Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_500_Библиотеки_им_академика_М_И_Перельмана
.pdf
466
https://t.me/medicina_free
RADIOACTIVE IODINE THERAPY (RAIT)
B
x Preferred therapy for hyperthyroidism as it avoids surgery,
prolonged drug therapy with >90% cure rate; but proper follow
up is needed and facilities should be available (not much centers
are having)
x Administered orally as a single dose in capsule or liquid form
(Sodium iodide-131)
x Causes fibrosis and destruction of the thyroid over weeks to many
months causing hypothyroidism
x It is effective, safe, and does not require hospitalization
x Given orally as a single dose in a capsule or liquid form - I
given (6 to 8 milliCuries)
x Very few adverse effects as no other tissue absorbs RAI
SRB's Manual of Surgery
x But the effect is less rapid than drugs or thyroidectomy
x Goal is to make the patient hypothyroid
x Not recommended with patients of severe ophthalmopathy
x Not advisable in chronic smokers
x Pregnancy, breastfeeding, and recent lactation are contraindica-
tions
x A gland-specific dosage based on the estimated weight of the
gland and the 24-hour uptake is used. The dose of I
tered is 75–200 µCi/g of estimated thyroid tissue divided by the
percent of
x No evidence indicates that radioactive iodine therapy for hyperthy-
roidism causes the development of thyroid carcinoma or results
in increased mortality for any other form of cancer, including
leukemia
x Radioactive iodine should be avoided in children younger than 5
years. In children 5 to 10 years old,
the calculated activity of administered
children older than 10 years of age, radioactive iodine therapy is
acceptable if the activity is greater than 150 µCi/g of thyroid tissue
x Radioactive iodine should never be administered to pregnant
women, because it can cross the placenta and ablate the fetal
thyroid, resulting in hypothyroidism
x Risk of hyperparathyroidism may be there after RAI therapy
x Similarly, breastfeeding is a contraindication, as the radioiso-
tope is secreted in breast milk. Women will continue to receive
increased radiation to the breast from radioactive iodine for few
months after ceasing lactation
x It is standard practice to check for pregnancy before starting
radioactive iodine therapy and to recommend the patient not to
become pregnant for at least 12 months after the treatment.
excess fetal malformations or increased miscarriage rates have
been found in women previously treated with radioactive iodine
for hyperthyroidism.
123
I uptake in 24 hours
131
I therapy is acceptable if
131
I is less than 10 mCi. In
RADIOACTIVE IODINE
It is used both as a diagnostic as well as a therapeutic agent.
131
1. I
—is used for radioactive iodine therapy (β-rays are used).
123
2. I
—is used for diagnostic studies (γ-rays are used).
DIAGNOSIC USES
INDICATIONS FOR DIAGNOSTIC RADIOACTIVE
B
IODINE STUDY
x Doubtful toxicity; Autonomous toxic nodule
x Ectopic thyroid; Retrosternal thyroid
x After total thyroidectomy, to look for secondaries in follicular
carcinoma thyroid
131
adminis-
131
For diagnostic purpose I
previous day (dose—5 micro curie; T
123
is given orally in empty stomach on
(half-life) of I
1/2
hours and so it is suitable for diagnostic purpose). Patient should
not take L-thyroxine for 6 weeks prior to radioisotope study.
131
Thyroid treats this I
I
the thyroid from the circulation and gets incorporated into T3,
123
similar to inorganic I
127.
T4 and later released into circulation as protein bound iodide
(PBI). Normal value of PBI is 8 mgm%.
Using Gieger Muller’s gamma ray counter, scanning of thyroid
is
gland is done to visualize the gland.
Hot area suggests more uptake,
Warm area suggests normal uptake,
Cold area suggests no uptake.
123
I
radioisotope can be safely used in children and pregnancy
for diagnostic purpose only (5 micro
Note:
• If the patient is on T
days before radioisotope scan.
(60 µg/day) medication, the drug is stopped 10
3
curie) as the dose is low.
• Injection TRH, if given, radioisotope scan can be done in 24 hours.
• Presently I
malignancy β-rays are more used than γ-rays.
131
is also becoming popular as a diagnostic tool. For treating
• Technetium 99 scan is used for diagnostic purpose at present as it is
effective and faster (in 20 minutes). IV administration is used.
• Radioisotope study is done to look for secondaries by doing whole body
scanning (total body scinti graphy).
Therapeutic Uses
In primary thyrotoxicosis: It is the main therapy for Grave’s
disease after the age of 10 years except in pregnancy, lactation.
In autonomous toxic nodule, it is useful as remaining gland
still will function adequately after radiotherapy (As during
radiotherapy radioisotope will not be taken up by this retained
normal gland as it is suppressed in the presence of toxic
nodule which will function later adequately).
In follicular carcinoma of thyroid, after total thyroidectomy, if
there are secondaries elsewhere in the body, as in bones or
No
lungs, then radioiodine therapy is given. I131 is given as its
half-life is 8 days. It is given orally in a dose of 5 millicuries
(160 microcurie/g of thyroid). It ablates the residual disease in
the thyroid bed; facilitates the identification of the metastases
and therapy; makes the thyroglobulin estimation as a marker
of recurrence at a later period.
