mainly deals with technical aspects of radiation in pituitary tumors

1. PRESENTED BY :Dr SANDIP KUMAR BARIK
DEPT OF RADIOTHERAPY
MODERATOR: Dr RAJENDRA KUMAR

2. INTRODUCTION
 Pituitary or hypophysis cerebri is an endocrine gland situated in
relation to the base of the brain
 It is called the Master of endocrine orchestra
 It produces a number of hormones which control the secretions of
many other endocrine gland of the body

3. ANATOMY
 The pituitary gland or hypophysis is
an endocrinabout 15 mm in ant-post
and 12 mm in supero inferior axis
 It weighs about 0.5 gm.
 The pituitary gland occupies a cavity
of the sphenoid bone called sella
turcica
 Roof is formed by diaphragm sellae
 The stalk of pituitary is attached above
to the floor of third ventricle

4. Anatomy(cont..)
 Relations
 Superiorly:Diaphragma
sellae,optic
chiasma,infundibular recess of
3rd ventricle
 Inferiorly:Hypophyseal fossa
and its venous channels
 On each side :The cavernous
sinus with its content
Modified from Lechan RM. Neuroendocrinology of Pituitary Hormone Regulation. Endocrinology and Metabolism Clinics 16:475-501, 1987

5.  The anterior and intermediate
lobe arises from the Rathke’s
pouch
 The posterior lobe or
neurohypophysis arises from the
downward pocketing of third
ventricle.
 Posterior lobe releases hormones
the Oxytocin and Vasopressin
which are synthesised in the
supraoptic and paraventricular
nuclei in hypothalamus
 Anterior lobe releases hormones
ACTH,TSH,GH,FSH,LH,Prolactin

6. EPIDEMIOLOGY
 Pituitary neoplasm account for 10% to 15% of diagnosed primary
intracranial neoplasm
 3% -25% pituitary glands are identified by autopsy
 10% of healthy population has pituitary abnormality detected by MRI
 Approximately 70% are endocrinologically active
 Incidence of macroadenomas is similar between males and females
 However clinical manifestations of microadenomas are more in women

7. EPIDEMIOLOGY (Cont…)
 70% of adenomas present between the ages 30 -50 yrs
 Women have high incidence of pituitary adenomas(15-44 yrs)
 Annual incidence ranges from 0.5 to 0.7/100,000
 Etiology of most adenomas is unknown
 A genetic predisposition to develop adenomas has been described in
MEN I syndrome
Carney complex
Isolated familial somatotropinomas(IFS)

8. NATURAL HISTORY
 Usually has a long natural history with an insidious onset of symptoms
 Symptoms are usually present for years prior to diagnosis
 When small pituitary tumour tends to be smooth round tumours
 Macroadenomas are known for their local invasive properties
 Malignant behaviour with distant metastases is rare

9. CLINICAL PRESENTATIONS
 The presenting symptoms may be due to
Hormonal malfunction
Due to local tumour growth and pressure effect
 Endocrine abnormalities may be a consequence of hyper or hypo
secretion of pituitary hormones.
 Hypopituitarism
 Hyperpituitarism
Cushings syndrome
Hyperprolactinomas
Hyperthyroidism
Acromegaly

10. HYPOPITUITARISM
 Growth hormone deficiency:Short stature(Dwarfism)
 Gonadotrophins deficiency:Infertility,decreased sexual functions,loss
of secondary sexual characters,menstrual
irregularities
 TSH deficiency :Hypothyroidism
 ACTH deficiency :Hypocortisolism
 Prolactin deficiency :Lactation failure
 Vasopressin deficiency :Diabetes insipidus

11. HYPERPITUITARISM
 HYPERPROLACTINEMIA
 Most common cause of pituitary hormone hypersecretion
 Amennorhoea
 Galactorrhoea
 Infertility
 INCREASED GH
 Acromegaly in adults
 Frontal bossing
 Increased hand foot size
 Mandibular enlargement,Prognathism
 Large fleshy nose
 Proximal muscle wasting,carpal tunnel syndrome,macroglossia
 Gigantism in children

12.  INCREASED ACTH
 Causes cushing syndrome
 Central obesity
 Plethoric moon facies
 Purple striae,increased bruisability
 Glucose intolerence
 Acne,hirsuitism
 Proximal muscle weakness
 Hypertension
 Amennorhoea,infertility

13. FEATURES OF SELLAR MASS LESION
 PITUITARY
 Hypopituitarism
 OPTIC CHIASMA
 Bitemporal Hemianopia
 Superior temporal defect
 CAVERNOUS SINUS
 Ophthalmoplegia
 Ptosis
 Diplopia
 OTHERS
 Head ache
 Hydrocephalus
 Dementia

