Parathyroid imaging
A report skeleton for preoperative localisation of hyperfunctioning parathyroid tissue. It covers 99mTc-sestamibi dual-phase or dual-tracer scintigraphy, SPECT/CT and ¹⁸F-fluorocholine PET/CT, and follows the reporting section of the EANM 2021 parathyroid guideline. Location is described in the four thyroid quadrants for the surgeon.
Based on: EANM practice guidelines for parathyroid imaging (Petranović Ovčariček 2021)
PARATHYROID IMAGING
CLINICAL INDICATION:
[Primary hyperparathyroidism, preoperative localisation / persistent or recurrent disease after surgery / secondary (renal) hyperparathyroidism / MEN]
PTH [ ] pmol/L; calcium [ ] mmol/L; vitamin D [ ]; eGFR [ ]
Prior neck surgery: [none / parathyroidectomy / thyroidectomy, date]
Neck ultrasound: [result / not performed]; thyroid disease: [nodules / thyroiditis / none]
TECHNIQUE:
[Dual-phase 99mTc-sestamibi: [ ] MBq IV; planar at [10–15] min and [90–150] min]
[Dual-tracer subtraction: 99mTc-pertechnetate [ ] MBq / 123I [ ] MBq with 99mTc-sestamibi [ ] MBq; subtraction performed]
[SPECT/CT: skull base to heart base at [ ] min; CT DLP [ ] mGy·cm]
[18F-fluorocholine PET/CT: [ ] MBq; early [5] min acquisition and [60] min acquisition / single acquisition]
COMPARISON:
[Prior sestamibi / PET / ultrasound / 4D-CT / none]
FINDINGS:
Thyroid: [normal / nodules at [ ] / diffuse uptake]
Lesion [1]:
Site: [right / left] [upper / lower] thyroid quadrant, [posterior to / inferior to] the lobe, depth [ ]
or ectopic site: [retro-oesophageal / retrotracheal / tracheo-oesophageal groove / intrathymic / mediastinal / carotid sheath / undescended, submandibular / intrathyroidal]
Tracer behaviour: [focal uptake increasing or retained on delayed images / washout on delayed images / residual focus after subtraction / focal choline uptake above background]
CT correlate: [soft-tissue nodule [ ] mm, hypodense to thyroid / none]
Seen on: [early planar / delayed planar / subtraction / SPECT/CT / PET/CT]
Additional lesions: [none / lesion 2: [ ]]
Concordance with ultrasound: [concordant / discordant / not available]
Incidental findings: [ ]
IMPRESSION:
1. [Single / multiple] focus of hyperfunctioning parathyroid tissue: [site in quadrant terms, or ectopic site]
2. [No scintigraphic evidence of hyperfunctioning parathyroid tissue; small, hyperplastic or multiglandular disease is not excluded]
3. [Recommendation, e.g. 18F-fluorocholine PET/CT after negative or inconclusive conventional imaging]Before you sign
- Locate each lesion for the surgeon in one of the four thyroid quadrants, give its depth or ectopic site, and name the images that show it. Ectopic glands and undetected multiglandular disease are the two main reasons surgery fails.
- Report thyroid nodules too. They can be mistaken for an adenoma, or they may need resection at the same operation.
- On dual-phase imaging, increasing or sustained uptake on the delayed image compared with the early image is positive. Rapid washout is more common in hyperplastic glands and does not exclude them.
- Thyroid nodules, thyroiditis and cervical lymph nodes cause most false positives on sestamibi. On choline PET, the usual culprits are reactive nodes, oxyphil thyroid adenomas and thyroid remnants.
- Sensitivity falls sharply in multiglandular disease. A single focus does not exclude further hyperfunctioning glands, especially in secondary hyperparathyroidism or MEN.
- Standard first-line imaging is sestamibi with SPECT/CT plus neck ultrasound. ¹⁸F-fluorocholine PET/CT is the second-line test after negative or inconclusive imaging and may also be used as an alternative first-line method.
- Record PTH, calcium, prior neck surgery and the ultrasound result. The guideline advises concordant localisation by two techniques whenever possible.
Sources
- Petranović Ovčariček P, Giovanella L, Carrió Gasset I, et al. The EANM practice guidelines for parathyroid imaging. Eur J Nucl Med Mol Imaging. 2021;48:2801–22.
- Hindié E, Ugur O, Fuster D, et al. 2009 EANM parathyroid guidelines. Eur J Nucl Med Mol Imaging. 2009;36:1201–16.