Counting Rate Characteristics and Image Distortion in Preclinical PET Imaging During Radiopharmaceutical Therapy.

Unlabelled: PET may provide important information on the response during radiopharmaceutical therapy (RPT). Emission of radiation from the RPT radionuclide may disturb coincidence detection and impair image resolution. In this study, we tested the feasibility of performing intratherapeutic PET on 3 preclinical PET systems.

Online dosimetry for temoporfin-mediated interstitial photodynamic therapy using the canine prostate as model.

Online light dosimetry with real-time feedback was applied for temoporfin-mediated interstitial photodynamic therapy (PDT) of dog prostate. The aim was to investigate the performance of online dosimetry by studying the correlation between light dose plans and the tissue response, i.e.

Cerenkov Luminescence Imaging for Accurate Placement of Radioactive Plaques in Episcleral Brachytherapy of Intraocular Tumors.

Purpose: The purpose of this study was to determine the feasibility of using Cerenkov luminescence imaging (CLI) to facilitate plaque placement during episcleral brachytherapy of intraocular tumors.

Methods: Ruthenium-106 (Ru-106) decays to rhodium-106, which in turn emits high-energy beta particles. When the electrons propagate through the eyewall, the so-called Cerenkov effect leads to emission of weak light, which can be captured by high-sensitivity charge-couple device (CCD) cameras.

Intratherapeutic biokinetic measurements, dosimetry parameter estimates, and monitoring of treatment efficacy using cerenkov luminescence imaging in preclinical radionuclide therapy.

Unlabelled: In recent years, there has been increasing interest in noninvasive Cerenkov luminescence imaging (CLI) of in vivo radionuclide distribution in small animals, a method proven to be a high-throughput modality for confirmation of tracer uptake. 11B6 is an IgG1 monoclonal antibody that is specific to free human kallikrein-related peptidase 2, an antigen abundant in malignant prostatic tissue. Free human kallikrein-related peptidase 2 was targeted in prostate cancer xenografts using (177)Lu-labeled 11B6 in either murine or humanized forms for radionuclide therapy.

Design and validation of a fiber optic point probe instrument for therapy guidance and monitoring.

Optical techniques for tissue diagnostics currently are experiencing tremendous growth in biomedical applications, mainly due to their noninvasive, inexpensive, and real-time functionality. Here, we demonstrate a hand-held fiber optic probe instrument based on fluorescence/reflectance spectroscopy for precise tumor delineation. It is mainly aimed for brain tumor resection guidance with clinical adaptation to minimize the disruption of the standard surgical workflow and is meant as a complement to the state-of-the-art fluorescence surgical microscopy technique.

(68)Ga-labeled superparamagnetic iron oxide nanoparticles (SPIONs) for multi-modality PET/MR/Cherenkov luminescence imaging of sentinel lymph nodes.

The aim of this study was to develop (68)Ga-SPIONs for use as a single contrast agent for dynamic, quantitative and high resolution PET/MR imaging of Sentinel Lymph Node (SLN). In addition (68)Ga enables Cherenkov light emission which can be used for optical guidance during resection of SLN. SPIONs were labeled with (68)Ga in ammonium acetate buffer, pH 5.

Pharmacokinetic and biodistribution study following systemic administration of Fospeg®--a Pegylated liposomal mTHPC formulation in a murine model.

Fospeg® is a newly developed photosensitizer formulation based on meso-tetra(hydroxyphenyl)chlorin (mTHPC), with hydrophilic liposomes to carry the hydrophobic photosensitizer to the target tissue. In this study the pharmacokinetics and biodistribution of Fospeg® were investigated by high performance liquid chromatography at various times (0.5-18 hours) following systemic i.

Nanoparticle uptake in tumors is mediated by the interplay of vascular and collagen density with interstitial pressure.

