Thyroid Disease

Variant: 1 Palpable thyroid nodule. Not goiter. Euthyroid. Initial imaging.

Procedure	Appropriateness Category	Relative Radiation Level
US thyroid	Usually Appropriate	O
CT neck with IV contrast	May Be Appropriate	☢☢☢
CT neck without IV contrast	May Be Appropriate	☢☢☢
MRI neck without and with IV contrast	Usually Not Appropriate	O
MRI neck without IV contrast	Usually Not Appropriate	O
CT neck without and with IV contrast	Usually Not Appropriate	☢☢☢
I-123 uptake scan neck	Usually Not Appropriate	☢☢☢
FDG-PET/CT whole body	Usually Not Appropriate	☢☢☢☢
I-131 uptake scan and Tc-99m pertechnetate scan neck	Usually Not Appropriate	☢☢☢☢

Variant: 2 Suspected goiter. Initial imaging.

Procedure	Appropriateness Category	Relative Radiation Level
US thyroid	Usually Appropriate	O
CT neck without IV contrast	Usually Appropriate	☢☢☢
MRI neck without and with IV contrast	May Be Appropriate	O
MRI neck without IV contrast	May Be Appropriate	O
CT neck with IV contrast	May Be Appropriate	☢☢☢
I-123 uptake scan neck	May Be Appropriate	☢☢☢
I-131 uptake scan and Tc-99m pertechnetate scan neck	May Be Appropriate	☢☢☢☢
CT neck without and with IV contrast	Usually Not Appropriate	☢☢☢
FDG-PET/CT whole body	Usually Not Appropriate	☢☢☢☢

Variant: 3 Thyrotoxicosis. Initial imaging.

Procedure	Appropriateness Category	Relative Radiation Level
US thyroid	Usually Appropriate	O
I-123 uptake scan neck	Usually Appropriate	☢☢☢
I-131 uptake scan and Tc-99m pertechnetate scan neck	Usually Appropriate	☢☢☢☢
MRI neck without and with IV contrast	Usually Not Appropriate	O
MRI neck without IV contrast	Usually Not Appropriate	O
CT neck with IV contrast	Usually Not Appropriate	☢☢☢
CT neck without and with IV contrast	Usually Not Appropriate	☢☢☢
CT neck without IV contrast	Usually Not Appropriate	☢☢☢
FDG-PET/CT whole body	Usually Not Appropriate	☢☢☢☢

Variant: 4 Primary hypothyroidism. Initial imaging.

Procedure	Appropriateness Category	Relative Radiation Level
US thyroid	Usually Not Appropriate	O
MRI neck without and with IV contrast	Usually Not Appropriate	O
MRI neck without IV contrast	Usually Not Appropriate	O
CT neck with IV contrast	Usually Not Appropriate	☢☢☢
CT neck without and with IV contrast	Usually Not Appropriate	☢☢☢
CT neck without IV contrast	Usually Not Appropriate	☢☢☢
I-123 uptake scan neck	Usually Not Appropriate	☢☢☢
FDG-PET/CT whole body	Usually Not Appropriate	☢☢☢☢
I-131 uptake scan and Tc-99m pertechnetate scan neck	Usually Not Appropriate	☢☢☢☢

Variant: 5 Preoperative evaluation of differentiated thyroid cancer.

Procedure	Appropriateness Category	Relative Radiation Level
US thyroid	Usually Appropriate	O
CT neck with IV contrast	Usually Appropriate	☢☢☢
MRI neck without and with IV contrast	May Be Appropriate	O
MRI neck without IV contrast	May Be Appropriate	O
CT neck without IV contrast	May Be Appropriate	☢☢☢
CT neck without and with IV contrast	Usually Not Appropriate	☢☢☢
I-123 scan whole body	Usually Not Appropriate	☢☢☢
FDG-PET/CT whole body	Usually Not Appropriate	☢☢☢☢
I-131 scan whole body	Usually Not Appropriate	☢☢☢☢
Octreotide scan whole body	Usually Not Appropriate	☢☢☢☢

Variant: 6 Early imaging after treatment of differentiated thyroid cancer.

