Evaluation of two-dimensional electronic portal imaging device using integrated images during volumetric modulated arc therapy for prostate cancer

BackgroundThe aim of the study was to evaluate analysis criteria for the identification of the presence of rectal gas during volumetric modulated arc therapy (VMAT) for prostate cancer patients by using electronic portal imaging device (EPID)-based in vivo dosimetry (IVD).Materials and methodsAll measurements were performed by determining the cumulative EPID images in an integrated acquisition mode and analyzed using PerFRACTION commercial software. Systematic setup errors were simulated by moving the anthropomorphic phantom in each translational and rotational direction. The inhomogeneity regions were also simulated by the I’mRT phantom attached to the Quasar phantom. The presence of small and large air cavities (12 and 48 cm³) was controlled by moving the Quasar phantom in several timings during VMAT. Sixteen prostate cancer patients received EPID-based IVD during VMAT.ResultsIn the phantom study, no systematic setup error was detected in the range that can happen in clinical (< 5-mm and < 3 degree). The pass rate of 2% dose difference (DD2%) in small and large air cavities was 98.74% and 79.05%, respectively, in the appearance of the air cavity after irradiation three quarter times. In the clinical study, some fractions caused a sharp decline in the DD2% pass rate. The proportion for DD2% < 90% was 13.4% of all fractions. Rectal gas was confirmed in 11.0% of fractions by acquiring kilo-voltage X-ray images after the treatment.ConclusionsOur results suggest that analysis criteria of 2% dose difference in EPID-based IVD was a suitable method for identification of rectal gas during VMAT for prostate cancer patients.     

In vivo imaging the motility of monocyte/macrophage during inflammation in diabetic mice

Diabetes, as a chronic metabolic disease, can impair the immune function of monocytes/macrophages (MMs). However, it is unclear how MM immune response to inflammation with the development of diabetes, and whether immune response around the inflammatory foci depends on the depth in tissue. Footpad provides a classical physiological site for monitoring cellular behavior during inflammation, but limited to the superficial dermis due to the strong scattering of footpad. Herein, we used confocal microscopy to monitor the motility of MMs in deeper tissue around inflammatory foci with the development of type 1 diabetic (T1D) mice through a switchable footpad skin optical clearing window. Delayed‐type hypersensitivity (DTH) model was elicited on the footpad of T1D. Results demonstrated that progressive T1D led to the gradually potentiated MM recruitment and increased expression of monocyte chemoattractant protein‐1 during DTH, but MM migration displacement, motion velocity and motility coefficient were significantly attenuated. Besides, MMs from the deeper dermis had a much larger migration displacement than those from superficial dermis at early stages of DTH but an opposite tendency at late stages for non‐T1D, while progressive T1D obscured this difference gradually. This study will be helpful for investigating the influences of progressive metabolic diseases on immune response. MM motion trajectory at depth of superficial dermis and the deeper dermis at AOVA (heat‐aggregated ovalbumin)—4 hours and AOVA—72 hours on non‐T1D (A) and T1D—4 weeks (B). Mean motility coefficient (C) at the 2 depths. Data were pooled from 6 mice per group. *P < .05 and **P < .01 compared among different T1D disease durations. #P < .05 compared between different depths.      

活体动物体内光学成像技术的研究进展

生物发光和荧光成像作为近年来新兴的活体动物体内光学成像技术,以其操作简便及直观性成为研究小动物活体成像的一种理想方法,在生命科学研究中得以不断发展。利用这种成像技术,可以直接实时观察标记的基因及细胞在活体动物体内的活动及反应。利用光学标记的转基因动物模型可以研究疾病的发生发展过程,进行药物研究及筛选等。本文综述了现有活体动物体内光学成像技术的原理、应用领域及发展前景,比较了生物发光与几种荧光技术的不同特点和应用。     

Classification of established atopic dermatitis in children with the in vivo imaging methods

