bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conductive SISI Test
Authors: Byers Vincent W. 
Published: October 2014

The conductive SISI (short increment sensitivity index) test is an indirect procedure to estimate bone-conduction thresholds for middle ear pathology patients. A series of SISI tests are run, beginning at 20 dB S.L. and increasing in 10 dB S.L. steps, until a 100% SISI score is obtained. The following equation predicts the bone-conduction threshold: [Formula: see text] The results of 25 conductive SISI tests on a conductive hearing loss group indicate that the equation approximates the measured B.C. threshold. There was no statistical difference between the predicated B.C. thresholds (12.4 dB) and measured B.C. thresholds (10.4 dB) for the group.
Breast Cancer Screening: Potential Role of Computer-Aided Detection (CAD)
Authors: Feig Stephen A. 
Published: October 2014

Four separate studies conducted as blinded retrospective radiologist reviews of screening mammograms where cancer subsequently developed found lesions requiring work-up or biopsy in 25% to 41% of cases. Three non-blinded retrospective reviews by radiologists identified 57% to 75% of cancers. Among breast cancers detected by radiologists on blinded retrospective review in one study, computer aided detection (CAD) would have found 77%. These studies suggest that improved cancer detection rates could result if radiologists who interpret screening mammography were aided by computers. One prospective study initiated on that premise found that CAD increased the screening detection rate by 19.5%. At the current state-of-the-art, CAD performs best for cancers presenting as calcifications, less well for cancers appearing as spiculated masses, and least well for cancers appearing as circumscribed masses. CAD does not seem to increase false positive call back rates for additional imaging work-up or to increase false positive biopsy rates.
CyberKnife Radiotherapy for Localized Prostate Cancer: Rationale and Technical Feasibility
Authors: King Christopher R. , Lehmann Joerg , Adler John R. , Hai Jenny 
Published: October 2014

There is a clear dose response for localized prostate cancer radiotherapy and there probably is a radiobiological rationale for hypo-fractionation. Combining the two should maximize tumor control and increase the therapeutic ratio. This study examines the rationale and technical feasibility of CyberKnife radiotherapy (a robotic arm-driven linear accelerator) for localized prostate cancer. Its ability to deliver non-coplanar non-isocentric arcs can yield maximally conformal isodoses. It is the only integrated system capable of target position verification and real-time tracking during delivery of conformal stereotactic radiotherapy. Inverse planning with the CyberKnife is used to design a course of radiotherapy for localized prostate cancer. Fiducial markers within the gland are used to verify organ position and track organ motion via an orthogonal pair of electronic x-ray imaging devices and provide real-time feedback correction to the robotic arm during delivery. Conformal isodose curves and dose volume histograms (DVH) are used to compare with an optimized Intensity-Modulated Radiotherapy (IMRT) plan actually delivered to the study patient based upon CT scan-derived organ volumes. The CyberKnife can produce superior DVHs for sparing of rectum and bladder and excellent DVHs for target coverage compared with IMRT, and possesses dose heterogeneities to the same degree as IMRT plans. Because of the significantly longer delivery times required it would be best suited for hypo-fractionated regimens. Such dose regimens might allow for biologically equivalent dose escalation without increased normal tissue toxicity. Since the CyberKnife can verify organ position and motion and correct for this in real-time it is the ideal means of achieving such excellent DVHs without a compromise in doses to normal tissues. These capabilities are essential if one contemplates hypo-fractionated regimens with large dose-per-fraction sizes (>5Gy to 10Gy) and dose-escalation.
Gentlemen (and Ladies), Choose your Weapons: Gamma Knife vs. Linear Accelerator Radiosurgery
Authors: Stieber Volker W. , Bourland J. Daniel , Tomé Wolfgang A. , Mehta Minesh P. 
Published: October 2014

