Gestational Trophoblastic Disease

Variant: 1 Suspected or initial diagnosis of gestational trophoblastic disease (GTD).

Procedure	Appropriateness Category	Relative Radiation Level
US duplex Doppler pelvis	Usually Appropriate	O
US pelvis transabdominal	Usually Appropriate	O
US pelvis transvaginal	Usually Appropriate	O
Radiography chest	May Be Appropriate	☢
MRI head without and with IV contrast	Usually Not Appropriate	O
MRI head without IV contrast	Usually Not Appropriate	O
MRI pelvis without and with IV contrast	Usually Not Appropriate	O
MRI pelvis without IV contrast	Usually Not Appropriate	O
CT abdomen and pelvis with IV contrast	Usually Not Appropriate	☢☢☢
CT abdomen and pelvis without IV contrast	Usually Not Appropriate	☢☢☢
CT chest with IV contrast	Usually Not Appropriate	☢☢☢
CT chest without and with IV contrast	Usually Not Appropriate	☢☢☢
CT chest without IV contrast	Usually Not Appropriate	☢☢☢
CT head with IV contrast	Usually Not Appropriate	☢☢☢
CT head without and with IV contrast	Usually Not Appropriate	☢☢☢
CT head without IV contrast	Usually Not Appropriate	☢☢☢
CT abdomen and pelvis without and with IV contrast	Usually Not Appropriate	☢☢☢☢
FDG-PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢☢

Variant: 2 Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).

Procedure	Appropriateness Category	Relative Radiation Level
US duplex Doppler pelvis	Usually Appropriate	O
US pelvis transabdominal	Usually Appropriate	O
US pelvis transvaginal	Usually Appropriate	O
Radiography chest	Usually Appropriate	☢
MRI pelvis without and with IV contrast	Usually Appropriate	O
CT abdomen and pelvis with IV contrast	Usually Appropriate	☢☢☢
CT chest with IV contrast	Usually Appropriate	☢☢☢
MRI head without and with IV contrast	May Be Appropriate	O
MRI pelvis without IV contrast	May Be Appropriate (Disagreement)	O
CT chest without IV contrast	May Be Appropriate	☢☢☢
CT head with IV contrast	May Be Appropriate	☢☢☢
FDG-PET/CT skull base to mid-thigh	May Be Appropriate	☢☢☢☢
MRI head without IV contrast	Usually Not Appropriate	O
CT abdomen and pelvis without IV contrast	Usually Not Appropriate	☢☢☢
CT chest without and with IV contrast	Usually Not Appropriate	☢☢☢
CT head without and with IV contrast	Usually Not Appropriate	☢☢☢
CT head without IV contrast	Usually Not Appropriate	☢☢☢
CT abdomen and pelvis without and with IV contrast	Usually Not Appropriate	☢☢☢☢

Variant: 3 Surveillance of GTN, including refractory, relapsed, or quiescent GTN.

Procedure	Appropriateness Category	Relative Radiation Level
US duplex Doppler pelvis	Usually Appropriate	O
US pelvis transabdominal	Usually Appropriate	O
US pelvis transvaginal	Usually Appropriate	O
MRI head without and with IV contrast	Usually Appropriate	O
CT abdomen and pelvis with IV contrast	Usually Appropriate	☢☢☢
CT chest with IV contrast	Usually Appropriate	☢☢☢
MRI head without IV contrast	May Be Appropriate (Disagreement)	O
MRI pelvis without and with IV contrast	May Be Appropriate	O
MRI pelvis without IV contrast	May Be Appropriate (Disagreement)	O
CT chest without IV contrast	May Be Appropriate	☢☢☢
CT head with IV contrast	May Be Appropriate	☢☢☢
CT head without and with IV contrast	May Be Appropriate	☢☢☢
CT abdomen and pelvis without and with IV contrast	May Be Appropriate (Disagreement)	☢☢☢☢
FDG-PET/CT skull base to mid-thigh	May Be Appropriate	☢☢☢☢
Radiography chest	Usually Not Appropriate	☢
CT abdomen and pelvis without IV contrast	Usually Not Appropriate	☢☢☢
CT chest without and with IV contrast	Usually Not Appropriate	☢☢☢
CT head without IV contrast	Usually Not Appropriate	☢☢☢

Variant: 4 Assessment of complications: GTD and GTN.

