Nuclear Medicine Head and Neck Region. Bán Zsuzsanna, MD University of Pécs, Department of Nuclear Medicine

Transcription

1 Nuclear Medicine Head and Neck Region Bán Zsuzsanna, MD University of Pécs, Department of Nuclear Medicine

2 Thyroid scintigraphy Parathyroid scintigraphy F18-FDG PET examinations in head and neck cancer

3 Thyroid scintigraphy With the help of NIS (Na + /I Symporter), radiotracer is taken up into the thyroid gland, similarly to not radioactive iodine

4 Thyroid scintigraphy In most of the examinations, radiotracer is: 99mTc-Pertechnetate (iv.) Trapped but not organified Imaging: minutes after injection (I-123, I-131: in special cases)

5 Image Acquisition: Making planar image from anterior view Instrumentation: Gamma camera Supine position of the patient, with the neck extended by a pillow placed under the shoulders After palpating the thyroid Using markers to identify anatomical landmarks and the location of palpable nodules

6 Normal thyroid scintigram

7 Thyroid scintigraphy Evaluation of the scintigram: shape, size, location of the thyroid gland uniformity and intensity of uptake size and location of any areas of increased or decreased uptake function of palpable nodules Taking notice of US finding and anamnestic data

8 Enlargement of the thyroid gland (diffuse goitre) A patient with Graves-Basedow disease Marker on sternal notchsubsternal goitre

9 Hot (hyperfunctioning) nodule 1. Increased uptake compared to the rest of the thyroid (In case of toxic multinodular goitre: increased uptake in multiple locations)

10 Hot nodule 2.

11 Cold nodule 1. 1 cm!

12 Cold nodule 2. The examination can't distinguish between benign and malignant cold nodules. About 5 % of cold nodules are malignant.

13 Subacut Thyroiditis

14 Low 99mTc-uptake in the thyroid gland A lot of causes, e.g.: Hypothyreosis Thyroid hormone substitution Thyroiditis (destructive phase) CT examination with iodinated contrast agent Vitamines, food - containing iodine Amiodarone therapy Some other drugs

15 Ectopic thyroid tissue 99mTc-Pertechnetate 131I

16 Radioiodine thyroid uptake Calculating 131I administered activity, for patients to be treated for hyperthyroidism with radioiodine

17 Radioiodine thyroid uptake Na-131I per os ( MBq, fasting state) Measuring: after hrs. or on the 7th day) with gamma camera (scintillation detector) Calculation: neck counts thigh counts Uptake (%) = x 100 phantom counts background counts

18 Parathyroid scintigraphy

19 Parathyroides

20 Pathophysiology Increased production and secretion of PTH - bone disease - nephrolithiasis - gastrointestinal symptoms Primary, secundary, tertiary hyperparathyreoidism (adenoma, hyperplasia, adenoma developing in secondary hyperplasia)

21 Parathyroid scintigraphy Imaging of hypermetabolic tissue with special methods A specific tracer for parathyroid tissue does not exist! Normal parathyroides are not visualisable (because of their low size).

22 Indication: Localising hyperfunctioning parathyroid tissue in case of hyperparathyroidism (suspicious tissue by US, ectopy, prior unsuccesful surgery )

23 Double-tracer parathyroid scintigraphy subtraction scanning Tracer 1.: 99mTc-sestamibi taken up not only by the hyperfunctioning parathyroid glands but also by the thyroid tissue Tracer 2.: 99mTc-Pertechnetate taken up by the thyroid gland only Subtraction: the thyroid scan can be digitally subtracted from the parathyroid scan to remove the thyroid activity and enhance the visualization of parathyroid adenoma/hyperplasia

24 Dual-phase or washout parathyroid scintigraphy Radiopharmaceutical: 99mTc-sestamibi Early (10 15 min post-injection) and delayed (2 h post-injection) planar images Sestamibi is taken up in both normal thyroid tissue and in hyperfunctioning parathyroid glands but washout from normal thyroid tissue is faster

25 Parathyroid adenoma, planar images 99mTc-Pertechnetate 99mTc-sestamibi

26 Parathyroid adenoma, subtraction

27 Parathyroid adenoma, SPECT

28 Parathyroid adenoma, SPECT-CT

29 18F-FDG PET examinations in head and neck malignancies Increased uptake of F18-FDG (glucose analogue) by tumour cells 18F: positron radiation Imaging: with PET camera (better: hybride imaging, PET-CT)

30 18F-FDG PET examinations in head and neck cancer Pharyngeal, laryngeal cancer (squamous cell carcinomas) Primary staging Therapy response evaluation, detecting residual or recurrent tumour tissue, restaging Detect unknown primary tumour in patients with a squamous cell carcinoma neck metastasis

31 Supraglottic tumor, FDG PET-CT

32 F18-FDG PET examination in thyroid carcinomas Papillary, folliculary carcinomas in suspicion of metastases not uptaking radioiodine (patients with elevated thyroglobulin levels and normal radioiodine whole body scintigraphy Hürtle-cell carcinomas, anaplastic carcinomas, some medullary carcinomas - staging, monitoring therapy

33 Thyroid carcinoma metastases, not uptaking radioiodine SPECT-CT examination following 131I therapy F18-FDG PET-CT examination

34 Thank You for Your Attention!