The endocrine System - thyroid Flashcards
name the tissue layers of the kneck?
endocrine, respiratory & alimentary layer
where does the throid gland sit?
On the surface of the trachea, anterior to neck and inferior to the larynx
name the arterial and venous involved in the thyroid?
arterial - sup & inf thyroid artery, venous- thyroid veins, internal jugular vein & brachiocephalic vein.
Name the nodes involved in the drainage of the thyroid gland?
upper & lower cervical nodes, pre-tracheal nodes & paratracheal nodes
Where do nerves of the thyroid gland devrive from?
cervical sympathetic ganglia
what is the thyroids function?
secretes hormone; thyroxine & triiodothyronine & calcitonin (regulates calcium levels
what do the thyroid hormones do?
regulate metabolic rate, maintain blood pressure, growth & development
name 3 epidemiology and 3 aetiology factors of thyroid cancer?
rare 0.4 of all cancers, UK incidence is 1/100,000, more common in >30
genetic condition, hereditary, radiation induced
thyroid cancer presenting signs symptoms?
neck nodules, enlarged nodes, hoarseness, neck pain, pressure symptoms
what are thyroid diagnostic investigations?
FMH, examination, ultrasound & fine needle aspiration cytology, RADIOACTIVE IODINE 131 scan, CT & MRI
what staging system is used?
TNM: t1, t1a, t1b, t2 - all limited to the thyroid, t3+ advanced disease
name thyroid histological types of cancer?
papillary, follicular, medullary, anaplastic, mixed
what is the management of each histology type?
papillary & follicular - surgery & post op radioactice ioine 131
medullary - Radical surgery
Anaplastic - Radical surgery & radiotherapy
name the types of surgery used
total lobectomy, total thyroidectomy, & central compartment node dissection
typical dose & fractionation of thyroid cancer?
60Gy 30# relatively radioresistant - spinal cord shielding after 35gy - 40Gy, palliative 30Gy 10#
name some facts about iondine 131 for thyroid treatment?
low iodine diet needed (dont eat; fish & seafood, sweets), 3GBq, used for papillary & follicular cancer, no sex, radioactive
what is the patient positioning and techniques used for thyroid cancer?
supine, beam directional shell, chin raised
radical - 3D conformal Rt using ant & post obligue fields, phased, wedges used
palliative - ant & post parallel opposed
highlight the palliative & radical fields
dependent on extent of tumour & nodes involved
palliative - sup = mastoid process. inf = carina of trachea, lat = cover clavicular nodes
Radical - sup = hyoid bone, inf= sternal notch, ant = include skin, post = parallel to cord, includes anterior margin of vertebrae
name early & late side effects of radiotherapy for thyroid cancer?
laryngitis, oesophagitis, hairloss, weightloss, lymphoedema, dental problems, secondary malignancy