Unlabelled: Nanoparticle delivery into solid tumors is affected by vessel density, interstitial fluid pressure (IFP) and collagen, as shown in this article by contrasting the in vivo macroscopic quantitative uptake of 40 nm fluorescent beads in three tumor types.The fluorescence uptake was quantified on individual animals by normalization with the transmitted light and then normalized to normal tissue uptake in each mouse. Mean data for uptake in individual tumor lines then showed expected trends with the largest uptake in the most vascularized tumor line.

Quantitative Cherenkov emission spectroscopy for tissue oxygenation assessment.

Measurements of Cherenkov emission in tissue during radiation therapy are shown to enable estimation of hemoglobin oxygen saturation non-invasively, through spectral fitting of the spontaneous emissions from the treated tissue. Tissue oxygenation plays a critical role in the efficacy of radiation therapy to kill tumor tissue. Yet in-vivo measurement of this has remained elusive in routine use because of the complexity of oxygen measurement techniques.

Cerenkov emission induced by external beam radiation stimulates molecular fluorescence.

Purpose: Cerenkov emission is induced when a charged particle moves faster than the speed of light in a given medium. Both x-ray photons and electrons produce optical Cerenkov photons in everyday radiation therapy of tissue; yet, this phenomenon has never been fully documented. This study quantifies the emissions and also demonstrates that the Cerenkov emission can excite a fluorophore, protoporphyrin IX (PpIX), embedded in biological phantoms.

Drug quantification in turbid media by fluorescence imaging combined with light-absorption correction using white Monte Carlo simulations.

Accurate quantification of photosensitizers is in many cases a critical issue in photodynamic therapy. As a noninvasive and sensitive tool, fluorescence imaging has attracted particular interest for quantification in pre-clinical research. However, due to the absorption of excitation and emission light by turbid media, such as biological tissue, the detected fluorescence signal does not have a simple and unique dependence on the fluorophore concentration for different tissues, but depends in a complex way on other parameters as well.

System for interstitial photodynamic therapy with online dosimetry: first clinical experiences of prostate cancer.

The first results from a clinical study for Temoporfin-mediated photodynamic therapy (PDT) of low-grade (T1c) primary prostate cancer using online dosimetry are presented. Dosimetric feedback in real time was applied, for the first time to our knowledge, in interstitial photodynamic therapy. The dosimetry software IDOSE provided dose plans, including optical fiber positions and light doses based on 3-D tissue models generated from ultrasound images.

Photodynamic therapy: superficial and interstitial illumination.

Photodynamic therapy (PDT) is reviewed using the treatment of skin tumors as an example of superficial lesions and prostate cancer as an example of deep-lying lesions requiring interstitial intervention. These two applications are among the most commonly studied in oncological PDT, and illustrate well the different challenges facing the two modalities of PDT-superficial and interstitial. They thus serve as good examples to illustrate the entire field of PDT in oncology.

A matrix-free algorithm for multiple wavelength fluorescence tomography.

In the recent years, there has been an increase in applications of non-contact diffusion optical tomography. Especially when the objective is the recovery of fluorescence targets. The non-contact acquisition systems with the use of a CCD-camera produce much denser sampled boundary data sets than fibre-based systems.

In vivo photosensitizer tomography inside the human prostate.

Interstitial photodynamic therapy (IPDT) provides a promising means to treat large cancerous tumors and solid organs inside the human body. The treatment outcome is dependent on the distributions of light, photosensitizer, and tissue oxygenation. We present a scheme for reconstructing the spatial distribution of a fluorescent photosensitizer.

Lower cognitive performance in 81-year-old men with greater nocturnal blood pressure dipping.

Abnormal day-to-night blood pressure (BP) pattern have been found to be associated with cerebrovascular damage, yet studies of the elderly 80 years of age and above, for whom the risk pattern may be different due to ageing and age-associated diseases, are lacking. Ninety-seven 81-year-old men underwent ambulatory BP monitoring and were given six cognitive tests, 79 of the men completing the cognitive test battery. The odds ratio (OR) for performing one standard deviation below the mean on any cognitive test was calculated using a forward stepwise logistic regression model, confounding factors being controlled for.

