In utero DDT exposure and breast density before age 50

Prior studies in the Child Health and Development Studies (CHDS) found in utero exposure to the pesticide, dichlorodiphenyltrichloroethane (DDT), increased breast cancer risk by age 52. Mammographic density is considered a primary risk factor for breast cancer. We conducted a study of 309 daughters from the CHDS to examine in utero DDT exposure and mammographic density in midlife. Among daughters with high (>75th percentile) exposure to p,p’-Dichlorodiphenyldichloroethylene (DDE), p,p’-DDT was significantly correlated with increased dense area and percent density regardless of her body mass in midlife. In the subset of women with lower (<75th percentile) p,p-DDE, p,p’-DDT was associated with increased non-dense breast area. This was explained by adjustment for midlife BMI suggesting that p,p’-DDT may be obesogenic. In aggregate our findings indicate that early life p,p’-DDT exposure impacts breast density in a complex way that depends on the hosts biological ability to sequester and process DDT and levels of exposure.     

Accuracy of 11-Gauge Vacuum-Assisted Core Biopsy of Mammographic Breast Lesions

Background: Image-guided percutaneous biopsy has largely replaced excisional biopsy of mammographic lesions. Vacuum-assisted core biopsy has improved sampling of such lesions. The objectives of this study were to define the accuracy of the vacuum-assisted 11-gauge stereotactic core biopsy in sampling of atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS) and to define histologic and mammographic features of target lesions, which predict sampling errors.Methods: Between October 1996 and March 2000, 1341 patients underwent stereotactic 11-gauge vacuum-assisted biopsy. Patients with ADH or DCIS were encouraged to undergo excisional biopsy.Results: Surgical excision of 37 ADH lesions revealed 5 missed DCIS lesions and 1 missed invasive cancer. Twelve of 91 DCIS lesions were upstaged to invasive cancer upon excision. The underestimation rate was highest in patients with DCIS when the target lesion for biopsy was a zone of calcifications >1.5 cm. No correlation existed between the histologic features of DCIS lesions diagnosed by stereotactic biopsy and the presence of infiltrating disease on excision.Conclusions: Vacuum-assisted 11-gauge stereotactic core biopsy understages 13.2% and 13.5% of DCIS and ADH lesions, respectively. In patients with DCIS found by stereotactic biopsy, a target zone of calcifications >1.5 cm is associated with a higher underestimation rate of infiltrating disease.     

Characterization of responses and comparison of calibration factor for commercial MOSFET detectors

A commercial metal oxide silicon field effect transistor (MOSFET) dosimeter of model TN502-RD has been characterized for its linearity, reproducibility, field size dependency, dose rate dependency, and angular dependency for Cobalt-60 (⁶⁰Co), 6-MV, and 15-MV beam energies. The performance of the MOSFET clearly shows that it is highly reproducible, independent of field size and dose rate. Furthermore, MOSFET has a very high degree of linearity, with r-value > 0.9 for all 3 energies. The calibration factor for 2 similar MOSFET detectors of model TN502-RD were also estimated and compared for all 3 energies. The calibration factor between the 2 similar MOSFET detectors shows a variation of about 1.8% for ⁶⁰Co and 15 MV, and for 6 MV it shows variation of about 2.5%, indicating that calibration should be done whenever a new MOSFET is used. However, the detector shows considerable angular dependency of about 8.8% variation. This may be due to the variation in radiation sensitivity between flat and bubble sides of the MOSFET, and indicates that positional care must be taken while using MOSFET for stereotactic radiosurgery and stereotactic radiotherapy dosimetric applications.     

乳腺X线实质分型及其发生乳腺癌的危险性

乳腺二级预防已被公认为是降低乳腺癌死亡率的有效途径。乳腺X线摄影是进行乳腺癌普查的主要手段,该方法不但有助于发现无临床体征的早期乳腺癌,而且可以藉其对乳腺实质的不同分型,判断其发生乳腺癌的不同潜在危险性,从而有助于明确须重点予以监视的普查对象,以提高普查效益。     

Mammographic breast density and the risk of breast cancer: A systematic review and meta-analysis

ObjectivesMammographic density is a well-defined risk factor for breast cancer and having extremely dense breast tissue is associated with a one-to six-fold increased risk of breast cancer. However, it is questioned whether this increased risk estimate is applicable to current breast density classification methods. Therefore, the aim of this study was to further investigate and clarify the association between mammographic density and breast cancer risk based on current literature.MethodsMedline, Embase and Web of Science were systematically searched for articles published since 2013, that used BI-RADS lexicon 5th edition and incorporated data on digital mammography. Crude and maximally confounder-adjusted data were pooled in odds ratios (ORs) using random-effects models. Heterogeneity regarding breast cancer risks were investigated using I² statistic, stratified and sensitivity analyses.ResultsNine observational studies were included. Having extremely dense breast tissue (BI-RADS density D) resulted in a 2.11-fold (95% CI 1.84–2.42) increased breast cancer risk compared to having scattered dense breast tissue (BI-RADS density B). Sensitivity analysis showed that when only using data that had adjusted for age and BMI, the breast cancer risk was 1.83-fold (95% CI 1.52–2.21) increased. Both results were statistically significant and homogenous.ConclusionsMammographic breast density BI-RADS D is associated with an approximately two-fold increased risk of breast cancer compared to having BI-RADS density B in general population women. This is a novel and lower risk estimate compared to previously reported and might be explained due to the use of digital mammography and BI-RADS lexicon 5th edition.     

