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Central Nervous System Tumors in
Children

Dr Sasikumar Sambasivam
DNB Resident
Radiation Oncology
Introduction
• 20% to 25% of all malignancies that occur in childhood
• etiology remains largely unknown
• Only 2% to 5% c...
CNS tumors in children
Astrocytic Tumors
• Diffusely infiltrating astrocytomas,
– Diffuse astrocytomas (WHO grade II),(or fibrillary)
– Anaplasti...
Low-Grade Astrocytomas (WHO Grades I and II)

Astrocytic
Tumors

• Cerebellar astrocytomas (15% to 20% of all CNS
tumors),...
• Pilocytic astrocytomas :
• MC of all primary CNS tumors
• the anterior optic pathway, the
cerebellum
• well circumscribe...
Management of LGA
• Surgery is the mainstay of treatment.

Astrocytic
Tumors

• Complete resection –likely-- in smaller,we...
Astrocytic
• Regarding Radiotherapy in LGA:
Tumors
– Not indicated after complete resection.
– Indicated in incomplete res...
Astrocytic
Tumors—
LGA

• Dose: 50 to 54 Gy as std of care
• Technique:
– EBRT –conventional fractionation
– Radiosurgery
...
High-Grade Astrocytomas (WHO Grades III and IV)

•
•
•
•
•
•

Astrocytic
Tumors

5% of all CNS tumors in children
Adolesce...
Brainstem Gliomas

Astrocytic
Tumors

Low grade, favorable, tumors:
Focal (solid/cystic) intrinsic tumors
Dorsal exophytic...
DIPG
• Brain stem enlargement
• Extn to Mid brain and medulla in 2/3 rds
• Mostly fibrillary astrocytomas with a propensit...
Astrocytic Tumors

Management of Brainstem Tumors
Ependymal Tumors
•
•
•
•
•
•
•
•
•

5% to 10% of all Paediatric CNS Tumors
Infants and children younger than age 5 years
S...
Choroid Plexus Tumors
• Choroid plexus papilloma (WHO grade I) and choroid
plexus carcinoma (WHO grade III).
• 2% to 4% in...
Embryonal Tumors
• 2nd MCtype of CNS tumor in the pediatric age
• Most are PNETs ---undifferentiated round cell tumors wit...
•
•
•
•

Medulloblastoma

Embryonal Tumors

15% to 20% of all paediatric CNST
Median age 6 years
MC site-cerebellar vermis...
Medulloblastoma

• CT and MRI –
• appear as solid masses
• that enhance usually fairly homogeneously with
contrast materia...
Medulloblastoma
Chang Staging System for Metastases in Patients with Medulloblastoma
M0

No metastases

M1

Tumor cells fo...
Medulloblastoma

• Outcome:
– Age,
– Presence of leptomeningeal spread at presentation
and
– completeness of surgical rese...
Management of Standard-Risk Medulloblastoma
• >3 years- post op RT-craniospinal axis to a dose of 35 to 36 Gy
followed by ...
Management of High-Risk Medulloblastoma
• M0-- it would be logical to consider using a
radiotherapy dose to residual disea...
Management of Medulloblastoma in Infants
•
•
•
•

20% to 40% of all CNS tumors in infants
Desmoplastic /nodular/extensive ...
Medulloblastoma

• POG study in Infants: Chemotherapy alone: 5
Y OAS :69%
• RT still an important component
– Most recurre...
Medulloblastoma

Cranio Spinal Irradiation
• CSI –Std of Care
• Coverage of entire target volume that includes the
meninge...
Treatment Techniques-CSI

Medulloblastoma

• The CTV for CSI has an irregular shape that consists
of the whole of the brai...
Medulloblastoma

Patient Positioning and Immobilization

• Prone/ Supine*
• full-body immobilization
• using neck extensio...
Technical Considerations for Craniospinal Irradiation
Problem
Target volume definition may be difficult using
conventional...
Target Volume Definition

Medulloblastoma

• CT simulation is
– necessary to ensure adequate coverage of CTV in subfrontal...
Medulloblastoma

• In the lumbar region, it is important to avoid an
excessively wide field that will result in unnecessar...
Medulloblastoma
• CT simulation with CT-MRI co registration ---required
for accurate determination of the target volume fo...
Medulloblastoma

