Microwave imaging for neoadjuvant chemotherapy monitoring: initial clinical experience.

INTRODUCTION: Microwave tomography recovers images of tissue dielectric properties, which appear to be specific for breast cancer, with low-cost technology that does not present an exposure risk, suggesting the modality may be a good candidate for monitoring neoadjuvant chemotherapy. METHODS: Eight patients undergoing neoadjuvant chemotherapy for locally advanced breast cancer were imaged longitudinally five to eight times during the course of treatment. At the start of therapy, regions of interest (ROIs) were identified from contrast-enhanced magnetic resonance imaging studies. During subsequent microwave examinations, subjects were positioned with their breasts pendant in a coupling fluid and surrounded by an immersed antenna array. Microwave property values were extracted from the ROIs through an automated procedure and statistical analyses were performed to assess short term (30 days) and longer term (four to six months) dielectric property changes. RESULTS: Two patient cases (one complete and one partial response) are presented in detail and demonstrate changes in microwave properties commensurate with the degree of treatment response observed pathologically. Normalized mean conductivity in ROIs from patients with complete pathological responses was significantly different from that of partial responders (P value = 0.004). In addition, the normalized conductivity measure also correlated well with complete pathological response at 30 days (P value = 0.002). CONCLUSIONS: These preliminary findings suggest that both early and late conductivity property changes correlate well with overall treatment response to neoadjuvant therapy in locally advanced breast cancer. This result is consistent with earlier clinical outcomes that lesion conductivity is specific to differentiating breast cancer from benign lesions and normal tissue.

Contamination artifact that mimics in-situ carcinoma on contrast-enhanced digital mammography.

PURPOSE: Contrast-enhanced digital mammography (CEDM) is an advanced breast imaging technique using iodinated intravenous contrast to detect breast cancer. This article describes imaging features of a skin contamination artifact on CEDM that mimics in-situ carcinoma in a case series. MATERIALS AND METHODS: Five patients were identified whose CEDM images demonstrated apparent calcifications and non-mass enhancement suspicious for in-situ carcinoma, with no subsequent evidence of disease. Retrospective image analysis was performed on the unprocessed image data, processed images, and imaging parameters. Dual-energy mammographic technique was performed on two breast phantoms with varying degrees of topical contrast contamination. RESULTS: Temporal analysis confirmed the suspicious finding was neither an abnormality of the compression paddle nor the receptor. Comparison of LE and HE images demonstrated the suspicious finding attenuated near the K-edge of iodine, suggesting contrast contamination. Iodinated contrast applied to the surface of breast phantoms replicated the artifact, with a pattern of apparent enhancement similar to the appearance of in-situ carcinoma. CONCLUSION: Skin contamination with iodinated contrast can result in an artifact on post-contrast digital mammography that mimics the appearance of in-situ carcinoma.