64-slice CT shines in mapping breast tumor extent

November 29, 2006

Move over MRI and ultrasonography: 64-slice CT is staking a claim in assessment of tumor extent in patients with locally advanced breast cancer ahead of conservation surgery.

Move over MRI and ultrasonography: 64-slice CT is staking a claim in assessment of tumor extent in patients with locally advanced breast cancer ahead of conservation surgery.

Neoadjuvant therapy before surgery is common in these cases. To avoid recurrence, it is vital to accurately measure tumor extent.

A small study from the University of Rome Tor Vergata found that dynamic contrast-enhanced 64-slice CT was superior to both ultrasound and 3D dynamic MRI for evaluating residual cancer after neoadjuvant chemotherapy. The study consisted of 36 women with biopsy-proven locally advanced breast cancer.

Researchers performed two dynamic contrast-enhanced scans, one taken 60 seconds after administration of contrast and a second after a three-minute delay. Maximum intensity projection and multiplanar reformatted images enabled visualization of breast cancer extent and assessment of histological size.

Of the total study group, 26 responded to therapy. Dynamic CT most closely agreed with pathology results, boasting 86% accuracy. In comparison, MRI's accuracy was 80%, and ultrasound scored 72%.

CT was particularly good with fatty breasts, said radiology resident Dr. Francesca Bolacchi, who presented results. The findings have encouraged use of 64-slice CT in patients who have undergone neoadjuvant therapy and are scheduled for surgery.