What type of computed tomography (CT) scan, with or without contrast, is used to evaluate for metastasis after salpingo-oophorectomy (removal of the ovary and fallopian tube) that showed an ovarian neoplasm?

From the Guidelines

For evaluating metastasis after salpingo-oophorectomy that revealed an ovarian neoplasm, I strongly recommend a contrast-enhanced CT scan of the abdomen and pelvis, with oral contrast, as the imaging modality of choice. This recommendation is based on the most recent and highest quality evidence from the American College of Radiology 1. The use of contrast-enhanced CT allows for improved detection of metastatic lesions by highlighting differences in vascularity between normal tissue and tumor deposits.

Key Considerations

• The scan should extend from the diaphragm to the symphysis pubis to evaluate common sites of ovarian cancer spread, including peritoneal surfaces, omentum, lymph nodes, and liver 1.
• Depending on the histological type of the ovarian neoplasm, consideration should also be given to including a chest CT to evaluate for thoracic metastases, particularly for high-grade or advanced-stage tumors 1.
• Timing of the scan is important, typically performed 4-6 weeks post-surgery to allow for healing and to establish a baseline for future surveillance.
• Intravenous contrast is preferable for detection and characterization of lesions suspected to represent tumor deposits, unless contraindicated 1.

Alternative Imaging Modalities

• FDG-PET/CT is also considered an equivalent alternative to CT for evaluating metastasis, particularly in cases where CT is indeterminate 1.
• MRI may be used as an alternative to CT in certain cases, such as borderline tumors or ovarian cancers that have been previously staged with fertility preservation, or for patients whose CT findings are inconclusive 1. However, CT remains the most widely used imaging method for detecting recurrence.

Conclusion is not needed as per the guidelines, the above recommendation is based on the latest evidence 1.

From the Research

Computed Tomography (CT) Scan for Metastasis Evaluation

To evaluate for metastasis after salpingo-oophorectomy that showed an ovarian neoplasm, the following types of CT scans can be used:

• Contrast-enhanced CT scan: This type of scan uses intravenous iodine contrast medium to provide more accurate diagnosis with higher confidence 2.
• Non-contrast CT scan: This type of scan may not provide as much detail as contrast-enhanced CT scan, but can still be used to evaluate for metastasis.

Comparison with Other Imaging Modalities

CT scan can be compared with other imaging modalities such as:

• Ultrasound: Ultrasound may be an alternative to CT scan in ovarian cancer staging, including peritoneal and lymph-node evaluation and prediction of non-resectability based on abdominal markers of non-resectability 3.
• MRI: Whole-body magnetic resonance imaging with diffusion-weighted sequence (WB-DWI/MRI) may perform better than CT scan in the assessment of overall peritoneal carcinomatosis 3.
• PET/CT: Integrated FDG-PET/CT has been used successfully for the diagnosis, staging, restaging, therapy monitoring and prognostic prediction of ovarian cancer 2, 4.

Postoperative CT Scan Findings

After salpingo-oophorectomy, the following abnormalities may be seen on CT scan:

• Thickened round ligaments with bulbous masses at the surgically transected ends 5.
• Vaginal vault thickening 5.
• Subtle omental bed stranding or nodularity 5.
• Peritoneal thickening underlying the scar 5.
• Asymmetrical rectus abdominis muscles adjacent to the surgical scar or thickened scar tissue in the anterior abdominal wall 5.