• Another option in Std Risk: reduced target volume
for the boost
• Fukunaga –Johnson et.al found a low r...
Medulloblastoma

Whole post fossa Vs Reduced Volume Boost
Medulloblastoma
Medulloblastoma

Treatment Planning and Delivery

• In general, photons in the 6 to 10 MV range provide
satisfactory cover...
• The field junction, which is over the cervical cord at a level
that avoids the inclusion of the teeth in the exit of the...
Supratentorial PNET

Embryonal Tumors

• <5% of all CNS tumors in the pediatric age group
• The median age at presentation...
Supratentorial PNET

• The standard of care --– >3 years with S-PNETs without leptomeningeal
spread consists of ---maximal...
Atypical Teratoid/Rhabdoid Tumor
• Uncommon, highly malignant embryonal tumor
unique to childhood
• Peak– birth to 2 yrs
•...
Diagnosis

ATRT

• MRI Magnetic resonance imaging of the brain and spine
• Lumbar puncture to look for M1 disease
• CT of ...
ATRT

• Sx-induction chemotherapy early RT(CSI)-
Consolidation Chemo
• DOSE• < 3 yr, up to 24 Gy to whole brain and spi...
Germ Cell Tumors
• GCT of CNS-morphologic homologues of
germinal neoplasms arising in the gonads and at
other extragonadal...
GCTs
• Asia---account for as many as 15% to 18% of all CNS
tumors occurring in childhood
• 10 to 12 years. Boys more frequ...
Bi- or multifocal disease around the third ventricle is seen in
approximately 10%

GCTs

•CE MRI of the spinal axis is an ...
Germinoma
• Unifocal disease and without leptomeningeal spread -radiotherapy (CSI and boost)
• A combined approach using p...
Non germinomatous GCT
• A multimodality approach that includes both
chemotherapy and radiotherapy appears to be
associated...
Classification of Nongerminomatous Germ Cell Tumors
Good prognosis
Mature teratoma

Poor prognosis
Teratoma with malignant...
Tumors of the Sellar Region
• Craniopharyngioma,
– Adamantinomatous craniopharyngioma
– Papillary craniopharyngioma

• Xan...
Craniopharyngioma
• Benign partly cystic epithelial tumors that arise
in the sellar region from remnants of Rathke's
pouch...
Craniopharyngioma
• Children typically present with neuroendocrine deficits,
especially diabetes insipidus and growth fail...
Craniopharyngioma
• On neuroimaging:
– with solid and cystic
areas in varying
proportions;
– calcification is seen
in the ...
Craniopharyngioma

• Complete surgical resection(Transsphenoidal
approach), as confirmed on postoperative imaging, is
asso...
Craniopharyngioma

• Role of RT as sole therapy:
– After biopsy
– After incomplete surgery
– At progression
– Recurrence

...
Craniopharyngioma

• EBRT
– Target Volume: entire lesion with preop MRI
– 0.5 cm margin or even 0 cm can be justified for ...
Radiation Dose Fractionation in Children
• Conventionally 1.8 Gy / Fr
• Avg dose: 54.5- 55.8 Gy
• If it is a primary tumor...
Issues regarding RT in children
• Neurocognitive sequelae
• Myelinization and functional maturation of the CNS
continue un...
To Minimize the long-term effects
•
•
•
•
•
•
•
•
•

Avoidance of radiotherapy altogether
Delay to radiotherapy for young ...
Follow up
• During treatment:
•
•
•
•

For vomitting ,headache
ICT
Fatigue
Usually recover quickly after treatment

• Afte...
Thank you.
Central nervous system tumors in children
Central nervous system tumors in children
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Central nervous system tumors in children

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CNS tumors in children.Comprehensively discussed for Radiotherapy Aspects.

