Mapping melanoma lymphoscintigraphy data onto a 3D anatomically based model

This study describes three-dimensional (3D) visualization of two-dimensional (2D) melanoma lymphatic mapping data, to provide a framework for analysis of melanoma spread patterns and a platform for recording new lymphoscintigraphy (LS) data more accurately in 3D. Specifically, the Sydney Melanoma Unit's LS database of over 5000 patients' primary cutaneous melanoma sites and sentinel lymph nodes have been mapped from 2D images onto a 3D anatomically based model. Anatomically accurate model geometries were created using the Visible Human dataset, giving a bicubic finite element skin mesh and discrete sentinel lymph node model. The full dataset of 2D melanoma site coordinates, excluding the head and neck, has been transformed onto this 3D skin mesh via free-form deformation and projection techniques. Sentinel lymph nodes were mapped onto the generic lymph node model for each patient. Preliminary spatial analysis indicates that a patient with a primary melanoma on the torso around the waist (on the standardized 3D model this region is 180 mm above and 130 mm below the umbilicus) with lymphatic drainage to the left axilla or left groin, will have a 17.7% probability of dual drainage to both node fields, with 95% confidence limits between 14.5 and 21.0%

Three−dimensional visualisation of lymphatic drainage patterns in patients with cutaneous melanoma

BACKGROUND: Lymphoscintigraphy accurately maps lymphatic drainage from sites of cutaneous melanoma to the draining sentinel lymph nodes. The Sydney Melanoma Unit has accumulated lymphoscintigraphy data from over 5000 patients with cutaneous melanoma over more than 15 years, collectively revealing patterns of skin lymphatic drainage. We aimed to map these data onto a three-dimensional computer model to provide improved visualisation and analysis of lymphatic drainage from sites of cutaneous melanoma. METHODS: Lymphoscintigraphy data from 5239 patients with cutaneous melanoma were collected between July 27, 1987 and Dec 16, 2005. 4302 of these patients had primary melanoma sites below the neck, and were included in this analysis. From these patients, two-dimensional lymphoscintigraphy data were mapped onto an anatomically based three-dimensional computer model of the skin and lymph nodes. Spatial analysis was done to visualise the relation between primary melanoma sites and the locations of sentinel lymph nodes. FINDINGS: We created three-dimensional, colour-coded heat maps that showed the drainage patterns from melanoma sites below the neck to individual lymph-node fields and to many lymph-node fields. These maps highlight the inter-patient variability in skin lymphatic drainage, and show the skin regions in which highly variable drainage can occur. To enable interactive and dynamic analysis of these data, we also developed software to predict lymphatic drainage patterns from melanoma skin sites to sentinel lymph-node fields. INTERPRETATION: The heat maps confirmed that the commonly used Sappey's lines are not effective in predicting lymphatic drainage. The heat maps and the interactive software could be a new resource for clinicians to use in preoperative discussions with patients with melanoma and other skin cancers that can metastasise to the lymph nodes, and could be used in the identification of sentinel lymph-node fields during follow-up of such patients

Distribution and Speciation of Nutrient Elements around Micropores

© 2009 Soil Science Society of AmericaIn Australia a class of soils known as duplex soils covers approximately 20% of the continent. Their defining characteristic is a sharp texture contrast between the A (or E) and B horizon. The upper B horizon at the point of contact with the E horizon is often highly sodic and of such a high strength that root growth and proliferation, water conductivity, aeration, water storage, and water uptake are restricted. Roots growing in these soils rely on channels created by previous roots or cracks arising from shrink–swell forces associated with seasonal wetting and drying. Although the characteristics of rhizospheres compared with the soil matrix are well documented there is a paucity of knowledge about how long these changes persist after roots decay. This knowledge is fundamental to our understanding of root growth in duplex soils in which plants rely on pore networks formed by previous plants to proliferate in the subsoil. In this study we investigated the heterogeneous chemistry of micropores in situ using synchrotron-based µ-x-ray fluorescence spectroscopy (XRF), µ-x-ray absorption near edge structure spectroscopy (XANES), and extended µ-x-ray absorption fine structure spectroscopy (EXAFS). The distribution maps of Ca, Mn, Fe, Cu, and Zn at micrometer resolution were collected using µ-XRF. Subsequently, specific locations with higher concentrations (hot spots) of Mn, Fe, Cu, or Zn were selected and XANES and EXAFS spectra were collected to study the speciation of these elements around the micropore compared with the soil matrix. The µ-XRF maps showed that Mn was depleted around one of the micropores studied but accumulated around another micropore. Copper and Zn accumulated around the micropores, whereas Ca was predominantly inside micropores. There was no difference between matrix and micropore surface with respect to the distribution of Fe. Around micropores Mn was present in reduced form (Mn II) and Fe was in its oxidized form (Fe III). Manganese and Cu were present in the form of phosphates, Fe as Fe oxides, and Zn as Zn phosphates and adsorbed Zn.Laurence Jassogne, Ganga Hettiarachchi, David Chittleborough and Ann McNeil