“In a sense, every tool is a machine—the hammer, the ax, and the chisel. And every machine is a tool. The real distinction is between one man using a tool with his hands and producing an object that shows at every stage the direction of his will and the impression of his personality; and a machine which is producing, without the intervention of a particular man, objects of a uniformity and precision that show no individual variation and have no personal charm. The problem is to decide whether the objects of machine production can possess the essential qualities of art.” —Sir Herbert Read (1893–1968), British critic and poet. Art and Industry, pt. 1, Horizon (1953). “But lo! men have become the tools of their tools.” —Henry David Thoreau (1817–1862), U.S. philosopher, author, naturalist. “Economy,” Waiden (1854). This article compares and contrasts Gamma Knife® radiosurgery with linear accelerator-based radiosurgery; where appropriate, Cyberknife™ technology is discussed. Topics covered are: positioning of the head (invasive versus non-invasive positioning systems); collimator construction; beam properties; beam arrangements; treatment planning; and issues regarding manpower (including a discussion of patient repositioning during treatment), machine availability, and financial considerations.
Assessment of the Accuracy of a Conventional Simulation for Radiotherapy of Head and Skull Base Tumors
Authors: Gross Markus W. , Spahn Ute , Engenhart-Cabillic Rita 
Published: October 2014

In this prospective study we investigated the absolute accuracy of the conventional simulation in head and skull base tumors. 41 isocenters in 40 consecutive patients with tumors of the head and skull base were included. In all cases a rigid stereotactic mask system was used for non-invasive fixation. The stereotactic (“calculated”) coordinates of the isocenter were defined by the treatment planning computer. Each patient underwent a physical simulation using exclusively anatomical reference points to define the “preliminary” isocenter. The displacement between its coordinates and those of the stereotactic target point was recorded in X-, Y- and Z-direction with help of the targeting device, and the spatial error was calculated. Additionally, the patients were stratified by basal or calvarial tumor site to estimate the importance of the basal bone structures in the simulation accuracy. The influence of the learning effect on simulation accuracy was also determined. The results showed an accuracy of set-up at the linac within 1 mm in all three directions as calculated from orthogonal portal films. Mean shift of the isocenter coordinates obtained from physical simulation compared to the calculated stereotactic coordinates was 2.15 mm, 2.54 mm, and 2.69 mm for X-, Y-, and Z-direction, respectively. Mean spatial displacement amounted 5.06 mm, and the median was 4.50 mm. No significant difference could be noted between basal and calvarial location of the isocenter. A significant “learning effect” was observed with a decrease in spatial shift with increasing patient numbers. This effect was stronger in basal lesions, whereas calvarial lesions showed only a minor, insignificant effect. In conclusion, a physical simulation requires a safety margin of 5 mm in PTV definition in addition to other factors, e.g. organ movement.
Heavy Ion Therapy: Status and Perspectives
Authors: Jäkel O. , Schulz-Ertner D. , Karger C.P. , Nikoghosyan A. , Debus J. 
Published: October 2014

Starting with the pioneering work at the University of California in Berkeley in 1977, heavy ion radiotherapy has been of increasing interest especially in Japan and Europe in the last decade. There are currently 3 facilities treating patients with carbon ions, two of them in Japan within a clinical setting. In Germany, a research therapy facility is in operation and the construction of a new hospital based facility at the Heidelberg university will be started soon. An outline of the current status of heavy ion radiotherapy is given with emphasis to the technical aspects of the respective facilities. This includes a description of passive and active beam shaping systems, as well as their implications for treatment planning and dosimetry. The clinical trials and routine treatments performed at the German heavy ion facility are summarized. An overview over the upcoming new facilities and their technical possibilities is given. It is discussed what the necessary improvements are to fully exploit the potential of these facilities. Especially the new Heidelberg facility with the possibility of active beam scanning in combination with the first isocentric gantry for ions and offering beams of protons, helium, oxygen and carbon ions has implications on treatment planning, dosimetry and quality assurance. The necessary and ongoing developments in these areas are summarized. The new facilities also offer the possibilities to perform more extensive clinical studies and to explore future indications for radiotherapy with heavy ions. An overview over the indications and treatment schemes is also given.
The Increased Biological Effectiveness of Heavy Charged Particles: From Radiobiology to Treatment Planning
Authors: Krämer M. , Weyrather W. K. , Scholz M. 
Published: October 2014