Low ambulatory blood pressure is associated with lower cognitive function in healthy elderly men.

Introduction: Low blood pressure (BP) has been found to be associated with cerebrovascular damage in the elderly. Studies of the relation of ambulatory BP to cognitive function in elderly persons aged 80 years or above is lacking, however.

Methods: Ninety-seven 81-year-old men from the population study 'Men born in 1914' underwent ambulatory BP monitoring and were given a cognitive test battery, 79 subjects completing all six tests.

Low nocturnal blood pressure is associated with reduced cerebral blood flow in the cohort "Men born in 1914".

Background: "Men born in 1914" is a population-based cohort study of the epidemiology of cardiovascular and cerebral disease. Little is known about how diurnal variation in blood pressure (BP) levels influence cerebral perfusion in very elderly populations.

Objectives: To study the association between systolic (SBP) and diastolic BP (DBP) levels, during the day and at night, expressed through 24 h ambulatory BP monitoring (ABPM) and regional cerebral blood flow (rCBF) disturbances.

Realtime light dosimetry software tools for interstitial photodynamic therapy of the human prostate.

Photodynamic therapy (PDT) for the treatment of prostate cancer has been demonstrated to be a safe treatment option capable of inducing tissue destruction and decreasing prostate specific antigen (PSA) levels. However, prostate-PDT results in large intra- and interpatient variations in treatment response, possibly due to biological variations in tissue composition and short-term response to the therapeutic irradiation. Within our group, an instrument for interstitial PDT on prostate tissue has been developed that combines therapeutic light delivery and monitoring of light transmission via numerous bare-ended optical fibers.

Spatially varying regularization based on spectrally resolved fluorescence emission in fluorescence molecular tomography.

Fluorescence molecular tomography suffers from being mathematically ill-conditioned resulting in non-unique solutions to the reconstruction problem. In an attempt to reduce the number of possible solutions in the underdetermined system of equations in the reconstruction, we present a method to retrieve a spatially varying regularization map outlining the feasible inclusion position. This approach can be made very simple by including a few multispectral recordings from only one source position.

Fluorescence monitoring of a topically applied liposomal Temoporfin formulation and photodynamic therapy of nonpigmented skin malignancies.

Meso-tetra(hydroxyphenyl)chlorin (mTHPC) (INN: Temoporfin) is a potent photodynamically active substance in clinical use today. Usually, the substance is given systemically and a known drawback with this administration route is a prolonged skin light sensitization. For the first time to our knowledge, a liposomal Temoporfin gel formulation for topical application was studied in connection with photodynamic therapy (PDT) of nonpigmented skin malignancies in humans.

Cerebral microdialysis of patients with severe traumatic brain injury exhibits highly individualistic patterns as visualized by cluster analysis with self-organizing maps.

Objective: To analyze patterns of cerebral microdialysis in patients with traumatic brain injury and, with a neural network methodology, investigate pattern relationships to intracranial pressure and cerebral perfusion pressure.

Design: Retrospective.

Setting: University hospital, adult neurosurgical intensive care unit.

Home care aides in the administration of medication.

Objective: To assess to what extent home care aides (HCAs) within the social services are engaged in medication administration, including their knowledge of how to perform this work correctly, and also to assess their knowledge of pharmacology, adverse drug effects, diseases, and symptoms. Furthermore, we wanted to study if there were any changes to be seen in these areas since a previous study.

Design: A repeated survey, carried out in 1998, 5 years after a cross-sectional study.

[Unqualified home care aides put the patient at risk. Better knowledge concerning drug administration must be required].

During the last few years the home care services have had to face an increased responsibility for medical tasks. A study in the city of Malmö in 1993, repeated in 1998, shows that 95% of the health care assistants are engaged in the administration of medication. The studies demonstrate that health care assistants have inadequate knowledge not only about medicines and their administration but also about common diseases and their symptoms.