Phase I results for the Efficacy of Ultrasound-Guided Cryoablation of Small Unifocal Invasive Ductal Breast Cancer

Sanarus Visica 2™ Treatment System May Offer Same Therapeutic Benefits as Lumpectomy with Improved Cosmesis and Lower Cost

In December 2008, an early clinical study using the Visica 2™ Treatment System confirmed the effectiveness of ultrasound-guided cryoablation for the complete eradication of small (≤ 15 mm) unifocal invasive ductal breast cancer (IDC). Initial data from this multi-center study were presented at the 94th Scientific Assembly of the Radiological Society of North America (RSNA) held November 29 – December 5, 2008.

“New Findings on Contrast-Enhanced Magnetic Resonance Imaging, the ‘Black Hole’ and ‘Cryohalo’ are Markers for the Efficacy of Ultrasound-Guided Cryoablation of Small Unifocal Invasive Ductal Breast Cancer.” Presented by Gary Levine, MD, Director of Breast Imaging at Hoag Breast Care Center, Newport Beach, CA.

This study was designed to evaluate the ability of breast contrast enhanced MRI to assess the effectiveness of ultrasound guided cryoablation for the local treatment of small unifocal invasive ductal (IDC) breast cancer. “With a large body of evidence demonstrating the ability of cryoablation to destroy cancerous and noncancerous tumors of the liver, prostate, kidney and breast, the gating factor for the treatment of breast cancer tumors was the ability to visualize the extent of the tumor in advance and confirm target destruction post-procedure,” said Dr. Levine.

Patients (n=15) in the study with newly diagnosed IDC underwent an early pre-ablation contrast enhanced MRI (CEMRI) to establish the MRI enhancement pattern. Ultrasound-guided cryoablation was then performed using the Visica Treatment System. A delayed CEMRI was performed approximately 4 weeks post ablation followed by a standard surgical lumpectomy. The early and delayed CEMRI findings were correlated with the surgical histopathology.

In all 15 cases, the post ablation MRI’s showed no suspicious contrast enhancement remaining at the targeted tumor site. Histopathology confirmed complete tumor kill within the intended ablation zone. In 3 cases, histopathology confirmed residual DCIS and/or small satellite lesions outside the cryoablation zone.

In explaining the clinical relevance of the study, Dr. Levine stated, “We are very encouraged that our preliminary results demonstrate that in selected early IDC breast cancers, cryoablation with MRI confirmation may offer the same therapeutic benefit as lumpectomy with less morbidity, improved cosmesis and less cost.