Development of Preclinical Ultrasound Imaging Techniques to Identify and Image Sentinel Lymph Nodes in a Cancerous Animal Model.

Lymph nodes (LNs) are believed to be the first organs targeted by colorectal cancer cells detached from a primary solid tumor because of their role in draining interstitial fluids. Better detection and assessment of these organs have the potential to help clinicians in stratification and designing optimal design of oncological treatments for each patient. Whilst highly valuable for the detection of primary tumors, CT and MRI remain limited for the characterization of LNs. B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) can improve the detection of LNs and could provide critical complementary information to MRI and CT scans; however, the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) guidelines advise that further evidence is required before US or CEUS can be recommended for clinical use. Moreover, knowledge of the lymphatic system and LNs is relatively limited, especially in preclinical models. In this pilot study, we have created a mouse model of metastatic cancer and utilized 3D high-frequency ultrasound to assess the volume, shape, and absence of hilum, along with CEUS to assess the flow dynamics of tumor-free and tumor-bearing LNs in vivo. The aforementioned parameters were used to create a scoring system to predict the likelihood of a disease-involved LN before establishing post-mortem diagnosis with histopathology. Preliminary results suggest that a sum score of parameters may provide a more accurate diagnosis than the LN size, the single parameter currently used to predict the involvement of an LN in disease.

Comparison of Acorn and Fluted Reamers on Tibial Tunnel Outer Aperture Dimensions in ACL Reconstruction.

The aim of this study was to determine if the type of reamer used in tibial tunnel creation during anterior cruciate ligament (ACL) reconstruction influences the dimensions of the tunnel's outer aperture. Tibial tunnels were created in tibial saw bones by reaming over a guidewire using an 8 mm acorn or fluted reamer in an antegrade manner. Reaming was aimed either in line with the guidewire, or with 10-degree inferior/superior deviation in relation to the wire. The shape and size of the outer aperture of the tibial tunnel were compared between the two reamers. When using the acorn reamer, a 10-degree deviation in relation to the guidewire resulted in minimal change in outer aperture length (mean 13.6 vs. 15.6 mm, p = 0.11) and width (11.6 vs. 11.1 mm, p = 0.51). However, when using the fluted reamer, although the aperture width showed no substantial change with reamer/guidewire deviation (11.4 vs. 11.2 mm, p = 0.71), the mean length almost doubled (14.7 vs. 28.1 mm, p = 0.002). The use of a fluted reamer when reaming the tibial tunnel creates a distal aperture which is inconsistently sized, larger, and of oblong shape compared with an acorn-shaped reamer. This should be taken in consideration when using a fluted reamer for creating the tibial tunnel in ACL reconstruction.

Surgeon-led Intraoperative Ultrasound Localization for Nonpalpable Breast Cancers: Results of 5 Years of Practice.

BACKGROUND: The uptake of breast screening has led to a rise in the number of nonpalpable breast cancer diagnoses. Breast conserving therapy (BCT) is the treatment of choice for early breast cancer, and this requires localization of the lesion. Commonly detection is achieved by wire-guided localization in the radiology department. This technique has complications and requires utilization of a radiologist. Intraoperative ultrasound (IOUS) has been shown to be a safe alternative, but there is little data on its use. The aim of this study is to report the use of surgeon-led IOUS over the past 5 years, assessing the ability to detect lesions and the re-excision rate for involved margins. PATIENTS AND METHODS: A retrospective observational study was performed on consecutive patients undergoing IOUS-marked BCT between 2014 and 2018. The technique is described, and patients' records were reviewed to assess the histologic specimen reports and need for subsequent re-excision. RESULTS: Ninety-five IOUS BCT operations were performed. Every cancer was identified by IOUS and removed. Fourteen margins were positive and required re-excision. Of these, only 2 contained residual tumor. CONCLUSION: This is the first data from the United Kingdom for IOUS skin marking without wire localization. IOUS is a safe method of localization in BCT. It offers advantages both to the patient and the unit as it reduces pressure on the radiology department.