14. DIAGNOSTIC WORKUP
 Detailed History and complete physical examination
 Confirmation of diagnosis
 Radiological Examination
MRI-preferred modality
better visualisation of soft tissue and vascular structure
CT Scan
 Biopsy –In a case of non secreting lesion

15.  STAGING WORKUP: Chest x ray
USG Whole abdomen
 General condition:
Complete blood count
Kidney function tests
liver function test
Urine analysis

16.  HORMONAL ANALYSIS
 Serum Prolactin level
 Growth hormone:basal growth hormone level
IGF-I
Glucose suppression,insulin tolerence
 ACTH Hypersecretion:
Serum ACTH,Dexamethasone supression test
24 hrs urine for 17-hydroxy corticosteroids
and free cortisol
 Gonadal function:FSH,LH,Esradiol,Testosterone
 Thyroid function test
 Adrenal function:basal plasma,urinary steroids
cortisol response to insulin induced hypoglycaemia

17. CLASSIFICATION OF PITUITARY TUMOURS
 ANATOMICAL SIZE
 Microadenoma(<10 mm)
 Macroadenoma(>10 mm)
 PHYSIOLOGICAL
 Ant pituitary
1. Prolactin
2. Growth hormone
3. Adrenocorticotrophic hormone
4. Leutinizing hormone
5. Follicle stimulating hormone
6. Thyroid stimulating hormone
 Post pituitary
1. Oxytocin
2. Vasopressin

18. Classification(Cont…)
 ACCORDING TO CLINICAL SYMPTOMS
 Functional
 Non functionaL
 ACCORDING TO EXTENT OF EXPANSION OR EROSION OF
SELLA
 Grade 0: Intrapituitary microadenoma with normal sellar appearance
 Grade I: Nml-sized sella with asymmetric floor
 Grade II: Enlarged sella with an intact floor
 Grade III: Localized erosion of sellar floor
 Grade IV: Diffuse destruction of floor

19. Classification(Cont…)
 ACCORDING TO SUPRASELLAR EXTENSION
 Type A: Tumor bulges into the chiasmatic cistern
 Type B: Tumor reaches the floor of the 3rd ventricle
 Type C: Tumor is more voluminous with extension into the 3rd ventricle
up to the foramen of Monro
 Type D: Tumor extends into temporal or frontal fossa

20. PATHOLOGICAL CLASSIFICATIONS
 Ant Pituitary has 5 specific cell
types
 Somatotrophs:produces growth
hormone,acidophilic
 Lactotrophs:produces
prolactin,acidophilic
 Corticotrophs:produces
ACTH,MSH,basophilic
 Thyrotrophs:produces TSH,basophilic
 Gonadotrophs:FSH,LH,basophilic
 Post pituitary:pituicytes and non
myelinated fibres

21. MANAGEMENT
 Observation
 Surgery
 Radiotherapy

22. OBSERVATION
 In asymptomatic non secreting microadenomas
 Small asymptomatic prolactinomas
2 -4 mm no testing required
5-9 mm MRI can be done once yearly
 Indications for intervention
Tumour growth on imaging
symptoms of hypersecretion
development of visual field defects

23. < 10 mm > 10 mm
Evaluate for:
Evaluate for • Hormonal Hypersecretion
Hormonal • Hormonal Hyposecretion
Hypersecretion
• Visual Changes/defects
Hormonal or Visual
Normal Abnormalities No Abnormalities
Observe Observe
Treatment

24. SURGERY
INDICATIONS
 It is the first line treatment for most symptomatic pituitary tumours
 Useful when medical or radiotherapy fails
 When prompt relief from mass effect and hormone secretion is
required
 Pituitary apoplexy

25.  TYPES
 MICROSCOPIC TRANSSEPTAL TRANSSPHENOIDAL
 Current standard surgical procedure
 Safe procedure with mortality rate 0.5%
 Contraindications are sphenoid sinusitis,ectatic midline carotid
arteries,lateral surpasellar extent

26.  ENDOSCOPIC TRANSNASAL
TRANSSPHENOIDAL
 Allows better visualisation of
pituitary gland,ghyophyseal
stalk,cavernous sinuses,optic nerve
and suprasallar areas
 .TRANSCRANIAL
 Requires craniotomy and retraction
of frontal lobes
 Used for large invasive tumours with
significant suprasellar extension
 When transsphenoidal approach is
contraindicated