The increased biological effectiveness of heavy charged particle beams like e.g., carbon ions in the tumor volume in comparison to the lower effectiveness in the surrounding healthy tissue represents one of the major rationales for their application in tumor therapy. This increased effectiveness also characterizes the advantage of heavier ions compared to proton beams. The increased effectiveness has to be taken into account in treatment planning in order to estimate the corresponding photon equivalent doses in normal and tumor tissues, thus allowing a link e.g., to normal tissue dose limits in conventional photon therapy. Due to the complex dependencies of RBE on parameters like dose, beam energy, LET, atomic number and cell or tissue type, the relevant RBEs cannot be solely determined from experimental data. Therefore, within the framework of the pilot project of tumor therapy with carbon ions performed at GSI Darmstadt, treatment planning is based on a biophysical model, which has been extensively tested. The paper first summarizes the essential systematic dependencies of RBE on different parameters like e.g., dose, LET, atomic number and cell type. The basic principle of the biophysical model is then introduced, and special emphasis is given to the application of the model to in vivo and clinical endpoints. Model predictions are compared to experimental data in vitro and in vivo. Finally, the implementation of the biophysical model in the treatment planning procedure is presented. The biological verification of the whole treatment planning procedure is explained and examples of patient treatment plans are given.
Cryosurgery for Lung Cancer: Clinical Results and Technical Aspects
Authors: Maiwand M. O. , Asimakopoulos G. 
Published: October 2014

Lung carcinoma is the most frequently diagnosed malignancy in the world, with the incidence increasing through the 20th century. Presentation may be as a tumor mass primarily obstructing the central bronchial lumen, or a mass infiltrating lung tissue. Cryosurgery can be used as a method of palliative treatment for both these endobronchial and extra-bronchial presentations. The aim of this study is two-fold: to present data relating to our extensive experience in treating obstructing endobronchial tumors and to present our initial results of direct cryosurgery to infiltrating lung tumor masses. During a nine-year period, 521 consecutive patients (male:female ratio 1.8:1) with a mean age of 67.9 years who had advanced obstructive tracheobronchial malignant tumors underwent cryosurgery with a mean of 2.4 treatments per patient. Hemoptysis, cough, dyspnoea and chest pain improved by at least one class in 76.4%, 69.0%, 59.25% and 42.6% (p<0.01) of symptomatic patients respectively. Quality of life studies showed that the mean Karnofsky score improved from 60 ± 7 to 75 ± 8 and the mean WHO score from 3.04 ± 0.7 to 2.20 ± 0.56. There were 7 (1.2%) in-hospital deaths, and 2-year survival was 15.9%. Direct cryosurgery to carcinoma of the lung was performed on 15 patients at exploratory thoracotomy. Results showed an increase in FEV1 from 1.80 ± 0.6 liters to 1.95 ± 0.8 (8.3%) liters and in FVC from 2.50 ± 0.8 to 2.68 ± 0.8 liters (7.2%). The Karnofsky score improved from 68 ± 9 to 78 ± 10 and the WHO score from 2.63 ± 0.81 to 2.38 ± 0.78 (9.6%). Major symptoms including cough, dyspnoea, and hemoptysis were assessed and showed improvement in 77.8%, 66.7%, and 100% (p<0.01) of symptomatic patients respectively. Patients were followed for a mean period of 18 months (range 4–84 months). Median survival from the date of surgery (Kaplan-Meier, 95%Cl) was 11.6 (6.8 to 18.2) months, range 1 to 84 months. Cryosurgery provides a safe and effective method for the palliation of advanced central bronchial obstructive tumors, and compares favorably with other methods in terms of safety, cost, and complications. Initial experience suggests that similar palliation may be achieved by cryosurgery applied to advanced parenchymal tumor masses.
Geomatics for Precise 3D Breast Imaging
Authors: Alto Hilary 
Published: October 2014

