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- Altai, Mohamed, et al.
(författare)
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Selection of an optimal cysteine-containing peptide-based chelator for labeling of Affibody molecules with 188-Re
- 2013
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 40:Suppl. 2, s. S219-S220
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Affibody molecules constitute a class of small (7 kDa) scaffold proteins that can be engineered to have excellent tumor targeting properties. High reabsorption in kidneys complicates development of affibody molecules for radionuclide therapy. In this study, we evaluated the influence of the composition of cysteine-containing C-terminal peptide-based chelators on the biodistribution and renal retention of 188Re-labeled anti-HER2 affibody molecules. Biodistribution of affibody molecules containing GGXC or GXGC peptide chelators (where X is G, S, E or K) was compared with biodistribution of a parental affibody molecule ZHER2:2395 having a KVDC peptide chelator. All constructs retained low picomolar affinity to HER2-expressing cells after labeling. The biodistribution of all 188Re-labeled affibody molecules was in general comparable, with the main observed difference found in the uptake and retention of radioactivity in excretory organs. The 188Re-ZHER2:V2 affibody molecule with a GGGC chelator provided the lowest uptake in all organs and tissues. The renal retention of 188Re-ZHER2:V2 (3.1±0.5 %ID/g at 4 h after injection) was 55-fold lower than retention of the parental 188Re-ZHER2:2395 (172±32 %ID/g). We show that engineering of cysteine-containing peptide-based chelators can be used for significant improvement of biodistribution of 188Re-labeled scaffold proteins, particularly reduction of their uptake in excretory organs.
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- Bajc, Marika, et al.
(författare)
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Perfusion SPECT in patients with suspected pulmonary embolism.
- 2013
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 40:9, s. 1432-1437
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Ventilation/perfusion tomography (V/PSPECT), with new interpretation criteria and newer tracers for ventilation imaging, has markedly improved the diagnostic yield in acute pulmonary embolism (PE). Here, we evaluated the diagnostic performance of perfusion SPECT (PSPECT) without ventilation imaging. METHODS: We studied 152 patients with clinically suspected PE who had been examined with both V/PSPECT and multidetector computed tomographic angiography (MD-CTA). The diagnosis or exclusion of PE was decided by the referring clinician based on both the V/PSPECT and/or MD-CTA findings in combination with the clinical findings. PSPECT images were retrospectively examined by a physician with experience in the interpretation of planar perfusion scans who was blinded to clinical, V/PSPECT and MD-CTA data. PSPECT images were interpreted without the aid of chest radiography. All the patients who were deemed to have PE were given anticoagulant therapy. RESULTS: Of the 152 patients, 59 (39 %) received a final diagnosis of PE, and 19 (32 %) had associated cardiopulmonary diseases such as pneumonia, COPD, or left heart failure. PSPECT correctly identified 53 (90 %) of the 59 patients with PE. The specificity was 88 of 93 (95 %). None of the PSPECT images was rated nondiagnostic. PSPECT yielded an overall diagnostic accuracy of 93 % (95 % confidence interval, CI, 87-96 %). At the observed PE prevalence of 39 %, the positive and negative predictive values of PSPECT were 91 % (95 % CI, 80-97 %) and 94 % (95 % CI, 86-97 %), respectively. CONCLUSION: In managing critically ill patients, PSPECT might be a valid alternative to V/PSPECT or MD-CTA since it was able to identify most patients with PE with a low false-positive rate and no inconclusive results.
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| 15. |
- Barrington, Sally F., et al.
(författare)
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Concordance between four European centres of PET reporting criteria designed for use in multicentre trials in Hodgkin lymphoma
- 2010
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 37:10, s. 1824-1833
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Tidskriftsartikel (refereegranskat)abstract
- To determine if PET reporting criteria for the Response Adapted Treatment in Hodgkin Lymphoma (RATHL) trial could enable satisfactory agreement to be reached between 'core' laboratories operating in different countries. Four centres reported scans from 50 patients with stage II-IV HL, acquired before and after two cycles of Adriamycin/bleomycin/vinblastine/dacarbazine. A five-point scale was used to score response scans using 'normal' mediastinum and liver as reference levels. Centres read scans independently of each other. The level of agreement between centres was determined assuming (1) that uptake in sites involved at diagnosis that was higher than liver uptake represented disease (conservative reading), and (2) that uptake in sites involved at diagnosis that was higher than mediastinal uptake represented disease (sensitive reading). There was agreement that the response scan was 'positive' or 'negative' for lymphoma in 44 patients with a conservative reading and in 41 patients with a sensitive reading. Kappa was 0.85 (95% CI 0.74-0.96) for conservative reading and 0.79 (95% CI 0.67-0.90) for sensitive reading. Agreement was reached in 46 and 44 patients after discussion for the conservative and sensitive readings, respectively. The criteria developed for reporting in the RATHL trial are sufficiently robust to be used in a multicentre setting.
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| 22. |
- Choo, I. L. H., et al.
