col. trirat boonya-ussadorn

Col. Trirat Boonya-ussadorn

1. Thyroid study in Nuclear Medicine

(cont.)

Thyroid uptake

Thyroid scan: for thyroid nodule (99mTc-

pertechnetate), CA thyroid (I-131)

2. NM radionuclide therapy

I-131 in Hyperthyroidism

I-131 in thyroid cancer

Treatment of bone pain in bony metastasis

I-131 uptake : 2 hrs and 24 hrs.

Normal at 24 hrs = 15-30% (variable)

Grave’s disease 60-80%

Toxic multinodular 50-60%

Drug effect on thyroid uptake

Thyroid hormone

Antithyroid drug: PTU, MMI

Vitamin

Cordarone

Contrast media

Food effect on thyroid uptake

Sea food

Iodinated salt

Discontinue ATD and foods effect on thyroid uptake 1 wk.

NPO

Oral administration of tracer dose of I-131 10 uCi

I-131 uptake 2 hrs and 24 hrs.

Differentiated low and high uptake of

thyrotoxicosis

Using for calculation of administrated

dose of RAI for treating hyperthyroidism

Confirmation of hyperthyroidism: DDx

hyperthyrodism vs thyroiditis


(cont.)

Thyroid uptake







Radiopharmaceuticals 99mTc-pertechnetate

I-131

I-123

Indications Thyroid nodules

Ectopic thyroid

Thyroiditis

Graves’ disease

Multinodular toxic goiter (Plummer’s disease)

Solitary hyperfunctioning adenoma (toxic adenoma)

Thyroid cancer

2 ways for performing thyroid scan

Tc-99m Pertechnetate ( IV injection )

dose 3-5 mCi: 140 keV, half life 6 hrs

I-131 (oral): 364 keV, half life 8 days

Tc-99m pertechnetate

Total body scan (TBS) or Whole body scan (WBS) with I-131

ใชใ้นการตรวจและติดตามผลการรกัษาผูป่้วยที่รกัษาดว้ยไอโอดนีรงัส ี(I-131)

ซ่ึงอาศยัรงัสเีบตามา Irradiate เซลลข์องตอ่มไทรอยดท์ี่ เป็นมะเร็งใหห้มดไป การท าสแกนแบบน้ีจะสามารถบอกไดว้า่ยงัมเีซลลม์ะเร็งของตอ่มไทรอยด์

หลงเหลืออยูห่รือไม ่ถา้มกีารแพร่กระจายไปที่ อ่ืนจะเหน็ไดจ้ากภาพสแกนจะไดท้ า

การรกัษาซ า้จนไมม่เีซลลข์องตอ่มไทรอยดเ์หลืออยู ่

off Levothyroxine (Eltroxin, Euthyrox) 1 mo

low iodine diet 1 wk

NPO

Administration of tracer dose

1-5 mCi

Waiting for 48 – 72 hrs

Scan the whole body


(cont.)

Thyroid uptake







Hyperthyroidism

Well-diff CA thyroid

Radiopharmaceutical

for specific tumor

Treating bone pain of

metastatic disease

I-131

I-131

I-131 MIBG

Sr-89

Sm-153 EDTMP

Oral form : solution, capsule

I-131---- Xe-131+ gamma ray (γ) 364 keV +

beta ray (β) 192 keV

Half life = 8.06 days

Rx:

1. Hyperthyroidism : Graves’ disease, Toxic

multinodular goiter, Toxic adenoma

2. Well-differentiated thyroid CA: Papillary,

Follicular

Physiologic I-131 uptake :

1. Thyroid gland

2. Salivary glands

3. Gastric mucosa

Excreted via urine and can cross placenta


(cont.)

Thyroid uptake







Thyrotoxicosis = increased TFT

Hyperthyroidism = Thyrotoxicosis from

hyperfunctioning thyroid

Diffuse toxic goiter (Graves’ disease)

Toxic multinodular goiter (Plummer disease)

Toxic adenoma

Diffuse enlargement of thyroid gland

Exophthalmos

Pretibial myxedema

เหน่ือยงา่ย ใจสั่น มือสั่น

กนิจุ หิวบอ่ย

น ้าหนักลด

ขี้รอ้น เหง่ือออกมาก

ทอ้งเสยี

ประจ าเดือนนอ้ย

infertility

AF

CHF

Periodic paralysis

( hypoK+ )

Exophthalmos

Eyelid retraction

Osteoporosis

Indication of I-131***

1. Medication failure

> 2 yrs

High dose of ATD

Recurrence

Poor compliance

Drug allergy: agranulocytosis

2. Surgical failure

Withdraw drug and food effected 1 wk.

NPO

Thyroid uptake 2 and 24 hours

Oral administration of I-131

F/U in the next 3 months

Admit in hospital is not necessary.

FT3 or T3 : Hyperthyroid

FT4 : Hypothyroid, Eltroxin/ Euthyrox

(Levothyroxine, LT4)

TSH

Full effect of RAI will occur within 3

months

Euthyroid

No remission

Hypothyroidism

Nausea and vomiting (radiation sickness)

Transient hyperthyroidism or thyroid storm

Thyroiditis (neck swelling)

Induce malignancy ?

Induce teratogenic effect ?

Induce infertility ?

***PREGNANCY*** LACTATION


(cont.)

Thyroid uptake





I-131 in thyroid cancer Treatment of bone pain in bony metastasis

Well differentiated CA thyroid***

Poorly differentiated CA thyroid

Anaplastic CA

Medullary CA

Papillary CA

Follicular CA

Metastatic disease from well diff CA

Post–Op for 4-6 wks

+/- Dx Total body scan

(DxTBS with I-131)

Calculated dose of RAI

Oral administration of RAI

Admit until radiation dose is decreased to

accepted level.

Post I-131 TBS before discharged

Home med : Thyroid hormone (Eltroxin, Euthyrox,

Levothyroxine/LT4)

F/U: stimulated Tg +/- TBS with I-131 in 6 months

Preparation for TBS

Induce hypothyroidism

***TSH stimulation***

by discontinuing thyroid hormone 4-6 weeks.

Avoid high iodine diet and drug 1 wk.

Serum thyroid hormone (FT4)

TSH

Thyroglobulin (Tg)

Antithyroglobulin (TgAb)

TBS shows negative result

Continue thyroid hormone

TBS shows residual tumor or thyroid tissue

Repeat dose of RAI treatment

TBS post I-131 treatment 100-200 mCi

Diagnosis TBS with I-131 1-3 mCi

RAI for treatment of CA thyroid usually is high dose ,100 – 200 mCi

Neck swelling

Sialadinitis

Nausea, vomiting, radiation sickness

Hemorrhage (CNS, spinal)

LATE EFFECT

Hypothyroidism

Lung fibrosis

Induce malignancy ?

Induce teratogenic effect ?

Induce infertility ?


(cont.)

Thyroid uptake







Sr-89

Pure beta ray

Can be used as OPD case

Effective treatment in bone pain due to

bone metastasis from CA prostate, breast

cancer

No serious side effect

Sm-153 EDTMP

Emit both gamma and beta ray

Preparation : Bone scan, blood chemistry

especially CBC .

Patient should be admitted at lease 4 hrs

After treatment for 24-72 hrs, the patient

should be performed scan

col. trirat boonya-ussadorn

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