Usefulness of automated breast volume scanner (ABVS) for monitoring tumor response to neoadjuvant treatment in breast cancer patients: preliminary results

OBJECTIVE: We investigated the accuracy of Automated Breast Volume Scanner (ABVS) compared to handheld ultrasound (HHUS) for monitoring tumor response to neoadjuvant treatment (NAT) in breast cancer (BC).PATIENTS AND METHODS: All the patients submitted to biopsy in our Institution, from January 2017 to May 2017, proven invasive BC and eligible for NAT, were enrolled in this prospective study. The participants underwent ABVS, HHUS, dynamic contrast-enhanced Magnetic Resonance Imaging (DCE-MRI) and mammography at the beginning of NAT and ABVS. HHUS and DCE-MRI at the halfway point of therapy and before the surgery. DCE-MRI was considered the standard of reference. Two breast radiologists (R1, R2), with fifteen and five years of experience in breast imaging, independently assigned a visibility score (ordinal 5-point scale) to ABVS, HHUS, and DCE-MRI. Diagnostic performance of ABVS and HHUS as measured by sensitivity, specificity, positive and negative predictive values (PPV and NPV) was calculated. Correlations between ABVS and MRI, and between HHUS and MRI were analyzed using Pearson's correlation test.RESULTS: A total of 21 patients were enrolled. 189 examinations were performed. The comparison between ABVS and DCE-MRI was similar for the both readers: ABVS had a sensitivity of 63,16%, specificity of 83,58%, PPV of 76,60%, NPV of 72,73%, accuracy of 74,19% (R1) and a sensitivity of 54.54%, specificity of 85.51%, PPV of 75%, NPV of 70,24%, accuracy of 71.77% (R2). The comparison between HHUS and DCE-MRI showed that HHUS had a sensitivity of 63,16 %, specificity of 83,58%, PPV of 76,60%, NPV of 72,73%, accuracy of 74,19% (R1) and a sensitivity of 36.84%, specificity of 85.07%, PPV of 67.74%, NPV of 61.29%, accuracy of 62.90% (R2). The calculated Pearson's correlation coefficient r values were 7.8 for HHUS vs. DCE-MRI and 28.5 for ABVS vs. DCE-MRI (R1) and 7.8 for HHUS vs. DCE-MRI and 22.4 for ABVS vs. DCE-MRI (R2). Statistical significance of ABVS and HHUS was p < 0.0001 and 0.005 < p < 0.01, respectively (R1, R2).CONCLUSIONS: DCE-MRI is recommended for the tumor response assessment. ABVS, a product of the biotechnology development, providing reproducible images, in addition to DCE-MRI, can be a potentially useful tool for the monitoring of response to NAT.