Precautions in RAI therapy: Sleep alone for 7 days; avoid
hugging, kissing (children) for 7 days; keep away from people
for 6 feet for 3 days; plenty of water to drink to ush the isotope
in urine and prevent radiation cystitis; laxatives to void constipation to prevent radiation enteritis; one should not share utensils,
bed, clothes with others for 3 days; wash clothes and utensils
separately; wash hands frequently; avoid public places or transports for 5 days; take low iodine diet for 7 days.
Contraindications for RAI Therapy: Pregnancy/females desiring
to have pregnancy within 1 year/ lactating mothers and children.
Problems in RAI Therapy: Permanent thyroid failure with
hypothyroidism; effects will be seen only after 3 months;
This I
123
123
is 13
enters
T
https://t.me/medicina_free
ophthalmopathy and dermopathy will be worsened; it may induce
hyperparathyroidism; sialadenitis with salivary enlargement and
dry mouth and loss of taste or metallic taste. In men, it decreases
the sperm count temporarily for 2 months; sperm banking may
be better prior to start of RAI therapy. Acute radiation sickness;
radiation thyroiditis; pain, bleeding, swelling at the metastatic
site are other problems.
Advantages: It is safe; does not require longer hospitalization
(if dose is >30 mCi); administration is oral (solution/capsule
[one capsule = 50 mCi]; solution is better to take and easier
to adjust the dose). RAI dose: (Thyroid mass [gram] X 80-200
uCi)/% uptake.
Dose of radioactive iodine
T
Diagnostic Therapeutic
• For thyroid-5-50
microcurie
• For whole body iodine
scan 5–10 millicurie in
• Residual thyroid
ablation—50 mCi
• Bone secondaries from
FCT—200–240 mCi
72 hours
Lung secondaries from
•
FCT—180 mCi
Radioactive isotopes used in thyroid
Isotopes
123
I
124
I
125
I
131
I
132
I
Tc 99 scan*
Used mainly for malignancy in thyroid itself. It is sensitive, con-
*
venient, low radiation exposure, inexpensive, with good images
but nonspecific and not used for therapy.
Lithium is also used as isotope for diagnosis in thyroid diseases.
Technetium is better to identify nonfunctioning secondaries.
B
x High dose of retinoic acid will make I
cells (70 mg/daily for 2 weeks)
x Fertility should be avoided for 1 year after I
x Avoid contrast CT in thyroid diseases as much as possible
because I
x MRI is ideal when radioiodine therapy is needed
Note:
Route of
administration
Oral 13 hr
PET scan in
thyroid cancer
Oral 60 days
Oral 8 days
Oral 2.3 hr
IV 6 hr
REMEMBER
131
study in later period will be difficult
Half-life Type of
rays
γ rays
4 days
γ rays
β, γ rays
131
to concen trate in tumour
131
therapy
• Toxic thyroid in pregnancy: Radioiodine therapy is absolutely contrain-
dicated in pregnancy (High-risk to foetus). Antithyroid drugs can be
administered carefully. But, the problem here is that both TSH and
antithyroid drugs cross the placental barrier and baby born may be
hypothyroid and goitrous. Propylthiouracil is preferred in pregnancy.
Subtotal/total thyroidectomy can be done in second trimester.
• Toxic thyroid in children: Radioiodine therapy is absolutely contraindi-
cated in children below 5 years. Recurrence rate is also very high after
surgery. So proposed treatment is initially antithyroid drugs are given
until adolescent period and then subtotal thyroidectomy OR Radioactive
iodine therapy (after the age of 10 years).
• Thyrocardiac: Severe cardiac damage (partly or wholly) resulting from
hyperthyroidism, usually secondary type, requires proper opinion from
cardiologists and treatment with propranolol. Subtotal thyroidectomy
is the treatment.
• In a patient with thyrotoxicosis, with recent onset of proptosis: Early
thyroidectomy has to be avoided, because early surgery may precipitate
malignant exophthalmos. Here the patient has to be treated initially
with antithyroid drugs and if required with steroids, until the proptosis
remains static for six months. Then subtotal thyroidectomy is done.
• Since half-life of L-thyroxine is 7 days, propranolol and antithyroid drugs
have to be continued for 7 days after thyroidectomy.
• T3 Thyrotoxicosis should be suspected if the clinical picture is sugges-
tive of toxicosis, but routine tests for thyroid function are within normal
range.
THYROID NEOPLASMS
A. Benign
Follicular adenoma can be – Colloid (do not have potential for
microinvasion; commonest type); Fetal (microfollicular – has
potential for microinvasion); Embryonal (atypical – has potential for microinvasion); Hurthle cell/oxyphil or oncocytic (has
potential for microinvasion); hyalinising trabecular adenoma.
Note:
• All adenomas are invariably follicular.
• Colloid adenoma is the commonest.
• The existence of papillary adenoma is doubtful; it is invariably a low-
grade papillary carcinoma.
B. Malignant (Dunhill classification).
a. Differentiated—80%
1. Papillary carcinoma (60%).
2. Follicular carcinoma (17%).
3. Papillofollicular carcinoma behaves like papillary carcinoma of thyroid.
4. Hurthle cell carcinoma behaves like folli cular carcinoma.
b. Undifferentiated—20%
Anaplastic carcinoma (13%)
c. Medullary carcinoma (6%)
d. Malignant lymphoma (4%)
e. Secondaries in thyroid (rare)—from colon, kidney, mela-
noma, breast.
