Physicians may be able to use a combination of two imaging techniques based on sound and light waves to differentiate early-stage cancers from benign lesions, according to a study published in Radiology (2010 Jun 22. [Epub ahead of print]).
According to background information provided by the authors, when mammography and ultrasound cannot determine whether a suspicious breast lesion is malignant or benign, physicians typically recommend a needle biopsy to extract samples of the suspicious tissue for laboratory testing. In current clinical practice, 70-80% of biopsies performed reveal benign lesions, leading to unnecessary cost and anxiety for women.
The study, led by Quing Zhu, PhD, professor of bioengineering at the University of Connecticut, sought to investigate the potential of ultrasound-guided optical tomography, an emerging noninvasive imaging technique, as a means of reducing the number of breast biopsies.
Included in the study were 178 consecutive women between the ages of 21 and 89 years who underwent ultrasound-guided diffuse optical tomography (DOT) on a previously identified solid lesion, followed by a biopsy. Using DOT to measure light absorption within the tissue, researchers computed total hemoglobin levels and correlated the measurements with biopsy results.
Researchers reported that both maximum and average total hemoglobin levels were significantly higher in the malignant group than in the benign group. Specifically, laboratory examination of tissue samples revealed two in situ carcinomas, 35 carcinomas that measured less than 2 cm, 24 carcinomas greater than 2 cm, and 114 benign lesions.
“Based on our results, we believe that ultrasound-guided diffuse optical tomography holds promise as an adjunct to diagnostic mammography and ultrasound for distinguishing early-stage invasive breast cancers from benign lesions,” said Dr. Zhu. “We expect this technology will be used to help radiologists evaluate small to intermediate size lesions that are harder to diagnose with conventional imaging technologies.”