Procedure	Appropriateness Category	Relative Radiation Level
US pelvis transvaginal	Usually Appropriate	O
CT abdomen and pelvis with IV contrast	Usually Appropriate	☢☢☢
CT chest with IV contrast	Usually Appropriate	☢☢☢
US duplex Doppler pelvis	May Be Appropriate	O
US pelvis transabdominal	May Be Appropriate	O
Radiography chest	May Be Appropriate	☢
MRI head without and with IV contrast	May Be Appropriate	O
MRI head without IV contrast	May Be Appropriate	O
MRI pelvis without and with IV contrast	May Be Appropriate	O
MRI pelvis without IV contrast	May Be Appropriate	O
CT abdomen and pelvis without IV contrast	May Be Appropriate	☢☢☢
CT chest without and with IV contrast	May Be Appropriate (Disagreement)	☢☢☢
CT chest without IV contrast	May Be Appropriate	☢☢☢
CT head with IV contrast	May Be Appropriate	☢☢☢
CT head without and with IV contrast	May Be Appropriate	☢☢☢
CT head without IV contrast	May Be Appropriate	☢☢☢
CT abdomen and pelvis without and with IV contrast	May Be Appropriate (Disagreement)	☢☢☢☢
FDG-PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢☢

Panel Members

Summary of Literature Review

Introduction/Background

Special Imaging Considerations

Discussion of Procedures by Variant

Variant 1: Suspected or initial diagnosis of gestational trophoblastic disease (GTD).

Variant 1: Suspected or initial diagnosis of gestational trophoblastic disease (GTD).
A. US Pelvis Transvaginal

Variant 1: Suspected or initial diagnosis of gestational trophoblastic disease (GTD).
B. US Pelvis Transabdominal

Variant 1: Suspected or initial diagnosis of gestational trophoblastic disease (GTD).
C. US Duplex Doppler Pelvis

Variant 1: Suspected or initial diagnosis of gestational trophoblastic disease (GTD).
D. Radiography Chest

Variant 1: Suspected or initial diagnosis of gestational trophoblastic disease (GTD).
E. CT Chest

Variant 1: Suspected or initial diagnosis of gestational trophoblastic disease (GTD).
F. CT Head

Variant 1: Suspected or initial diagnosis of gestational trophoblastic disease (GTD).
G. CT Abdomen and Pelvis

Variant 1: Suspected or initial diagnosis of gestational trophoblastic disease (GTD).
H. MRI Head

Variant 1: Suspected or initial diagnosis of gestational trophoblastic disease (GTD).
I. MRI Pelvis

Variant 1: Suspected or initial diagnosis of gestational trophoblastic disease (GTD).
J. FDG-PET/CT Skull Base to Mid-Thigh

Variant 2: Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).

Variant 2: Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).
A. US Pelvis Transvaginal

Variant 2: Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).
B. US Pelvis Transabdominal

Variant 2: Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).
C. US Duplex Doppler Pelvis

Variant 2: Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).
D. Radiography Chest

Variant 2: Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).
E. CT Chest

Variant 2: Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).
F. CT Head

Variant 2: Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).
G. CT Abdomen and Pelvis

Variant 2: Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).
H. MRI Head

Variant 2: Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).
I. MRI Pelvis

Variant 2: Staging and risk assessment: suspected or established diagnosis of gestational trophoblastic neoplasia (GTN).
J. FDG-PET/CT Skull Base to Mid-Thigh

Variant 3: Surveillance of GTN, including refractory, relapsed, or quiescent GTN.

