Chapter 84 CNS Tumors In Children Flashcards Preview

Perez and Brady's Principles and Practice of Radiation Oncology 6th Edition > Chapter 84 CNS Tumors In Children > Flashcards

Flashcards in Chapter 84 CNS Tumors In Children Deck (225):
1

What percentage of childhood malignancies known with genetic predisposition?

2-5%

2

What are the genetic predisposition in childhood malignancies?

1.Neurofibromatosis types 1(NF-1) and 2 (NF-2)
2.Tuberous Sclerosis
3.Nevoid basal cell(Gorlin's) syndrome
4.Familial adenomatous polyposis
5.Li-Fraumeni syndrome

3

What is the main predisposing factor of childhood malignancies?

Majority remains with no predisposing factors

4

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?

1. Age at treatment
2. Tumor location
3. Treatment factors(RT volume, dose and use of chemotherapy)

5

What intervention could be used for helping patients with RT induced deficits?

The following can be start soon after treatment for best results
1. Cognitive or behavioral therapy
2. Pharmacotherapy
3. Exercise

6

Endocrine deficit are very common after RT. Which harmone deficiency is primarily responsible that correlates with dose of RT?

Growth harmone

7

Which harmone deficiency is primarily responsible that is seen after CSI?

Thyroid harmone

8

What percentage of CNS malignancies occurs in childhood?

20-25%

9

What strategies could be used to avoid or minimize long term effects of treatment for pediatric brain tumor?

1. Avoidance of RT altogether
2. Delay of RT for age 3-8 years by chemotherapy
3. Use of daily anesthesia, improved immobilization, daily pretreatment image verification
4. Use of new RT modalities eg Proton
5. Use of reduced RT target volume eg in medulloblastoma
6. Reduce RT dose eg in medulloblastoma
7. Use of small fraction size in radiosensitive tumor eg germinoma 1.5Gy/Fx
8. HFRT eg current Europian studies in Medulloblastoma

10

During patient positioning and immobilization in CSI, what maneuver will help avoid dentition in exit dose from superior aspect of spinal field?

Neck extension with careful selection of level for junction of brain and spinal fields

11

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?

MRI findings

12

During CSI, what percentage of variation of dose along spinal axis will require use of dose compensation and how can we achieve that?

>10%
Using MLC

13

What are possible solutions for field matching over cervical spine/risk of over- or under dosage?

1. Angle brain fields
2. Use half beam blocks for brain fields
3. Use couch rotation or match line wedge

14

What are possible solutions for irradiation of normal tissue thyroid gland?

Care of level of junction

15

Most common CNS tumor in pediatric age group?

Medulloblastoma

16

Most common CNS tumors in adult group?

High grade glioma

17

WHO classification of Astrocytic tumors
Grade I
Grade II
Grade III
Grade IV

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

What are low grade glioma?

What is the overall survival rates at 10 and 15 years

Grade I/II

80-100%

19

Group LGGs according to an anatomic locations

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

What is most common Astrocytoma in pediatric age group?

Pilocytic Astrocytoma

21

Name the sites accounting for almost all of LGAs, Pilocytic

Cerebellum
Anterior Optic Pathway

22

Describe macroscopic features of Pilocytic Astrocytoma

Well circumscribed, associated cystic component.

23

Describe microscopic features of Pilocytic Astrocytoma

Biphasic pattern
1. Varying proportion of compacted bipolar cells with Rosenthal fibers
2. Loosely textured multipolar cells with microcysts and granular bodies

24

Features compatible with Pilocytic Astrocytoma but not a sign of malignancy

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