Thermoluminescence study of Mn doped lithium tetraborate powder and pellet samples synthesized by solution combustion synthesis

In this paper, the thermoluminescence (TL) dosimetric characteristics under beta-ray, x-ray and gamma-ray excitations of powder and pellet Mn-doped lithium tetraborates (LTB) which were produced by solution combustion synthesis technique were investigated, and the results were compared with that of TLD-100 chips. The chemical composition and morphologies of the obtained LTB and Mn-doped LTB (LTB:Mn) were confirmed by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) and scanning electron microscopy (SEM) with EDX. LTB:Mn was studied using luminescence spectroscopy. In addition, the effects of sintering and annealing temperatures and times on the thermoluminescence (TL) properties of LTB:Mn were investigated. The glow curves of powder samples as well as pellet samples exposed to different beta doses exhibited a low temperature peak at about 100 °C followed by an intense principal high temperature peak at about 260 °C. The kinetic parameters (E, b, s) associated with the prominent glow peaks were estimated using Tm-Tstop, initial rise (IR) and computerized glow curve deconvolution (CGCD) methods. The TL response of integral TL output increased linearly with increasing the dose in the range of 0.1-10 Gy and was followed by a superlinearity up to 100 Gy both for powder and pellet samples using beta-rays. Powder and pellet LTB:Mn were irradiated to a known dose by a linear accelerator with 6 and 18 MV photon beams, 6-15 MeV electron beams and a traceable 137Cs beam to investigate energy response. Further, TL sensitivity, fading properties and recycling effects related with beta exposure of LTB:Mn phosphor were evaluated and its relative energy response was also compared with that of TLD-100 chips. The comparison of the results showed that the obtained phosphors have good TL dose response with adequate sensitivity and linearity for the measurement of medical doses

Outcomes of high-risk breast lesions diagnosed using image-guided core needle biopsy: results from a multicenter retrospective study

PURPOSEThe clinical management of high-risk lesions using image-guided biopsy is challenging. This study aimed to evaluate the rates at which such lesions were upgraded to malignancy and identify possible predictive factors for upgrading high-risk lesions.METHODSThis retrospective multicenter analysis included 1.343 patients diagnosed with high-risk lesions using an image-guided core needle or vacuum-assisted biopsy (VAB). Only patients managed using an excisional biopsy or with at least one year of documented radiological follow-up were included. For each, the Breast Imaging Reporting and Data System (BI-RADS) category, number of samples, needle thickness, and lesion size were correlated with malignancy upgrade rates in different histologic subtypes. Pearson’s chi-squared test, the Fisher–Freeman–Halton test, and Fisher’s exact test were used for the statistical analyses.RESULTSThe overall upgrade rate was 20.6%, with the highest rates in the subtypes of intraductal papilloma (IP) with atypia (44.7%; 55/123), followed by atypical ductal hyperplasia (ADH) (38.4%; 144/375), lobular neoplasia (LN) (12.7%; 7/55), papilloma without atypia (9.4%; 58/611), flat epithelial atypia (FEA) (8.7%; 10/114), and radial scars (RSs) (4.6%; 3/65). There was a significant relationship between the upgrade rate and BI-RADS category, number of samples, and lesion size Lesion size was the most predictive factor for an upgrade in all subtypes.CONCLUSIONADH and atypical IP showed considerable upgrade rates to malignancy, requiring surgical excision. The LN, IP without atypia, pure FEA, and RS subtypes showed lower malignancy rates when the BI-RADS category was lower and in smaller lesions that had been adequately sampled using VAB. After being discussed in a multidisciplinary meeting, these cases could be managed with follow-up instead of excision

İnsan meme kanserlerinde Ki-67'nin immunohistışimik yöntemlerle gösterilmesi ve bunun prognozla ilişkisi

Meme kanserlerinde, tümör proliferatif fraksiyonun (TPF) prognostik önemi olduğu gösterilmiştir. Son çalışmalarda hücre siklusunun istirahat halindeki fazı dışındaki tüm fazları boyunca pozitif bulunan, nükleer bir antijen olan Ki-67’nin meme tümörlerindeki prognostik önemi yoğun olarak araştırılmaktadır. Bu çalışmada prognoza ilişkin iki morfolojik parametre olarak Ki-67 işaretlemesi ve nükleoler organize edici bölge (AgNOR) boyanması, 35 meme karsinomu olgusunda incelenmiş, sonuçlar birbiri ve tümör boyutu, histolojik derece ve aksiller lenf nodülü tutulumu ile karşılaştırılmıştır. Ki-67 immunreaktivitesinin değerlendirilmesi amacı ile dondurulmuş doku kesitlerinde alkalen fosfataz anti-alkalen fosfataz yöntemiyle immünperoksidaz boyanması uygulanmış ve pozitif boyanan hücre oranının saptanması amacıyla rastgele seçilen en az 1000 hücre sayılmıştır. Ag-NOR sayısının saptanması için kolloid gümüşle boyanan kesitlerde, rastgele seçilmiş en az 100 hücre sayılmış ve her tümör için ortalama bir skor belirlenmiştir. Tüm olgularda ortalama TPF değerleri, Ki-67 için %9.9, Ag-NOR için %7.4 olarak saptanmış, bu değerler birbiri ile kıyaslanmış, sonuçlar istatiksel olarak anlamlı bulunmuştur (p0.01). Tümör boyutu, histolojik derecesi ve metastatik lenf nodülü sayısı ile Ki-67 immünreaktivitesi ve ortalama NOR sayısı arasında belirgin bir korelasyon görülmemiştir. Bu bulgular , Ki-67 ve Ag-NOR boyamalarının TPF değerlerini belirlemede benzer iki yöntem olduğunu göstermektedir, ancak mitotik indeksin Ki-67 ile saptanması Ag-NOR boyanmasına kıyasla daha güvenilir bir yöntem olarak ortaya çıkmaktadır.Tumor proliferative fraction (TPF) has been shown to have prognostic significance in breast cancer. Recent studies have begun exploring the nuclear antigen Ki-67 which is present in all phases of the cell cycle except the resting phase. The current study was performed on 35 cases of breast carcinoma using Ki-67 labeling and argyrophilic nucleolar organizer region (Ag-NOR) staining as the two morphometric parameters associated with prognosis and the results were correlated with each other, plus the tumor size, histologic grade and axillary lymph node status. Immunoperoxidase staining by the alkaline phosphatase anti-alkaline phosphatase method was performed on the frozen tissue sections for the evaluation of Ki-67 immunoreactivity and a minimum of 1000 randomly selected cells were calculated for the determination of the percentage of stained cells. The mean number of NOR was counted in a minimum of 100 randomly selected cells on colloid silver-stained sections and an average score was determinated for each tumor. The mean TPF values for all cases were 9.9% by Ki-67 and 7.4% by Ag-NOR staining, which correlated significantly at p0.01. No significant positive correlation was found between the tumor size, histologic grading of the tumor, and the number of lymph node metases with Ki-67 immunoreactivity, and mean number of NOR. These data suggest that both Ki-67 and Ag-NOR stainings are two related methods in the determination of TPF values, but assesing the mitotic index with Ki-67 is a more reliable method when compared with Ag-NOR staining