Despite some disagreement in the literature regarding modality choice to diagnose lung metastases, patients with suspected or confirmed GTN are often initially evaluated with chest CT at many institutions. Although micrometastases are not thought to impact survival, their presence increases the likelihood of other areas of metastatic involvement and should trigger other anatomic imaging [19]. Otherwise stated, the negative predictive value of chest CT in patients with GTN is high and of substantial clinical value because hepatic or brain metastases are very unlikely in the absence of pulmonary metastases [37]. Because the lungs are the most common site of GTN metastases, the use of IV contrast is not necessary to improve lesion detection. The use of low-dose CT as a means to assess pulmonary metastases in patients with GTN was evaluated in a small study comparing standard- and low-dose CT examinations [42]. Although the number of nodules detected on the low-dose CT protocols was significantly less than the number identified on standard-dose CT examinations, the disease staging and risk score of the patients were not impacted. The EOTTD expressed a strong preference for MRI over CT for neurologic staging in a study that assessed the level of agreement among an expert panel regarding the management of patients with GTD [6]. However, in the setting of urgent neurologic findings that are due to space-occupying or hemorrhagic metastases, the ACR Gestational Trophoblastic Disease MRI Pelvis In women with GTN, pelvic MRI can delineate uterine and vaginal masses, and may provide useful detail regarding the depth of local invasion [44,46,61]. Local staging information is particularly relevant in patients with ETT or PSTT because these tumors may have extensive uterine involvement [14,15,52]. ETT and PSTT are both relatively chemoresistant, and surgical resection may have a primary role in therapy if the tumor is confined to the uterus.
Gestational Trophoblastic Disease. Despite some disagreement in the literature regarding modality choice to diagnose lung metastases, patients with suspected or confirmed GTN are often initially evaluated with chest CT at many institutions. Although micrometastases are not thought to impact survival, their presence increases the likelihood of other areas of metastatic involvement and should trigger other anatomic imaging [19]. Otherwise stated, the negative predictive value of chest CT in patients with GTN is high and of substantial clinical value because hepatic or brain metastases are very unlikely in the absence of pulmonary metastases [37]. Because the lungs are the most common site of GTN metastases, the use of IV contrast is not necessary to improve lesion detection. The use of low-dose CT as a means to assess pulmonary metastases in patients with GTN was evaluated in a small study comparing standard- and low-dose CT examinations [42]. Although the number of nodules detected on the low-dose CT protocols was significantly less than the number identified on standard-dose CT examinations, the disease staging and risk score of the patients were not impacted. The EOTTD expressed a strong preference for MRI over CT for neurologic staging in a study that assessed the level of agreement among an expert panel regarding the management of patients with GTD [6]. However, in the setting of urgent neurologic findings that are due to space-occupying or hemorrhagic metastases, the ACR Gestational Trophoblastic Disease MRI Pelvis In women with GTN, pelvic MRI can delineate uterine and vaginal masses, and may provide useful detail regarding the depth of local invasion [44,46,61]. Local staging information is particularly relevant in patients with ETT or PSTT because these tumors may have extensive uterine involvement [14,15,52]. ETT and PSTT are both relatively chemoresistant, and surgical resection may have a primary role in therapy if the tumor is confined to the uterus.