Interventional Radiology clinical trials

Using Color Doppler US Artifact to Identify Tumor Markers

Before neoadjuvant chemotherapy (NACT) in cases of locally advanced breast cancer, malignant masses in the breast and biopsy-proven tumor involvement axillary lymph nodes are marked with metallic markers. The primary objective of this marking is to establish the precise localization of the tumor which response to NACT partial or completely. However, selecting the marker with ultrasound (US) proves challenging in many instances. Research studies indicate that patients with occult markers are observed at a frequency of 24%. Some studies propose that the twinkling artifact serves as a reliable method for accurately indicating the localization of certain tumor markers. This artifact is deemed particularly helpful for lesions situated in the axilla or posterior of the breast, which may not be visible with US and are undetectable with mammography. In the context of Color Doppler examination, the investigators have noted the presence of another color Doppler artifact which can aid in determining marker localization. When the pulse repetition frequency (PRF) is reduced and the color gain is increased, color noise, termed as color confusion or blooming artifact/effect, is observed within the color steer. While this color confusion tends to mask healthy tissues, it has been observed that the tumor marker remains unaffected by the blooming effect. Consequently, this artifact serves to distinctly reveal the borders and localization of the tumor marker. In some studies, it has been stated that the twinkling artifact, which is a color Doppler artifact and whose mechanism is not fully understood, is a reliable method to accurately indicate the localization of some tumor markers. It has been reported that this artifact will be very helpful, especially in lesions located in the axilla or posterior of the breast, which cannot be seen with US and cannot be detected with mammography . In Color Doppler examination, we saw that another color Doppler artifact, such as the twinkling artifact, could also be helpful in determining marker localization. When the PRF is reduced and the color gain is increased, color noise, which is selected as color confusion and can be called blooming artifact or blooming effect-like, is observed in all structures within the color steer. While healthy tissues are masked by this color confusion, the tumor marker is protected from the blooming effect. Thus, with this artifact, tumor marker borders and localization are clearly revealed.