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Central nervous system tumors in children

  1. 1. Central Nervous System Tumors in Children Dr Sasikumar Sambasivam DNB Resident Radiation Oncology
  2. 2. Introduction • 20% to 25% of all malignancies that occur in childhood • etiology remains largely unknown • Only 2% to 5% can be ascribed to a genetic predisposition with – neurofibromatosis types 1 and 2, – tuberous sclerosis, – nevoid basal cell (Gorlin's) syndrome, – the adenomatous polyposis syndromes, and Li-Fraumeni syndrome. – ionizing radiation used for diagnostic or therapeutic purposes
  3. 3. CNS tumors in children
  4. 4. Astrocytic Tumors • Diffusely infiltrating astrocytomas, – Diffuse astrocytomas (WHO grade II),(or fibrillary) – Anaplastic astrocytoma (WHO grade III), – Glioblastoma multiforme (WHO grade IV) and variants, • • • • Pilocytic astrocytoma (WHO grade I),(MC) Pleomorphic xanthoastrocytoma, Desmoplastic cerebral astrocytoma of infancy, Subependymal giant cell astrocytoma.
  5. 5. Low-Grade Astrocytomas (WHO Grades I and II) Astrocytic Tumors • Cerebellar astrocytomas (15% to 20% of all CNS tumors), • Hemispheric astrocytomas (10% to 15%), • Midline supratentorial tumors, including the corpus callosum, lateral and third ventricles, and the hypothalamus and thalamus (10% to 15%), • Optic pathway tumors (app 5% ) • Brainstem LGA (10% to 15% of all; 20% to 30% of these are LGA), • LGA of the spinal cord (3% to 6% of all; approximately 60% of these are LGA).
  6. 6. • Pilocytic astrocytomas : • MC of all primary CNS tumors • the anterior optic pathway, the cerebellum • well circumscribed and frequently have an associated cystic component • histologically --a biphasic pattern : compacted bipolar cells with Rosenthal fibers and loose-textured multipolar cells with microcysts and granular bodies. Astrocytic Tumors
  7. 7. Management of LGA • Surgery is the mainstay of treatment. Astrocytic Tumors • Complete resection –likely-- in smaller,wellcircumscribed and those in noneloquent parts. • Role of postop RT following lesser degrees of tumor resection remains unclear • IF adj RT – avoided in infants and 2-3 yrs of age, by starting on CT. • CT for Children with NF-1
  8. 8. Astrocytic • Regarding Radiotherapy in LGA: Tumors – Not indicated after complete resection. – Indicated in incomplete resection in situations when tumor progression would compromise neurologic function .  The clearest indication for radiotherapy is in patients with progressive and/or symptomatic disease that is unresectable GTV : Preop volumes CTV : for a well circumscribed tumor margin of 1 cm or even GTV= CTV , around the GTV as seen on T1 W CEMRI. If infiltrative, margins of 1 to 1.5 cm as seen on T2 W FLAIR
  9. 9. Astrocytic Tumors— LGA • Dose: 50 to 54 Gy as std of care • Technique: – EBRT –conventional fractionation – Radiosurgery – Brachytherapy • Follow up: Imaging studies • OAS at 10 and 15 years : 80 to 100 %
  10. 10. High-Grade Astrocytomas (WHO Grades III and IV) • • • • • • Astrocytic Tumors 5% of all CNS tumors in children Adolescents GBM –MC Site: Cerebrum Surgery --std of care Post op RT always indicated dose ranging from 50- 54 Gy if feasible upto 60 Gy • Role of chemo as for adults – yet to be established • Poor Prognosis
  11. 11. Brainstem Gliomas Astrocytic Tumors Low grade, favorable, tumors: Focal (solid/cystic) intrinsic tumors Dorsal exophytic tumors Cervicomedullary tumors Unfavorable tumors: Diffuse intrinsic (pontine)tumors(DIPG)(70-80% ) Primitive neuroectodermal tumors Atypical teratoid/rhabdoid tumors
  12. 12. DIPG • Brain stem enlargement • Extn to Mid brain and medulla in 2/3 rds • Mostly fibrillary astrocytomas with a propensity for malignant change • Multiple cranial N palsies,ataxia • MRI if shows ring enhancement – high grade • Biopsy not preferred • Poor prognosis • Surgery no role. • Chemo no role • RT as a direct intervention • Hypo/hyperfractionation vs Conventional: No diff Astrocytic Tumors
  13. 13. Astrocytic Tumors Management of Brainstem Tumors
  14. 14. Ependymal Tumors • • • • • • • • • 5% to 10% of all Paediatric CNS Tumors Infants and children younger than age 5 years Supra and infratentorial Signs of raised intracranial pressure Well circumscribed, with displacement rather than invasion Completeness of the surgical resection – is a matter of outcome If residual– second look Sx Post op Local RT- Std of Care The role of chemotherapy--?