Variant 3: Surveillance of GTN, including refractory, relapsed, or quiescent GTN.
A. US Pelvis Transvaginal

Variant 3: Surveillance of GTN, including refractory, relapsed, or quiescent GTN.
B. US Pelvis Transabdominal

Variant 3: Surveillance of GTN, including refractory, relapsed, or quiescent GTN.
C. US Duplex Doppler Pelvis

Variant 3: Surveillance of GTN, including refractory, relapsed, or quiescent GTN.
D. Radiography Chest

Variant 3: Surveillance of GTN, including refractory, relapsed, or quiescent GTN.
E. CT Chest

Variant 3: Surveillance of GTN, including refractory, relapsed, or quiescent GTN.
F. CT Head

Variant 3: Surveillance of GTN, including refractory, relapsed, or quiescent GTN.
G. CT Abdomen and Pelvis

Variant 3: Surveillance of GTN, including refractory, relapsed, or quiescent GTN.
H. MRI Head

Variant 3: Surveillance of GTN, including refractory, relapsed, or quiescent GTN.
I. MRI Pelvis

Variant 3: Surveillance of GTN, including refractory, relapsed, or quiescent GTN.
J. FDG-PET/CT Skull Base to Mid-Thigh

Variant 4: Assessment of complications: GTD and GTN.

Variant 4: Assessment of complications: GTD and GTN.
A. US Pelvis Transvaginal

Variant 4: Assessment of complications: GTD and GTN.
B. US Pelvis Transabdominal

Variant 4: Assessment of complications: GTD and GTN.
C. US Duplex Doppler Pelvis

Variant 4: Assessment of complications: GTD and GTN.
D. Radiography Chest

Variant 4: Assessment of complications: GTD and GTN.
E. CT Chest

Variant 4: Assessment of complications: GTD and GTN.
F. CT Head

Variant 4: Assessment of complications: GTD and GTN.
G. CT Abdomen and Pelvis

Variant 4: Assessment of complications: GTD and GTN.
H. MRI Head

Variant 4: Assessment of complications: GTD and GTN.
I. MRI Pelvis

Variant 4: Assessment of complications: GTD and GTN.
J. FDG-PET/CT Skull Base to Mid-Thigh

Summary of Recommendations

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.

Safety Considerations in Pregnant Patients

Imaging of the pregnant patient can be challenging, particularly with respect to minimizing radiation exposure and risk. For further information and guidance, see the following ACR documents:

· ACR–SPR Practice Parameter for the Safe and Optimal Performance of Fetal Magnetic Resonance Imaging (MRI)

· ACR-SPR Practice Parameter for Imaging Pregnant or Potentially Pregnant Patients with Ionizing Radiation

· ACR-ACOG-AIUM-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetrical Ultrasound