Incidence and Spread
Annual incidence of thyroid cancers is 3.7 per 1,00,000
population. It is common in females (3:1).
Papillary carcinoma mainly spreads through lymphatics;
follicular through blood; anaplastic through lymphatics and
blood.
Aetiology of Thyroid Malignancy
Radiation either external or radioiodine can cause papillary
carcinoma thyroid. There was increased incidence of thyroid
467
CHAPTER 6 Thyroid
Dissatisfaction and discouragement are not caused by the absence of things but the absence of vision.
468
https://t.me/medicina_free
carcinoma among children following exposure to ionising
radiation after the Chernobyl nuclear disaster in Ukraine in
1986; in children in Marshall island after atomic bomb testing.
Earlier irradiation was practised to head and neck region
to treat benign conditions like tonsillitis, adenoids, thymus
enlargement, acne vulgaris, haeman giomas during first two
decades of life. As a consequence papillary carcinoma of
thyroid became common in these individuals. Radiotherapy
received in adolescent period for Hodgkin’s lymphoma may
predispose to papillary carcinoma.
Pre-existing multinodular goitre. It can turn into follicular
carcinoma of thyroid.
SRB's Manual of Surgery
Medullary carcinoma thyroid is often familial.
Hashimoto’s thyroiditis may predispose to NHL/papillary
carcinoma of thyroid.
Familial.
Elevated TSH is observed in papillary carcinoma of thyroid.
Genetic—Cowden syndrome is differentiated thyroid carci-
noma, carcinoma breast, multiple hamartomas. It is due
to germ cell mutation of PTEN tumour suppressor gene.
Oncogenes—C myc, C erb, C fos, Ras are associated thyroid
neoplasms.
DIFFERENTIAL DIAGNOSIS FOR CARCINOMA THYROID
B
x Multinodular goitre
x Riedel’s thyroiditis
x Solitary nodule of other
causes
PAPILLARY CARCINOMA OF THYROID (PCT)
It is 70–80% common. Common in females and younger
age group.
Aetiology (see above)
Radiation either external or radioactive iodine therapy.
TSH levels in the blood of these patients are high and so it is
called as hormone dependent tumour.
A
B
Figs. 6.39A and B: (A) Fungating follicular carcinoma thyroid in a female.
(B) Pulsatile vascular skull secondaries from FCT in a male patient.
Fig. 6.40: Papillary carcinoma of thyroid with nodal infiltration—
diagrammatic representation.
WOOLNER CLASSIFICATION
B
Types
i. Occult primary (<1.5 cm); ii. Intrathyroidal.
iii. Extrathyroidal.
Note:
• Micropapillary carcinoma is a tumour, clinically not detectable or less
than 1 cm.
• Encapsulated variant of papillary carcinoma, like adenoma shows
capsule with local invasion, commonly nodal spread; it often mimics
hyperplastic nodule; but this type carries good prognosis.
• Diffuse sclerosing variant is seen in children which is very aggressive
type with lymphocytic infiltration; it shows near 100% nodal spread; it
carries poor prognosis.
• Encapsulated papillary variant and follicular carcinoma may be found
together as papillofollicular (Lindsay tumour); it behaves like papillary
carcinoma with good prognosis.
Gross
It can be soft, firm, hard, cystic. It can be solitary or multinodular.
It contains brownish black fluid.
Fig. 6.41: Papillary carcinoma thyroid (PTC) in male patient. Male
https://t.me/medicina_free
patient is high-risk patient. But PTC and all thyroid carcinomas are
more common in females.
Microscopy
It shows cystic spaces, papillary projections with psammoma
bodies (50% cases), malignant cells with ‘Orphan Annie eye’
nuclei (intranuclear cytoplasmic inclusions), nuclear groove,
nuclear pseudoinclusions.
Orphan Annie eye nuclei are identified in histology (paraffin
section of formalin tissue). It is not seen in FNAC. Orphan
Annie is strip cartoon character with empty circled eyes.
Tall cell type of papillary carcinoma (10% of papillary
carcinomas) is very aggressive type seen in elderly, 30%
show capsular and vascular invasion, with 25–30% 5–year
survival rate.
Columnar type is seen only in males with near 100% mortality
in 5 years.
Diagnosis
FNAC of thyroid nodule and lymph node.
Radioisotope scan shows cold nodule.
TSH level in the blood is higher.
Plain X-ray neck shows fine calcification whereas nodular
goitre shows coarse—ring/rim calcification.
US neck to identify non-palpable nodes in neck and also
lymph node.
MRI may be useful.
Treatment
Total or near total thyroidectomy, with central node compart-
ment dissection (level VI).
Suppressive dose of L-thyroxine 0.3 mg OD life long. TSH
level should be <0.1 m U/L.
Lateral cervical/neck node dissection (LCND) levels IIA, III, IV
and VB) or MRND (with preservation of sternocleidomastoid,
IJV, spinal accessory nerve) is done depending on involve-
ment of one side or both (if node positive on imaging or FNAC
only as therapeutic).
