Radioactive seed localization is the preferred technique in nonpalpable breast cancer compared with wire-guided localization and radioguided occult lesion localization.

OBJECTIVES: Three commonly used techniques for localization of nonpalpable breast cancer are radioactive seed localization (RSL), wire-guided localization (WGL) and radioguided occult lesion localization (ROLL). In this study, we analysed the surgical margins of these three techniques. METHODS: Women diagnosed with nonpalpable breast cancer undergoing breast-conserving surgery with one of the above-mentioned techniques were retrospectively included. The primary outcome parameter was tumour-free margin rate. Secondary outcomes were re-excision rate, recurrence of disease and volume of removed tissue. RESULTS: In total, 272 women were included in whom RSL (n=69), WGL (n=76) or ROLL (n=137) was performed. RSL showed a higher tumour-free margin rate [64 (92.8%)] compared with WGL [51 (67.1%)] and ROLL [113 (82.5%)] (P=0.001). In our multivariable analysis, RSL showed a higher tumour-free margin rate as well compared with WGL (P=0.036) and ROLL (P=0.049). Also, fewer re-excisions were encountered using RSL [5 (7.2%)] compared with WGL [13 (17.1%)] and ROLL [15 (10.9%)] (P=0.171). In 11 patients (WGL n=2, ROLL n=9), recurrence of disease occurred, despite a radical excision. The mean resection volumes were comparable within the three groups. CONCLUSION: RSL results in a higher tumour-free margin rate in nonpalpable breast tumours compared with WGL and ROLL. Therefore, we prefer using RSL in nonpalpable breast tumours.

In vivo optical microscopy of peripheral nerve myelination with polarization sensitive-optical coherence tomography.

Assessing nerve integrity and myelination after injury is necessary to provide insight for treatment strategies aimed at restoring neuromuscular function. Currently, this is largely done with electrical analysis, which lacks direct quantitative information. In vivo optical imaging with sufficient imaging depth and resolution could be used to assess the nerve microarchitecture. In this study, we examine the use of polarization sensitive-optical coherence tomography (PS-OCT) to quantitatively assess the sciatic nerve microenvironment through measurements of birefringence after applying a nerve crush injury in a rat model. Initial loss of function and subsequent recovery were demonstrated by calculating the sciatic function index (SFI). We found that the PS-OCT phase retardation slope, which is proportional to birefringence, increased monotonically with the SFI. Additionally, histomorphometric analysis of the myelin thickness and g-ratio shows that the PS-OCT slope is a good indicator of myelin health and recovery after injury. These results demonstrate that PS-OCT is capable of providing nondestructive and quantitative assessment of nerve health after injury and shows promise for continued use both clinically and experimentally in neuroscience.

Real-time in vivo assessment of the nerve microenvironment with coherent anti-Stokes Raman scattering microscopy.

BACKGROUND: Current analysis of nerve injury and repair relies largely on electrophysiologic and ex vivo histologic techniques. In vivo architectural assessment of a nerve without removal or destruction of the tissue would greatly assist in the grading of nerve injury and in the monitoring of nerve regeneration over time. Coherent anti-Stokes Raman scattering microscopy is an optical process with particular sensitivity for high-lipid-containing molecules such as myelin. This in vivo nonthermal technique offers high-resolution images that the authors aim to evaluate in both normal and injured nerves. METHODS: A demyelinating crush injury was reproduced in the sciatic nerves of Sprague-Dawley rats (n = 12). Animals were randomized into groups, and coherent anti-Stokes Raman scattering microscopy was undertaken at day 1 and weekly up to 4 weeks after injury. Functional analysis was undertaken weekly and histomorphometry was completed after imaging. RESULTS: All animals demonstrated loss of sciatic nerve function following injury. Recovery was documented, with functional data approaching normal at 3 and 4 weeks. Demyelination was confirmed in nerves up to 2 weeks after injury. Remyelination was observed in the 3-week group and beyond. Imaging of normal nerve revealed structured myelin bundles. These results were consistent with histologic findings that showed a statistically significant improvement in myelination over time. CONCLUSIONS: The authors conclude that coherent anti-Stokes Raman scattering microscopy has the ability to image the peripheral nerve following demyelinating crush injury. This technology, which permits in vivo, real-time microscopy of nerves at a resolution of 5 mum, could provide invaluable diagnostic and prognostic information regarding intraneural preservation and recovery following injury.