The document provides an overview of the parathyroid glands' location, size, and role in hyperparathyroidism management through nuclear medicine. It outlines procedures for non-invasive identification of hyperfunctioning parathyroid tissues, including patient preparations and techniques for scintigraphy. Additionally, it emphasizes the importance of imaging protocols and includes precautions for pregnant and nursing patients.

1. TECHNOLOGIST
NUCLEAR MEDICINE DEPARTMENT
SABAH WOMEN AND CHILDREN HOSPITAL

2. Where Are The
Parathyroid Glands?

 Typically there are four
parathyroid glands located
alongside and sometimes within
the thyroid gland.
 There are usually two parathyroid
glands near the left lobe of the
thyroid and two near the right lobe.
 They are small, oval-shaped glands
each approximately 6 x 4 x 2 mm
and weighing approximately 30–50
mg., (about the size of a pea).

3. Parathyroid Study..

 Nuclear medicine has an active role in the management of
patients with hyperparathyroidism by identifying the sites of
excess parathyroid hormone production, that is, the localization
of a probable adenoma in a patient with hyperparathyroidism.
 Parathyroid adenomas are found in diverse localizations
alongside, behind, and within the thyroid as well as in areas
somewhat distant from the thyroid such as high or low in the
neck or mediastinum. For this reason, there is a significant need
for a method to accurately and non invasively identify the
location of excess parathyroid hormone production.
 It is important to include the entire chest in the imaging field in
all parathyroid imaging protocols for evaluation of potential
ectopic sites.

4. Indication

 Localization of hyperfunctioning parathyroid tissue (adenoma/
hyperplasia) in primary hyperparathyroidism is useful before
surgery to help the surgeon localize the lesion, thus shortening
the time of the procedure.
 Localization of hyperfunctioning parathyroid tissue in patients
with persistent or recurrent disease

5. Contraindication

 Pregnant women

6. Precaution

 Discontinuation of breast feeding for nursing mothers for 24
hours after imaging.

7. Patient Preparation

 Patient might be advised by Medical Officer to discontinue
usage of iodide-containing medications that can cause iodine
saturation.
 Radiological studies with iodine-containing contrast media
should be avoided 4 weeks prior to the parathyroid
scintigraphy.
 Treatment with Carbimazole or Propylthiouracil should be
with held 3 days prior to the scan.
 Thyroid replacement hormone should be discontinued for 2
weeks prior to scan.
 Whereas for secondary hyperthyroidism, active Vitamin D
should be withheld for at least 1 week, native Vitamin D for 4
weeks and calcimimetics for 2 weeks prior to the scan (need to
be discussed with Nuclear Medicine Specialist/Nephrologist)

8. Radiopharmaceutical

 99mTechnetium-sestamibi adult: 18-22 mCi
 99mTechnetium-tetrofosmin adult: 18-22 mCi
 99mTechnetium-pertechnetate adult: 2-10 mCi
 Child: As per body weight (Refer to Gilday’s Chart)
 Technique of administration: Intravenous Injection

9. Protocol

Washout
Dual phase parathyroid
scintigraphy exploits the
different washout timing that
some radiotracers show in
thyroid and parathyroid tissues:
to find parathyroid
hyperfunctioning tissue,
washout timing of radiotracer
from the parathyroid must be
slower than from thyroid tissue.
Subtraction
99mTc-sestamibi is myocardial perfusion
tracer and is taken up not only by the
hyperfunctioning parathyroid glands
but also by thyroid tissue. Hence, the
necessity of comparison with a second
tracer, which is taken up by the thyroid
gland only, such as 99mTechnetium-pertechnetate.
The distributions of the 2
tracers can be visually compared and,
afterwards, the thyroid scan can be
digitally subtracted from the
parathyroid scan to remove the thyroid
activity and enhance the visualization of
parathyroid tissue.

10. Instrument

 PHILIPS Dual-head Gamma Camera
 Low Energy High Resolution (LEHR) collimator
 High Energy Low Resolution (Pinhole) collimator

11. Procedure

 Make sure the Gamma Kamera room is ready.
 Call Patient in the post-injection room.
 Explain patient about the procedure.
 Position the patient on the table in the supine position with a
pillow positioned under the shoulders which allow the head to
drop back and extends the neck. Secure the head so that it does
not move from side to side.
 Make sure the patient is comfortable and cover the patient with
blanket before starting the procedure to ensure patient is warm.
 Tell the patient not to move while performing the scan.

12. Washout Procedure

 Static ANT/POST 20 mins after injection of Tetrofosmin
 SPECT
If needed
 Pinhole
 Static Tetrofosmin 60 mins after inject
 Pinhole
 If needed
SPECT
 Static Tetrofosmin delayed 2 hours after inject
 SPECT
If needed
 Pinhole
[Delayed 3 hours after inject if necessary]
 Static
 Pinhole
If needed
 SPECT

13. Subtraction Procedure

 Static ANT/POST 20 mins after injection of Tc99m
 SPECT
If needed
 Pinhole
 Pinhole Tetrofosmin 60 mins after inject
 Static
 If needed
SPECT
 Static Tetrofosmin delayed 2 hours after inject
 SPECT
If needed
 Pinhole
[Delayed 3 hours after inject if necessary]
 Pinhole
 Static
 SPECT
If needed

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17. 
Cont..
 After the completion of the scan, inform the Medical Officer in charge to
review the scan images.
 Be ready to repeat scan or perform additional scan if ordered by the
Medical Officer in charge.
 Assist the patient to get up and ask the patient to have rest while
waiting in the post-injection room.
 Remind patient to take plenty of water and to keep at least 1-2 meter
away from children and pregnant ladies for at least 6 hours from the
time of the radiopharmaceutical injection.
 Inform and pass the “Penilaian Selepas Skan Radionuklid” form to the
Nurse in charge at the counter or injection room regarding the patient
release.
 Proceed to image processing by referring to the Standard Operating
Procedure of Parathyroid Scan Processing.

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21. Preferences

 International Atomic Energy Agency: Nuclear Medicine Resources
Manual, 2006
 SNM Practice Guideline for Parathyroid Scintigraphy 4.0
 2009 EANM Parathyroid Guidelines
 Distance Assisted Training Programme for Nuclear Medicine
Technologists: Parathyroid Imaging, Version 3.1
 Nuclear Medicine Technology and Techniques by Donald R. Bernier,
Paul E. Chstistian, James K. Langan

22. Thank You