Radioactive iodine therapy (RAIT) if tumour is multicentric,
>1 cm size, presence of nodes, extrathyroidal spread, high-
risk group.
‘Berry picking’ (picking up the enlarged lymph nodes) earlier
practiced is not done now.
469
CHAPTER 6 Thyroid
Spread
It is a slowly progressive and less aggressive tumour.
It is commonly multicentric.
It spreads within the gland through intrathyroidal lymphatics
to other lobe, comes out of the capsule and spreads to
cervical lymph nodes.
Usually there is no blood spread. Extrathyroidal disease—
invasion into thyroid capsule can cause blood-borne secondaries occasionally.
Clinical Features
Soft or hard or firm, solid or cystic, solitary or multi nodular
thyroid swelling.
Compression features are uncommon in papillary carcinoma
thyroid.
Often discrete lymph nodes in the neck (40%) are palpable.
May present with secondaries in neck lymph nodes with
occult primary.
Fig. 6.42: Papillary carcinoma thyroid, operated specimen.
Note:
• If tumour is <1.0 cm, solitary, low grade, probably unicentric, hemithy-
roidectomy is done with proper follow up at regular intervals.
• Suppressive dose of L-thyroxine can cause osteoporosis and so often
needs calcium and Vitamin D supplementation.
Prognosis
Prognosis is good and it is one of the curable malignancies.
Don’t spend a dollars’ worth of time for ten cents worth of results.
470
https://t.me/medicina_free
AMES SCORING
B
A : Age. Age less than 40 years has got better prognosis
: Distant metastasis
M
: Extent of the primary tumour
E
: Size of the tumour. Size less than 4 cm has got better prognosis
S
Contd...
x It is not very useful in follicular carcinoma as it is difficult to
differentiate it from follicular adenoma as the main feature in
follicular carcinoma is capsular invasion/vascular invasion which
are not made out in F
NAC
AGES SCORING
B
A : Age less than 40 years has got better prognosis
G : Pathologic grade of the tumour
: Extent of the primary tumour
E
: Size of the primary tumour. Size less than 4 cm has got better
S
prognosis
SRB's Manual of Surgery
Note:
• Lymph node status does not alter the prognosis of papillary carcinoma
of thyroid.
• MACIS scoring system is metastases, age, and completeness of exci-
sion, invasion, and size.
• All scoring systems categorise the patients as high risk for death—40%
in 20 years; low risk for death—1% in 20 years. 80% of patients are
in low risk for death. Low death risk is achieved by complete clearance
of macroscopic tumour without any possible retaining of the disease
during first surgery.
• Follow-up: Regular estimation of TSH levels, helps to monitor recur-
rence.
• Thyroid paradox: Cellular tumours are soft, and cystic tumours are firm
or hard (tensely cystic). It is observed in papillary carcinoma of thyroid.
PSAMMOMA BODIES ARE SEEN IN:
B
Papillary carcinoma thyroid; Meningioma; Serous cystadenoma of
ovary
BERRY’S IN THYROID
B
x Berry ligament; Berry sign; Berry picking
ROLE OF ULTRASOUND (US) IN THYROID DISEASES
B
x To detect number, size, nature of the nodules (cystic/solid/
complex) (complex means cystic and solid together—more suspicious of carcinoma). Size up to 2 mm can be detected
x US guided FNAC is very useful
x US at regular intervals is advisable to observe a small nodule
in thyroid
x To detect recurrent nodule
x To find out the invasion/spread/vascularity/status of carotid artery
and internal jugular vein
x To find out enlarged lymph nodes in neck
FOLLICULAR CARCINOMA OF THYROID (FCT)
It is 10–15% common. It is common in females.
It can occur either de novo or in a pre-existing multinodular
goitre.
Thyroglobulin immunostaining is positive.
A
Figs. 6.43A and B: (A) Advanced carcinoma of thyroid with
compression features with dilated veins; (B) Follicular carcinoma of
thyroid in a male patient. It involved mainly left lobe but it is extensive
and spreading to soft tissues adjacent to it.
B
Types
a. Noninvasive—blood spread not common.
b. Invasive—blood spread common.
Typical features: Capsular invasion and angioinvasion.
Spread
It is a more aggressive tumour.
It spreads mainly through blood into the bones, lungs, liver.
Bone secondaries are commonly seen in skull (frontal bone),
long bones and ribs; in the skull, it is typically warm, vascular,
localized, nonmobile and pulsatile. As both outer and inner
tables of the skull is disrupted and since it is DTC metastases
it contains colloid; so brain pulsation is transmitted to scalp
across the disrupted skull tables through fluid colloid.
It can also spread to lymph nodes in the neck occasionally
(10%).
ROLE OF FNAC IN THYROID SWELLING
B
x Highly sensitive in papillary carcinoma of thyroid and also its
nodal spread
x Useful to differentiate between benign and malignant
x Should be done in all thyroid diseases especially when there is a
nodule or multiple nodules
x Useful in lymphoma/anaplastic carcinoma/medullary carcinoma
thyroid/Hashimotos thyroiditis
Contd...
Clinical Features
Swelling in the neck, firm or hard and nodular.
Tracheal compression/infiltration and stridor.
Dyspnoea, haemoptysis, chest pain when there are lung
secondaries.
