Development of a high-speed small-angle infrared thermography system in EAST.

A high-speed infrared small-angle infrared thermography system (SATS) has been developed and installed on the Experimental Advanced Superconducting Tokamak (EAST) for measuring the surface temperature of the divertor target to calculate the high heat flux induced by Edge Localized Modes (ELMs) and providing observation means for the further physical study of some key parameters, such as power decay length λq and the characteristic time of different types of ELMs. An endoscopic optical system is applied to realize the SATS for clear imaging of the divertor plate area and protection from the harm of impurity deposition and latent tungsten ablation during discharge. The field of view (FOV) of the endoscopic optical system is designed to be 13° in the horizontal direction and 9° in the vertical direction. As a consequence, ∼35° of coverage of the lower-outer divertor and a small part of the lower-inner divertor in toroidal are covered by the FOV with a spatial resolution of around 2 mm/pixel. This paper presents a detailed description of the new SATS and the preliminary experimental diagnostic results. The radial distribution of heat flux induced by an ELM crash was demonstrated.

[Study on the correlation between ceramic and chronic obstructive pulmonary disease in Foshan City].

Objective: To study the correlation between ceramic and chronic obstructive pulmonary disease (COPD), and explore its related risk factors. Methods: In January 2021, five representative ceramic enterprises were selected from Chancheng District, Nanhai District, Gaoming District and Sanshui District of Foshan City. The ceramic workers who came to Chancheng Hospital of Foshan First People's Hospital for physical examination from January to October 2021 were selected as the research objects, and 525 people were included. Conduct questionnaire survey and pulmonary function test. Logistic regresion was performed to analyze the influencing facters of COPD among ceramic workers. Results: The subjects were (38.51±1.25) years old, 328 males and 197 females, and the detection rate of COPD was 9.52% (50/525). The incidence of respiratory symptoms such as dyspnea, chronic cough, wheezing and chest tightness, the detection rates of abnormal lung age, abnormal lung function and COPD in males were higher than those in females (P<0.05). The logistic regression analysis showed that male, age, working years, smoking status and family history of COPD were the risk factors for COPD among ceramic workers (P<0.05) . Conclusion: The ceramic workers are the high risk population of COPD. We should do a good job in health education, and do a regular physical examination to find the changes of lung function in time, and prevent the occurrence of COPD as soon as possible.

A case of renal γ2 heavy-chain deposition disease accompanied by rapid progressive renal failure.

BACKGROUND: The recently described heavy-chain deposition disease (HCDD) is a comparatively rare monoclonal immunoglobulin disorder characterized histopathologically by glomerular and tubular basement membrane deposition of nonamyloidotic monoclonal heavy chains without associated light chains. METHOD: We have described a case of γ2-HCDD presenting with proteinuria, microhematuria, severe hypertension, and rapidly progressive renal failure, which serum creatinine level was only 1.52 mg/dL in early stage HCDD, and the clinicopathologic features of this case have been compared with other reported cases of γ2-HCDD. RESULTS: Renal biopsy disclosed nodular sclerosing glomerulopathy. Immunofluorescence analysis revealed IgG2 (2+) heavy chain and C3 (+) in the mesangium and along the capillary walls and tubular basement membranes without IgA, IgM, κ and λ light chains. Electron microscopy revealed electron-dense deposits along the glomerular and tubular basement membranes as well as in the mesangium. Moreover, regardless of therapy, the condition of the patient progressively deteriorated, with less than 3 months of renal survival. CONCLUSION: Rapid progressive renal failure was a common feature in both cases of γ2-HCDD. We propose that a possible link exists between prognosis of renal HCDD and the subclass of heavy chain deposited in the kidney.

Four-dimensional targeting error analysis in image-guided radiotherapy.