  15. 15. Choroid Plexus Tumors • Choroid plexus papilloma (WHO grade I) and choroid plexus carcinoma (WHO grade III). • 2% to 4% in paediatric CNS Tumors(<3 Y) • MC--lateral ventricles causing obstruction to CSF flow • Surgery is the treatment of choice-both for the primary lesion and for macroscopic metastatic deposits • RT benefits +; But CT preferred d/t age.
  16. 16. Embryonal Tumors • 2nd MCtype of CNS tumor in the pediatric age • Most are PNETs ---undifferentiated round cell tumors with divergent patterns of differentiation as follows: – Ependymoblastoma, – Medulloblastoma, • Desmoplastic medulloblastoma • Large cell medulloblastoma – Supratentorial PNET. • Two tumor types with distinctly different histologies that appear to evolve by different genetic pathways also are included in the category of embryonal tumors: – Medulloepithelioma, – Atypical teratoid/rhabdoid tumor.
  17. 17. • • • • Medulloblastoma Embryonal Tumors 15% to 20% of all paediatric CNST Median age 6 years MC site-cerebellar vermis and projects into the fourth ventricle Types: • • • • Desmoplastic/nodular With Extensive nodularity Anaplastic Large cell • Frequency of spinal seeding at diagnosis -30-40% • CEMRI of the Craniospinal axis (Solid masses with uniform enhancement) • CSF cytology– IOC primarily (to be obtained preoperatively or 2-3 wks postop) • Rarely spread outside the CNS -to lymph nodes and bone
  18. 18. Medulloblastoma • CT and MRI – • appear as solid masses • that enhance usually fairly homogeneously with contrast material
  19. 19. Medulloblastoma Chang Staging System for Metastases in Patients with Medulloblastoma M0 No metastases M1 Tumor cells found in cerebrospinal fluid M2 Gross nodular seeding in the cerebellar, cerebral subarachnoid space, or in the third or lateral ventricles M3 Gross nodular seeding in the spinal subarachnoid space M4 Metastases outside the central nervous system
  20. 20. Medulloblastoma • Outcome: – Age, – Presence of leptomeningeal spread at presentation and – completeness of surgical resection • Risk categories: standard and high risk. – Std Risk: complete or subtotal resection with <1.5 cm2 of residual tumor and no evidence of CSF dissemination (M0) – High risk : larger volume(>1.5 cm2) residual tumor and those with evidence of CSF dissemination at diagnosis.
  21. 21. Management of Standard-Risk Medulloblastoma • >3 years- post op RT-craniospinal axis to a dose of 35 to 36 Gy followed by a boost to the whole posterior fossa to a total dose of 54 to 55.8 Gy, traditionally. (others: reduced post fossa boost) • An alternative strategy consists of reduced-dose CSI followed by a boost to the posterior fossa to a total dose of 55.8 Gy in combination with systemic chemotherapy(Vincristine and Cisplatin) – CCG Pilot study: 23.4 GyCSI f/b adj V,CCNU,P ;PFS: 79% at 5 Y – CCG /POG Phase III RCT – Vincristine /Cyclo/Cisplatin—EFS 85% at 4 yrs – Current CCG study -18Gy in children 3-8 yrs--- Pending results
  22. 22. Management of High-Risk Medulloblastoma • M0-- it would be logical to consider using a radiotherapy dose to residual disease in the posterior fossa higher than the standard 55.8 Gy • M1 disease – controversial and may be treated like M2/3 – Chemotherapy – COG pilot study with Carboplatin (M2/3) – New studies -HART with Pre and Post RT -CT
  23. 23. Management of Medulloblastoma in Infants • • • • 20% to 40% of all CNS tumors in infants Desmoplastic /nodular/extensive nodularity –Common But worser than the older children The rate of complete resection is lower in this age group • The frequency of leptomeningeal seeding at diagnosis is higher (as much as 50%) • Chemotherapy has been used in an attempt to either delay or avoid radiotherapy altogether due to effects on cognition by RT
  24. 24. Medulloblastoma • POG study in Infants: Chemotherapy alone: 5 Y OAS :69% • RT still an important component – Most recurrences as early as 6 to 12 months – North American study –RT limited to a volume of tumor bed plus CTV of 1 cm margin for children without Lepto meningeal seeding
  25. 25. Medulloblastoma Cranio Spinal Irradiation • CSI –Std of Care • Coverage of entire target volume that includes the meninges overlying the brain and spine including the extensions along the nerve roots is critical