Recurrent laryngeal nerve involvement causes hoarseness
of voice, +ve ‘Berry’s sign’ signifies advanced malignancy
(infiltration into the carotid sheath and so absence of carotid
pulsation).
Well localised, nonmobile, soft, fluctuant (because of colloid
https://t.me/medicina_free
content) and pulsatile (as both inner and outer tables of skull
bone are disrupted allowing brain pulsation to get transmitted)
secondaries in the skull. Secondaries can also occur in long
bones also.
Fig. 6.44: Secondaries in the skull in a patient who underwent
thyroidectomy earlier for follicular carcinoma thyroid.
Fig. 6.45: Secondaries in the skull from thyroid primary. Note welllocalised, warm, pulsatile, vascular tumour with underlying bone
erosion. It is common in flat bone like skull/ribs/sternum/scapula. Most
common in frontoparietal part of skull.
Fig. 6.46: CT skull showing secondaries from follicular
carcinoma thyroid.
Fig. 6.47: X-ray skull showing secondaries with lytic lesions from
follicular carcinoma of thyroid as primary.
Investigations
Most often FNAC is inconclusive, because capsular and
angioinvasion, which are the main features in follicular
carcinoma, cannot be detected by FNAC.
Frozen section biopsy was said to be useful earlier; but it is
questionable now. In 15% cases frozen section biopsy may
be inconclusive or facility for frozen section biopsy may not
be available in many places, then initial hemithyroidectomy
is done.
Ultrasound abdomen, chest X-ray, X-ray bones are the other
investigations required, CT head, body scan.
Trucut biopsy gives tissue diagnosis, but danger of haem-
orrhage and injury to vital structures like trachea, recur-
rent laryngeal nerve, vessels are likely. It may be useful in
lymphoma and anaplastic carcinoma; but it is not very well
accepted.
Treatment
Total thyroidectomy is done along with central node compart-
ment dissection (level VI).
Lateral cervical/neck node dissection (LCND) levels IIA, III, IV
and VB) or MRND (with preservation of sternocleidomastoid,
IJV, spinal accessory nerve) is done depending on involve-
ment of one side or both (if node positive on imaging or FNAC
only as therapeutic).
Postoperative radioactive iodine (I
of 100 mCi (3700 MBq). Patient should be kept in isolation;
excreta disposal and vomitus, blood, saliva should be in
separate leak proof thrash bags.
Maintenance dose of L-thyroxine 0.1 mg OD or T
day is given lifelong. Immediate thyroxin supplementation is
often not started following surgery to keep TSH level raised
131
) therapy with a dose
80 mg/
3
471
CHAPTER 6 Thyroid
Happiness is always an inside job.
472
https://t.me/medicina_free
so that all extrathyroidal tissues that take up iodine will also
take up radioiodine to achieve optimum radioablation. TSH
level should be more than 30 mIU/L for this.
On table frozen section biopsy is useful in negative FNAC
but doubtful cases. Definitive procedure is undertaken once
frozen section report comes on table. But in frozen section
biopsy itself, 15% of follicular carcinoma report may be
inconclusive or negative which causes difficulty in taking decision. In such occasion, hemithyroidectomy is done and once
histology report of follicular carcinoma is obtained completion
thyroidectomy is done usually immediately within a week. If
biopsy report is delayed, then completion thyroidectomy is
SRB's Manual of Surgery
done after 6–12 weeks.
¾
If iodine isotope scan detects remnant disease, then
30–100 mCi of radio-ablation dose of I
131
is given orally.
RT will destroy occult microscopic disease. Post-ablation
isotope scanning is done in 8 days. Later in intermediate
and high risk patients, follow up body scan is done once
in 6 months. Serum thyroglobulin estimation is done for
6–12 months, later once in 6 months; neck US at 6, 12
months and annually for 5 years. Raise in thyroglobulin
level indicates for further whole body isotope scan. To
detect metastases radioisotope I
131
100–200 mCi is given
and 250–300 mCi is given for bone.
¾
Prior to radioactive iodine therapy following precautions
should be taken—low iodine diet for 10 days; isolation
when dose is more than 30 mCi; increase intake of oral
fluid to maintain high urine output to avoid radioiodine
induced bladder injury; sucking of lemon to avoid sialadenitis; laxatives; reduced sperm count for 6–8 months;
pregnancy should be avoided for 6–12 months.
Secondaries in bone are treated by external radio therapy.
Internal fixation should be done whenever there is pathological fracture.
There is no role of chemotherapy for follicular carcinoma thyroid.
Fig. 6.48: Total thyroidectomy specimen—
done for carcinoma thyroid.
Follow-up
It is by radioisotope I
(6 months to one year) to look for secondaries.
Thyroglobulin estimation is a good follow-up method to
decide for radioisotope study. Normal value (3–40 ng/mL).
TG >50 ng/mL is abnormal. It should be done once in 3–6
months. Its raise signifies recurrent/metastatic disease.
Serum thyroglobulin level estimation is of no value in
preoperative assessment. After thyroidectomy thyroglobulin
secretion is stopped, hence its level should not be traceable
after total thyroidectomy.
Ultrasound neck or MRI neck to identify early relapse. MRI
neck is better.