Procedure	Appropriateness Category	Relative Radiation Level
US thyroid	Usually Appropriate	O
MRI neck without and with IV contrast	May Be Appropriate	O
CT neck with IV contrast	May Be Appropriate (Disagreement)	☢☢☢
I-123 scan whole body	May Be Appropriate	☢☢☢
I-131 scan whole body	May Be Appropriate (Disagreement)	☢☢☢☢
MRI neck without IV contrast	Usually Not Appropriate	O
CT neck without and with IV contrast	Usually Not Appropriate	☢☢☢
CT neck without IV contrast	Usually Not Appropriate	☢☢☢
FDG-PET/CT whole body	Usually Not Appropriate	☢☢☢☢
Octreotide scan whole body	Usually Not Appropriate	☢☢☢☢

Variant: 7 Suspected recurrence of differentiated thyroid cancer.

Procedure	Appropriateness Category	Relative Radiation Level
US thyroid	Usually Appropriate	O
MRI neck without and with IV contrast	Usually Appropriate	O
CT neck with IV contrast	Usually Appropriate	☢☢☢
I-123 scan whole body	Usually Appropriate	☢☢☢
MRI neck without IV contrast	May Be Appropriate	O
CT chest with IV contrast	May Be Appropriate	☢☢☢
CT chest without IV contrast	May Be Appropriate	☢☢☢
CT neck without IV contrast	May Be Appropriate	☢☢☢
FDG-PET/CT whole body	May Be Appropriate	☢☢☢☢
I-131 scan whole body	May Be Appropriate	☢☢☢☢
CT chest without and with IV contrast	Usually Not Appropriate	☢☢☢
CT neck without and with IV contrast	Usually Not Appropriate	☢☢☢
Octreotide scan whole body	Usually Not Appropriate	☢☢☢☢

Variant: 8 Suspected recurrence of medullary thyroid cancers.

Procedure	Appropriateness Category	Relative Radiation Level
US thyroid	Usually Appropriate	O
MRI neck without and with IV contrast	Usually Appropriate	O
CT chest with IV contrast	Usually Appropriate	☢☢☢
CT neck with IV contrast	Usually Appropriate	☢☢☢
MRI abdomen without and with IV contrast	May Be Appropriate	O
MRI abdomen without IV contrast	May Be Appropriate	O
MRI complete spine without and with IV contrast	May Be Appropriate	O
MRI complete spine without IV contrast	May Be Appropriate	O
MRI neck without IV contrast	May Be Appropriate	O
Bone scan whole body	May Be Appropriate	☢☢☢
CT abdomen with IV contrast	May Be Appropriate	☢☢☢
CT chest without IV contrast	May Be Appropriate	☢☢☢
CT neck without IV contrast	May Be Appropriate	☢☢☢
CT abdomen without and with IV contrast	May Be Appropriate	☢☢☢☢
FDG-PET/CT whole body	May Be Appropriate	☢☢☢☢
CT abdomen without IV contrast	Usually Not Appropriate	☢☢☢
CT chest without and with IV contrast	Usually Not Appropriate	☢☢☢
CT neck without and with IV contrast	Usually Not Appropriate	☢☢☢
DOTATATE PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢
I-123 scan whole body	Usually Not Appropriate	☢☢☢
I-131 scan whole body	Usually Not Appropriate	☢☢☢☢
Octreotide scan whole body	Usually Not Appropriate	☢☢☢☢

Panel Members

Jenny K. Hoang, MBBS, MHA^a; Jorge D. Oldan, MD^b; Susan J. Mandel, MD^c; Bruno Policeni, MD^d; Vikas Agarwal, MD^e; Judah Burns, MD^f; Julie Bykowski, MD^g; H Benjamin. Harvey, MD, JD^h; Amy F. Juliano, MDⁱ; Tabassum A. Kennedy, MD^j; Gul Moonis, MD^k; Jeffrey S. Pannell, MD^l; Matthew S. Parsons, MD^m; Jason W. Schroeder, MDⁿ; Rathan M. Subramaniam, MD, PhD, MPH^o; Matthew T. Whitehead, MD^p; Amanda S. Corey, MD^q.

Summary of Literature Review

Introduction/Background

Special Imaging Considerations

Discussion of Procedures by Variant

Variant 1: Palpable thyroid nodule. Not goiter. Euthyroid. Initial imaging.

Variant 1: Palpable thyroid nodule. Not goiter. Euthyroid. Initial imaging.
A. CT neck

Variant 1: Palpable thyroid nodule. Not goiter. Euthyroid. Initial imaging.
B. FDG-PET/CT whole body

Variant 1: Palpable thyroid nodule. Not goiter. Euthyroid. Initial imaging.
C. MRI neck

Variant 1: Palpable thyroid nodule. Not goiter. Euthyroid. Initial imaging.
D. US thyroid

Variant 1: Palpable thyroid nodule. Not goiter. Euthyroid. Initial imaging.
E. Radionuclide uptake and scan

Variant 2: Suspected goiter. Initial imaging.