  26. 26. Treatment Techniques-CSI Medulloblastoma • The CTV for CSI has an irregular shape that consists of the whole of the brain and spinal cord and overlying meninges • Some use the lower borders of lateral whole-brain fields are matched to the cephalad border of a posterior spine field • Some use a moving junction between the brain and spine fields to minimize the risk of underdose or overdose in the cervical spinal cord
  27. 27. Medulloblastoma Patient Positioning and Immobilization • Prone/ Supine* • full-body immobilization • using neck extension together with careful selection of the level for the junction of the brain and spine fields – – it is possible to avoid including the dentition in the exit from the superior aspect of the spinal field, and thus any damage to developing teeth that may result in stunted tooth growth, impaction, incomplete calcification, delayed development, and caries.
  28. 28. Technical Considerations for Craniospinal Irradiation Problem Target volume definition may be difficult using conventional simulation Prone position uncomfortable, difficult to monitor airway Field matching over cervical spine, risk of overor underdosage Choice of extended SSD or second field for treatment of spinal axis Inhomogeneity along spinal axis Medulloblastoma Possible Solutions Use CT simulation with CT-MRI co registration Supine position preferred Angle brain fields Use half beam block for brain fields Use couch rotation or match line wedge Two fields preferred Use compensator, MLC Irradiation of normal tissues: Mandible/teeth Thyroid Heart Neck extension Care with level of junction Use lower junction GI tract Care with width of spine field Use electrons, IMRT, protons Use electrons, IMRT, protons Gonads Care with lower limit and width of spine field GI, gastrointestinal; IMRT, intensity-modulated radiation therapy; MLC, multileaf collimator; SSD, source-skin distance.
  29. 29. Target Volume Definition Medulloblastoma • CT simulation is – necessary to ensure adequate coverage of CTV in subfrontal region:Cribriform plate – invaluable in identifying the lateral aspect of CTV for the spine field that includes the extensions of the meninges along the nerve roots to the lateral aspects of the spinal ganglia. • The field, which must be wide enough to encompass the intervertebral foramina in the lumbar region, can be blocked laterally in the dorsal region to avoid unnecessary irradiation of the heart and lungs
  30. 30. Medulloblastoma • In the lumbar region, it is important to avoid an excessively wide field that will result in unnecessary irradiation of the bone marrow and gonads. • MRI is required to determine the lower limit of CTV for the spine field. • Traditionally the lower border of the spine field was placed at the lower border of the second sacral vertebra, but it is well documented that the lower border of the thecal sac can be as high as L5 or as low as S3. • It is below S2 in 7% of children ; MRI is helpful.
  31. 31. Medulloblastoma • CT simulation with CT-MRI co registration ---required for accurate determination of the target volume for the posterior fossa boost, both for definition of the target volume and for contouring of critical normal structures such as the cochlea, pituitary/hypothalamus, and brain that will allow accurate estimation of the dose to these structures. • CSI is followed by a boost to posterior fossa • Traditionally entire post fossa received 54 to 55.8 Gy • Sparing of at risk organs – a consideration
  32. 32. Medulloblastoma • Another option in Std Risk: reduced target volume for the boost • Fukunaga –Johnson et.al found a low risk of isolated failure outside tumor bed in posterior fossa and SFOP studies support this approach. • Optimal CTV for a reduced volume post fossa boost remains to be defined • But anatomically confined expansion of 1.5cm around GTV – reasonable (Current COG study)
  33. 33. Medulloblastoma Whole post fossa Vs Reduced Volume Boost
  34. 34. Medulloblastoma
  35. 35. Medulloblastoma Treatment Planning and Delivery • In general, photons in the 6 to 10 MV range provide satisfactory coverage of the PTV. • A variation of dose along the spinal axis of >10% will require the use of dose compensation that can be achieved using dynamic MLCs • To cover the clinical target volume for craniospinal irradiation, lateral opposed fields are used to treat the brain and a direct posterior field is used to cover the spinal axis. • Electrons are also used to treat spinal axis.
