A theoretical four-compartment model to evaluate separate kidney technetium-99m-MAG3 kinetics in humans

A theoretical four-compartment model to evaluate separate kidney technetium-99m-MAG3 kinetics in humans.BackgroundPharmacokinetic modeling based on compartmentalization has provided a valuable tool to assess the clearance patterns of various glomerular and tubular agents. However, no models have been proposed thus far that combine vascular data and imaging data in order to gain a deeper knowledge on renal pathophysiology, and to obtain more diagnostic information of clinical relevance. To this aim, we propose a four-pool model for the evaluation of separate renal function.MethodsIn a group of ten normal volunteers and twenty patients with various renal diseases, we tested the four-pool model based on the identification of the two kidneys as two distinct pools. This approach made it possible to integrate the separate kidney contributions deriving from in vivo imaging data, and allows the researcher to quantitate many parameters specific to each kidney.ResultsThe parameters TERR, TERL, MRTR, MRTL, νR, νL, k3R-1, k3L-1 permit the normal from abnormal states of renal function to be differentiated, as well as monolateral from bilateral renal disease to be separated within the abnormal function group.ConclusionsThe proposed approach combines the advantages of plasma clearance methods with those derived by gamma-camera imaging, and makes it possible to quantitate the differential renal function. This feature may be clinically relevant in renal transplant donors, where full knowledge of renal pathophysiology could guide the procedure

Our experience of liver Epithelioid Hemangioendothelioma: from a misdiagnosis to liver transplantation with long term follow-up

Malignant Hepatic Epithelioid hemangioendothelioma (HEHE) is an uncommon vascular tumor of intermediate malignant potential. HEHE is a rare tumor and it is difficult to diagnose for surgeons, hepatologists, radiologists and pathologists. So, misdiagnosis with a delay of the treatment is not uncommon. We describe a case of a young woman with a diagnosis of HEHE made 6 years after the first evidence of liver mass with a very long term follow-up after surgical treatment. She had two diagnoses of Hepatocellurar carcinoma (HCC) and a diagnosis of Cholangiocarcinoma after three different fine needle biopsies. After clinical observation, a new laparoscopic core biopsy was performed. In a first time approach, considering clinical and radiological patterns, a diagnosis of Budd-Chiari Syndrome was finally made. For that the patient underwent an orthotopicliver transplantation (OLTx). The surgical sample histological analysis allowed a definitive diagnosis of HEHE. At last, at follow up 7 years after three OLTx the patient is still alive and in good health with no evidence of recurrence

Epitaxy of ultrathin CoO films studied by XPD and GIXRD

CoO layers have been grown by exposing to oxygen the (001) body-centered-tetragonal (bct) surface of a Co ultrathin film epitaxially grown on Fe(001). Different oxide thicknesses in the 2-15 ML range have been investigated by means of synchrotron-radiation-based techniques. X-ray photoelectron spectroscopy has been used to check the formation of the oxide films; X-ray photoelectron diffraction has given information concerning the symmetry of their unit cell; grazing incidence X-ray diffraction has allowed to evaluate precisely their in-plane lattice constant. The films show a CoO(001) rocksalt structure, rotated by 45degrees with respect to the bct Co substrate, with the [100] direction parallel to the substrate [110] direction. Their in-plane lattice constant increases as a function of thickness, to release the in-plane strain due to the 3% mismatch between the bulk CoO phase and the underlying substrate

Dosimetry of high intensity electron beams produced with dedicated accelerators in Intra-Operative Radiation Therapy (IORT)

The technique of High Dose Intra-Operative Radiation Therapy (HDR-IORT) consists in the delivery of irradiation immediately following the removal of a cancerous mass, where the same incision is used to direct the radiation to the tumour bed. Given its particular characteristics, IORT requires dose measurements that are different from those requested in external radiotherapy treatments. The main reason lies in the fact that in this case a single high dose must be delivered to a volume target whose extension and depths will be determined directly during the operation. Since the possibility of devising a treatment plan using a TPS (Treatment Planning System) is not available, it is necessary to know the physical and geometric characteristics of the beam. Defining the physical characteristics of the beam entails both measuring the delivered dose and defining (monitoring) procedures. In any case a much higher dose will be released than occurs with conventional external accelerators. The ionization chamber recommended by the standard protocols for radiotherapy cannot be used because of the ion recombination inside the gas. In this work we propose the use of a calorimetric phantom, the Dosiort, to measure the beam properties. We describe the main characteristics and some preliminary results of the Dosiort System, which is proposed within the framework of a research project of the INFN (Italian National Institute of Nuclear Physics). The set-up is a solid phantom of density approaching 1 g/cc with sensitive layers of scintillating fibres at fixed a position in a calorimetric configuration for the containment of electrons of energy 4−12 MeV. The prototype will be able to define the physical and geometrical characteristics of the electron beam (quality, isotropy, homogeneity, etc) and to measure the parameters needed to select the energy, the intensity and the Monitor Units (MU) for the exposition: Percentage Depth Dose; Beam profiles; Isodose curves; Values of dose f- or MU