Further Treatment
If secondaries are detected therapeutic dose Ra I
orally. L-thyroxine has to be stopped 6 weeks prior to RT, then
required dose of Ra I
Radio remnant ablation (RRA)
¾
Initially thyroid radioisotope scan is done. If patient is
on 300 µg suppressive dose of L-thyroxine, it should
be stopped for 3–6 weeks so as to achieve serum TSH
level above 30 M IU/l or two intramuscular injections of
0.9 mg of recombinant human TSH is given.
123
scan done at regular inter vals
131
is given (50–150 m curie).
131
is given
Hurthle Cell Carcinoma
Hurthle cell carcinoma is a variant of follicular carcinoma of
thyroid which contains abundant oxyphill cells. It spreads more
commonly to regional lymph nodes than follicular carcinoma
of thyroid.
Note:
• Hurthle cell carcinoma does not take up I
131
• It secretes thyroglobulin
• It has got poorer prognosis than follicular cell carcinoma
• 30% multicentric
99m
•
Tc sestamibi scan is very useful for Hurthle cell carcinoma
• Regional nodes are more commonly involved than follicular carcinoma
• 20% show distant spread
• Abundant oxyphill cells (Askanazy) are specific
• Total thyroidectomy, MRND and TSH suppression is the treatment
DIFFERENTIATED THYROID CARCINOMA (DTC)
DTC is a spectrum of disease derived from follicular cells.
Both papillary and follicular carcinomas are grouped under
this. 90% of thyroid malignancies are differentiated one.
Papillary (PTC), follicular (FTC) and Hurthle cell carcinomas
are DTCs. Insular variety is poorly DTC having intermediate
position between DTC and anaplastic; it can cause bone and
lung spread; it is common in younger age group; p53 and
p21 are negative; with 40% 10-year survival.
AGES (Mayo Clinic, Hay); AMES (Lahey clinic); MACIS; Sloan
Kettering scoring – are different scoring systems used for
DTCs. Sloan Kettering scoring includes low, intermediate and
high-risk groups. First three scoring systems have low- and
high-risk groups.
Papillary spreads through nodes; follicular through blood.
FCT causes pulsatile vascular secondaries in skull.
Incidence of thyrotoxicosis in DTCs is 2%.
Galectin – 3, RET/PTC rearrangements, CD44, leukocyte
https://t.me/medicina_free
common antigen (LCA), cytokeratin are the probable tumour
markers under evaluation. For indeterminate, FNAC molecular
markers are used to identify RAS and BRAF mutations.
TNM staging for DTCs (AJCC 2018) are:
¾
T - Tumour: Tx – Primary cannot be assessed; T0 – no
evidence of primary tumour; T1 - <2 cm – (T1a <1 cm;
T1b 1–2 cm); T2- 2–4 cm; T3a - >4 cm limited to thyroid;
T3b – Gross extrathyroidal extension invading strap
muscles only from a tumour of any sized; T4a – Gross
extrathyroidal extension invading into subcutaneous
tissue, larynx, trachea, oesophagus and recurrent
laryngeal nerve; T4b – Gross extrathyroidal invasion to
prevertebral fascia, carotid encasement or involvement of
mediastinal vessels. Suffix ‘s’ is added for solitary nodule;
‘m’ added to multiple nodules.
¾
N - Regional nodes (central/lateral neck compartment/
superior mediastinal) –
assessed.
N0 – no nodes; N0a – one or more cytologi-
cally or histologically confirmed benign nodes;
Nx – regional nodes cannot be
N0b – No
radiological or clinical evidence of locoregional nodes.
N1a – spread to level VI (pre/paratracheal, prelaryngeal)
and level VII (mediastinal) nodes, unilateral or bilateral.
N1b – Nodal spread unilateral or bilateral or contralateral
lateral lymph nodes of level I, II, III, IV, V or retropharyngeal nodes. Suffix ‘san’ is sentinel node; ‘f’ is FNAC or
Core biopsy.
¾
M - Metastases – c M0 – no distant spread. cM1 – distant
spread present. pM1 – distant spread microscopically
confirmed . Note: Age is included in staging which is an
important factor.
¾
Age at diagnosis: <55 years OR >55 years.
AJCC prognostic stage groups (2018) for DTCs:
¾
Age less than 55 years:
–
Stage I – Any T, Any N, M0;
–
Stage II—Any T, any N, M1.
¾
Age more than 55 years:
–
Stage I—T1/T2, N0/Nx, M0.
–
Stage II—T1/T2, N1, M0; T3a/T3b, Any N M0.
–
Stage III—T4a, Any N, M0.
–
Stage IVA—T4b, Any N, M0;
–
Stage IVB—Any T, Any N; M1.
