Dr Jenny WorrallIS RADIOIODINE SAFE

IN CHILDREN?

Delivered as oral capsule or solution

Active isotope I131

Uptake by thyroid glandβ particle releaseDestruction of follicular

cells

WHAT IS RADIOIODINE?

Used to treat disorders of the thyroid gland Hyperthyroidism Thyroid cancer

Concerns about radiation exposure

Caution in adopting radioiodine therapy

Divided approaches to treatment of

hyperthyroidism

Enabling clinicians, patients and families to

make informed choices

WHY IS IT IMPORTANT?

Overactive thyroid gland

Graves’ disease: 95% of cases

Common features:

Palpitations Tremor Restlessness/Poor concentration Fatigue Insomnia GI Upset Eye problems Goitre

HYPERTHYROIDISM

MANAGEMENT OPTIONS

β Blocker

Antithyroid medications (eg carbimazole)

Surgical resection

Radioiodine

14 year old femaleDiagnosed with Graves’ age 8Shaky, nervous, anxious, thirsty and hungryMild goitre & eye signsTreated with Carbimazole 30mg/dayTrial without aged 11 – returnedConcern about side effects of antithyroid medication –

opted for radioiodine treatment

CASE STUDY

Radiation: I131

Increased risk thyroid cancer:

Highest amongst youngestRisk 3x greater in iodine

deficient areas Increased risk up to dose

of 2Gy

CHERNOBYLA LESSON FROM HISTORY: EFFECTS OF

EXTERNAL EXPOSURE TO RADIATION

CHERNOBYL

Immediate effects:

Vomiting, thyroiditis, thyroid nodulesHypothyroidism (90%)Thyroid storm: tachycardia, jaundice,

dehydration, agitation, confusion

SAFETY OF THERAPEUTIC RADIOIODINE

LONG TERM EFFECTS OF RADIOIODINE

• No increased risk• Deficiency, dose, lethality

Thyroid malignancy

• e.g. leukaemia• Risk matched that for surgical approach

Other malignancies

• No increased risk to offspring • Developing foetus – hypothyroidismRisk to

offspring

• Worsened in up to 15% of adults• No evidence that this is true for children

Ophthalmology

Little evidence that therapeutic radioiodine is associated with increased long-term risk

Definitive treatment – rapid resolution of symptoms

Should be one of a range of options offered to patients and their families as first line treatment

CONCLUSION

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Fre i tas JE , Swanson DP , Gross MD, S i s son JC . I od ine -131 : Op t ima l Therapy fo r Hyper thy ro id i sm in Ch i ld ren and Ado lesc en ts? Jou rna l o f Nuc lea r Med ic ine . 1979 ;20 :847-50 .

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Cur ren t Paed ia t r i c s . 2004 ;14 (6 ) :430 -7 . Kazakov VS , Demidch ik EP , As takhova LN. Thyro id Cance r Af t e r Chernoby l . Na tu re . 1992;359 :21 . Mc Cormac k S , D .M . M , Woo M , Lev i t sky LL , Ross DS , M i s ra M . Rad ioac t i ve Iod ine fo r

Hyper thy ro id i sm in Ch i ld ren and Ado lescen ts : Re fe rra l Ra te and Response to Trea tment . C l i n i c a l Endoc r ino logy. 2009;71 :884-91 .

NHS Cho i ces . Thyro id , ove rac t i ve - Compl i c a t i ons . 2010 . [Ac cessed : 15 /03 /11 ] Ava i lab le f rom: h t tp : / /www.nhs .uk /Cond i t ions /Thyro id - over-ac t i ve /Pages /Comp l i ca t i ons .a spx

Read CH , Tansey M J , Menda Y. A 36 year Ret ro spec t ive Ana lys i s o f t he Efficacy and Sa fe ty o f Rad ioac t ive Iod ine i n Trea t i ng Young Grave ' s Pa t ien t s . J ou rna l o f C l i n i c a l Endoc r ino logy & Metabo l i sm. 2004 ;89 :4229-33 .

Ross DS . Rad io i od ine T herapy fo r Hyper thy ro id i sm. New Eng land Jou rna l o f Med i c ine . 2011;364 :542-50 .

Seanger EL , Thoma GE , Tompk ins EA. In c idence o f Leukemia Fo l l ow ing Trea tment o f Hyper thy ro id i sm. J ou rna l o f t he Amer i can Med ica l Assoc ia t ion . 1968;205 (12) :855-62 .

REFERENCES