· ACR Manual on Contrast Media

· ACR Manual on MR Safety

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.	Altieri A, Franceschi S, Ferlay J, Smith J, La Vecchia C. Epidemiology and aetiology of gestational trophoblastic diseases. Lancet Oncol. 2003;4(11):670-678.
2.	Goldstein DP, Berkowitz RS. Current management of gestational trophoblastic neoplasia. Hematol Oncol Clin North Am. 2012;26(1):111-131.
3.	Lurain JR. Gestational trophoblastic disease I: epidemiology, pathology, clinical presentation and diagnosis of gestational trophoblastic disease, and management of hydatidiform mole. Am J Obstet Gynecol. 2010;203(6):531-539.
4.	Hoffner L, Surti U. The genetics of gestational trophoblastic disease: a rare complication of pregnancy. Cancer Genet. 2012;205(3):63-77.
5.	Worley MJ, Jr., Joseph NT, Berkowitz RS, Goldstein DP. Women with a partial mole during their first pregnancy and diagnosed earlier in gestation are at increased risk of developing gestational trophoblastic neoplasia. Int J Gynecol Cancer. 2014;24(5):941-945.
6.	Bolze PA, Attia J, Massardier J, et al. Formalised consensus of the European Organisation for Treatment of Trophoblastic Diseases on management of gestational trophoblastic diseases. Eur J Cancer. 2015;51(13):1725-1731.
7.	Mangili G, Lorusso D, Brown J, et al. Trophoblastic disease review for diagnosis and management: a joint report from the International Society for the Study of Trophoblastic Disease, European Organisation for the Treatment of Trophoblastic Disease, and the Gynecologic Cancer InterGroup. Int J Gynecol Cancer. 2014;24(9 Suppl 3):S109-116.
8.	Shih Ie M. Gestational trophoblastic neoplasia--pathogenesis and potential therapeutic targets. Lancet Oncol. 2007;8(7):642-650.
9.	Berkowitz RS, Goldstein DP. Clinical practice. Molar pregnancy. N Engl J Med. 2009;360(16):1639-1645.
10.	Seckl MJ, Sebire NJ, Berkowitz RS. Gestational trophoblastic disease. Lancet. 2010;376(9742):717-729.
11.	Berkowitz RS, Goldstein DP. Current management of gestational trophoblastic diseases. Gynecol Oncol. 2009;112(3):654-662.
12.	Piura E, Piura B. Brain metastases from gestational trophoblastic neoplasia: review of pertinent literature. Eur J Gynaecol Oncol. 2014;35(4):359-367.
13.	Lurain JR. Gestational trophoblastic disease II: classification and management of gestational trophoblastic neoplasia. Am J Obstet Gynecol. 2011;204(1):11-18.
14.	Kuru O, Cetin C, Iyibozkurt C, Yavuz E. Placental site trophoblastic tumor: report of a tertiary center experience. Eur J Gynaecol Oncol. 2015;36(6):708-710.
15.	Moutte A, Doret M, Hajri T, et al. Placental site and epithelioid trophoblastic tumours: diagnostic pitfalls. Gynecol Oncol. 2013;128(3):568-572.
16.	Doll KM, Soper JT. The role of surgery in the management of gestational trophoblastic neoplasia. Obstet Gynecol Surv. 2013;68(7):533-542.
17.	Fulop V, Szigetvari I, Szepesi J, Vegh G, Zsirai L, Berkowitz RS. The Role of Surgery in the Management of Gestational Trophoblastic Neoplasia The Hungarian Experience. J Reprod Med. 2016;61(5-6):197-204.
18.	Hanna RK, Soper JT. The role of surgery and radiation therapy in the management of gestational trophoblastic disease. Oncologist. 2010;15(6):593-600.
19.	Soper JT. Gestational trophoblastic disease. Obstet Gynecol. 2006;108(1):176-187.
20.	Kohorn EI. International Society for the Study of Trophoblastic Diseases. The FIGO 2002 Staging and Risk Factor Scoring System for Gestational Trophoblastic Disease. Update and Critical Discussion: 2015. Available at: http://isstd.org/wp-content/uploads/2016/05/Chapter-7-FIGO-classification.pdf.
21.	Fowler DJ, Lindsay I, Seckl MJ, Sebire NJ. Routine pre-evacuation ultrasound diagnosis of hydatidiform mole: experience of more than 1000 cases from a regional referral center. Ultrasound Obstet Gynecol. 2006;27(1):56-60.
