Development of a novel program for conversion from tetrahedral-mesh-based phantoms to DICOM dataset for radiation treatment planning: TET2DICOM.

PURPOSE: Tetrahedral mesh (TM)-based computational human phantoms have recently been developed for evaluation of exposure dose with the merit of precisely representing human anatomy and the changing posture freely. However, conversion of recently developed TM phantoms to the Digital Imaging and Communications in Medicine (DICOM) file format, which can be utilized in the clinic, has not been attempted. The aim of this study was to develop a technique, called TET2DICOM, to convert the TM phantoms to DICOM datasets for accurate treatment planning. MATERIALS AND METHODS: The TM phantoms were sampled in voxel form to generate the DICOM computed tomography images. The DICOM-radiotherapy structure was defined based on the contour data. To evaluate TET2DICOM, the shape distortion of the TM phantoms during the conversion process was assessed, and the converted DICOM dataset was implemented in a commercial treatment planning system (TPS). RESULTS: The volume difference between the TM phantoms and the converted DICOM dataset was evaluated as less than about 0.1% in each organ. Subsequently, the converted DICOM dataset was successfully implemented in MIM (MIM Software Inc., Cleveland, USA, version 6.5.6) and RayStation (RaySearch Laboratories, Stockholm, Sweden, version 5.0). Additionally, the various possibilities of clinical application of the program were confirmed using a deformed TM phantom in various postures. CONCLUSION: In conclusion, the TM phantom, currently the most advanced computational phantom, can be implemented in a commercial TPS and this technique can enable various TM-based applications, such as evaluation of secondary cancer risk in radiotherapy.

TomoMQA: Automated analysis program for MVCT quality assurance of helical tomotherapy.

PURPOSE: In this study, we developed a simple but useful computer program, called TomoMQA, to offer an automated quality assurance for mega-voltage computed tomography (MVCT) images generated via helical tomotherapy. METHODS: TomoMQA is written in MATLAB and contains three steps for analysis: (a) open the DICOM dataset folder generated via helical tomotherapy (i.e., TomoTherapy® and Radixact™), (b) call the baseline data for the consistency test and click the "Analysis" button (or click the "Analysis" button without the baseline data and export the results as the baseline data), and (c) print an analyzed report. The overall procedure for the QA analysis included in TomoMQA is referred from the TG-148 recommendation. Here, the tolerances for MVCT QA were implemented from TG-148 recommended values as default; however, it can be modified by a user manually. RESULTS: To test the performance of the TomoMQA program, 15 MVCTs were prepared from five helical tomotherapy machines (1 of TomoTherapy® HD, 2 of TomoTherapy® HDA, and 2 of Radixact™) in 3 months and the QA procedures were performed using TomoMQA. From our results, the evaluation revealed that the developed program can successfully perform the MVCT QA analysis irrespective of the type of helical tomotherapy equipment. CONCLUSION: We successfully developed a new automated analysis program for MVCT QA of a helical tomotherapy platform, called TomoMQA. The developed program will be made freely downloadable from the TomoMQA-dedicated website.

Inter- and intra-observer variability in contouring of the prostate gland on planning computed tomography and cone beam computed tomography.

PURPOSE: To investigate inter-/intra-observer variability in defining the prostate by use of planning computed tomography (PCT) and cone beam CT (CBCT) with magnetic resonance image (MRI) as guidance prior to the introduction of an adaptive radiotherapy for prostate cancer. MATERIAL AND METHODS: We reviewed PCT and firstly acquired CBCT datasets of each ten patients with prostate cancer. Three physicians independently delineated the prostate based on PCT and CBCT with MRI as guidance, allowing determination of inter-physician variability. Two physicians repeated prostate contouring three times in total to investigate intra-physician variability. We compared delineated prostate volumes in terms of the generalized conformity index (CI(gen)), maximum variation ratio (MVR), and center of mass (COM). RESULTS: There were no significant inter-/intra-observer differences in the estimation of prostate volume on both PCT and CBCT. For both inter- and intra-observer variability in contouring the prostate gland, there were no significant differences in MVR between PCT and CBCT. The CI(gen) for inter-observer variability was 0.74 by PCT and 0.69 by CBCT. The CI(gen) for intra-observer variability on PCT and CBCT was 0.84 and 0.81 for observer 2 and 0.76 and 0.73 for observer 3. COM analyses showed that the greatest inter-/intra-observer variability was in the measurement of the prostate apex and base. With respect to CI(gen) and COM analysis for the inter-observer variability, more precise delineation of the prostate was possible on PCT than CBCT. More precise contouring in terms of both CI(gen) and COM was demonstrated by observer 2 than observer 3. CONCLUSIONS: Despite some ambiguity in apex and base level, there was a good consistency in delineating the gland on CBCT plus MRI-guided modification both among/within observer(s), without any significant difference from the consistency in defining the prostate on PCT. This study provides a framework for future studies of CBCT imaging of the prostate.

