**Northern Lincolnshire and Goole NHS Foundation Trust - Nuclear Medicine** 

<WRAP onlyprint>
When this document is not viewed in the Nuclear Medicine Wiki, the reader is responsible for checking that it is the most current version. 
This can be checked at nlag.heynm.org.uk
</WRAP>
[[sqlite:unused:unused:unused:/home/heynmorg/public_html/wikifarm/nlag/data/meta/sops/database.db|
SELECT sop AS "SOP Code",title AS "Title",reviewdate AS "Review Date" FROM sops WHERE sop='REF022'|0]] 
<WRAP onlyprint>
\\  
</WRAP>
^  Authorised By  ^  Authorising Role  ^  Authorisation Signature \\  (only on master paper copy)  ^  Date Authorised  |
|  Prof G Avery  |  ARSAC Licence Holder  |    |  2025-01-16  |

====== REF022 - Thyroid Metastases Imaging (I123 Whole Body Scan) ======
See [[referral_criteria:ref000-how_to_refer_to_nlagnm|REF000 - Referring to Nuclear Medicine (NLAG)]] for details on how to refer. 

=====  Description =====
The main function of the thyroid gland is to concentrate and organify inorganic iodine, to store the iodinated compounds and then release them as active hormones into the circulation. Iodine-123 is an iodine radiopharmaceutical appropriate for thyroid imaging. Iodine-123 is therefore also able to determine the presence and extent of residual functioning thyroid tissue shortly post-thyroidectomy and, after I-131 ablation, to detect the presence and location of functioning thyroid cancer, recurrences and/or metastases. 


[[sqlite:unused:unused:unused:/home/heynmorg/public_html/wikifarm/nlag/data/meta/arsac/database2019.db|SELECT fullname AS "ARSAC Licence Holders" FROM practitionerlicences INNER JOIN practitioners,procedurecodes,praclicproc,nuclides,chemicalforms ON practitionerlicences.practitioner=practitioners.id AND praclicproc.plicid=practitionerlicences.id AND praclicproc.procid=procedurecodes.id AND procedurecodes.nuclide_id=nuclides.id AND procedurecodes.chemicalform_id=chemicalforms.id AND practitionerlicences.certificateactive='Y' WHERE procedure_code='123I-93-143'  AND date('now')<=expirydate  ORDER BY expirydate|0]]


[[sqlite:unused:unused:unused:/home/heynmorg/public_html/wikifarm/nlag/data/meta/employers_procedures/drl_database.db|
SELECT nuclide AS Nuclide, pharmaceutical_form AS "Pharmaceutical Form",  
local_drl AS "Local DRL (MBq)" FROM drls INNER JOIN nuclides ON drls.nuclide_id=nuclides.id 
WHERE drls.id=10|0]]

^Typical Radiation Dose (mSv)  | 7.8  | 

===== Staff Entitled to Refer =====
  * The referrer may be any UK registered medical practitioner currently employed in Secondary Care.
  * Referrals from Primary Care will be accepted if the investigation has been suggested by a a Secondary Care Specialist or a Consultant Radiologist in a report from a previous investigation; or following discussion with a Consultant Radiologist.  Details of such suggestions or discussions should be included on the request form.

===== Supplementary Drugs =====
  * Sodium chloride for parenteral use (0.9% w/v).

===== Contraindications =====
^Patient Demographics  | Pregnancy [([[http://s3.amazonaws.com/rdcms-snmmi/files/production/public/docs/Scintigraphy%20for%20Differentiated%20Thyroid%20Cancer%20V3%200%20(9-25-06).pdf|Society of Nuclear Medicine Procedure Guideline for Scintigraphy for Differentiated Papillary and Follicular Thyroid Cancer. Journal of Nuclear Medicine 2006)]])][([[http://onlinelibrary.wiley.com/doi/10.1111/cen.12515/pdf|British Thyroid Association Guidelines for the Management of Thyroid Cancer; third edition.  British Thyroid Association 2014)]])]  \\  Breast Feeding  |
^Allergies  | NB: Suspected "iodine allergy" is **NOT** a contraindication[([[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3965283/|Puchalski AR & Chopra IJ. Radioiodine treatment of differentiated thyroid cancer despite history of ‘iodine allergy’. Endocrinol Diabetes Metab Case Rep. 2014; 2014: 130084]])] |

===== Patient Preparation =====
  * Patients should be asked to follow a low iodine diet for 2 weeks prior to imaging, ideally to achieve a 24 hour urine output of less than 50mcg of iodine, although this need not be measured on a routine basis.   [(#1)][(#2)]
  * Leave at least 8 weeks between administration of iodinated contrast media (as used in CT and X-ray procedures) and administration of the I-123[(#2)]
  * Avoid iodine medications containing iodine (e.g. antiseptics, eye drops, iodinated multivitamins or mineral supplements) for a minimum of 4 weeks[(Guidelines for radioiodine therapy of differentiated thyroid cancer, Luster, M et al. Eur J Nucl Med Mol Imaging 2008 Oct;35(10):1941-59)],
  * TSH should be elevated to greater than 30mIU/l.  This can be achieved by withdrawing T4 for four weeks prior to imaging, with T3 replacement for two weeks and no hormone replacement for a further two weeks; **or**   by administration of thyrogen on the two days before the administration of the I-123. [(#1)] [(#2)].
    * The referrer must advise whether to use hormone withdrawal or thyrogen stimulation.  
  * Amiodarone can affect the uptake of radioiodines. If the patient is taking Amiodarone, this must be discussed with the ARSAC licence holder prior to administration. Note that amiodarone may have to be withdrawn for 12 months to ensure optimal conditions for I-131 ablation therapy.
 

===== Clinical Indication(s) =====

|To determine the presence and extent of residual functioning thyroid tissue and the presence and location of functioning thyroid cancer (post radioiodine ablation therapy)  |


\\
~~DISCUSSION~~