Atopic dermatitis (AD) is a cutaneous disease resulting from a defective barrier and dysregulated immune response. The severity scoring of atopic dermatitis (SCORAD) is used to classify AD. Noninvasive imaging approaches supplementary to SCORAD were investigated. Cr:forsterite laser‐based microscopy was employed to analyze endogenous third‐harmonic generation (THG) and second‐harmonic generation (SHG) signals from skin. Imaging parameters were compared between different AD severities. Three‐dimensional reconstruction of imaged skin layers was performed. Finally, statistic models from quantitative imaging parameters were developed for predicting disease severity. Our data demonstrate that THG signal intensity of lesional skin in AD were significantly increased and was positively correlated with AD severity. Characteristic gray level co‐occurrence matrix (GLCM) values were observed in more severe AD. In the 3D reconstruction video, individual dermal papilla and obvious fibrosis in the upper papillary dermis were easily identified. Our estimation models could predict the disease severity of AD patients with an accuracy of nearly 85%. The THG signal intensity and characteristic GLCM patterns are associated with AD severity and can serve as quantitative predictive parameters. Our imaging approach can be used to identify the histopathological changes of AD objectively, and to complement the SCORAD index, thus improving the accuracy of classifying AD severity.      

The ‘Gator’ Mouse Suit for early bioluminescent metastatic breast cancer detection and nanomaterial signal enhancement during live animal imaging

Optical imaging is a cornerstone of modern oncologic research. The aim of this study is to determine the value of a new tool to enhance bioluminescent and fluorescent sensitivity for facilitating very‐low‐level signal detection in vivo. Experimental: For bioluminescent imaging experiments, a luciferase expressing breast cancer cell line with metastatic phenotype was implanted orthotopically into the mammary fat pad of mice. For fluorescent imaging experiments, near‐infrared (NIR) nanoparticles were injected intratumorally and subcutaneously into mice. Images were compared in mice with and without application of the ‘Gator’ Mouse Suit (GMS). Results: The GMS was associated with early detection and quantification of metastatic bioluminescent very‐low‐level signal not possible with conventional imaging strategies. Similarly, NIR nanoparticles that were undetectable in locations beyond the primary injection site could be visualized and their very‐low‐level signal quantifiable with the aid of the GMS. Conclusion: The GMS is a device which has tremendous potential for facilitating the development of bioluminescent models and fluorescent nanomaterials for translational oncologic applications. Copyright © 2010 John Wiley & Sons, Ltd.     

NIR spectroscopic imaging to map hemoglobin + myoglobin oxygenation,their concentration and optical pathlength across a beating pig heart during surgery

The purpose of this paper is to demonstrate that near‐infrared (NIR) spectroscopic imaging can provide spatial distribution (maps) of the absolute concentration of hemoglobin + myoglobin, oxygen saturation parameter and optical pathlength, reporting on the biochemico‐physiological status of a beating heart in vivo. The method is based on processing the NIR spectroscopic images employing a first‐derivative approach. Blood‐pressure‐controlled gating compensated the effect of heart motion on the imaging. All the maps are available simultaneously and noninvasively at a spatial resolution in the submillimeter range and can be obtained in a couple of minutes. The equipment has no mechanical contact with the tissue, thereby leaving the heart unaffected during the measurement. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Generation of a syngeneic mouse model to study the intraperitoneal dissemination of ovarian cancer with in vivo luciferase imaging

In order to facilitate the discovery and investigation of anti‐cancer therapeutics under physiological conditions, we have engineered the ovarian cancer cell line, HM‐1/luc, in mice. This cell stably expresses firefly luciferase and produces light that can be detected using an in vivo imaging system (IVIS). Parental HM‐1 cells cause severe carcinomatous peritonitis to B6C3F1 mice, but not to C57BL6 mice. Established HM‐1/luc cells showed pathologically similar findings to HM‐1 cells. HM‐1/luc cells were injected into the peritoneal cavity of B6C3F1 mice and IVIS 2000 was conducted weekly after inoculation to monitor intra‐peritoneal tumor growth. The mice were divided into three groups: non‐CDDP‐treated (control) and CDDP‐treated (0.2 and 0.4 mg). A disease‐suppressive effect of the CDDP was reflected by the significantly prolonged survival of the CDDP‐treated mice (control 23 ± 1.9 days, CDDP 0.2 mg 29.6 ± 2.9 days; p < 0.05); the total photon and area of flux were decreased. The optical imaging of intraperitoneal tumors via in vivo bioluminescence is effective for noninvasive monitoring and semi‐quantitative analysis. Our syngeneic mouse model has the relevant clinical features of ovarian cancer, which makes it a useful model for developing new ovarian cancer therapies. Copyright © 2009 John Wiley & Sons, Ltd.