Thyroid nodule other imaging findings: Difference between revisions
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=== Radionuclide thyroid scan/scintigraphy === | === Radionuclide thyroid scan/scintigraphy === | ||
* Using either [[Pertechnetate|technetium 99 mTc pertechnetate]] or [[I-123 thyroid imaging|I123]] | |||
* [[Radionuclide|Radionuclide scan]] is contraindicated during [[pregnancy]] | |||
* [[Scintigraphy|Thyroid scintigraphy]] is useful to determine the functional status of a nodule. It is specifically indicated in patients with thyroid nodule and a low [[serum]] [[TSH]] to determine if the nodule has autonomous functioning. | |||
* In [[scintigraphy]], [[iodine]] [[radioisotopes]] (more commonly used; usually [[I-123 thyroid imaging|I-123]]) or [[Technetium-99m|technetium pertechnetate (99Tc)]], are injected and then the [[radioisotope]] uptake time by the [[thyroid gland]] is measured.4406304 16910877 | |||
* High [[radioisotope]] uptake=Hot nodule: | |||
** Hyperfunctioning nodules | |||
* Low [[radioisotope]] uptake=Cold nodule: | |||
** Most [[benign]] nodules | |||
** Most [[malignant]] thyroid nodules | |||
* Post therapy whole-body [[iodine]] scanning is typically conducted approximately 1 week after [[RAIU|RAI]] therapy to visualize [[metastases]]. | |||
* | |||
==== Diagnostic whole-body RAI scans ==== | ==== Diagnostic whole-body RAI scans ==== | ||
DxWBS, either following thyroid hormone withdrawal or rhTSH, 6–12 months after remnant ablation may be of value in the follow-up of patients with high or intermediate risk of persistent disease, but should be done with | * Diagnostic whole body scanning (DxWBS), either following [[thyroid]] [[hormone]] withdrawal or recombinant hormone TSH (rhTSH), 6–12 months after remnant ablation may be of value in the follow-up of patients with high or intermediate risk of persistent disease, but should be done with [[I-123 thyroid imaging|I-123]] or low activity I-131. | ||
Torlontano M, Crocetti U, D’Aloiso L, Bonfitto N, Di Giorgio A, Modoni S, Valle G, Frusciante V, Bisceglia M, Filetti S, Schlumberger M, Trischitta V 2003 Serum thyroglobulin and 131I whole body scan after recombinant human TSH stimulation in the follow-up of low-risk patients with differentiated thyroid cancer. Eur J Endocrinol 148:19–24 | Torlontano M, Crocetti U, D’Aloiso L, Bonfitto N, Di Giorgio A, Modoni S, Valle G, Frusciante V, Bisceglia M, Filetti S, Schlumberger M, Trischitta V 2003 Serum thyroglobulin and 131I whole body scan after recombinant human TSH stimulation in the follow-up of low-risk patients with differentiated thyroid cancer. Eur J Endocrinol 148:19–24 | ||
=== FDG-PET scan === | === FDG-PET scan === | ||
* Improved diagnostic accuracy of indeterminate thyroid nodules | |||
* In patients with thyroid PET [[incidentaloma]], the incidence of primary [[thyroid malignancy]] is very high | |||
24902804 | 24902804 | ||
* There is insuffiecient evidence to recommend to or against routine clinical use | |||
* Usage indications: | |||
** Simple disease localization in [[thyroglobulin]] (Tg) positive, [[RAIU|RAI]] scan–negative patients | |||
Usage indications: | ** Initial staging and follow-up of high-risk patients with poorly differentiated [[thyroid cancers]] unlikely to concentrate [[RAIU|RAI]] in order to identify sites of disease that may be missed with [[RAIU|RAI]] scanning and conventional imaging. | ||
* | ** Initial staging and follow-up of invasive or [[metastatic]] [[Hurthle cell carcinoma]]. | ||
* Initial staging and follow-up of high-risk patients with poorly differentiated thyroid cancers unlikely to concentrate RAI in order to identify sites of disease that may be missed with RAI scanning and conventional imaging. | ** As a powerful prognostic tool for identifying which patients with known distant [[metastases]] are at highest risk for disease-specific [[mortality]]. | ||
* Initial staging and follow-up of invasive or metastatic Hurthle cell carcinoma. | ** As a selection tool to identify those patients unlikely to respond to additional [[RAIU|RAI]] therapy. | ||
* As a powerful prognostic tool for identifying which patients with known distant metastases are at highest risk for disease-specific mortality. | ** As a measurement of post treatment response following external beam irradiation, surgical resection, [[embolization]], or systemic therapy. | ||
* As a selection tool to identify those patients unlikely to respond to additional RAI therapy. | |||
* As a measurement of post treatment response following external beam irradiation, surgical resection, embolization, or systemic therapy. | |||