Canadian women have a one in nine chance of developing breast cancer during their lifetime. Mammography is the most common imaging technology used for breast cancer detection in its earliest stages through screening programs. Clusters of microcalcifications are primary indicators of breast cancer; the shape, size and number may be used to determine whether they are malignant or benign. However, overlapping images of calcifications on a mammogram hinder the classification of the shape and size of each calcification and a misdiagnosis may occur resulting in either an unnecessary biopsy being performed or a necessary biopsy not being performed. The introduction of 3D imaging techniques such as standard photogrammetry may increase the confidence of the radiologist when making his/her diagnosis. In this paper, traditional analytical photogrammetric techniques for the 3D mathematical reconstruction of microcalcifications are presented. The techniques are applied to a specially designed and constructed x-ray transparent Plexiglas phantom (control object). The phantom was embedded with 1.0 mm x-ray opaque lead pellets configured to represent overlapping microcalcifications. Control points on the phantom were determined by standard survey methods and hand measurements. X-ray films were obtained using a LORAD M-III mammography machine. The photogrammetric techniques of relative and absolute orientation were applied to the 2D mammographic films to analytically generate a 3D depth map with an overall accuracy of 0.6 mm. A Bundle Adjustment and the Direct Linear Transform were used to confirm the results.
Value of Electrical Impedance Scanning (EIS) in the Evaluation of BI-RADS™ III/IV/V-Lesions
Authors: Diebold Thomas , Jacobi Volkmar , Scholz Bernhard , Hensel Conny , Solbach Christine , Kaufmann Manfred , Viana Fernando , Balzer Joern , Peters Jutta , Vogl Thomas 
Published: October 2014

Two hundred and fifty-six (256) patients (72% preoperative, 28% pre-Mammotome) were prospectively examined with EIS using the TS 2000 (TransScan Research and Development Center, Israel; temporarily distributed by Siemens, Erlangen) with the “LOS”-software (level of suspicion). All exams were performed with the targeted scan probe, the observer knowing all clinical and imaging facts. The area of the lesions was examined with EIS at least with 5 single scans. The evaluation included a scaling of lesions from 1 (surely benign) up to 5 (highly suggestive for malignancy) as well as the additional notification of spots. Results of EIS were based upon the automatic scaling which is provided by the software and were compared with mammography and histology. Furthermore the influence of the histology, size of lesions, and presence/absence of spots on the EIS results were analyzed. Histology revealed benign results in 138 lesions and malignant results in 118 lesions (DCIS=61, ID-Ca=51, IL-Ca=5, mucinous Ca=1). Mammography as expected yielded high values with 91% sensitivity and 62% specificity. Overall sensitivity of EIS was 75.4%, specificity 42.03%, negative predictive value 66.7% and positive predictive value 52.7% (89 TP, 58 TN, 80 FP, 29 FN). EIS was false negative in 20 ID-Ca, 3 IL-Ca, 1 IDL-Ca, 4 DCIS, and 1 mucinous carcinoma. Sensitivity and specificity of EIS did not differ for the different histological differentiations neither for the degree of invasion. Also the additional notification of “spots” didn't show a correlation to malignancy. There were significant differences of the sensitivity of EIS regarding the tumor size. While EIS correctly diagnosed 85% of lesions <10 mm in size, only 64% of lesions >10 mm were detected. Most frequent lesion types for false positives were mastopathy (55/80 FP) and fibroadenoma (21/80 FP). Patient acceptance of EIS was perfect and there were no drop outs because of movement artifacts. In conclusion the “LOS”-software clearly improved the clinical performance of the TS 2000 as compared to the initial software. The high sensitivity of EIS in small cancers which was found in our study may indicate an advantage of this method. However, the overall sensitivity and specificity with this setup of EIS is still far too low. Further improvements especially including the measurement of higher frequencies should be realized.
Performance Evaluation of Image Processing Algorithms in CADe
Authors: Wirth Michael A. 
Published: October 2014

One of the key limitations of existing image processing algorithms for computer-aided detection (CADe) is that they are often designed and evaluated in an ad hoc manner. This paper characterizes some of the issues and shortcomings in existing performance evaluation paradigms for image processing algorithms in breast cancer screening, particularly in the context of computer aided detection. We present the framework for establishing a performance evaluation process using standardized criteria. We conclude with some specific recommendations to improve the infrastructure for evaluation the performance of image processing algorithms.
Novel use of Single X-Ray Absorptiometry for Measuring Breast Density
Authors: Shepherd John A. , Herve Lionel , Landau Jessie , Fan Bo , Kerlikowske Karla , Cummings Steve R. 
Published: October 2014