Image-guided therapy (IGT) involves acquisition and processing of biomedical images to actively guide medical interventions. The proliferation of IGT technologies has been particularly significant in image-guided radiotherapy (IGRT), as a way to increase the tumor targeting accuracy. When IGRT is applied to moving tumors, image guidance becomes challenging, as motion leads to increased uncertainty. Different strategies may be applied to mitigate the effects of motion: each technique is related to a different technological effort and complexity in treatment planning and delivery. The objective comparison of different motion mitigation strategies can be achieved by quantifying the residual uncertainties in tumor targeting, to be detected by means of IGRT technologies. Such quantification requires an extension of targeting error theory to a 4D space, where the 3D tumor trajectory as a function of time measured (4D Targeting Error, 4DTE). Accurate 4DTE analysis can be represented by a motion probability density function, describing the statistical fluctuations of tumor trajectory. We illustrate the application of 4DTE analysis through examples, including weekly variations in tumor trajectory as detected by 4DCT, respiratory gating via external surrogates and real-time tumor tracking.

Design and testing of a simulation framework for dosimetric motion studies integrating an anthropomorphic computational phantom into four-dimensional Monte Carlo.

We have designed a simulation framework for motion studies in radiation therapy by integrating the anthropomorphic NCAT phantom into a 4D Monte Carlo dose calculation engine based on DPM. Representing an artifact-free environment, the system can be used to identify class solutions as a function of geometric and dosimetric parameters. A pilot dynamic conformal study for three lesions ( approximately 2.0 cm) in the right lung was performed (70 Gy prescription dose). Tumor motion changed as a function of tumor location, according to the anthropomorphic deformable motion model. Conformal plans were simulated with 0 to 2 cm margin for the aperture, with additional 0.5 cm for beam penumbra. The dosimetric effects of intensity modulated radiotherapy (IMRT) vs. conformal treatments were compared in a static case. Results show that the Monte Carlo simulation framework can model tumor tracking in deformable anatomy with high accuracy, providing absolute doses for IMRT and conformal radiation therapy. A target underdosage of up to 3.67 Gy (lower lung) was highlighted in the composite dose distribution mapped at exhale. Such effects depend on tumor location and treatment margin and are affected by lung deformation and ribcage motion. In summary, the complexity in the irradiation of moving targets has been reduced to a controlled simulation environment, where several treatment options can be accurately modeled and quantified The implemented tools will be utilized for extensive motion study in lung/liver irradiation.

A method of calculating a lung clinical target volume DVH for IMRT with intrafractional motion.

The motion of lung tumors from respiration has been reported in the literature to be as large as 1-2 cm. This motion requires an additional margin between the Clinical Target Volume (CTV) and the Planning Target Volume (PTV). In Intensity Modulated Radiotherapy (IMRT), while such a margin is necessary, the margin may not be sufficient to avoid unintended high and low dose regions to the interior on moving CTV. Gated treatment has been proposed to improve normal tissues sparing as well as to ensure accurate dose coverage of the tumor volume. The following questions have not been addressed in the literature: (a) what is the dose error to a target volume without a gated IMRT treatment? (b) What is an acceptable gating window for such a treatment. In this study, we address these questions by proposing a novel technique for calculating the three-dimensional (3-D) dose error that would result if a lung IMRT plan were delivered without a gated linac beam. The method is also generalized for gated treatment with an arbitrary triggering window. IMRT plans for three patients with lung tumors were studied. The treatment plans were generated with HELIOS for delivery with 6 MV on a CL2100 Varian linear accelerator with a 26 pair MLC. A CTV to PTV margin of 1 cm was used. An IMRT planning system searches for an optimized fluence map phi(x,y) for each port, which is then converted into a dynamic MLC file (DMLC). The DMLC file contains information about MLC subfield shapes and the fractional Monitor Units (MUs) to be delivered for each subfield. With a lung tumor, a CTV that executes a quasiperiodic motion z(t) does not receive phi(x,y), but rather an Effective Incident Fluence EIF(x,y). We numerically evaluate the EIF(x,y) from a given DMLC file by a coordinate transformation to the Target's Eye View (TEV). In the TEV coordinate system, the CTV itself is stationary, and the MLC is seen to execute a motion -z(t) that is superimposed on the DMLC motion. The resulting EIF(x,y) is input back into the dose calculation engine to estimate the 3-D dose to a moving CTV. In this study, we model respiratory motion as a sinusoidal function with an amplitude of 10 mm in the superior-inferior direction, a period of 5 s, and an initial phase of zero.