22.	Kirk E, Papageorghiou AT, Condous G, Bottomley C, Bourne T. The accuracy of first trimester ultrasound in the diagnosis of hydatidiform mole. Ultrasound Obstet Gynecol. 2007;29(1):70-75.
23.	Savage JL, Maturen KE, Mowers EL, et al. Sonographic diagnosis of partial versus complete molar pregnancy: A reappraisal. J Clin Ultrasound 2017;45:72-78.
24.	Schmid P, Nagai Y, Agarwal R, et al. Prognostic markers and long-term outcome of placental-site trophoblastic tumours: a retrospective observational study. Lancet. 2009;374(9683):48-55.
25.	Himoto Y, Kido A, Minamiguchi S, et al. Prenatal differential diagnosis of complete hydatidiform mole with a twin live fetus and placental mesenchymal dysplasia by magnetic resonance imaging. J Obstet Gynaecol Res. 2014;40(7):1894-1900.
26.	Kutuk MS, Ozgun MT, Dolanbay M, Batukan C, Uludag S, Basbug M. Sonographic findings and perinatal outcome of multiple pregnancies associating a complete hydatiform mole and a live fetus: a case series. J Clin Ultrasound. 42(8):465-71, 2014 Oct.
27.	Sebire NJ, Foskett M, Paradinas FJ, et al. Outcome of twin pregnancies with complete hydatidiform mole and healthy co-twin. Lancet. 2002;359(9324):2165-2166.
28.	Buza N, Hui P. Immunohistochemistry and other ancillary techniques in the diagnosis of gestational trophoblastic diseases. Semin Diagn Pathol. 2014;31(3):223-232.
29.	Muminhodzic L, Bogdanovic G. Ultrasonographic signs of partial hydatidiform mole. Med Arch. 2013;67(3):205-208.
30.	Malek M, Moradi B, Mousavi AS, Ahmadinejad N, Kazemi MA, Gity M. Complementary Role of Ultrasound in Management of Gestational Trophoblastic Disease. Iran J Radiol. 2015;12(2):e13955.
31.	Seckin KD, Baser E, Yeral I, Togrul C, Ozdal B, Gungor T. The impact of ultrasonographic lesion size and initial human chorionic gonadotropin values on treatment success in cases with complete hydatidiform mole. Eur Rev Med Pharmacol Sci. 2013;17(24):3381-3384.
32.	Dipi RM, Amin MS, Islam MN, Khan NA, Chaiti MM, Hossain MM. Comparison of transabdominal and transvaginal sonography in the evaluation of uterine mass with histopathological correlation. Mymensingh Med J. 22(1):69-74, 2013 Jan.
33.	Garavaglia E, Gentile C, Cavoretto P, Spagnolo D, Valsecchi L, Mangili G. Ultrasound imaging after evacuation as an adjunct to beta-hCG monitoring in posthydatidiform molar gestational trophoblastic neoplasia. Am J Obstet Gynecol. 2009;200(4):417 e411-415.
34.	Lin LH, Bernardes LS, Hase EA, Fushida K, Francisco RP. Is Doppler ultrasound useful for evaluating gestational trophoblastic disease? Clinics (Sao Paulo). 2015;70(12):810-815.
35.	Asmar FTC, Braga-Neto AR, de Rezende-Filho J, Villas-Boas JMS, Charry RC, Maesta I. Uterine artery Doppler flow velocimetry parameters for predicting gestational trophoblastic neoplasia after complete hydatidiform mole, a prospective cohort study. Clinics (Sao Paulo). 2017;72(5):284-288.
36.	Shaaban AM, Rezvani M, Haroun RR, et al. Gestational Trophoblastic Disease: Clinical and Imaging Features. RadioGraphics. 2017;37(2):681-700.
37.	Seckl MJ, Sebire NJ, Fisher RA, Golfier F, Massuger L, Sessa C. Gestational trophoblastic disease: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2013;24 Suppl 6:vi39-50.
38.	Price JM, Lo C, Abdi S, et al. The Role of Computed Tomography Scanning of the Thorax in the Initial Assessment of Gestational Trophoblastic Neoplasia. Int J Gynecol Cancer. 2015;25(9):1731-1736.
39.	Mutch DG, Soper JT, Baker ME, et al. Role of computed axial tomography of the chest in staging patients with nonmetastatic gestational trophoblastic disease. Obstet Gynecol. 1986;68(3):348-352.
