Transcript Cancer Screening in Acromegaly

Thyroid Diseases
Steve Orme
Leeds
Introduction
Background
Basic Principles
Clinical Syndromes
Summary
Hypothesis Testing?
Appreciate Limitation of Laboratory
Investigations
Treat ‘Normal Ranges’ with the Disdain
they Deserve
Avoid Medicine by Proxy
Do not Over Investigate
Basic Principles
Too Much Hormone
Measure at Nadir
Try to Suppress
Evaluate Their 24 Hour Secretion
Measure the preceding Hormone
(Elevated Free T4, Measure TSH)
Basic Principles
Too Little Hormone
Measure at Peak
Try to Stimulate
Measure the preceding Hormone
(Low Free T4, Measure TSH)
Basic Principles
Try to Determine Aetiology
Supplementary Hormone Tests
Immunology
*Radiology/ Nuclear Medicine
(* Use Sparingly)
Basic Principles
Remember 1 in 20 Blood Investigations
Will be ‘Abnormal’ In An Average
‘Normal’ Patient
Reference Range :- Mean (95 % Confidence
Interval) Small Sample Size
Thyroid Disease
Hypothyroidism
Thyrotoxicosis
Thyroid Nodules/ Cancer
Amiodarone Induced Thyroid Disease
Hypothyroidism
Myxoedema
Hashimoto’s Thyroiditis
Post Surgery/Radioactive Iodine
Therapy
Secondary/Tertiary
Hypothyroidism
Free T4 & TSH
TPO Antibodies
Investigate possible co-existing Autoimmune Diseases
Thyroid Imaging Not Indicated
Treatment Strategies
Dictated by Diagnosis
Graves Disease
Trial of Drugs
Toxic Nodule
Multinodular Goitre
I
131
131
I /Surgery
Graves Disease
Pharmacology of CBZ/PTU
CBZ
Plasma T 1/2 6-8 Hrs
Crosses Placenta &
Breast Epithelium
>10 more Potent than
PTU
Duration of Action
>24 Hrs
PTU
Plasma T 1/2 1-2 Hrs
Minimal Placental &
Breast Transfer
Duration of Action 1224 Hrs
Graves Disease
Drug Therapy (Adverse Effects)
Minor/Common (5-10%)
Pruritis
Urticarial Rash
Arthralgia
Fever
Graves Disease
Drug Therapy (Adverse Effects)
Uncommon
Abnormal Taste (CBZ)
GI Upset
Hypoglycaemia (Anti-Insulin Antibodies)
Graves Disease
Drug Therapy (Adverse Effects)
Major (Rare or *Very Rare)
Agranulocytosis
Aplastic Anaemia*
Thrombocytopenia*
Hepatitis (PTU)*
Cholestatic Jaundice (CBZ)*
Lupus-like Syndrome*
Graves Disease
Drug Therapy (Adverse Effects)
Minor Usually Transient
Major (Agranulocytosis) Idiosyncratic.
Onset more Likely in the First 3 Months,
High-Dose Therapy and the Elderly.
Graves Disease
Drug Therapy
(Dose, Frequency and Duration)
Titration
Block and Replacement Regimen
Graves Disease
Managing Relapse
Relapse Rate 60% (10 Years Off Rx)
No difference between 6 Months of Block
and Replacement Regimen and 18
Months of Titration
Further Relapses Inevitable After First
Failed Trial Of Medication.
Graves Disease
Predicting Relapse
Young Patients
Large Goitre
Presence of TAO
High Levels of TSH-receptor Antibody at
Diagnosis.
Graves Disease
Managing Relapses
I131
Thyroid Surgery
Long-term Low-dose Thionamide Therapy
Radioactive Iodine Therapy
Counsel Patients
Avoid Pre-Treatment with PTU
Special Measures
Carefully Monitor Thyroid Status for at
Least 6 Months
Thyroid Surgery
Choose Your Surgeon Carefully
Counsel Patients
Pre-Treatment Mandatory
Special Measures
Carefully Monitor Thyroid and Calcium
Status for at Least 6 Months Post OP
Long-term Data Base Follow UP
Thyroid Nodules & Cancer
Nodules are Common Thyroid Cancer is
not (80 Cases per year in West Yorkshire)
Refer Palpable nodules
Early Diagnosis Improves Prognosis
Management Should be through an
Endocrine Cancer MDT
Thyroid Nodules & Cancer
Prognosis for Most Cases of Well
Differentiated Thyroid Carcinoma is Good
Most Patients Require TotalThyroidectomy , I131 Radio-ablation and
TSH Suppressive Doses of T4
Life Long Specialist Monitoring is
Mandatory
Amiodarone
Benzofuranic Derivative
Contains 37% Iodine
50-100 times RDI
Amiodarone
Inhibits Type I & II 5’- deiodinase
Cytotoxic to Thyroid Cells
Affects Thyroid Autoimmunity
Acts on Thyroid Hormone Receptors
Euthyroid Patients on
Amiodarone
Have Elevated Free T4
Low Normal Total T3
High Normal or Transiently Elevated TSH
Amiodarone
Pattern of Thyroid Disease is related to
Population Iodine Intake
In the UK 2 % AIT 15% AIH
Amiodarone Induced
Thyrotoxicosis
Onset Explosive
Median Duration of Therapy 3Yrs
Unexplained Deterioration
Weight Loss
Overt Signs of Thyrotoxicosis Absent
Amiodarone Induced
Thyrotoxicosis
Type I
Goitre Present
Iodine Uptake &
Colour Flow Doppler
Increased
Type II
No Small/Goitre
Inflammatory Markers
Increased
Low Iodine uptake
and Colour Flow
Doppler
Subsequent
Hypothyroidism
Amiodarone Induced
Thyrotoxicosis
Type I
Carbimazole
Potassium
Perchlorate
Radioactive Iodine
Surgery
Type II
Prednisolone
Surgery
Amiodarone Induced
Hypothyroidism
Females
Pre-existing Autoimmune Thyroid Disease
Positive TPO Antibodies
Treat as Primary Hypothyroidism
Summary
‘Where Observation is Concerned,
Chance Favours Only The Prepared
Mind’
(Lois Pasteur 1822-95AD)