Larson SM, Robbins R 2002 Positron emission tomography in thyroid cancer management. Semin Roentgenol 37:169–174. 316. | Larson SM, Robbins R 2002 Positron emission tomography in thyroid cancer management. Semin Roentgenol 37:169–174. 316. | ||
| Line 50: | Line 44: | ||
False-positive 18FDG-PET findings can be due to: | False-positive 18FDG-PET findings can be due to: | ||
* Inflammatory lymph nodes | * Inflammatory [[lymph nodes]] | ||
* Suture granulomas | * Suture [[granulomas]] | ||
* Increased muscle activity | * Increased [[muscle]] activity | ||
Therefore, cytologic or histologic confirmation is required before one can be certain that an 18FDG-positive lesion represents metastatic disease. | Therefore, cytologic or histologic confirmation is required before one can be certain that an 18FDG-positive lesion represents metastatic disease. | ||
==== Iodine 131 single photon emission computed tomography (SPECT)=CT fusion imaging ==== | ==== Iodine 131 single photon emission computed tomography (SPECT)=CT fusion imaging ==== | ||
* May provide superior lesion localization after remnant ablation, but it is still a relatively new imaging modality | |||
==References== | ==References== | ||
Revision as of 19:34, 25 October 2017
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Other Imaging Studies
Radionuclide thyroid scan/scintigraphy
- Using either technetium 99 mTc pertechnetate or I123
- Radionuclide scan is contraindicated during pregnancy
- Thyroid scintigraphy is useful to determine the functional status of a nodule. It is specifically indicated in patients with thyroid nodule and a low serum TSH to determine if the nodule has autonomous functioning.
- In scintigraphy, iodine radioisotopes (more commonly used; usually I-123) or technetium pertechnetate (99Tc), are injected and then the radioisotope uptake time by the thyroid gland is measured.4406304 16910877
- High radioisotope uptake=Hot nodule:
- Hyperfunctioning nodules
- Low radioisotope uptake=Cold nodule:
- Post therapy whole-body iodine scanning is typically conducted approximately 1 week after RAI therapy to visualize metastases.
Diagnostic whole-body RAI scans
- Diagnostic whole body scanning (DxWBS), either following thyroid hormone withdrawal or recombinant hormone TSH (rhTSH), 6–12 months after remnant ablation may be of value in the follow-up of patients with high or intermediate risk of persistent disease, but should be done with I-123 or low activity I-131.
Torlontano M, Crocetti U, D’Aloiso L, Bonfitto N, Di Giorgio A, Modoni S, Valle G, Frusciante V, Bisceglia M, Filetti S, Schlumberger M, Trischitta V 2003 Serum thyroglobulin and 131I whole body scan after recombinant human TSH stimulation in the follow-up of low-risk patients with differentiated thyroid cancer. Eur J Endocrinol 148:19–24
FDG-PET scan
- Improved diagnostic accuracy of indeterminate thyroid nodules
- In patients with thyroid PET incidentaloma, the incidence of primary thyroid malignancy is very high
24902804
- There is insuffiecient evidence to recommend to or against routine clinical use
- Usage indications:
- Simple disease localization in thyroglobulin (Tg) positive, RAI scan–negative patients
- Initial staging and follow-up of high-risk patients with poorly differentiated thyroid cancers unlikely to concentrate RAI in order to identify sites of disease that may be missed with RAI scanning and conventional imaging.
- Initial staging and follow-up of invasive or metastatic Hurthle cell carcinoma.
- As a powerful prognostic tool for identifying which patients with known distant metastases are at highest risk for disease-specific mortality.
- As a selection tool to identify those patients unlikely to respond to additional RAI therapy.
- As a measurement of post treatment response following external beam irradiation, surgical resection, embolization, or systemic therapy.
Larson SM, Robbins R 2002 Positron emission tomography in thyroid cancer management. Semin Roentgenol 37:169–174. 316.
Leboulleux S, Schroeder PR, Busaidy NL, Auperin A, Corone C, Jacene HA, Ewertz ME, Bournaud C, Wahl RL,Sherman SI, Ladenson PW, Schlumberger M 2009 Assessment of the incremental value of recombinant TSH stimulation before FDG PET=CT imaging to localize residual differentiated thyroid cancer. J Clin Endocrinol Metab 94:1310–1316.
False-positive 18FDG-PET findings can be due to:
- Inflammatory lymph nodes
- Suture granulomas
- Increased muscle activity
Therefore, cytologic or histologic confirmation is required before one can be certain that an 18FDG-positive lesion represents metastatic disease.
Iodine 131 single photon emission computed tomography (SPECT)=CT fusion imaging
- May provide superior lesion localization after remnant ablation, but it is still a relatively new imaging modality