Variant 2: Suspected goiter. Initial imaging.
A. CT neck

Variant 2: Suspected goiter. Initial imaging.
B. FDG-PET/CT whole body

Variant 2: Suspected goiter. Initial imaging.
C. Radionuclide uptake and scan

Variant 2: Suspected goiter. Initial imaging.
D. MRI neck

Variant 2: Suspected goiter. Initial imaging.
E. US thyroid

Variant 3: Thyrotoxicosis. Initial imaging.

Variant 3: Thyrotoxicosis. Initial imaging.
A. CT neck

Variant 3: Thyrotoxicosis. Initial imaging.
B. FDG-PET/CT whole body

Variant 3: Thyrotoxicosis. Initial imaging.
C. Radionuclide uptake and scan

Variant 3: Thyrotoxicosis. Initial imaging.
D. MRI neck

Variant 3: Thyrotoxicosis. Initial imaging.
E. US thyroid

Variant 4: Primary hypothyroidism. Initial imaging.

Variant 4: Primary hypothyroidism. Initial imaging.
A. CT neck

Variant 4: Primary hypothyroidism. Initial imaging.
B. FDG-PET/CT whole body

Variant 4: Primary hypothyroidism. Initial imaging.
C. Radionuclide uptake and scan

Variant 4: Primary hypothyroidism. Initial imaging.
D. MRI neck

Variant 4: Primary hypothyroidism. Initial imaging.
E. US thyroid

Variant 5: Preoperative evaluation of differentiated thyroid cancer.

Variant 5: Preoperative evaluation of differentiated thyroid cancer.
A. CT neck

Variant 5: Preoperative evaluation of differentiated thyroid cancer.
B. FDG-PET/CT whole body

Variant 5: Preoperative evaluation of differentiated thyroid cancer.
C. Whole-body scintigraphy

Variant 5: Preoperative evaluation of differentiated thyroid cancer.
D. MRI neck

Variant 5: Preoperative evaluation of differentiated thyroid cancer.
E. Octreotide Scan with SPECT or SPECT/CT Chest and Abdomen

Variant 5: Preoperative evaluation of differentiated thyroid cancer.
F. US thyroid

Variant 6: Early imaging after treatment of differentiated thyroid cancer.

Variant 6: Early imaging after treatment of differentiated thyroid cancer.
A. CT neck

Variant 6: Early imaging after treatment of differentiated thyroid cancer.
B. FDG-PET/CT whole body

Variant 6: Early imaging after treatment of differentiated thyroid cancer.
C. MRI neck

Variant 6: Early imaging after treatment of differentiated thyroid cancer.
D. Octreotide Scan with SPECT or SPECT/CT Chest and Abdomen

Variant 6: Early imaging after treatment of differentiated thyroid cancer.
E. US thyroid

Variant 6: Early imaging after treatment of differentiated thyroid cancer.
F. Whole-body scintigraphy

Variant 7: Suspected recurrence of differentiated thyroid cancer.

Variant 7: Suspected recurrence of differentiated thyroid cancer.
A. CT chest

Variant 7: Suspected recurrence of differentiated thyroid cancer.
B. CT neck

Variant 7: Suspected recurrence of differentiated thyroid cancer.
C. FDG-PET/CT whole body

Variant 7: Suspected recurrence of differentiated thyroid cancer.
D. Whole-body scintigraphy

Variant 7: Suspected recurrence of differentiated thyroid cancer.
E. MRI neck

Variant 7: Suspected recurrence of differentiated thyroid cancer.
F. Octreotide Scan with SPECT or SPECT/CT Chest and Abdomen

Variant 7: Suspected recurrence of differentiated thyroid cancer.
G. US thyroid

Variant 8: Suspected recurrence of medullary thyroid cancers.