(författare)
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Astrocytosis measured by C-11-deprenyl PET correlates with decrease in gray matter density in the parahippocampus of prodromal Alzheimer's patients
- 2014
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 41:11, s. 2120-2126
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Tidskriftsartikel (refereegranskat)abstract
- Purpose The Alzheimer's disease (AD) pathology is characterized by fibrillar amyloid deposits and neurofibrillary tangles, as well as the activation of astrocytosis, microglia activation, atrophy, dysfunctional synapse, and cognitive impairments. The aim of this study was to test the hypothesis that astrocytosis is correlated with reduced gray matter density in prodromal AD. Methods Twenty patients with AD or mild cognitive impairment (MCI) underwent multi-tracer positron emission tomography (PET) studies with C-11-Pittsburgh compound B (C-11-PIB), F-18-Fluorodeoxyglucose (F-18-FDG), and C-11-deuterium-L-deprenyl (C-11-DED) PET imaging, as well as magnetic resonance imaging (MRI) scanning, cerebrospinal fluid (CSF) biomarker analysis, and neuropsychological assessments. The parahippocampus was selected as a region of interest, and each value was calculated for four different imaging modalities. Correlation analysis was applied between DED slope values and gray matter (GM) densities by MRI. To further explore possible relationships, correlation analyses were performed between the different variables, including the CSF biomarker. Results A significant negative correlation was obtained between DED slope values and GM density in the parahippocampus in PIB-positive (PIB+ve) MCI patients (p = 0.025) (prodromal AD). Furthermore, in exploratory analyses, a positive correlation was observed between PIB-PET retention and DED binding in AD patients (p = 0.014), and a negative correlation was observed between PIB retention and CSF A beta 42 levels in MCI patients (p = 0.021), while the GM density and CSF total tau levels were negatively correlated in both PIB+ve MCI (p = 0.002) and MCI patients (p = 0.001). No significant correlation was observed with FDG-PET and with any of the other PET, MRI, or CSF biomarkers. Conclusions High astrocytosis levels in the parahippocampus of PIB+ve MCI (prodromal AD) patients suggest an early preclinical influence on cellular tissue loss. The lack of correlation between astrocytosis and CSF tau levels, and a positive correlation between astrocytosis and fibrillar amyloid deposition in clinical demented AD together indicate that parahippocampal astrocytosis might have some causality within the amyloid pathology.
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| 24. |
- Danad, Ibrahim, et al.
(författare)
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Coronary risk factors and myocardial blood flow in patients evaluated for coronary artery disease : a quantitative [15O]H2O PET/CT study
- 2012
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 39:1, s. 102-112
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThere has been increasing interest in quantitative myocardial blood flow (MBF) imaging over the last years and it is expected to become a routinely used technique in clinical practice. Positron emission tomography (PET) using [15O]H2O is the established gold standard for quantification of MBF in vivo. A fundamental issue when performing quantitative MBF imaging is to define the limits of MBF in a clinically suitable population. The aims of the present study were to determine the limits of MBF and to determine the relationship among coronary artery disease (CAD) risk factors, gender and MBF in a predominantly symptomatic patient cohort without significant CAD.MethodsA total of 128 patients (mean age 54 ± 10 years, 50 men) with a low to intermediate pretest likelihood of CAD were referred for noninvasive evaluation of CAD using a hybrid PET/computed tomography (PET/CT) scanner. MBF was quantified with [15O]H2O at rest and during adenosine-induced hyperaemia. Obstructive CAD was excluded in these patients by means of invasive or CT-based coronary angiography.ResultsGlobal average baseline MBF values were 0.91 ± 0.34 and 1.09 ± 0.30 ml·min−1·g−1 (range 0.54–2.35 and 0.59–2.75 ml·min−1·g−1) in men and women, respectively (p < 0.01). However, no gender-dependent difference in baseline MBF was seen following correction for rate–pressure product (0.98 ± 0.45 and 1.09 ± 0.30 ml·min−1·g−1 in men and women, respectively; p = 0.08). Global average hyperaemic MBF values were 3.44 ± 1.20 ml·min−1·g−1 in the whole study population, and 2.90 ± 0.85 and 3.78 ± 1.27 ml·min−1·g−1 (range 1.52–5.22 and 1.72–8.15 ml·min−1·g−1) in men and women, respectively (p < 0.001). Multivariate analysis identified male gender, age and body mass index as having an independently negative impact on hyperaemic MBF.ConclusionGender, age and body mass index substantially influence reference values and should be corrected for when interpreting hyperaemic MBF values.
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| 26. |
- de Haan, Stefan, et al.
(författare)
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Parametric imaging of myocardial viability using ¹⁵O-labelled water and PET/CT : comparison with late gadolinium-enhanced CMR
- 2012
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 39:8, s. 1240-1245
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Tidskriftsartikel (refereegranskat)abstract
- PurposeThe perfusable tissue index (PTI) is a marker of myocardial viability. Recent technological advances have made it possible to generate parametric PTI images from a single [15O]H2O PET/CT scan. The purpose of this study was to validate these parametric PTI images.MethodsThe study population comprised 46 patients with documented or suspected coronary artery disease who were studied with [15O]H2O PET and late gadolinium-enhanced (LGE) cardiac magnetic resonance imaging (CMR).ResultsOf the 736 myocardial segments included, 364 showed some degree of LGE. PTI and perfusable tissue fraction (PTF) diminished with increasing LGE. The areas under the curve of the PTI and PTF, used to predict (near) transmural LGE on CMR, were 0.86 and 0.87, respectively. Optimal sensitivity and specificity were 91 % and 73 % for PTI and 69 % and 87 % for PTF, respectively.ConclusionPTI and PTF assessed with a single [15O]H2O scan can be utilized as markers of myocardial viability in patients with coronary artery disease.