  36. 36. • The field junction, which is over the cervical cord at a level that avoids the inclusion of the teeth in the exit of the spinal field, usually is moved weekly to avoid over- or underdosage
  37. 37. Supratentorial PNET Embryonal Tumors • <5% of all CNS tumors in the pediatric age group • The median age at presentation is 3 years • Tumors arising in the cerebral hemispheres in particular are often very large at diagnosis • On imaging they are often quite heterogeneous with cystic or necrotic areas and areas of hemorrhage. • Leptomeningeal seeding—40% • MRI of the spinal axis and CSF cytology are mandatory prior to treatment.
  38. 38. Supratentorial PNET • The standard of care --– >3 years with S-PNETs without leptomeningeal spread consists of ---maximal surgical resection followed by postoperative radiotherapy – (CSI plus a boost to doses similar to those used for high-risk medulloblastoma) followed by chemotherapy
  39. 39. Atypical Teratoid/Rhabdoid Tumor • Uncommon, highly malignant embryonal tumor unique to childhood • Peak– birth to 2 yrs • Composed of rhabdoid cells with or without fields resembling a classical PNET • Diagnosed on the basis of the characteristic molecular findings, namely deletion and/or mutation of INI1 locus on Chromosome 22 • Most commonly arises in the posterior fossa • Leptomeningeal seeding in 1/3 at presentation
  40. 40. Diagnosis ATRT • MRI Magnetic resonance imaging of the brain and spine • Lumbar puncture to look for M1 disease • CT of chest and abdomen to check for a tumor • Bone Marrow Aspiration and Bone marrow biopsy • Bone scan. • It is difficult to diagnosis AT/RT only from radiographic study; HPR is essential with IHC and Cytogenetic study
  41. 41. ATRT • Sx-induction chemotherapy early RT(CSI)- Consolidation Chemo • DOSE• < 3 yr, up to 24 Gy to whole brain and spinal cord, and boost local site up to 54 to 56 Gy. • > 3 yr up to 36 Gy to whole brain and spinal cord, and boost local site up to 56 Gy.
  42. 42. Germ Cell Tumors • GCT of CNS-morphologic homologues of germinal neoplasms arising in the gonads and at other extragonadal sites. – Germinoma, – Embryonal carcinoma, – Yolk sac tumor (endodermal sinus tumor), – Choriocarcinoma, – Mature teratoma, – Immature teratoma, – Teratoma with malignant transformation, – Mixed germ cell tumors
  43. 43. GCTs • Asia---account for as many as 15% to 18% of all CNS tumors occurring in childhood • 10 to 12 years. Boys more frequently than girls, with a ratio of approximately 3:1 • CNS germ cell tumors arise from primordial germ cells in structures about the third ventricle, with the region of the pineal gland being the most common site of origin, followed by the suprasellar region. – Nongerminomatous germ cell tumors are the most common tumor type in the former area, and germinomas in the latter
  44. 44. Bi- or multifocal disease around the third ventricle is seen in approximately 10% GCTs •CE MRI of the spinal axis is an essential part of the work-up to exclude leptomeningeal dissemination, which is found at diagnosis in <10% of patients with germinomas and 10% to 15% of patients with NGGCT. •Serum and CSF tumor markers – Elevated--beta HCG (<100 IU/mL) may be seen with pure germinomas that often contain syncytiotrophoblastic cells. – Higher levels ofbeta hCGare more suggestive of a choriocarcinoma. – An elevated AFP is diagnostic of a yolk sac tumor.
  45. 45. Germinoma • Unifocal disease and without leptomeningeal spread -radiotherapy (CSI and boost) • A combined approach using platinum-based chemotherapy followed by reduced-volume, reduceddose radiotherapy is a very attractive option that is being investigated by many groups, with disease-free survival rates in the 90% to 96% range. • Hence options: – craniospinal radiotherapy, – limited volume (whole-ventricle) radiotherapy alone, and – chemotherapy followed by whole ventricle or local radiotherapy
  46. 46. Non germinomatous GCT • A multimodality approach that includes both chemotherapy and radiotherapy appears to be associated with the best outcome • Favourable--- Whole Ventricle RT • Unfavourable --- CSI and Boost • A dose of 36 Gy is used, followed by a boost to the primary site to a total dose of 54 Gy.