Variant 8: Suspected recurrence of medullary thyroid cancers.
A. Bone scan whole body

Variant 8: Suspected recurrence of medullary thyroid cancers.
B. CT abdomen

Variant 8: Suspected recurrence of medullary thyroid cancers.
C. CT chest

Variant 8: Suspected recurrence of medullary thyroid cancers.
D. CT neck

Variant 8: Suspected recurrence of medullary thyroid cancers.
E. DOTATATE PET/CT skull base to mid-thigh

Variant 8: Suspected recurrence of medullary thyroid cancers.
F. FDG-PET/CT whole body

Variant 8: Suspected recurrence of medullary thyroid cancers.
G. Whole-Body Scintigraphy

Variant 8: Suspected recurrence of medullary thyroid cancers.
H. MRI abdomen

Variant 8: Suspected recurrence of medullary thyroid cancers.
I. MRI complete spine

Variant 8: Suspected recurrence of medullary thyroid cancers.
J. MRI neck

Variant 8: Suspected recurrence of medullary thyroid cancers.
K. Octreotide Scan with SPECT or SPECT/CT Chest and Abdomen

Variant 8: Suspected recurrence of medullary thyroid cancers.
L. US thyroid

Summary of Highlights

Supporting Documents

The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.

For additional information on the Appropriateness Criteria methodology and other supporting documents, please go to the ACR website at https://www.acr.org/Clinical-Resources/Clinical-Tools-and-Reference/Appropriateness-Criteria.

Appropriateness Category Names and Definitions

Appropriateness Category Name	Appropriateness Rating	Appropriateness Category Definition
Usually Appropriate	7, 8, or 9	The imaging procedure or treatment is indicated in the specified clinical scenarios at a favorable risk-benefit ratio for patients.
May Be Appropriate	4, 5, or 6	The imaging procedure or treatment may be indicated in the specified clinical scenarios as an alternative to imaging procedures or treatments with a more favorable risk-benefit ratio, or the risk-benefit ratio for patients is equivocal.
May Be Appropriate (Disagreement)	5	The individual ratings are too dispersed from the panel median. The different label provides transparency regarding the panel’s recommendation. “May be appropriate” is the rating category and a rating of 5 is assigned.
Usually Not Appropriate	1, 2, or 3	The imaging procedure or treatment is unlikely to be indicated in the specified clinical scenarios, or the risk-benefit ratio for patients is likely to be unfavorable.

Relative Radiation Level Information

Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, because of both organ sensitivity and longer life expectancy (relevant to the long latency that appears to accompany radiation exposure). For these reasons, the RRL dose estimate ranges for pediatric examinations are lower as compared with those specified for adults (see Table below). Additional information regarding radiation dose assessment for imaging examinations can be found in the ACR Appropriateness Criteria^® Radiation Dose Assessment Introduction document.

Relative Radiation Level Designations
Relative Radiation Level*	Adult Effective Dose Estimate Range	Pediatric Effective Dose Estimate Range
O	0 mSv	0 mSv
☢	<0.1 mSv	<0.03 mSv
☢☢	0.1-1 mSv	0.03-0.3 mSv
☢☢☢	1-10 mSv	0.3-3 mSv
☢☢☢☢	10-30 mSv	3-10 mSv
☢☢☢☢☢	30-100 mSv	10-30 mSv
*RRL assignments for some of the examinations cannot be made, because the actual patient doses in these procedures vary as a function of a number of factors (e.g., region of the body exposed to ionizing radiation, the imaging guidance that is used). The RRLs for these examinations are designated as “Varies.”