EUROPEAN CONSENSUS REPORT DEFINED THREE RISK
B
CATEGORIES FOR DTC
Very low risk
Unifocal T1 (<1 cm)
and favorable histology (classical or follicular variant of papillary and
minimal invasive follicular carcinoma)
Low risk
T1 (>1 cm) or T2 N0 M0 or multifocal T1 N0 M0
High risk
Any T3 and T4 or any T, N1, or any M1
N0 M0, no extension beyond the thyroid capsule
AMERICAN THYROID ASSOCIATION FOR PREDICTING THE
B
RISK OF RECURRENCE
Low risk—90% of patients
x T1–2 N0 M0 and absence of aggressive histology or vascular
invasion
x Microscopic tumour clearance
x No spread to node/blood
x No capsular/vascular invasion
x Extrathyroid I
x 25-year mortality is 2%
Intermediate risk
x T3 or tumour with aggressive histology or vascular invasion
x Microscopic perithyroid invasion
x Vascular invasion
High-risk
x T4 or any T, N1 or M1
x Incomplete tumour removal
x Macroscopic invasion
x Distant spread
x Extrathyroid bed I
x 25 years mortality is 46%
131
uptake is not found
131
uptake present
Investigations
US neck is essential investigation. It shows the nature, size,
margin, echogenicity, vascularity, nodal status, invasion
through thyroid capsule. Lymph node may show loss of
hilus, round shape, hypoechogenicity, cystic changes and
calcification, with increased peripheral vascularity.
FNAC of the nodule (US-guided is ideal); it is very useful in
PTC; but not much useful in FCT. FNAC of the lymph node is
useful; thyroglobulin estimation of the lymph node aspirate
is very useful.
Functional status should be checked—T3, T4, TSH. TSH may
be raised in PTC.
MRI of neck if needed only; CT is not done as iodine contrast
is not used; if needed, should be done as non-contrast CT.
Treatment
Total thyroidectomy with either prophylactic (in T3 and T4 of T
staging) or therapeutic (when involved sonologically or FNAC
or frozen section [of node] wise) central cervical (compartment) node dissection (CCND). Prelaryngeal, pre and paratracheal, nodes above the level of innominate vein and up
to carotids and hyoid bone are removed often may be with
thymus (compartment). CC
treats micrometastases (90% in PTC in central nodes) which
may be often the cause for recurrence or persistence of
disease; central nodes being primary nodes are commonly
involved. It also provides accurate RAI dosing; lowers the
postoperative serum thyroglobulin level which facilitates the
accurate TG monitoring during follow up. Reoperation of
CCND is technically difficult after total thyroidectomy as a
separate sitting. But there is no oncological survival benefit
and increased chances of postoperative hypoparathyroidism
ND provides accurate staging;
473
CHAPTER 6 Thyroid
Take time to think—It is the source of power.
474
https://t.me/medicina_free
and recurrent laryngeal nerve injury. Lateral cervical node
dissection (LCND. Nodes -IIA, III, IV and VB) is done only
when it shows the evidence of involvement (by FNAC or US);
there is no role for prophylactic LCND.
Only hemithyroidectomy is done if tumour is <1 cm; node
negative; unifocal and intrathyroidal disease.
Radioactive iodine therapy (RAIT)—RAIT reduces the recur-
rence; ablates the possible small residual thyroid tissue in
thyroid bed; treats the potential possible micrometastases
sites in remnant thyroid or lymph nodes or at distant sites.
So it facilitates the proper thyroglobulin surveillance during
follow up. RAIT is indicated in tumor >1 cm, extracap-
SRB's Manual of Surgery
sular thyroid invasion or locoregional extension, high-risk
group, unfavorable histological subtype (follicular, diffuse
sclerosing, or tall cell-variant papillary cancer), multifocal
Follow-up
Proper clinical examination in the neck for residual/nodal
disease and for distant spread.
Serum thyroglobulin measurement — ≤0.2 ng/mL (IRMA
assay) after TSH suppression; Tg antibody level (TgAb)
estimation. Serum thyroglobulin estimation is done along
with TgAb.
RAI whole body scan (WBS). It is done 3 months after RAIT;
then once in 12 months.
TSH estimation is done once in 6 months.
USG neck/USG-guided FNAC/MRI neck.
USG-guided FNAC of lymph node and Tg measurement in
FNAC fluid washout (FNAC-Tg).
When there is negative I
follow up, PET scan is indicated.
131
scan with elevated TG during
disease; BRAF positive tumor in the specimen. Criteria for
RAI are—TSH should be >30 mU/ml. L-Thyroxine replace-
Central Node Compartment Neck Dissection
ment is stopped 3–4 weeks before radioiodine treatment;
OR - in time being switch over to T3 80 mg/day and RAI in
7 days; OR - When L-thyroxine withdrawal is not advisable,
TSH stimulation was achieved using Recombinant Human
Thyrotropin (rhTSH) (0.9 mg IM one dose—2 consecutive
131
days; after 24 hours RAI given). Dose of I
– usually—3700
MBq (100 mCi); for metastases, it is 200 mCi.
Suppression hormone therapy using high dose L thyroxine—
dose is to make TSH level <0.1 mu/L; orally—morning 30
minutes before food. Problems with TSH suppression are—
subclinical thyrotoxicosis; cardiac irregularities; osteoporosis. Suppression therapy is now recommended to high risk
group of DTC patients (200-300 mg/day); in low risk group,
maintenance dose of 100 mg once a day morning before food
is recommended.
Medical therapy: Mainly for advanced DTC; Targeted therapy
using—Sorafenib (
Nov, 2013 FDA approval); Vandetanib;
cabozatinib (FDA approved).
Metastatic disease: Total thyroidectomy; RAIT; external
RT for bone, brain and lung metastases; targeted medical
therapy; surgical excision of the isolated bone secondaries
like clavicle or sternum.