Using serial imaging data to model variabilities in organ position and shape during radiotherapy.

A model is proposed for incorporating the effects of organ motion into the calculation of dose in a statistical fashion based on serial imaging measurements of organ motion. These measurements can either come from a previously studied population of patients, or they can be specific to the particular patient undergoing therapy. The statistical distribution underlying the measurements of organ motion, including the changes in organ shape, is reconstructed non-parametrically without requiring any assumptions about its functional form. The model is thus capable of simulating organ motions that are not present in the original measurements, yet nonetheless come from the same underlying statistical distribution. The present model overcomes two particular limitations of many organ motion models: (a) the fact that they do not account for changes in organ shape, and (b) the fact that they make physically unrealistic assumptions about the functional form of the statistical distribution of organ motion, such as assuming that it is Gaussian. The present model can form the foundation of methods for the more accurate and clinically relevant calculation of the dose to the target volume and normal tissues.

Numerical analysis of a model of organ motion using serial imaging measurements from prostate radiotherapy.

We previously proposed a model for incorporating the effects of organ motion, including the changes in organ shape, into the calculation of dose in a statistical fashion based on serial imaging measurements of organ motion. In the present paper, numerical studies were used to investigate how the accuracy of the statistical calculation of dose depends on the number of organ motion measurements provided as input into the model. The dose calculated statistically with the model was consistently more accurate than the one obtained by directly resampling the serial measurements of organ motion. It was also more robust relative to the random variabilities present in the input organ motion measurements. The results confirm that the model can reproduce the statistical distribution of the organ motions measured in a serial imaging study, including the changes in organ shape, without making any assumptions about the functional form of this distribution. The model allows a more accurate calculation of dose to be performed from a given number of measurements of organ motion than would otherwise be obtained by directly resampling the measured data. It thus maximizes the information that is extracted from serial imaging measurements.

A variable critical-volume model for normal tissue complication probability.

Predicting late-term normal-tissue complication probability (NTCP) after radiotherapy is an important factor in the optimization of conformal radiotherapy. We propose a new NTCP model, based on the properties of the high dose region. The principal assumption of the new model is that a whole-organ complication will occur when the radiation damage to a normal organ volume (a portion of the total organ) exceeds a threshold value. The dose threshold for complications varies with the size of the volume (percent of the total organ). We hypothesize that a complication occurs if the complication threshold is exceeded for any organ volume. We used the average dose to a volume as a measure of radiation damage to that volume. Also, we used the power law to scale the average dose to various organ volumes to a whole-organ equivalent dose, and to identify the volume with the most harmful dose-size combination-the critical volume. We used a logistic distribution to calculate the probability that the patient will develop a complication, given the dose delivered to the critical volume. We used a maximum likelihood fit to estimate the model parameters for late-term rectal complications in a set of patients treated for prostate carcinoma with external photon beam radiotherapy (EBRT). Good correspondence was found between the experimental data and the model predictions.

alpha-, beta-, gamma-catenin, and p120(CTN) expression during the terminal differentiation and fusion of human mononucleate cytotrophoblasts in vitro and in vivo.

The cadherins play key roles in the formation and organization of the mammalian placenta by mediating cellular interactions and the terminal differentiation of trophoblastic cells. Although cadherin function is regulated by the cytoplasmic proteins, known as the catenins, the identity and expression pattern(s) of the catenins present in the trophoblastic cells of the human placenta have not been characterized. In these studies, we have determined that alpha-, beta-, gamma-catenin, and p120(ctn) expression levels are high in villous cytotrophoblasts isolated from the human term placenta but decline as these cells undergo aggregation and fusion to form syncytium with time in culture. In contrast, the expression levels of these four catenin subtypes remained constant in non-fusing JEG-3 choriocarcinoma cells at all of the time points examined in these studies. alpha-, beta-, gamma-catenin, and p120(ctn) expression was further immunolocalized to the mononucleate cells present in these two trophoblastic cell cultures. Similarly, intense immunostaining for all four catenins was detected in the mononucleate villous cytotrophoblasts of the human first trimester placenta. Collectively, these observations demonstrate that the expression levels of alpha-, beta-, gamma-catenin, and p120(ctn) are tightly regulated during the formation of multinucleated syncytium in vitro and in vivo.