Ultrasound-guided sialo-irrigation with a saline-air mixture as the contrast medium.

Ultrasound (US)-guided salivary gland irrigation is a popular conservative treatment method that improves the success rate and reduces complications of the sialo-irrigation procedure. US is routinely used for evaluation of various salivary gland diseases because of its easy accessibility and absence of ionizing radiation. US also allows dynamic studies with real-time imaging during diagnostic or surgical procedures. However, conventional US images have limitations in salivary duct visualization. Although US images acquired with saline irrigation have improved visualization because of ductal system dilation by the pulling effect, the resultant image quality remains insufficient for diagnosis. Therefore, contrast agents are required during US-guided sialo-irrigation procedures to produce diagnostic image quality. Air bubbles in saline solution have high echogenicity and enhance image quality by acting as a US contrast agent. The aim of this study was to assess the clinical significance of US-guided sialo-irrigation with a saline-air contrast medium, to estimate its diagnostic and treatment efficacy, and to examine the procedure in two patients. In the study, two patients underwent US-guided salivary gland irrigation with air-bubble mixed saline solution. During the procedure, we were able to visualize the salivary gland duct and subsequently irrigate and clean the inside of the duct. As a result, the patients' symptoms were relieved and saline solution mixed with air bubbles was confirmed to be an effective contrast agent.

[Two cases of Fitz-Hugh-Curtis syndrome in acute phase].

Fitz-Hugh-Curtis syndrome has been defined as perihepatitis accompanying pelvic inflammatory disease caused by Neisseria gonorrhoeae and Chlamydia trachomatis. In the acute phase, patients usually complain of severe right upper quadrant pain of sudden onset. The pain is sharp, pleuritic and most intense at the level of the right lower rib margin and thus it is frequently confused with acute cholecystitis or pleurisy. Definitive diagnosis of Fitz-Hugh-Curtis syndrome needs invasive procedures such as laparoscopy or laparotomy, but considering that Fitz-Hugh-Curtis syndrome is a benign condition that can be cured by oral administration of appropriate antibiotics, noninvasive diagnosis is desirable. Recently, we have experienced two cases of Fitz-Hugh-Curtis syndrome in acute phase accompanied with sharp and pleuritic right upper quadrant pain. In one case, pelvic inflammatory disease was not definite, so at first we mistook it for acute cholecystitis and reactivation of chronic hepatitis B. In the other case, Fitz-Hugh-Curtis syndrome followed the preceding, typical pelvic inflammatory disease. Both cases were diagnosed noninvasively and treated successfully by oral administration of antibiotics.

In Vivo Effects of Preservative-free and Preserved Prostaglandin Analogs: Mouse Ocular Surface Study.

PURPOSE: Chronic use of topical hypotensive agents induces several side effects caused by preservatives. The purpose of this study was to evaluate the effects of prostaglandin analogs with varying concentrations of benzalkonium chloride (BAC), preservative-free (PF), and alternative preservatives on mouse corneal tissue. METHODS: Thirty-five, 8- to 10-week-old female C57BL/6 mice (five mice for each group) were used for this study. To the control group, we applied normal saline, and to each drug-treated group we applied 0.02% BAC, bimatoprost 0.01% (with BAC 0.02%), latanoprost 0.005% (with BAC 0.02%), travoprost 0.004% (with 0.001% polyquad) or tafluprost 0.0015% with/without 0.001% BAC, once a day (9 p.m.) for 4 weeks. Corneal fluorescein staining was evaluated in all groups. After harvest, the corneal tissues were embedded in paraffin and then Hematoxylin-Eosin stain was performed for histopathological examination. Immunofluorescence staining was done against TNF-α, IL-6, HLA DR, pJNK, and pAkt. RESULTS: In corneal fluorescein staining, severe punctate epithelial keratitis was seen in the groups of 0.02% BAC, 0.02% BAC containing bimatoprost 0.01% and latanoprost 0.005%. The surface desquamation, irregular surface, loss of cell borders, anisocytosis and stromal shrinkage were observed in the groups of BAC-containing eye drops. Moreover, the groups treated with BAC-containing eye drops have high inflammatory markers, significantly decreased cell viability-related signal, pAkt, and higher apoptosis-inducing signal, pJNK, than the control group. On the other hand, travoprost 0.004% and PF tafluprost 0.0015% have less cellular morphologic changes, lower inflammation, and higher cellular viability than BAC-containing formulations. CONCLUSIONS: Corneal damage, increased inflammation and apoptosis and low cell viability were observed in BAC-containing groups. PF or alternatively preserved glaucoma medications seem to be a reasonable and viable alternative to those preserved with BAC.