References

1.	Smith-Bindman R, Lebda P, Feldstein VA, et al. Risk of thyroid cancer based on thyroid ultrasound imaging characteristics: results of a population-based study. JAMA Intern Med. 173(19):1788-96, 2013 Oct 28.
2.	Stang MT, Armstrong MJ, Ogilvie JB, et al. Positional dyspnea and tracheal compression as indications for goiter resection. Arch Surg. 147(7):621-6, 2012 Jul.
3.	Hobbs HA, Bahl M, Nelson RC, et al. Journal Club: incidental thyroid nodules detected at imaging: can diagnostic workup be reduced by use of the Society of Radiologists in Ultrasound recommendations and the three-tiered system?. AJR Am J Roentgenol. 202(1):18-24, 2014 Jan.
4.	Vaccarella S, Franceschi S, Bray F, Wild CP, Plummer M, Dal Maso L. Worldwide Thyroid-Cancer Epidemic? The Increasing Impact of Overdiagnosis. N Engl J Med. 375(7):614-7, 2016 Aug 18.
5.	Sosa JA, Hanna JW, Robinson KA, Lanman RB. Increases in thyroid nodule fine-needle aspirations, operations, and diagnoses of thyroid cancer in the United States. Surgery. 154(6):1420-6; discussion 1426-7, 2013 Dec.
6.	Deandreis D, Al Ghuzlan A, Leboulleux S, et al. Do histological, immunohistochemical, and metabolic (radioiodine and fluorodeoxyglucose uptakes) patterns of metastatic thyroid cancer correlate with patient outcome?. Endocr Relat Cancer. 18(1):159-69, 2011 Feb.
7.	Hoang JK, Langer JE, Middleton WD, et al. Managing incidental thyroid nodules detected on imaging: white paper of the ACR Incidental Thyroid Findings Committee. J. Am. Coll. Radiol.. 12(2):143-50, 2015 Feb.
8.	Tessler FN, Middleton WD, Grant EG, et al. ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee. J Am Coll Radiol. 2017;14(5):587-595.
9.	Lim H, Devesa SS, Sosa JA, Check D, Kitahara CM. Trends in Thyroid Cancer Incidence and Mortality in the United States, 1974-2013. JAMA. 317(13):1338-1348, 2017 04 04.
10.	American College of Radiology. ACR Appropriateness Criteria®: Neuroendocrine Imaging. Available at: https://acsearch.acr.org/docs/69485/Narrative/.
11.	Sohn SY, Choi JH, Kim NK, et al. The impact of iodinated contrast agent administered during preoperative computed tomography scan on body iodine pool in patients with differentiated thyroid cancer preparing for radioactive iodine treatment. Thyroid. 24(5):872-7, 2014 May.
12.	Padovani RP, Kasamatsu TS, Nakabashi CC, et al. One month is sufficient for urinary iodine to return to its baseline value after the use of water-soluble iodinated contrast agents in post-thyroidectomy patients requiring radioiodine therapy. Thyroid. 22(9):926-30, 2012 Sep.
13.	Rhee CM, Bhan I, Alexander EK, Brunelli SM. Association between iodinated contrast media exposure and incident hyperthyroidism and hypothyroidism. Arch Intern Med. 172(2):153-9, 2012 Jan 23.
14.	American College of Radiology. ACR–SPR Practice Parameter for the Performance of Scintigraphy and Uptake Measurement for Benign and Malignant Thyroid Disease. Available at: https://gravitas.acr.org/PPTS/GetDocumentView?docId=60+&releaseId=2
15.	Lin JS, Bowles EJA, Williams SB, Morrison CC. Screening for Thyroid Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force. [Review]. JAMA. 317(18):1888-1903, 2017 05 09.
16.	Haugen BR, Alexander EK, Bible KC, et al. 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. [Review]. Thyroid. 26(1):1-133, 2016 Jan.
17.	Chen AY, Bernet VJ, Carty SE, et al. American Thyroid Association statement on optimal surgical management of goiter. Thyroid. 24(2):181-9, 2014 Feb.
18.	Atkins HL, Klopper JF, Lambrecht RM, Wolf AP. A comparison of technetium 99M and iodine 123 for thyroid imaging. Am J Roentgenol Radium Ther Nucl Med 1973;117:195-201.
19.	Ross DS, Burch HB, Cooper DS, et al. 2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis. Thyroid. 2016;26(10):1343-1421.
20.	McKee A, Peyerl F. TSI assay utilization: impact on costs of Graves' hyperthyroidism diagnosis. Am J Manag Care. 2012;18(1):e1-14.
21.	Erdogan MF, Anil C, Cesur M, Baskal N, Erdogan G. Color flow Doppler sonography for the etiologic diagnosis of hyperthyroidism. Thyroid. 17(3):223-8, 2007 Mar.