A monitor unit verification calculation in intensity modulated radiotherapy as a dosimetry quality assurance.

In standard teletherapy, a treatment plan is generated with the aid of a treatment planning system, but it is common to perform an independent monitor unit verification calculation (MUVC). In exact analogy, we propose and demonstrate that a simple and accurate MUVC in intensity modulated radiotherapy (IMRT) is possible. We introduce the concept of modified Clarkson integration (MCI). In MCI, we exploit the rotational symmetry of scattering to simplify the dose calculation. For dose calculation along a central axis (CAX), we first replace the incident IMRT fluence by an azimuthally averaged fluence. Second, the Clarkson integration is carried over annular sectors instead of over pie sectors. We wrote a computer code, implementing the MCI technique, in order to perform a MUVC for IMRT purposes. We applied the code to IMRT plans generated by CORVUS. The input to the code consists of CORVUS plan data (e.g., DMLC files, jaw settings, MU for each IMRT field, depth to isocenter for each IMRT field), and the output is dose contribution by individual IMRTs field to the isocenter. The code uses measured beam data for Sc, Sp, TPR, (D/MU)ref and includes effects from multileaf collimator transmission, and radiation field offset. On a 266 MHz desktop computer, the code takes less than 15 to calculate a dose. The doses calculated with the MCI algorithm agreed within +/-3% with the doses calculated by CORVUS, which uses a 1 cm x 1 cm pencil beam in dose calculation. In the present version of MCI, skin contour variations and inhomogeneities were neglected.

Intensity modulated radiotherapy dose delivery error from radiation field offset inaccuracy.

In Intensity Modulated Radiotherapy (IMRT), irradiation is delivered in a number of small aperture subfields. The fluences shaped by these small apertures are highly sensitive to inaccuracies in multileaf collimator (MLC) calibration. The Radiation Field Offset (RFO) is the difference between a radiation and a light field at the Source to Axis Distance (SAD) for a MLC. An Intensity Modulated Radiotherapy (IMRT) system must incorporate a RFO by closing in all leaf openings. In IMRT, RFO inaccuracy will result in a dose error to the interior of a target volume. We analyze dosimetric consequences of incorporating a wrong RFO into the CORVUS, 1 cm x 1 cm, step and shoot, IMRT system. The following method was employed. First an IMRT plan is generated for a target volume in a phantom, which produces a set of dynamic MLC (DMLC) files with the correct RFO value. To simulate delivery with a wrong RFO value, we wrote a computer code that reads in the DMLC file with the correct RFO value and produces another DMLC with an incorrect RFO specified by a user. Finally the phantom was irradiated with the correct and the incorrect RFO valued DMLC files, and the doses were measured with an ionization chamber. The method was applied to 9 fields, 6 MV, IMRT plans. We measured Dose Error Sensitivity Factor (DESF) for each plan, which ranged from (0-8)% mm(-1). The DESF(x) is defined as a fractional dose error to a point (x) in a target volume per mm of the RFO error, i.e., DESF(x) is equivalent to ¿deltaD(x)/D(x)deltaRFO¿. Therefore, we concluded that for CORVUS, 6 MV, 1 cm x 1 cm, step and shoot IMRT, RFO must be determined within an accuracy of 0.5 mm if a fractional dose error to a target volume is to be less than 4%. We propose an analytic framework to understand the measured DESF's. From the analysis we conclude that a large DESF was associated with an DMLC file with small average leaf openings. For 1 cm x 1 cm, step and shoot IMRT, the largest possible DESF is predicted to be 20% mm(-1). In addition, we wrote computer code that can calculate a DESF of a DMLC file. The code was written in Mathematica 3.0. The code can be used to screen patient IMRT plans that are highly sensitive to a RFO error.

Use of three-dimensional spiral computed tomography imaging for staging and surgical planning of head and neck cancer.