Deguelin inhibits vasculogenic function of endothelial progenitor cells in tumor progression and metastasis via suppression of focal adhesion.

Deguelin is a nature-derived chemopreventive drug. Endothelial progenitor cells (EPCs) are bone-marrow (BM)-derived key components to induce new blood vessels in early tumorigenesis and metastasis. Here we determined whether deguelin inhibits EPC function in vitro and in vivo at doses not affecting cancer cell apoptosis. Deguelin significantly reduced the number of EPC colony forming units of BM-derived c-kit+/sca-1+ mononuclear cells (MNCs), proliferation, migration, and adhesion to endothelial cell monolayers, and suppressed incorporation of EPC into tube-like vessel networks when co-cultured with endothelial cells. Deguelin caused cell cycle arrest at G1 without induction of apoptosis in EPC. In a mouse tumor xenograft model, tumor growth, lung metastasis and tumor-induced circulating EPCs were supressed by deguelin treatment (2 mg/kg). In mice tranplanted with GFP-expressing BM-MNCs, deguelin reduced the co-localization of CD31 and GFP, suggesting suppression of BM-derived EPC incoporation into tumor vessels. Interestingly, focal adhesion kinase (FAK)-integrin-linked kinase (ILK) activation and actin polymerization were repressed by deguelin. Decreased number of focal adhesions and a depolarized morphology was found in deguelin-treated EPCs. Taken together, our results suggest that the deguelin inhibits tumorigenesis and metastasis via EPC suppression and that suppression of focal adhesion by FAK-integrin-ILK-dependent actin remodeling is a key underlying molecular mechanism.

The relevance of serum ghrelin concentration to severity of acute pancreatitis.

BACKGROUND/AIMS: Ghrelin has recently been reported as exerting a protective effect in the damaged pancreas in rats. We investigated the correlation between severity of acute pancreatitis and serum ghrelin concentrations. METHODS: Blood samples were collected three times (at admission, after 48 hours, and at discharge) from patients admitted with acute pancreatitis. We divided the patients into nonrisk and risk groups. The risk group was defined as the presence of at least one of following risk factors for severe acute pancreatitis: Ranson's score >/=3, acute physiology and chronic health evaluation (APACHE) II score >/=8, C-reactive protein (CRP) >/=150 mg/L, and CT severity index (CTSI) >/=4. Serum ghrelin concentrations were measured with RIA kit and analyzed based on clinical and biochemical parameters. RESULTS: A total of 53 patients was enrolled in this study: 28 in the nonrisk group and 25 in the risk group. At admission, the ghrelin concentration was significantly higher in the risk group (286.39+/-272.19 vs 175.96+/-138.87 pg/mL [mean+/-SD], p=0.049). However, the ghrelin concentration did not differ significantly between the two groups after 48 hours (p=0.450) and at discharge (p=0.678). The overall ghrelin concentration was significantly lower at admission than at discharge (240.65+/-247.96 vs 369.41+/-254.27 pg/mL, p=0.001). CONCLUSIONS: Patients with risk factors for severe acute pancreatitis have higher serum ghrelin concentrations.

Feasibility study on hybrid medical imaging device based on Compton imaging and magnetic resonance imaging.

In this paper, we propose a combined Compton camera/magnetic resonance imaging (MRI) scanner. For this, the table-top Compton camera currently under development in our laboratory is suitable, considering that it is not very large (i.e., a table-top size) and that it uses semiconductor detectors (for both the scatterer and absorber detectors), which in principle are not very sensitive to a magnetic field. The Compton camera takes three-dimensional images from a fixed position and, therefore, does not require a large ring-type structure, making it possible to fit it into an existing MRI system, without requiring major modifications to the system. In the present study, the potential of combining the table-top Compton camera and an MRI scanner for real simultaneous imaging was demonstrated by fusing a Compton camera image of an instance of multi-tracing, generated by using Geant4 Monte Carlo simulations, with an MR image.