27. COMPLICATIONS OF SURGERY
 CSF rhinorrhoea
 Meningitis
 Haemorrhage
 Stroke
 Damage to pituitary
 Visual loss

28. RADIOTHERAPY
 INDICATIONS
1. Hypersecretion and mass effect due to large tumours
2. Incomplete resection of tumour
3. Progressive disease after surgery
4. Recurrent tumours

29. RADIOTHERAPY
 TECHNIQUES
 Conventional External Beam Radiotherapy
 Manual planning
 2D Planning
 3D CRT
 Fractionated Stereotactic Radiation Therapy
 Gammaknief Radiosurgery

30. MANUAL AND 2D PLANNING
 Positioning
 Supine with neck flexed and head at
45 degrees
 Pituitary board can be used to
achieve this
 Immobilisation done with
thermoplastic mask
 VOLUME
 The entire pituitary gland with
extensions and a margin of 1-1.5
cm

31.  PORTALS
 Two parallel and opp lat fields and one anterior or vertex beam that
enters above the eyes
 The centre of the pituitary is located at a point 2-2.5 anteriorly to tragus
and 2-2.5 cm superiorly to that point
 Taking this point as centre a field of( 4*4)cm-(6*6) cm is marked
 ENERGY
 4-10 Mev or Co 60
 DOSE
 Nonfunctioning tumours 45-50.4 Gy@1.8 Gy/#
 Functional tumours 50.4-54 Gy

32. 3D PLANNING
 Image based treatment planning using
a 3D technique is the standard of care
 Defining the tumour volume
 MRI,CT as well as clinical and surgical
findings should be used to define the
tumour volume
 CT simulation assists in defining
treatment volume
 GTV is the pituitary adenomas
including any extention into adjacent
anatomic regions
 CTV :GTV+5 mm in a clear defined
tumour
or entire sella and cavernous
sinus with invasive tumours
 PTV:CTV+5mm

33. FRACTIONATED STEREOTACTIC RADIOTHERAPY(FSRT)
 FSRT is characterised by improved patient localisation,tighter volume
definition more conformal isodose distributions
 It has better safety profile and efficacy
 IMMOBILISATION
Aim is to achieve a patient positioning error of less than 3mm by
various means like
Invasive halo ring
Radiocamera bite block
Non invasive Head frames

34. Stereotactic(cont…)
 TARGET VOLUME DELINEATION
 GTV is designed with help of MRI and extent of cavernous sinus
invasion should be included
 No additional margins is required for CTV
 PTV:CTV +2-3 mm margin
 TREATMENT PLANNING
 Depends on the delivery systems available
 Options include
Multiple spherical shots
Dynamic conformal arches
Nonisocentric robotic delivery
 DOSE
50.4 Gy in 28#@1.8Gy/#

35. STEREOTACTIC RADIOSURGERY
 Accepted treatment for smaller,radiologically well defined tumours located
at a distance (3-5 mm) from optic apparatus
 Contraindicated if optic chiasma is closer than (3 -5)mmto the tumour
 Delivery systems include linear accelerator and gamma knife
 Head is fixed with an appropriate stereotactic head frame and a high
resolution imaging study is obtained
 MRI used for gamma knief while ct scan for linear accelerator
 Gamma knife uses smallest collimators and maximum number of
isocentres .
 The dose to optic chiasma is limited to <8-9 Gy
 DOSE
 Non functioning (12-20Gy)
 Functioning (15-30 Gy)

37. RESULTS
MODALITY SURGERY SURG+POST GAMMA KNIEF
VS OP RT RADIOSURGERY
SURG+POSTO VS
P RT
RT ALONE
RESULTS Park et.al Grigsby et al Maschiro.et al
10 yrs Proggression Tumour control at
recurrence rate free survival at 5 5 yrs is 93.6% and
2.3%with yrs 96% and 20 endocrinological
rt,50.5%only yrs 88% improvement is
surgery 80.3%
CONCLUSION Post op RT Surg+rt had a Results are similar
should be greater control to #EBRT but
preffered of local disease gamma knief
seems to be safer
in terms of
complications

38. COMPLICATIONS OF RADIOTHERAPY
 ACUTE REACTIONS
1. Fatigue
2. Focal alopecia
3. Otitis
 CHRONIC REACTIONS
1. Hypopituitarism
2. Damage to optic apparatus
3. Secondary brain tumours
4. Brain necrosis

39. CONCLUSION
 Pituitary tumors are slow growing tumours.
 Surgery is the first choice of treatment
 Radiation is generally used as an adjuvant or salvage therapy
 Surgery followed by post op radiation produce better results
 Newer treatment modalities like gamma knife produce less
complications

40. THANKYOU