22.	Ota H, Amino N, Morita S, et al. Quantitative measurement of thyroid blood flow for differentiation of painless thyroiditis from Graves' disease. Clin Endocrinol (Oxf). 2007;67(1):41-45.
23.	Kurita S, Sakurai M, Kita Y, et al. Measurement of thyroid blood flow area is useful for diagnosing the cause of thyrotoxicosis. Thyroid. 15(11):1249-52, 2005 Nov.
24.	Alzahrani AS, Ceresini G, Aldasouqi SA. Role of ultrasonography in the differential diagnosis of thyrotoxicosis: a noninvasive, cost-effective, and widely available but underutilized diagnostic tool. [Review]. Endocr Pract. 18(4):567-78, 2012 Jul-Aug.
25.	Kravets I.. Hyperthyroidism: Diagnosis and Treatment. [Review]. Am Fam Physician. 93(5):363-70, 2016 Mar 01.
26.	Intenzo C, Jabbour S, Miller JL, et al. Subclinical hyperthyroidism: current concepts and scintigraphic imaging. [Review]. Clin Nucl Med. 36(9):e107-13, 2011 Sep.
27.	American Thyroid Association (ATA) Guidelines Taskforce on Thyroid Nodules and Differentiated Thyroid Cancer, Cooper DS, Doherty GM, et al. Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer.[Erratum appears in Thyroid. 2010 Jun;20(6):674-5], [Erratum appears in Thyroid. 2010 Aug;20(8):942 Note: Hauger, Bryan R [corrected to Haugen, Bryan R]]. Thyroid. 19(11):1167-214, 2009 Nov.
28.	Kouvaraki MA, Shapiro SE, Fornage BD, et al. Role of preoperative ultrasonography in the surgical management of patients with thyroid cancer. Surgery. 2003;134(6):946-954; discussion 954-945.
29.	Choi JS, Kim J, Kwak JY, Kim MJ, Chang HS, Kim EK. Preoperative staging of papillary thyroid carcinoma: comparison of ultrasound imaging and CT. AJR Am J Roentgenol. 193(3):871-8, 2009 Sep.
30.	Kim E, Park JS, Son KR, Kim JH, Jeon SJ, Na DG. Preoperative diagnosis of cervical metastatic lymph nodes in papillary thyroid carcinoma: comparison of ultrasound, computed tomography, and combined ultrasound with computed tomography. Thyroid. 18(4):411-8, 2008 Apr.
31.	Kocharyan D, Schwenter F, Belair M, Nassif E. The relevance of preoperative ultrasound cervical mapping in patients with thyroid cancer. Can J Surg. 59(2):113-7, 2016 Apr.
32.	Lee DW, Ji YB, Sung ES, et al. Roles of ultrasonography and computed tomography in the surgical management of cervical lymph node metastases in papillary thyroid carcinoma. Eur J Surg Oncol. 39(2):191-6, 2013 Feb.
33.	Lesnik D, Cunnane ME, Zurakowski D, et al. Papillary thyroid carcinoma nodal surgery directed by a preoperative radiographic map utilizing CT scan and ultrasound in all primary and reoperative patients. Head Neck. 36(2):191-202, 2014 Feb.
34.	Yeh MW, Bauer AJ, Bernet VA, et al. American Thyroid Association statement on preoperative imaging for thyroid cancer surgery. Thyroid. 25(1):3-14, 2015 Jan.
35.	Jeong HS, Baek CH, Son YI, et al. Integrated 18F-FDG PET/CT for the initial evaluation of cervical node level of patients with papillary thyroid carcinoma: comparison with ultrasound and contrast-enhanced CT. Clin Endocrinol (Oxf). 2006;65(3):402-407.
36.	Leboulleux S, Schroeder PR, Busaidy NL, et al. Assessment of the incremental value of recombinant thyrotropin stimulation before 2-[18F]-Fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography imaging to localize residual differentiated thyroid cancer. J Clin Endocrinol Metab. 94(4):1310-6, 2009 Apr.
37.	Momesso DP, Vaisman F, Yang SP, et al. Dynamic Risk Stratification in Patients with Differentiated Thyroid Cancer Treated Without Radioactive Iodine. J Clin Endocrinol Metab 2016;101:2692-700.
38.	Leger FA, Izembart M, Dagousset F, et al. Decreased uptake of therapeutic doses of iodine-131 after 185-MBq iodine-131 diagnostic imaging for thyroid remnants in differentiated thyroid carcinoma. Eur J Nucl Med. 25(3):242-6, 1998 Mar.
39.	Silberstein EB.. Comparison of outcomes after (123)I versus (131)I pre-ablation imaging before radioiodine ablation in differentiated thyroid carcinoma. J Nucl Med. 48(7):1043-6, 2007 Jul.