Growth, structure and epitaxy of ultrathin NiO films on Ag(001)

NiO ultrathin films have been grown on Ag(001) by Ni deposition in an O-2 atmosphere. The thickness range 5-50 NIL has been investigated. X-ray photoelectron spectroscopy has been used to study the stoichiometric composition and chemical purity of the oxide films. We found completely oxidized stoichiometric NiO films. Their contamination has been found to be limited to the topmost layers. Photoelectron diffraction has given information concerning the local crystal structure of the films. The film atomic geometry has been found to be the same independent of thickness in the 0-50 ML range. The films have the expected (001) rock-salt structure with the same in plane orientation as the Ag(001) substrate. Specular X-ray reflectivity has allowed a very accurate thickness evaluation and has given information on the width of the density gradients at the film-substrate and vacuum-film interfaces, found to be of the order of a few atomic layers

Dosimetry of high intensity electron beams produced with dedicated accelerators in Intra-Operative Radiation Therapy (IORT)

The technique of High Dose Intra-Operative Radiation Therapy (HDR-IORT) consists in the delivery of irradiation immediately following the removal of a cancerous mass, where the same incision is used to direct the radiation to the tumour bed. Given its particular characteristics, IORT requires dose measurements that are different from those requested in external radiotherapy treatments. The main reason lies in the fact that in this case a single high dose must be delivered to a volume target whose extension and depths will be determined directly during the operation. Since the possibility of devising a treatment plan using a TPS (Treatment Planning System) is not available, it is necessary to know the physical and geometric characteristics of the beam. Defining the physical characteristics of the beam entails both measuring the delivered dose and defining (monitoring) procedures. In any case a much higher dose will be released than occurs with conventional external accelerators. The ionization chamber recommended by the standard protocols for radiotherapy cannot be used because of the ion recombination inside the gas. In this work we propose the use of a calorimetric phantom, the Dosiort, to measure the beam properties. We describe the main characteristics and some preliminary results of the Dosiort System, which is proposed within the framework of a research project of the INFN (Italian National Institute of Nuclear Physics). The set-up is a solid phantom of density approaching 1 g/cc with sensitive layers of scintillating fibres at fixed a position in a calorimetric configuration for the containment of electrons of energy 4−12 MeV. The prototype will be able to define the physical and geometrical characteristics of the electron beam (quality, isotropy, homogeneity, etc) and to measure the parameters needed to select the energy, the intensity and the Monitor Units (MU) for the exposition: Percentage Depth Dose; Beam profiles; Isodose curves; Values of dose f- or MU

Study and realization of real-time in-depth dosimetry system for IORT (Intra operative radiation theraphy)

Intra Operative Radiation Therapy (IORT) is a technique based on delivery of a high dose of ionising radiation to the cancer tissue, after tumour ablation, during surgery, while reducing the exposure of normal surrounding tissue. Novac7 and Liac are new linear accelerators expressly conceived to perform in the operating room. These accelerators supply electron beams with high dose rate. Because of this peculiar characteristic, classical dosimetric techniques are not able to give at once a real-time response and an extensive measure of the absorbed dose. In past years the authors realized a prototype for IORT dosimetry able to give the real time bi-dimensional image of dose distribution on a single layer. In the framework of a research project funded by the INFN (Italian National Institute of Nuclear Physics), a collaboration between the Physics Department of Bologna, Italy, the Physics Department of Cosenza and the Medicine Department of Catanzaro, Italy, has studied a new system composed of six layers. Each layer includes two orthogonal bundles of scintillating optical fibres. The fibres are optically coupled with four arrays of photodiodes as read-out system. This new system will be able to characterize completely the electron beam in energy, intensity and spatial distribution. In real time it will be able to measure the 3D dose distribution, providing a full check of quality assurance for IORT. The various phases of design, development and characterization of the instrument will be illustrated, as well as some experimental tests performed with the prototype. We verified that the system is able to give a real time response, which is linear versus dose and not affected by the high dose rate. The conclusions confirm the capability of the instrument to overcome problems encountered with classic dosimetry, showing that the obtained results strongly encourage the continuation of this research