Power Spectral Analysis of Mammographic Parenchymal Patterns for Breast Cancer Risk Assessment

PURPOSE: The purpose of the study was to evaluate the usefulness of power law spectral analysis on mammographic parenchymal patterns in breast cancer risk assessment. MATERIALS AND METHODS: Mammograms from 172 subjects (30 women with the BRCA1/BRCA2 gene mutation and 142 low-risk women) were retrospectively collected and digitized. Because age is a very important risk factor, 60 low-risk women were randomly selected from the 142 low-risk subjects and were age matched to the 30 gene mutation carriers. Regions of interest were manually selected from the central breast region behind the nipple of these digitized mammograms and subsequently used in power spectral analysis. The power law spectrum of the form P(f) = B/f(beta) was evaluated for the mammographic patterns. The performance of exponent beta as a decision variable for differentiating between gene mutation carriers and low-risk women was assessed using receiver operating characteristic analysis for both the entire database and the age-matched subset. RESULTS: Power spectral analysis of mammograms demonstrated a statistically significant difference between the 30 BRCA1/BRCA2 gene mutation carriers and the 142 low risk women with an average beta values of 2.92 (+/-0.28) and 2.47(+/-0.20), respectively. An A (z) value of 0.90 was achieved in distinguishing between gene mutation carriers and low-risk women in the entire database, with an A (z) value of 0.89 being achieved on the age-matched subset. CONCLUSIONS: The BRCA1/BRCA2 gene mutation carriers and low-risk women have different mammographic parenchymal patterns. It is expected that women identified as high risk by computerized feature analyses might potentially be more aggressively screened for breast cancer.     

男性乳腺发育症的钼靶X线诊断

目的:探讨男性乳腺发育症的钼靶X线征象。方法:对26例临床检查发现乳房肿块或乳房增大的男性患者行钼靶X线CC位及MLO位摄影。观察乳房外形、乳房发育形态及腋下淋巴结情况。年龄16岁～82岁,平均年龄49.2岁。单纯左乳发育4例,单纯右乳发育2例,双乳发育20例。结果:26例患者X线诊断为男性乳腺发育症25例,误诊为乳腺肿瘤1例(后病理证明为乳腺发育症),合并乳腺增生22例,腋下淋巴结增大14例。结论:钼靶X线检查对男性乳腺发育症有明确的诊断意义。     

电子线放疗患者屏蔽防护实验研究

目的 探讨1~4层铅围裙（LA,0.5 mm铅当量/层）和自有专利防护装置（BSD,1~2 mm铅当量）对6~15 MeV电子线放疗时野外辐射剂量的屏蔽效果。方法 利用JR1152-B氟化锂热释光剂量片（TLD）,测量不同能量、不同限光筒大小、不同距离处,经不同层数铅围裙和不同厚度BSD屏蔽前、后的野外辐射剂量,计算出铅围裙和BSD对野外辐射的遮挡率,对比分析两种方法的屏蔽效果。结果 当限光筒不变时（10 cm×10 cm）,遮挡率随测量点的距离增加而增大（r=0.717,P < 0.05）,随电子线能量的增大而减小（r=-0.678,P < 0.05）;当能量不变时,遮挡率与限光筒的尺寸大小无相关性（P > 0.05）;对于6和9 MeV的较低能量电子线,1 mm Pb-BSD的遮挡率略高于2层铅围裙（t=2.519、2.662,P < 0.05）, 其变化范围分别为81.5%~95.3%和55.4%~84.6%;对于12和15 MeV的较高能量电子线,2 mm Pb-BSD的遮挡率略高于4层铅围裙（t=3.768、7.934,P < 0.05）,其变化范围分别为64.6%~93.4%和51.1%~92.4%。结论 铅围裙或BSD都能大幅减小野外辐射剂量,可望降低患者野外辐射二次致癌的风险,与铅围裙相比,BSD具有更明显的优势。     

Fetal radiation exposure: Is monitoring really needed?

The effect of fetal radiation during endoscopic retro-grade cholangiopancreatography (ERCP) on pregnant women is a very interesting topic. Smith et al recently estimated the fetal radiation exposure in pregnant women undergoing ERCPs using thermoluminescent dosimeters (TLDs). The authors concluded that TLDs are unnecessary during ERCP with modified techniques. We believe that an extreme caution is needed in clinical practice before drawing such conclusions when they are not strongly supported by enough experimental evidence. Therefore, we recommend that fetal radiation exposure be monitored in clinical practice by using dosimeters, bearing in mind that all relevant techniques to control and minimize the exposure must be applied.