
Lower rate of complete resection
Higher frequency of leptomeningeal seeding at diagnosis
Many patient don't receive optimal treatment
177
What is the recurrence period of medulloblastoma?
6-12 months
178
Standard of care for infant with standard risk of recurrence medulloblastoma according to North American Study
Nodular or desmoplastic
Without residual
Without leptomeningeal spread
RT with limited treatment volume of tumor bed + CTV margin of 1 cm
179
What is the treatment regimen for M2/M3 medulloblastoma in infants?
Intensive chemotherapy with RT highly individualized based on clinical situation and wishes of parents.
Experimental in stPNET
180
Relapse rate that correlated with target deviation
| MSFOP-93 and MSFOP-98
Relapse Rate Inadequate coverage
17% 1 site eg cribiform plate
28% 2 sites
67% 3 sites or more
181
Describe reduced volume PFB for standard risk medulloblastoma
GTV (macroscopic residual tumor+surgical bed) + 1.5 cm margin
This volume is under investigation in current COG study
182
Event free and overall survival were significantly worst when duration of treatment exceeded what period in medulloblastoma?
50 days
| As compared to 45-47 days in SIOP PNET-3 study
183
What is recommended when CSI is interrupted because of toxicity?
Treatment should continue to posterior fossa boost while toxicity recovers.
184
Define stPNET
Supratentorial Primitive Neuroectodermal Tumor are embryonal tumor composed of undifferentiated or poorly differentiated neuroepithelial cells
185
Enumerate Supratentorial Primitive Neuroectodermal Tumor
Cerebral neuroblastoma or Ganglioneuroblastoma
Medulloepithelioma
Ependymoblastoma
186
What are imaging findings of stPNET?
Heterogenous with cystic or necrotic areas and areas of hemorrhage
187
What is the percentage of leptomeningeal seeding present at diagnosis in stPNET?
40%
188
What is general principle of treatment of stPNET?
```
Approach similar to high risk medulloblastoma
Post operative (standard dose CSI + boost)and chemotherapy
```
189
What is the overall survival of stPNET?
30-50%
190
What are better prognostic factors of stPNET?
Smaller size
191
What are bad prognostic factors of stPNET?
What is overall survival with bad prognostication?
Younger age
M+
0-30%
192
What is the failure rate in medulloblastoma with M0 and M+?
Local failure with M0 is 42%
| Leptomeningeal failure with M+ is 43%
193
What age group Atypical Teratoid/Rhabdoid tumor(ATRT) are seen?
Birth to 2 years
194
What is the location of ATRT?
Any location within CNS including spine
195
Prognosis of ATRT with leptomeningeal spread
Very poor
196
Describe general principle of treatment of ATRT
Early RT(after 2 cycles of chemo)
Children younger than 6 mths with infratentorial tumor and younger than 12 mths with Supratentorial tumor receive RT after completion of chemo
Local RT with 1 cm CTV margin for localized disease and CSI for leptomeningeal spread
197
Incidence of CNS germ cell tumors
15-18% of all CNS tumors Asia
| 3-5% West
198
Where is the common location of CNS germ cell tumors?
Most common pineal gland
| Second most common suprasellar region
199
Describe imaging findings of CNS germ cell tumors
Solid mass
Teratoma are heterogenous with cyst, area of calcification, fat
Choriocarcinoma areas of hemorrhage
200
What is the percentage of meningeal dissemination in CNS germ cell tumors?
10% Germinoma
| 10-15% NGGCT
201
```
Measurement of serum and CSF tumor markers in
Germinoma
NGGCT
Choriocarcinoma
Yolk sac tumor
```
Germinoma B-HCG modest elevation 100IU/mL
| Yolk sac tumor AFP elevated
202
Most common location of NGGCTs
Pineal region
203
Most common location of Germinoma
Suprasellar region
204
Describe general principle of management of germinoma
Total dose to primary site 40-45Gy/1.5Gy(whole ventricular irradiation 30-36Gy)
CSI with leptomeningeal spread 21Gy
Chemotherapy with complete response followed by RT 24-30Gy
205
What is the disease free survival rate platinum based chemo followed by reduced volume, reduced dose RT
90-96%
206
Classify NGGCT according to prognosis
```
Good prognosis mature teratoma
Intermediate prognosis
Immature teratoma
Mixed germ cell tumor(germinoma with mature or immature teratoma)
Poor prognosis
Teratoma
Embryonal carcinoma
Yolk sac tumor
Choriocarcinoma
Mixed germ cell tumor
```
207
Treatment of mature teratoma
Surgery alone
208
Treatment of intermediate and poor prognosis NGGCTS
Platinum based chemo followed by RT
209
What is the dose prescription for NGGCTs
Whole ventricular volume or CSI 30-36Gy
| Primary site 54Gy
210
What are tumors of seller region?
Craniopharyngioma
| Pituitary adenoma
211
Where is the origin of craniopharyngioma?
Remnants of rathke's pouch
212
What is the common presentation of craniopharyngioma
Neuroendocrine deficits like diabetes insipidus and growth failure
213
What are imaging findings in craniopharyngioma
Solid and cystic area in varying proportion
Calcification is seen in majority
Solid portion and cystic capsule enhances with use of contrast
214
What is the long term tumor control(event free survival) at 3 years in craniopharyngioma
64%
215
What are indications of surgery in craniopharyngioma?
Smaller tumor
Sub diaphragmatic in location
Without hypothalamic involvement
216
Post surgery, what is the period of disease progression in craniopharyngioma?
Within first 2-3 years post surgery
217
What are indications of RT in craniopharyngioma?
Sole therapy after biopsy
After imcomplete surgery or time of progression /recurrence after surgery
Tumor heterogeneity
218
Describe target delineation and dose in craniopharyngioma
GTV + CTV margin varying from 0-0.5-1cm
54-55Gy
219
What changes can we expect in initial 2-3 months post-RT?
Cyst enlargement
220
What is the advantage of early recognition and cyst decompression in craniopharyngioma?
To further avoid neurologic compromise
221
What is the event free survival of craniopharyngioma?
80-100%
222
What are common presentation of functioning adenoma in each sex?
Menstrual irregularities and galactorrhea in girls
| Delayed puberty in boys
223
How do we manage prolactin and growth harmone secreting adenoma?
Medical management
224
What is the indication of RT in pituitary adenoma?
Surgery not possible
| Harmone remains elevated following surgery
225
Describe dose prescription and target delineation in pituitary adenoma?
GTV + CTV of 0.5 cm
45-50 Gy
