1. PRESENTED BY :Dr SANDIP KUMAR BARIK DEPT OF
RADIOTHERAPYMODERATOR: 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 contentModified 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 Rathkes
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
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) PHYSIOLOGICAL Ant pituitary1. Prolactin2.
Growth hormone3. Adrenocorticotrophic hormone4. Leutinizing
hormone5. Follicle stimulating hormone6. Thyroid stimulating
hormone Post pituitary1. Oxytocin2. 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 VisualNormal Abnormalities No
AbnormalitiesObserve Observe Treatment
24. SURGERYINDICATIONS 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 INDICATIONS1. Hypersecretion and mass effect
due to large tumours2. Incomplete resection of tumour3. Progressive
disease after surgery4. Recurrent tumours
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 [email protected] 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