We compare four different three-dimensional (3D) reconstruction methods of spiral computed tomography (CT) data for head and neck cancer to establish the method best suited for specific uses, eg, staging of lymph nodes and viewing of spatial relationships between the tumor, fascial spaces, adjacent soft tissues, and others structures. We evaluated a series of 10 patients (six men and four women), aged 32 to 60 years. Of these, five were histologically diagnosed with squamous cell carcinoma, two with lymphoma, one with thyroid cancer, one with Kikuchi's disease or necrotizing lymphadenitis, and one with esthesioneuroblastoma. All scans were obtained using high-resolution spiral CT (General Electric Medical Systems, Milwaukee, WI). The collimations used were 3 mm and 5 mm, matrix 512 x 512, and reconstruction interval not more than 3 mm. Scanning was performed from the skull base to the aortic arch. Iodinated contrast medium was injected so that the blood vessels were clearly differentiated from nodes. Different techniques of three-dimensional reconstruction were employed, including shaded surface display (SSD), multiplanar reconstructions (MPR), maximum intensity projection (MIP), 3D volume rendering (VR), and combined techniques. The reconstructions were performed in a variety of planes, including sagittal, coronal, and oblique views. In our series of selected patients, the technique of 3D VR showed potential advantages over other techniques. The MIP technique was useful in analyzing the patency of vessels and to exclude thrombus, compression, or displacement by tumor. The use of combined techniques such as SSD and MPR, accurately demonstrated the levels of lymph nodes and the relationship between the tumor projection of interest and various anatomic structures. In conclusion, 3D reconstruction of CT data is useful in the localization and staging of neck tumors and assists in surgical planning and radiation treatment.

Regulation of beta-catenin mRNA and protein levels in human villous cytotrophoblasts undergoing aggregation and fusion in vitro: correlation with E-cadherin expression.

The cellular mechanisms underlying the formation and organization of the human placenta remain poorly understood. Recent studies have demonstrated that E-cadherin, in association with the cytoplasmic protein known as beta-catenin, plays an integral role in the differentiation of the trophectoderm in the murine and bovine embryo. Although E-cadherin expression is regulated during the aggregation and fusion of human villous cytotrophoblasts, the expression of beta-catenin during the terminal differentiation of these primary cell cultures has not been determined. In this study, beta-catenin mRNA concentrations and protein expression were examined in primary cultures of human villous cytotrophoblasts using northern and western blot analysis. beta-catenin mRNA concentrations and protein expression were high in freshly isolated mononucleate cytotrophoblasts but decreased as these cells underwent aggregation and fusion to form syncytium. A similar pattern of expression was observed for the E-cadherin mRNA transcript and protein species present in these cell cultures. Immunoprecipitation studies demonstrated that the beta-catenin and E-cadherin protein species present in the mononucleate cytotrophoblasts were capable of forming intracellular complexes. In contrast, beta-catenin and E-cadherin mRNA and protein expression in JEG-3 choriocarcinoma cells remained constant over time in culture. beta-catenin and E-cadherin expression was subsequently immunolocalized to the aggregates of mononucleate cells present in both of these trophoblastic cell cultures and the villous cytotrophoblasts of the human first trimester and term placenta. Taken together, these observations indicate that the E-cadherin-beta-catenin complex plays a central role in the terminal differentiation of human trophoblasts in vitro and in vivo.

Volume rendering quantification algorithm for reconstruction of CT volume-rendered structures: Part I. Cerebral arteriovenous malformations.

Volume rendering is a visualization technique that has important applications in diagnostic radiology and in radiotherapy but has not achieved widespread use due, in part, to the lack of volumetric analysis tools for comparison of volume rendering to conventional visualization techniques. The volume rendering quantification algorithm (VRQA), a technique for three-dimensional (3-D) reconstruction of a structure identified on six principal volume-rendered views, is introduced and described. VRQA involves three major steps: 1) preprocessing of the partial surfaces constructed from each of six volume-rendered images; 2) merging these processed partial surfaces to define the boundaries of a volume; and 3) computation of the volume of the structure from this boundary information. After testing on phantoms, VRQA was applied to CT data of patients with cerebral arteriovenous malformations (AVM's). Because volumetric visualization of the cerebral AVM is relatively insensitive to operator dependencies, such as the choice of opacity transfer function, and because precise volumetric definition of the AVM is necessary for radiosurgical treatment planning, it is representative of a class of structures that is ideal for testing and calibration of VRQA. AVM volumes obtained using VRQA are intermediate to those obtained using axial contouring and those obtained using CT-correlated biplanar angiography (two routinely used visualization techniques for treatment planning for AVM's). Applications and potential expansions of VRQA are discussed.