Breast density is one of the strongest known breast cancer risk factors. Breast density has primarily been measured by either categorical scores of the proportion of opacity on a screening mammogram or as a ratio of the delineated dense area to the total breast area on a mammogram. These methods are limited by their subjectivity, their lack of absolute reference standards, and lack of automation for clinical use. We present a novel automated method for measuring breast composition we call Breast Compositional Density measured using single X-ray absorptiometry techniques, or BDSXA. BDSXA measures breast compositional density by comparing the opacity on the mammogram to two reference standards imaged with each breast. We present the mathematical derivation of BDSXA, methods for correcting for radiographic nonuniformity in the mammogram, and in vitro measures of accuracy and repeatability. Using phantoms, BDSXA has been shown to have a long-term repeatability of better than 2% for a breast composition range of 0 to 100% fibroglandular density.
NIR Spectroscopic Detection of Breast Cancer
Authors: Nioka S. , Chance B. 
Published: October 2014

Near infrared spectroscopy (NIRS) utilizes intrinsic optical absorption signals of blood, water, and lipid concentration available in the NIR window (600–1000 nm) as well as a developing array of extrinsic organic compounds to detect and localize cancer. This paper reviews optical cancer detection made possible through high tumor-tissue signal-to-noise ratio (SNR) and providing biochemical and physiological data in addition to those obtained via other methods. NIRS detects cancers in vivo through a combination of blood volume and oxygenation from measurements of oxy- and deoxy-hemoglobin giving signals of tumor angiogenesis and hypermetabolism. The Chance lab tends towards CW breast cancer systems using manually scannable detectors with calibrated low pressure tissue contact. These systems calculate angiogenesis and hypermetabolism by using a pair of wavelengths and referencing the mirror image position of the contralateral breast to achieve high ROC/AUC. Time domain and frequency domain spectroscopy were also used to study similar intrinsic breast tumor characteristics such as high blood volume. Other NIRS metrics are water-fat ratio and the optical scattering coefficient. An extrinsic FDA approved dye, ICG, has been used to measure blood pooling with extravasation, similar to Gadolinium in MRI. A key future development in NIRS will be new Molecular Beacons targeting cancers and fluorescing in the NIR window to enhance in vivo tumor-tissue ratios and to afford biochemical specificity with the potential for effective photodynamic anti-cancer therapies.
A Quantitative Study of the Effects of Ionizing Radiation on Endothelial Cells and Capillary-like Network Formation
Authors: Mao Xiao Wen 
Published: October 2014

The initial events of angiogenesis comprise endothelial cell activation, migration, and proliferation. The characteristics of retinal endothelial cells and capillaries are significantly altered in a number of diseases including cancer. Since radiation has been shown as a useful tool in radiotherapy by altering the proliferative changes, it is important to evaluate the responses of the endothelial cells and the capillary network to radiation. We quantified functional and kinetic responses of endothelial cells and capillaries to radiation in an in vitro model. An in vitro angiogenesis model was introduced in our study with endothelial cells cultured on an extracellular matrix gel in which hollow tube-like structures could be rapidly formed. Vessel formation was quantified using stereological techniques. The cell cycle kinetics of endothelial cells and accumulation of DNA damage after radiation were measured using laser scanning cytometry. To study the response of proliferative capillary-like structures to radiation, the vessel network was irradiated with 2 gray (Gy). To evaluate functional and kinetic responses and differentiation of endothelial cells to radiation, cells were irradiated with 2 and 6 Gy. Progressive time- and dose-dependent loss of endothelial cells occurred starting 24 hours after radiation. Vessel growth was significantly retarded at the higher dose. A significant percentage of DNA breaks were detected dose-dependently. A large percentage of G1 cells were measured in the irradiated endothelial cell population when compared to the respective sham-treated control population. These results indicate that radiation-induced endothelial cell injuries destroy the integrity of vascular structure. We postulated that apoptosis may represent a biologically relevant mechanism of radiation-induced endothelial cell damage.