What is the best imaging modality to evaluate for abdominal metastasis in a patient with a history of ovarian borderline (ovarian tumor of low malignant potential) tumor?

From the Guidelines

For evaluating abdominal metastasis in a patient with a history of ovarian borderline tumor, contrast-enhanced CT of the abdomen and pelvis is the recommended first-line imaging modality. This should be performed with both oral and intravenous contrast for optimal visualization of potential metastatic lesions. The scan should extend from the diaphragm to the symphysis pubis to ensure complete evaluation of potential spread patterns. CT imaging provides excellent spatial resolution and can effectively detect peritoneal implants, omental cake, ascites, lymphadenopathy, and organ metastases that may occur with ovarian tumors 1.

Some key points to consider when evaluating abdominal metastasis in this patient population include:

• The use of contrast-enhanced CT for detecting recurrence in the chest, abdomen, or pelvis, with reported sensitivity ranging from 58% to 84% and specificity in the range of 59% to 100% 1.
• The limitations of non-contrast-enhanced CT in identifying small peritoneal or mesenteric implants, or lymphadenopathy among bowel loops and other adjacent organs 1.
• The potential role of MRI with contrast as a complementary study, particularly for evaluating complex pelvic masses or when CT findings are equivocal, due to its superior soft tissue contrast 1.
• The usefulness of PET/CT in select cases where there is suspicion of metastasis but conventional imaging is negative, as it can detect metabolically active disease 1.
• The limited sensitivity of ultrasound for detecting small peritoneal implants, making it less preferred for comprehensive metastatic evaluation 1.

Overall, contrast-enhanced CT of the abdomen and pelvis remains the preferred imaging modality due to its wide availability, cost-effectiveness, and ability to rapidly image the entire abdomen and pelvis with high sensitivity for detecting metastatic disease 1.

From the Research

Imaging Modalities for Abdominal Metastasis

To evaluate abdominal metastasis in a patient with a history of ovarian borderline tumor, the following imaging modalities can be considered:

• Ultrasound: usually the first-line modality for imaging ovarian tumors 2
• MRI: reserved for further characterizing indeterminate cases 2
• CT: best used to stage tumors for both locoregional and distant metastatic disease 2, 3
• FDG-PET/CT: has a high diagnostic value in differentiating between malignant and benign tumors, and can be used for primary detection, disease staging, and establishing the prognosis 4, 3

Characteristics of Borderline Ovarian Tumors

Borderline ovarian tumors have the following characteristics:

• Less soft tissue and thinner walls/septations than malignant tumors 2
• Serous borderline tumors often have papillary projections 2
• Mucinous borderline tumors are often larger, multi-cystic, and more commonly unilateral 2
• May present with pseudomyxoma peritonei, making it difficult to distinguish from malignant mucinous carcinoma 2

Diagnostic Value of FDG-PET/CT

FDG-PET/CT has the following diagnostic value:

• High diagnostic value in differentiating between malignant and benign tumors 4
• Low diagnostic value in differentiating between borderline and benign tumors 4
• Can be used to establish the prognosis and detect relapse 3