40.	Alzahrani AS, AlShaikh O, Tuli M, Al-Sugair A, Alamawi R, Al-Rasheed MM. Diagnostic value of recombinant human thyrotropin-stimulated 123I whole-body scintigraphy in the follow-up of patients with differentiated thyroid cancer. Clin Nucl Med. 37(3):229-34, 2012 Mar.
41.	Mandel SJ, Shankar LK, Benard F, Yamamoto A, Alavi A. Superiority of iodine-123 compared with iodine-131 scanning for thyroid remnants in patients with differentiated thyroid cancer. Clin Nucl Med 2001;26:6-9.
42.	Fatourechi V, Hay ID, Mullan BP, et al. Are posttherapy radioiodine scans informative and do they influence subsequent therapy of patients with differentiated thyroid cancer?. Thyroid. 10(7):573-7, 2000 Jul.
43.	Sherman SI, Tielens ET, Sostre S, Wharam MD Jr, Ladenson PW. Clinical utility of posttreatment radioiodine scans in the management of patients with thyroid carcinoma. J Clin Endocrinol Metab. 78(3):629-34, 1994 Mar.
44.	Souza Rosario PW, Barroso AL, Rezende LL, et al. Post I-131 therapy scanning in patients with thyroid carcinoma metastases: an unnecessary cost or a relevant contribution?. Clin Nucl Med. 29(12):795-8, 2004 Dec.
45.	Schvartz C, Bonnetain F, Dabakuyo S, et al. Impact on overall survival of radioactive iodine in low-risk differentiated thyroid cancer patients. J Clin Endocrinol Metab. 97(5):1526-35, 2012 May.
46.	Tuttle RM, Tala H, Shah J, et al. Estimating risk of recurrence in differentiated thyroid cancer after total thyroidectomy and radioactive iodine remnant ablation: using response to therapy variables to modify the initial risk estimates predicted by the new American Thyroid Association staging system. Thyroid. 20(12):1341-9, 2010 Dec.
47.	Vaisman F, Shaha A, Fish S, Michael Tuttle R. Initial therapy with either thyroid lobectomy or total thyroidectomy without radioactive iodine remnant ablation is associated with very low rates of structural disease recurrence in properly selected patients with differentiated thyroid cancer. Clin Endocrinol (Oxf). 75(1):112-9, 2011 Jul.
48.	Ahn JE, Lee JH, Yi JS, et al. Diagnostic accuracy of CT and ultrasonography for evaluating metastatic cervical lymph nodes in patients with thyroid cancer. World J Surg. 32(7):1552-8, 2008 Jul.
49.	Yoshio K, Sato S, Okumura Y, et al. The local efficacy of I-131 for F-18 FDG PET positive lesions in patients with recurrent or metastatic thyroid carcinomas. Clin Nucl Med. 36(2):113-7, 2011 Feb.
50.	Schreinemakers JM, Vriens MR, Munoz-Perez N, et al. Fluorodeoxyglucose-positron emission tomography scan-positive recurrent papillary thyroid cancer and the prognosis and implications for surgical management. World J Surg Oncol. 10:192, 2012 Sep 17.
51.	Pellegriti G, Leboulleux S, Baudin E, et al. Long-term outcome of medullary thyroid carcinoma in patients with normal postoperative medical imaging. Br J Cancer. 88(10):1537-42, 2003 May 19.
52.	Sesti A, Mayerhoefer M, Weber M, et al. Relevance of calcitonin cut-off in the follow-up of medullary thyroid carcinoma for conventional imaging and 18-fluorine-fluorodihydroxyphenylalanine PET. Anticancer Res. 34(11):6647-54, 2014 Nov.
53.	Giraudet AL, Vanel D, Leboulleux S, et al. Imaging medullary thyroid carcinoma with persistent elevated calcitonin levels. J Clin Endocrinol Metab. 92(11):4185-90, 2007 Nov.
54.	Wells SA Jr, Asa SL, Dralle H, et al. Revised American Thyroid Association guidelines for the management of medullary thyroid carcinoma. [Review]. Thyroid. 25(6):567-610, 2015 Jun.
55.	Vreugdenburg TD, Ma N, Duncan JK, Riitano D, Cameron AL, Maddern GJ. Comparative diagnostic accuracy of hepatocyte-specific gadoxetic acid (Gd-EOB-DTPA) enhanced MR imaging and contrast enhanced CT for the detection of liver metastases: a systematic review and meta-analysis. [Review]. Int J Colorectal Dis. 31(11):1739-1749, 2016 Nov.
56.	Delorme S, Raue F. Medullary Thyroid Carcinoma: Imaging. [Review]. Recent Results Cancer Res. 204:91-116, 2015.
57.	Mirallie E, Vuillez JP, Bardet S, et al. High frequency of bone/bone marrow involvement in advanced medullary thyroid cancer. J Clin Endocrinol Metab. 2005;90(2):779-788.