Volume visualization in radiation treatment planning.

Radiation treatment planning (RTP), historically an image-intensive discipline and one of the first areas in which 3D information from imaging was clinically applied, has become even more critically dependent on accurate 3D definition of target and non-target structures in recent years with the advent of conformal radiation therapy. In addition to the interactive display of wireframe or shaded surface models of anatomic objects, proposed radiation beams, beam modifying devices, and calculated dose distributions, recently significant use has been made of direct visualization of relevant anatomy from image data. Dedicated systems are commercially available for the purpose of geometrically optimizing beam placement, implementing in virtual reality the functionality of standard radiation therapy simulators. Such "CT simulation" systems rely heavily on 3D visualization and on reprojection of image data to produce simulated radiographs for comparison with either diagnostic-quality radiographs made on a simulator or megavoltage images made using the therapeutic beams themselves. Although calculation and analysis of dose distributions is an important component of radiation treatment design, geometric targeting with optimization based on 3D anatomic information is frequently performed as a separate step independent of dose calculations.

Initial clinical experience with a video-based patient positioning system.

PURPOSE: To report initial clinical experience with an interactive, video-based patient positioning system that is inexpensive, quick, accurate, and easy to use. METHODS AND MATERIALS: System hardware includes two black-and-white CCD cameras, zoom lenses, and a PC equipped with a frame grabber. Custom software is used to acquire and archive video images, as well as to display real-time subtraction images revealing patient misalignment in multiple views. Two studies are described. In the first study, video is used to document the daily setup histories of 5 head and neck patients. Time-lapse cine loops are generated for each patient and used to diagnose and correct common setup errors. In the second study, 6 twice-daily (BID) head and neck patients are positioned according to the following protocol: at AM setups conventional treatment room lasers are used; at PM setups lasers are used initially and then video is used for 1-2 minutes to fine-tune the patient position. Lateral video images and lateral verification films are registered off-line to compare the distribution of setup errors per patient, with and without video assistance. RESULTS: In the first study, video images were used to determine the accuracy of our conventional head and neck setup technique, i.e., alignment of lightcast marks and surface anatomy to treatment room lasers and the light field. For this initial cohort of patients, errors ranged from sigma = 5 to 7 mm and were patient-specific. Time-lapse cine loops of the images revealed sources of the error, and as a result, our localization techniques and immobilization device were modified to improve setup accuracy. After the improvements, conventional setup errors were reduced to sigma = 3 to 5 mm. In the second study, when a stereo pair of live subtraction images were introduced to perform daily "on-line" setup correction, errors were reduced to sigma = 1 to 3 mm. Results depended on patient health and cooperation and the length of time spent fine-tuning the position. CONCLUSION: An interactive, video-based patient positioning system was shown to reduce setup errors to within 1 to 3 mm in head and neck patients, without a significant increase in overall treatment time or labor-intensive procedures. Unlike retrospective portal image analysis, use of two live-video images provides the therapists with immediate feedback and allows for true 3-D positioning and correction of out-of-plane rotation before radiation is delivered. With significant improvement in head and neck alignment and the elimination of setup errors greater than 3 to 5 mm, margins associated with treatment volumes potentially can be reduced, thereby decreasing normal tissue irradiation.

Antisteroidal compounds and steroid withdrawal down-regulate cadherin-11 mRNA and protein expression levels in human endometrial stromal cells undergoing decidualisation in vitro.

