Is there a role for a handheld gamma camera (TReCam) in the SNOLL breast cancer procedure?

BACKGROUND: Sentinel node and occult lesion localization (SNOLL) calls for a combination of two specific procedures: intraoperative detection of sentinel lymph node (SLN) and radio-guided occult lesion localization (ROLL). The safety and benefits of radio-guided localization in the surgical treatment of non-palpable breast cancer have been confirmed. The aim of this study was to evaluate the potential role for an intra-operative handheld tumor resection gamma camera (TReCam) in SNOLL procedures. METHODS: Fifteen patients were enrolled. The SNOLL procedure was performed in all patients with conventional lymphoscintigraphy (LS). TReCam was used to obtain nuclear imaging in the operating theater. Concordance between LS and TReCam images, duration of use and assessment of difficulties in data acquisition with TReCam were reported. RESULTS: Concordance for tumor localization between single-detector gamma probe and TReCam was excellent (15/15). The number of radioactive SLNs visualized between LS and TReCam was equivalent in 53.3% of cases (8/15). TReCam was considered to be very easy-to-use (12/15) or easy-to-use (3/15). Average duration of acquisition with TReCam was 4 minutes and 45 seconds for the SLN procedure, and 2 minutes and 10 seconds for lumpectomy. CONCLUSIONS: This study suggests that TReCam is easy-to-use and does not increase operative time. Its exact role in radio-guided surgery needs to be clearly defined in a larger study. However, its usefulness and benefits in radio-guided breast surgery seem to be promising.

PIXSIC: A Wireless Intracerebral Radiosensitive Probe in Freely Moving Rats.

The aim of this study was to demonstrate the potential of a wireless pixelated ß+-sensitive intracerebral probe (PIXSIC) for in vivo positron emission tomographic (PET) radiopharmacology in awake and freely moving rodents. The binding of [(11)C]raclopride to D2 dopamine receptors was measured in anesthetized and awake rats following injection of the radiotracer. Competitive binding was assessed with a cold raclopride injection 20 minutes later. The device can accurately monitor binding of PET ligands in freely moving rodents with a high spatiotemporal resolution. Reproducible time-activity curves were obtained for pixels throughout the striatum and cerebellum. A significantly lower [(11)C]raclopride tracer-specific binding was observed in awake animals. These first results pave the way for PET tracer pharmacokinetics measurements in freely moving rodents.

The usefulness of a preoperative compact imager, a hand-held gamma-camera for breast cancer sentinel node biopsy: final results of a prospective double-blind, clinical study.

UNLABELLED: The aim of this study was to compare the effectiveness of a hand-held preoperative compact imager (POCI) camera with conventional lymphoscintigraphy using a γ-camera for sentinel lymph node (SLN) detection in breast cancer. METHODS: The main objective was to demonstrate the noninferiority of the POCI relative to conventional lymphoscintigraphy and to compare the number of SLNs detected by the 2 imaging devices. Our study, a clinical prospective, double-blind, noninferiority study, planned to include 200 patients with early breast cancer and started in January 2006. A standard SLN protocol (4 periareolar injections of 37 MBq of (99m)Tc-nanocolloids, 2 h before lymphoscintigraphy) was performed preoperatively using a conventional γ-camera and then the POCI camera. Scans were obtained by 2 different nuclear medicine physicians unaware of each other's results. The day after, in the operating room, the surgeon, after receiving the previous results, used the counting probe for surgical SLN biopsy. The number and localization of axillary SLNs obtained by lymphoscintigraphy and the POCI and the duration of the whole procedure were determined. RESULTS: Among the 162 patients included, 138 were evaluable. The POCI detected more SLNs than did lymphoscintigraphy in 50 patients (36%), the same number of in 54 patients (39%), and fewer SLNs in 34 patients (25%), representing 84 (61%) discordant pairs. The noninferiority of preoperative compact imaging of axillary SLNs numbers was found to be statistically significant (95% confidence interval, 30%-52%, P = 0.025) using the McNemar test. The duration of acquisition was shorter using the POCI (<10 min in 84% [n = 117] of patients; mean, 7.5 ± 3.3 min) than lymphoscintigraphy (13% [n = 18] of patients; mean, 15.7 ± 3.4 min), with P < 0.001 using the McNemar test for paired proportions. CONCLUSION: Preoperative compact imaging using a hand-held camera was able to predict the number and localization of breast cancer SLNs and was not inferior to conventional lymphoscintigraphy in this study. Further studies will determine whether preoperative compact imaging could replace lymphoscintigraphy, especially in surgical centers without an on-site nuclear medicine department.

Improved sample injection and illumination for multicapillary systems.

Multicapillary electrophoresis continues to see improvements in speed, robustness, and reliability. This paper reports on our work on two components belonging to a multicapillary sequencer developed in our group. Injection of the DNA samples into the capillaries was optimized to make it reproducible and to reduce the amount of sample volume required. An alternative laser illumination of the capillaries was also developed. Light intensity in the capillaries was increased as a result of a step-by-step scanning of the laser and the use of microlenses in front of the capillaries.

Comparison of a thermo-associating matrix and a liquid polymer.

Capillary electrophoresis is still widely used for DNA sequencing. The quality of the replaceable sieving matrix is a key area for massive sequencing with regard to speed and efficiency. The T25 polymer has been tested extensively and compared to poly(N,N-dimethylacrylamide) (PDMA). In terms of peak resolution, both polymers perform similarly. On the other hand, the run time is much shorter with the T25 polymer.

Segmentation of quantitative ultrasonographic images of the calcaneus using elastic deformation of the flexible Fourier contour.

OBJECTIVE: This study investigated a new technique for automatic model-based segmentation of broadband ultrasound attenuation (BUA) images of the calcaneus. We determined whether this technique was able to improve osteoporotic fracture discrimination. METHODS: The segmentation process included 2 major steps: a model-building stage and the automatic segmentation of new image data sets via an elastic deformation of contour models. Broadband ultrasound attenuation was then averaged within the final contour (BUAwhole). The results of the segmentation were validated on a database of 256 patients by comparison of the clinical results obtained with the automatic circular region of interest (BUAcirc) currently implemented on a commercially available ultrasonography unit. All patients were selected by the same physician, who assessed that the fractures were caused by bone fragility on the basis of the circumstances under which fractures occurred and radiologic data. RESULTS: Short-term reproducibility assessed in 49 women was 3.5% and 3.98% for BUAcirc and BUAwhole, respectively. Both BUAcirc (age-adjusted T score, -3.78; P < .0005; age-adjusted odds ratio, 1.92; 95% confidence interval, 1.34-2.75; area under the receiver operating characteristic curve, 0.70) and BUAwhole (age-adjusted T score,-2.73; P < .01; age-adjusted odds ratio, 1.57; 95% confidence interval, 1.12-2.21; area under the curve, 0.67) performed equally well in discriminating healthy postmenopausal patients (n = 150) from those with fractures (n = 60). CONCLUSIONS: Fully automatic segmentation by parametrically deformable elastic models for contour using Fourier descriptors can be achieved with reasonable reproducibility and fracture risk prediction. The method is similar to existing methods (automatic circular region of interest); however, the new contour-based region of interest allows more flexible region of interest geometries and placement and potential adaptation to individual anatomy. The method could also possibly be extended to quantitative ultrasonographic imaging at different skeletal sites.