58.	Treglia G, Villani MF, Giordano A, Rufini V. Detection rate of recurrent medullary thyroid carcinoma using fluorine-18 fluorodeoxyglucose positron emission tomography: a meta-analysis. [Review]. Endocrine. 42(3):535-45, 2012 Dec.
59.	Koopmans KP, de Groot JW, Plukker JT, et al. 18F-dihydroxyphenylalanine PET in patients with biochemical evidence of medullary thyroid cancer: relation to tumor differentiation. J Nucl Med. 49(4):524-31, 2008 Apr.
60.	Ong SC, Schoder H, Patel SG, et al. Diagnostic accuracy of 18F-FDG PET in restaging patients with medullary thyroid carcinoma and elevated calcitonin levels. J Nucl Med. 48(4):501-7, 2007 Apr.
61.	Szakall S Jr, Esik O, Bajzik G, et al. 18F-FDG PET detection of lymph node metastases in medullary thyroid carcinoma. J Nucl Med. 43(1):66-71, 2002 Jan.
62.	Rubello D, Rampin L, Nanni C, et al. The role of 18F-FDG PET/CT in detecting metastatic deposits of recurrent medullary thyroid carcinoma: a prospective study. Eur J Surg Oncol. 34(5):581-6, 2008 May.
63.	Beheshti M, Pocher S, Vali R, et al. The value of 18F-DOPA PET-CT in patients with medullary thyroid carcinoma: comparison with 18F-FDG PET-CT. Eur Radiol. 19(6):1425-34, 2009 Jun.
64.	Treglia G, Castaldi P, Villani MF, et al. Comparison of 18F-DOPA, 18F-FDG and 68Ga-somatostatin analogue PET/CT in patients with recurrent medullary thyroid carcinoma. Eur J Nucl Med Mol Imaging. 39(4):569-80, 2012 Apr.
65.	Verbeek HH, Plukker JT, Koopmans KP, et al. Clinical relevance of 18F-FDG PET and 18F-DOPA PET in recurrent medullary thyroid carcinoma. J Nucl Med. 53(12):1863-71, 2012 Dec.
66.	Baudin E, Lumbroso J, Schlumberger M, et al. Comparison of octreotide scintigraphy and conventional imaging in medullary thyroid carcinoma. J Nucl Med. 1996;37(6):912-916.
67.	Ozkan ZG, Kuyumcu S, Uzum AK, et al. Comparison of 68Ga-DOTATATE PET-CT, 18F-FDG PET-CT and 99mTc-(V)DMSA scintigraphy in the detection of recurrent or metastatic medullary thyroid carcinoma. Nucl Med Commun. 36(3):242-50, 2015 Mar.
68.	Conry BG, Papathanasiou ND, Prakash V, et al. Comparison of (68)Ga-DOTATATE and (18)F-fluorodeoxyglucose PET/CT in the detection of recurrent medullary thyroid carcinoma. Eur J Nucl Med Mol Imaging. 37(1):49-57, 2010 Jan.
69.	Yamaga LYI, Cunha ML, Campos Neto GC, et al. 68Ga-DOTATATE PET/CT in recurrent medullary thyroid carcinoma: a lesion-by-lesion comparison with 111In-octreotide SPECT/CT and conventional imaging. Eur J Nucl Med Mol Imaging. 44(10):1695-1701, 2017 Sep.
70.	American College of Radiology. ACR Appropriateness Criteria® Radiation Dose Assessment Introduction. Available at: https://edge.sitecorecloud.io/americancoldf5f-acrorgf92a-productioncb02-3650/media/ACR/Files/Clinical/Appropriateness-Criteria/ACR-Appropriateness-Criteria-Radiation-Dose-Assessment-Introduction.pdf.

Disclaimer

The ACR Committee on Appropriateness Criteria and its expert panels have developed criteria for determining appropriate imaging examinations for diagnosis and treatment of specified medical condition(s). These criteria are intended to guide radiologists, radiation oncologists and referring physicians in making decisions regarding radiologic imaging and treatment. Generally, the complexity and severity of a patient’s clinical condition should dictate the selection of appropriate imaging procedures or treatments. Only those examinations generally used for evaluation of the patient’s condition are ranked. Other imaging studies necessary to evaluate other co-existent diseases or other medical consequences of this condition are not considered in this document. The availability of equipment or personnel may influence the selection of appropriate imaging procedures or treatments. Imaging techniques classified as investigational by the FDA have not been considered in developing these criteria; however, study of new equipment and applications should be encouraged. The ultimate decision regarding the appropriateness of any specific radiologic examination or treatment must be made by the referring physician and radiologist in light of all the circumstances presented in an individual examination.