The cellular mechanisms by which steroids and antisteroidal compounds modulate the function and/or integrity of the human endometrium remain poorly understood. We recently determined that the expression of the novel cadherin subtype, known as cadherin-11, is tightly regulated in endometrial stromal cells undergoing decidualisation in vivo and in vitro. To determine whether the actions of antisteroids on the endometrium are mediated, at least in part, by their ability to regulate the expression of this cell adhesion molecule, we examined the effects of the antiprogestin RU486 and the antiestrogen ICI 182,780 on cadherin-11 mRNA and protein expression levels in human endometrial stromal cells undergoing decidualisation in vitro. RU486 decreased the levels of the cadherin-11 mRNA transcript and protein species present in these cell cultures in a dose- and time-dependent manner. Similarly, ICI 182,780 was capable of reducing stromal cadherin-11 mRNA and protein expression levels in a dose-dependent manner, suggesting that the progesterone-mediated increase in cadherin-11 expression levels in human endometrial cells undergoing decidualisation in vitro is dependent on the presence of estrogens. Cadherin-11 expression levels also were reduced in endometrial stromal cell cultures subjected to progesterone withdrawal, an in vitro model for menstrual breakdown. These studies not only give us useful insight into the mechanism(s) by which progesterone regulates stromal cadherin-11 expression, but they strengthen our hypothesis that this cell adhesion molecule plays a central role in the remodeling processes that occur in the human endometrium in response to fluctuations in the levels of gonadal steroids.

Volumetric visualization of head and neck CT data for treatment planning.

PURPOSE: To demonstrate the utility of volume rendering, an alternative visualization technique to surface rendering, in the practice of CT based radiotherapy planning for the head and neck. METHODS AND MATERIALS: Rendo-avs, a volume visualization tool developed at the University of Chicago, was used to volume render head and neck CT scans from two cases. Rendo-avs is a volume rendering tool operating within the graphical user interface environment of AVS (Application Visualization System). Users adjust the opacity of various tissues by defining the opacity transfer function (OTF), a function which preclassifies voxels by opacity prior to rendering. By defining the opacity map (OTF), the user selectively enhances and suppresses structures of various intensity. Additional graphics tools are available within the AVS network, allowing for the manipulation of perspective, field of view, data orientation. Users may draw directly on volume rendered images, create a partial surface, and thereby correlate objects in the 3D scene to points on original axial slices. Information in volume rendered images is mapped into the original CT slices via a Z buffer, which contains the depth information (Z coordinate) for each pixel in the rendered view. Locally developed software was used to project conventionally designed GTV contours onto volume rendered images. RESULTS: The lymph nodes, salivary glands, vessels, and airway are visualized in detail without prior manual segmentation. Volume rendering can be used to explore the finer anatomic structures that appear on consecutive axial slices as "points." Rendo-avs allowed for acceptable interactivity, with a processing time of approximately 5 seconds per 256 x 256 pixel output image. CONCLUSIONS: Volume rendering is a useful alternative to surface rendering, offering high-quality visualization, 3D anatomic delineation, and time savings to the user, due to the elimination of manual segmentation as a preprocessing step. Volume rendered images can be merged with conventional treatment planning images to add anatomic information to the treatment planning process.

Cadherin-11 is a hormonally regulated cellular marker of decidualization in human endometrial stromal cells.

Cultured human endometrial stromal cells respond to the gonadal steroids, progesterone and 17beta-estradiol, with morphological and biochemical changes that are characteristic of decidualization in vivo. To date, the cellular mechanisms involved in the terminal differentiation of human endometrial stromal cells into decidual cells remain poorly understood. We have recently determined that the novel cadherin subtype, known as cadherin-11, is expressed by endometrial stromal cells undergoing decidualization during the luteal phase of the menstrual cycle and the decidua of pregnancy. In these studies, we have examined cadherin-11 mRNA and protein expression levels in human endometrial stromal cells undergoing steroid-mediated decidualization in vitro. Progesterone or a combination of progesterone and 17beta-estradiol increased stromal cadherin-11 mRNA and protein expression levels with time in culture. Maximum levels of cadherin-11 expression in these cell cultures correlated with a marked increase in IGFBP-1 mRNA levels, a biochemical marker of decidualization. In contrast, 17beta-estradiol had no effect on stromal cad-11 mRNA and protein expression or the levels of the IGFBP-1 mRNA transcript. Taken together, these observations demonstrate that cadherin-11 mRNA and protein expression levels are up-regulated during the terminal differentiation of endometrial stromal cells-suggesting that this cell adhesion molecule may serve as a useful cellular marker for decidualization.