  47. 47. Classification of Nongerminomatous Germ Cell Tumors Good prognosis Mature teratoma Poor prognosis Teratoma with malignant transformation Embryonal carcinoma Yolk sac tumor Intermediate prognosis Choriocarcinoma Immature teratoma Mixed germ cell tumors including a Mixed germ cell tumors consisting of component of embryonal carcinoma, yolk germinoma with either mature or immature sac tumor, choriocarcinoma, or teratoma teratoma with malignant transformation
  48. 48. Tumors of the Sellar Region • Craniopharyngioma, – Adamantinomatous craniopharyngioma – Papillary craniopharyngioma • Xanthogranuloma, • Pituitary adenomas.
  49. 49. Craniopharyngioma • Benign partly cystic epithelial tumors that arise in the sellar region from remnants of Rathke's pouch • MC in Children- adamantinomatous • 5% of intracranial tumors in children • 5 and 14 years. • have both suprasellar and intrasellar components
  50. 50. Craniopharyngioma • Children typically present with neuroendocrine deficits, especially diabetes insipidus and growth failure. • Visual-field deficits bitemporal hemianopia often go unnoticed initially. • Compression of the third ventricle may lead to hydrocephalus and symptoms and signs of raised intracranial pressure.
  51. 51. Craniopharyngioma • On neuroimaging: – with solid and cystic areas in varying proportions; – calcification is seen in the majority of cases. – The solid portions and the cyst capsule usually enhance with the use of contrast material.
  52. 52. Craniopharyngioma • Complete surgical resection(Transsphenoidal approach), as confirmed on postoperative imaging, is associated with long-term tumor control in 85% to 100% of patients • Patients with – tumors that are smaller and/or subdiaphragmatic in location and without hypothalamic symptoms would be managed surgically, – while other patients at higher risk for complications secondary to surgery would be managed with biopsy, cyst decompression, if necessary, and radiotherapy
  53. 53. Craniopharyngioma • Role of RT as sole therapy: – After biopsy – After incomplete surgery – At progression – Recurrence • Other options – Injection of radioactive colloid P32 and Y90--- if the lesion has a small solid comp. and a simple cyst – May be combined with Stereotactic RT to solid comp.
  54. 54. Craniopharyngioma • EBRT – Target Volume: entire lesion with preop MRI – 0.5 cm margin or even 0 cm can be justified for a CTV (Studies show excellent results) – Dose: 54-55 Gy over 30 fractions • During even after RT--Cyst may enlarge • Emergency cyst decompression may avoid further neuro complications
  55. 55. Radiation Dose Fractionation in Children • Conventionally 1.8 Gy / Fr • Avg dose: 54.5- 55.8 Gy • If it is a primary tumor of spinal cord: 50.4 Gy • In case of Germinomas: even doses of 1.5 Gy /fr and lower doses of 30 to 45 Gy • HFRT may be a useful strategy in situations where dose escalation cannot be obtained by conventional fractionation
  56. 56. Issues regarding RT in children • Neurocognitive sequelae • Myelinization and functional maturation of the CNS continue until well into adolescence and even into young adulthood. • Failure to acquire new knowledge and skills at an ageappropriate rate and show a progressive decline in IQ over time • Endocrine deficits
  57. 57. To Minimize the long-term effects • • • • • • • • • Avoidance of radiotherapy altogether Delay to radiotherapy for young children Use of focal rather than extended-field Use of daily anesthesia and improved immobilization techniques Use of image-based treatment planning New radiation modalities Reduction of the dose of radiotherapy Use of smaller fraction sizes where appropriate Use of hyperfractionated radiotherapy (HFRT)
  58. 58. Follow up • During treatment: • • • • For vomitting ,headache ICT Fatigue Usually recover quickly after treatment • After treatment: (apart from imaging) • For hormonal deficits (esp. Primary hypothyroidism in CSI by photons and GH deficit secondary to incln. Of hypothalamo pituitary axis) • Ophthalmology and audiology f/u • Access to neuropsychologist in case of special needs ,vocational assessment sos.
  59. 59. Thank you.

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