Prognosis
They usually carry good prognosis.
Tall/columnar cell, trabecular, scirrhous, solid types of papil-
lary carcinoma; oxyphilic, insular types of FCT carry poor
prognosis.
GAMES prognostic risk factors
T
Risk
type
Low Well
High Poorly
Grade
differentiation
differentiated
differentiated
Age Meta-
stases
<40
years
>40
years
None Intrath-
Nodes or
distant
Extent Sex
Female
yroidal
Extrathyroidal
Male
It is removal of paratracheal, tracheo-oesophageal, pretracheal
and prelaryngeal nodes along with thymus and thyroid enbloc
extending from hyoid bone above, brachiocephalic vein below,
carotids on both sides.
Completion Thyroidectomy
It is done after hemithyroidectomy if histology confirms as
differentiated thyroid cancer, either papillary or follicular.
It is indicated in—high-risk patients, age more than 45 years,
family history, size more than 1 cm, opposite side thyroid
nodule, nodal or distant spread, multifocal disease, extrathyroidal spread, capsular and vascular invasion.
Reasons for completion of total thyroidectomy are:
¾
In differentiated thyroid cancer (for follicular carcinoma of
thyroid) radioiodine I
131
is the treatment for blood spread
secondaries. It is only possible if entire thyroid gland is
removed to make radioiodine to concentrate on tumour
tissue to achieve the needed efficacy.
¾
In many indications papillary carcinoma of thyroid also
needs radioablation like extrathyroid spread, size more
than 4 cm, etc.
¾
During follow up, in DTCs/FCT thyroglobulin as a tumour
marker estimation at regular intervals (6 months; to
suspect tumour bed recurrence/metastases) can be done
if thyroid tissue is removed entirely.
¾
Papillary carcinoma of thyroid are multicentric with
intrathyroid spread and so completion thyroidectomy
is better.
Timing of completion thyroidectomy is within 7 days of first
surgery or after 6–12 weeks to allow the settling of inflammatory response (dissection and to get surgical planes is
difficult during this period).
ANAPLASTIC CARCINOMA OF THYROID
It is an undifferentiated very aggressive carcinoma (1%)
occurs commonly in elderly females.
It is a very aggressive tumour of short duration, presents
with a swelling in thyroid region which is rapidly progressive causing:
Fig. 6.49: Carcinoma of thyroid gland. It is anaplastic carcinoma. It
https://t.me/medicina_free
carries poor prognosis.
i. Stridor and hoarseness of voice due to tracheal obstruction.
ii. Dysphagia.
iii. Fixity to the skin.
iv. Positive Berry’s sign—involvement of carotid sheath leads
to absence of carotid pulsation.
Swelling is hard, with involvement of isthmus and lateral
lobes.
FNAC is diagnostic.
All anaplastic carcinomas are (Stage IV). T4a is intrathyroidal
anaplastic carcinoma—surgically resectable. T4b is extrathyroidal anaplastic carcinoma—surgically unresectable.
It shows p53 and p21 positive; causes multiorgan spread.
Tracheostomy and isthmectomy has got a role to relieve
respiratory obstruction temporarily.
Treatment is external radiotherapy, as usually thyroidec tomy
is not possible.
Adriamycin as chemotherapy.
However prognosis is poor. Lifespan is counted in few weeks
to months only. 5-year survival is less than 15%.
STAGE GROUPING FOR ANAPLASTIC/UNDIFFERENTIATED
B
THYROID CARCINOMA
All anaplastic thyroid cancers are considered stage IV
Stage IVA: Tumour is still within the thyroid and may be resectable
(removable by surgery).
Stage IVB: Tumour has grown outside of the thyroid and is not
resectable.
Stage IVC: The tumour is any size and may or may not have grown
outside of the thyroid.
always pre
Nearby lymph nodes ± but no distant spread.
sent.
Nearby lymph nodes ± but no distant spread.
Nearby lymph nodes ± but distant spread
475
CHAPTER 6 Thyroid
Fig. 6.50: Anaplastic carcinoma of thyroid with infiltration through
the capsule. It commonly encases the carotid artery causing Berry’s
sign positive.
Fig. 6.51: Anaplastic carcinoma of thyroid.
Voice can say both: What you have done and what you would not have done also !!
DE GROOT’S STAGING OF CARCINOMA THYROID
B
Stage 1: Limited to thyroid
Stage 2: Locoregional; nodal spread
Stage 3: Extrathyroidal invasion
Stage 4: Distant spread
Note: It is applicable to thyroid malignancies; but mainly used in
follicular carcinoma of thyroid.
FEATURES OF INFILTRATION
B
x Infiltration of strap muscles often with sternomastoid muscle
x Infiltration of laryngotracheal complex causing stridor and often
haemoptysis
x Infiltration of recurrent laryngeal nerve causes hoarseness of voice
x Infiltration of oesophagus causes dysphagia/odynophagia (painful
swallowing)
x Infiltration into carotid sheath causes absence of carotid pulsa-
tion—Berry’s sign
x Infiltration of cervical sympathetic chain causes Horner’s
syndrome
x Rarely infiltration into cranial nerves or brachial plexus can occur
Соседние файлы в папке Библиотека им академика М.И. Перельмана