40.	Hong DG, Cho YL, Park IS, Lee YS. Chest computed tomography before evacuation of hydatidiform mole. Eur J Gynaecol Oncol. 2009;30(2):151-154.
41.	Darby S, Jolley I, Pennington S, Hancock BW. Does chest CT matter in the staging of GTN? Gynecol Oncol. 2009;112(1):155-160.
42.	Xu XJ, Lou FL, Zhang MM, Pan ZM, Zhang L. Usefulness of low-dose CT in the detection of pulmonary metastasis of gestational trophoblastic tumours. Clin Radiol. 2007;62(10):998-1003.
43.	Strohl AE, Lurain JR. Postmolar choriocarcinoma: An independent risk factor for chemotherapy resistance in low-risk gestational trophoblastic neoplasia. Gynecol Oncol. 2016;141(2):276-280.
44.	Dhanda S, Ramani S, Thakur M. Gestational trophoblastic disease: a multimodality imaging approach with impact on diagnosis and management. Radiol Res Pract. 2014;2014:842751.
45.	Kani KK, Lee JH, Dighe M, Moshiri M, Kolokythas O, Dubinsky T. Gestatational trophoblastic disease: multimodality imaging assessment with special emphasis on spectrum of abnormalities and value of imaging in staging and management of disease. Curr Probl Diagn Radiol. 2012;41(1):1-10.
46.	Sefidbakht S, Hosseini F, Bijan B, Hamedi B, Azizi T. Qualitative and quantitative analysis of diffusion-weighted imaging of gestational trophoblastic disease: Can it predict progression of molar pregnancy to persistent form of disease? Eur J Radiol. 2017;88:71-76.
47.	Mangili G, Bergamini A, Giorgione V, et al. [(1)(8)F]fluorodeoxyglucose positron emission tomography/computed tomography and trophoblastic disease: the gynecologist perspective. Q J Nucl Med Mol Imaging. 2016;60(2):103-116.
48.	Soto-Wright V, Bernstein M, Goldstein DP, Berkowitz RS. The changing clinical presentation of complete molar pregnancy. Obstet Gynecol. 1995;86(5):775-779.
49.	Sun SY, Melamed A, Goldstein DP, et al. Changing presentation of complete hydatidiform mole at the New England Trophoblastic Disease Center over the past three decades: does early diagnosis alter risk for gestational trophoblastic neoplasia? Gynecol Oncol. 2015;138(1):46-49.
50.	El-Helw LM, Hancock BW. Treatment of metastatic gestational trophoblastic neoplasia. Lancet Oncol. 2007;8(8):715-724.
51.	Kohorn EI. Imaging practices in the diagnosis and management of gestational trophoblastic disease: an assessment. J Reprod Med. 2012;57(5-6):207-210.
52.	Shen X, Xiang Y, Guo L, et al. Analysis of clinicopathologic prognostic factors in 9 patients with epithelioid trophoblastic tumor. Int J Gynecol Cancer. 2011;21(6):1124-1130.
53.	Qin J, Ying W, Cheng X, et al. A well-circumscribed border with peripheral Doppler signal in sonographic image distinguishes epithelioid trophoblastic tumor from other gestational trophoblastic neoplasms. PLoS One. 2014;9(11):e112618.
54.	Shih IM, Kurman RJ. Epithelioid trophoblastic tumor: a neoplasm distinct from choriocarcinoma and placental site trophoblastic tumor simulating carcinoma. Am J Surg Pathol. 1998;22(11):1393-1403.
55.	Zhou Y, Lu H, Yu C, Tian Q, Lu W. Sonographic characteristics of placental site trophoblastic tumor. Ultrasound Obstet Gynecol. 2013;41(6):679-684.
56.	Agarwal R, Harding V, Short D, et al. Uterine artery pulsatility index: a predictor of methotrexate resistance in gestational trophoblastic neoplasia. Br J Cancer. 2012;106(6):1089-1094.
57.	Cavoretto P, Gentile C, Mangili G, et al. Transvaginal ultrasound predicts delayed response to chemotherapy and drug resistance in stage I low-risk trophoblastic neoplasia. Ultrasound in Obstetrics & Gynecology. 40(1):99-105, 2012 Jul.
58.	Sita-Lumsden A, Medani H, Fisher R, et al. Uterine artery pulsatility index improves prediction of methotrexate resistance in women with gestational trophoblastic neoplasia with FIGO score 5-6. BJOG. 2013;120(8):1012-1015.
