Preoperative RAS Mutational Analysis Is of Great Value in Predicting Follicular Variant of Papillary Thyroid Carcinoma

Follicular variant of papillary thyroid carcinoma (FVPTC), particularly the encapsulated subtype, often causes a diagnostic dilemma. We reconfirmed the molecular profiles in a large number of FVPTCs and investigated the efficacy of the preoperative mutational analysis in indeterminate thyroid nodules. BRAF V600E/K601E and RAS mutational analysis was performed on 187 FVPTCs. Of these, 132 (70.6%) had a point mutation in one of the BRAF V600E ( = 57), BRAF K601E ( = 11), or RAS ( = 64) genes. All mutations were mutually exclusive. The most common RAS mutations were at NRAS codon 61. FNA aspirates from 564 indeterminate nodules were prospectively tested for BRAF and RAS mutation and the surgical outcome was correlated with the mutational status. Fifty-seven and 47 cases were positive for BRAF and RAS mutation, respectively. Twenty-seven RAS-positive patients underwent surgery and all except one patient had FVPTC. The PPV and accuracy of RAS mutational analysis for predicting FVPTC were 96% and 84%, respectively. BRAF or RAS mutations were present in more than two-thirds of FVPTCs and these were mutually exclusive. BRAF mutational analysis followed by N, H, and KRAS codon 61 mutational analysis in indeterminate thyroid nodules would streamline the management of patients with malignancies, mostly FVPTC

Usefulness of Oncoplastic Volume Replacement Techniques after Breast Conserving Surgery in Small to Moderate-sized Breasts

BackgroundIn Korean women, many of whom have small to moderate-sized breasts, it is difficult to cover a partial breast defect using oncoplastic volume displacement techniques after removal of an adequate volume of tissue during oncologic surgery. In such cases, oncoplastic volume replacement techniques are more useful.MethodsFrom January 2007 to December 2011, 104 women underwent a total of 107 breast-conserving surgeries with various kinds of oncoplastic volume replacement techniques. We used latissimus dorsi (LD) myocutaneous flap for cases in which the resection mass was greater than 150 g. In case with a resection mass less than 150 g, we used regional flaps such as a lateral thoracodorsal flap, a thoracoepigastric flap, or perforator flaps such as an intercostal artery perforator (ICAP) flap or a thoracodorsal artery perforator (TDAP) flap.ResultsThe mean age was 46.1 years, and the average follow-up interval was 10.3 months. The patients underwent oncoplastic volume replacement techniques with a lateral thoracodorsal flap (n=9), thoracoepigastric flap (n=7), ICAP flap (n=25), TDAP flap (n=12), and LD flap (n=54). There was one case of congestion in an LD flap, and two cases of fat necrosis in an ICAP flap. Most of the patients were satisfied with the cosmetic results.ConclusionsOncoplastic volume replacement techniques can be reliable and useful for the correction of breast deformity after breast-conserving surgery, especially in patients with small to moderate-sized breasts

Surgical Techniques for Personalized Oncoplastic Surgery in Breast Cancer Patients with Small- to Moderate-Sized Breasts (Part 1): Volume Displacement

Despite the popularity of breast-conserving surgery (BCS), which constitutes 50-60% of all breast cancer surgeries, discussions regarding cosmetic results after BCS are not specifically conducted. The simple conservation of breast tissue is no longer adequate to qualify for BCS completion. The incorporation of oncological and plastic surgery techniques allows for the complete resection of local disease while achieving superior cosmetic outcome. Oncoplastic BCS can be performed in one of the following two ways: 1) volume displacement techniques and 2) volume replacement techniques. This study reports volume displacement surgical techniques, which allow the use of remaining breast tissue after BCS by glandular reshaping or reduction techniques for better cosmetic results. Thorough understanding of these procedures and careful consideration of the patient's breast size, tumor location, excised volume, and volume of the remaining breast tissue during the surgery in choosing appropriate patient and surgical techniques will result in good cosmetic results. Surgery of the contralateral breast may be requested to improve symmetry and may take the form of a reduction mammoplasty or mastopexy. The timing of such surgery and the merits of synchronous versus delayed approaches should be discussed in full with the patients. Because Korean women have relatively small breast sizes compared to Western women, it is not very easy to apply the oncoplastic volume displacement technique to cover defects. However, we have performed various types of oncoplastic volume displacement techniques on Korean women, and based on our experience, we report a number of oncoplastic volume displacement techniques that are applicable to Korean women with small- to moderate-sized breasts

Interferometric measurements of nonlinear optical properties for all optical switching applications in dielectric waveguides.

The successful implementation of nonlinear devices, for example for all-optical switching, depends critically on the availability of appropriate nonlinear optical materials. Most of the currently used methods to measure optical nonlinearities of materials are either indirect or inadequate for separating the fast electronic effects from slow thermo-optic processes. The motivation of this Ph.D. research was to develop a direct and accurate measurement method to evaluate the nonlinear optical properties of various, recently available waveguide materials for all-optical switching applications. A pulse modulated Mach-Zehnder scanning interferometer was built and revised to obtain a resolution of π/100 for nonlinear phase measurements. The evolution of this instrument included the development of single pulse extraction from a mode-locked pulse train, intensity modulation of single pulses, numerical Hilbert transformation of fringe data set, mode profile calculation inside waveguides with a numerical Fourier method, and a careful study of pulse breakup effect associated with instantaneous nonlinear phase shift. Electronic and thermal nonlinear refractive indices of various newly developed materials, especially DANS channel waveguides, DAN single crystal fibers, LiNbO₃ channel waveguide were examined with this method at the 1.32 μm wavelength. For the DAN single crystal cored fibers, the physical origin of the exceptionally large nonlinear phase changes in single crystal fibers was identified to be the cascading of two second order nonlinear processes. In the LiNbO₃ waveguide, cascaded nonlinear phase changes near the second harmonic phase matching temperature were demonstrated for the first time. Based on the results above, single crystal organic fibers appear very promising for ultrafast all optical switching applications. This demonstrates that the interferometric measurement method based on a scanning pulse modulated Mach-Zehnder Interferometer has proven to be one of the best methods for identifying nonlinear materials for all-optical switching applications at the 1.32 μm communications wavelength

Highly accurate wavelength scanned four-wave mixing experiment in an optical fiber and demonstration of retrieval of its linear and nonlinear optical parameters

Accurate wavelength scanned four-wave mixing (FWM) measurement results in an optical fiber are presented with two tunable laser sources near the dispersion-zero wavelength of the fiber. By comparing the measured FWM data with a simple analytic expression, we have demonstrated that important linear and nonlinear optical properties such as zero-dispersion wavelength, dispersion slope and nonlinear refractive index of the sample fiber. Highly accurate and repeatable measurement results for a sample fiber are presented. Temperature-dependent change in the chromatic dispersion of a fiber is also investigated.X11sciescopu

Novel phase-matching condition for a four-wave mixing experiment in an optical fiber

A new phase-matching condition for a four-wave-mixing (FWM) experiment in an optical fiber is proposed to simultaneously measure the linear and nonlinear optical properties of an optical fiber such as dispersion-zero wavelength, dispersion slop, and nonlinear refractive index. Several different dispersion shifted fibers (DSFs) and nonzero dispersion shifted fibers (NZDSFs) were tested to demonstrate the validity of our proposed method. We have also shown that experimental results are in good agreement with those obtained using a conventional measurement method. We believe that technique is a very powerful and efficient tool for zero-dispersion and dispersion slop mapping for already installed optical fibers. (c) 2005 Optical Society of America.X1166sciescopu