59.	Wang W, Tian X, Zhang T, Wang Y, Han Z, An R. Characteristics of Three-Dimensional Power Doppler in Gestational Trophoblastic Disease. Dis Markers. 2015;2015:917687.
60.	Lazovic B, Milenkovic V, Dordevic S. Treatment of gestational trophoblastic disease--a 10-year experience. Med Pregl. 2012;65(5-6):244-246.
61.	Allen SD, Lim AK, Seckl MJ, Blunt DM, Mitchell AW. Radiology of gestational trophoblastic neoplasia. Clin Radiol. 2006;61(4):301-313.
62.	Price JM, Hancock BW, Tidy J, Everard J, Coleman RE. Screening for central nervous system disease in metastatic gestational trophoblastic neoplasia. J Reprod Med. 2010;55(7-8):301-304.
63.	American College of Radiology. ACR Appropriateness Criteria®: Headache. Available at: https://acsearch.acr.org/docs/69482/Narrative/.
64.	American College of Radiology. ACR Appropriateness Criteria®: Acute Mental Status Change, Delirium, and New Onset Psychosis. Available at: https://acsearch.acr.org/docs/3102409/Narrative/.
65.	Kageyama S, Kanoto M, Sugai Y, et al. MR Imaging of Uterine Epithelioid Trophoblastic Tumor: A Case Report. Magn Reson Med Sci. 2016;15(4):411-415.
66.	Chang TC, Yen TC, Li YT, et al. The role of 18F-fluorodeoxyglucose positron emission tomography in gestational trophoblastic tumours: a pilot study. Eur J Nucl Med Mol Imaging. 2006;33(2):156-163.
67.	Lai CH, Yen TC, Chang TC. Positron emission tomography imaging for gynecologic malignancy. [Review] [53 refs]. Curr Opin Obstet Gynecol. 19(1):37-41, 2007 Feb.
68.	Mapelli P, Mangili G, Picchio M, et al. Role of 18F-FDG PET in the management of gestational trophoblastic neoplasia. Eur J Nucl Med Mol Imaging. 2013;40(4):505-513.
69.	Yen TC, Lai CH. Positron emission tomography in gynecologic cancer. [Review] [136 refs]. Seminars in Nuclear Medicine. 36(1):93-104, 2006 Jan.Semin Nucl Med. 36(1):93-104, 2006 Jan.
70.	Ngu SF, Chan KK. Management of Chemoresistant and Quiescent Gestational Trophoblastic Disease. Curr Obstet Gynecol Rep. 2014;3:84-90.
71.	Powles T, Savage P, Short D, Young A, Pappin C, Seckl MJ. Residual lung lesions after completion of chemotherapy for gestational trophoblastic neoplasia: should we operate? Br J Cancer. 2006;94(1):51-54.
72.	Dhillon T, Palmieri C, Sebire NJ, et al. Value of whole body 18FDG-PET to identify the active site of gestational trophoblastic neoplasia. J Reprod Med. 2006;51(11):879-887.
73.	Yang J, Xiang Y, Wan X, Feng F, Ren T. Analysis of the prognosis and related factors for patients with stage IV gestational trophoblastic neoplasia. Int J Gynecol Cancer. 2014;24(3):594-599.
74.	American College of Radiology. ACR-SPR Practice Parameter for Imaging Pregnant or Potentially Pregnant Patients with Ionizing Radiation. Available at: https://gravitas.acr.org/PPTS/GetDocumentView?docId=23+&releaseId=2.
75.	Iraha Y, Okada M, Toguchi M, et al. Multimodality imaging in secondary postpartum or postabortion hemorrhage: retained products of conception and related conditions. Jpn J Radiol. 2018;36(1):12-22.
76.	American College of Radiology. ACR–SPR Practice Parameter for the Safe and Optimal Performance of Fetal Magnetic Resonance Imaging (MRI). Available at: https://gravitas.acr.org/PPTS/GetDocumentView?docId=89+&releaseId=2.
77.	American College of Radiology. ACR-ACOG-AIUM-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetrical Ultrasound. Available at: https://gravitas.acr.org/PPTS/GetDocumentView?docId=28+&releaseId=2.
78.	American College of Radiology. Manual on Contrast Media. Available at: https://www.acr.org/Clinical-Resources/Contrast-Manual.
79.	Expert Panel on MR Safety, Kanal E, Barkovich AJ, et al. ACR guidance document on MR safe practices: 2013. J Magn Reson Imaging. 37(3):501-30, 2013 Mar.
80.	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.