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| 29. |
- Eriksson, Olof, et al.
(författare)
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Imaging the islet graft by positron emission tomography
- 2012
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 39:3, s. 533-542
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Forskningsöversikt (refereegranskat)abstract
- Clinical islet transplantation is being investigated as a permanent cure for type 1 diabetes mellitus (T1DM). Currently, intraportal infusion of islets is the favoured procedure, but several novel implantation sites have been suggested. Noninvasive longitudinal methodologies are an increasingly important tool for assessing the fate of transplanted islets, their mass, function and early signs of rejection. This article reviews the approaches available for islet graft imaging by positron emission tomography and progress in the field, as well as future challenges and opportunities.
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| 30. |
- Fondell, Amelie, et al.
(författare)
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Nuclisome : a novel concept for radionuclide therapy using targeting liposomes
- 2010
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 37:1, s. 114-123
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: For the treatment of cancer, the therapeutic potential of short-range, low-energy Auger-electron emitters, such as (125)I, is getting progressively wider recognition. The potency of Auger-electron emitters is strongly dependent on their location in close vicinity to DNA. We have developed a new two-step targeting strategy to transport (125)I into cancer-cell nuclei using PEG-stabilized tumour-cell targeting liposomes named "Nuclisome-particles". METHODS: In the present study, epidermal growth factor (EGF) was used as a tumour-cell-specific agent to target the EGF-receptor (EGFR) and the liposomes were loaded with (125)I-Comp1, a recently synthesized daunorubicin derivative. RESULTS: As analysed with cryo-TEM, the derivative precipitates inside liposomes at a drug-to-lipid molar ratio of 0.05:1. Receptor-specific uptake in cultured U-343MGaCl2:6 tumour cells of EGFR-targeting liposomes increased with time while non-specific and receptor-blocked uptake remained low. Nuclisome-particles were able to target single U-343MGaCl2:6 cells circulating in human blood during 4 h, with low uptake in white blood cells, as demonstrated in an ex vivo system using a Chandler loop. Autoradiography of targeted cells indicates that the grains from the radiolabelled drug are mainly co-localized with the cell nuclei. The successful targeting of the nucleus is shown to provide high-potency cell killing of cultured U-343MGaCl2:6 cells. At the concentration used, Nuclisome-particles were up to five orders of magnitude more effective in cell killing than EGFR-targeting liposomes loaded with doxorubicin. CONCLUSION: The results thus provide encouraging evidence that our two-step targeting strategy for tumour cell DNA has the potential to become an effective therapy against metastasizing cancer cells in the bloodstream.
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| 31. |
- Forsberg, Anton, et al.
(författare)
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Low background and high contrast PET imaging of amyloid-β with [11C]AZD2995 and [11C]AZD2184 in Alzheimer's disease patients
- 2013
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer-Verlag New York. - 1619-7070 .- 1619-7089. ; 40:4, s. 580-593
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to evaluate AZD2995 side by side with AZD2184 as novel PET radioligands for imaging of amyloid-β in Alzheimer's disease (AD).METHODS: In vitro binding of tritium-labelled AZD2995 and AZD2184 was studied and compared with that of the established amyloid-β PET radioligand PIB. Subsequently, a first-in-human in vivo PET study was performed using [(11)C]AZD2995 and [(11)C]AZD2184 in three healthy control subjects and seven AD patients.RESULTS: AZD2995, AZD2184 and PIB were found to share the same binding site to amyloid-β. [(3)H]AZD2995 had the highest signal-to-background ratio in brain tissue from patients with AD as well as in transgenic mice. However, [(11)C]AZD2184 had superior imaging properties in PET, as shown by larger effect sizes comparing binding potential values in cortical regions of AD patients and healthy controls. Nevertheless, probably due to a lower amount of nonspecific binding, the group separation of the distribution volume ratio values of [(11)C]AZD2995 was greater in areas with lower amyloid-β load, e.g. the hippocampus.CONCLUSION: Both AZD2995 and AZD2184 detect amyloid-β with high affinity and specificity and also display a lower degree of nonspecific binding than that reported for PIB. Overall [(11)C]AZD2184 seems to be an amyloid-β radioligand with higher uptake and better group separation when compared to [(11)C]AZD2995. However, the very low nonspecific binding of [(11)C]AZD2995 makes this radioligand potentially interesting as a tool to study minute levels of amyloid-β. This sensitivity may be important in investigating, for example, early prodromal stages of AD or in the longitudinal study of a disease modifying therapy.
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| 35. |
- Geijer, Håkan, 1961-, et al.
(författare)
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Somatostatin receptor PET/CT in neuroendocrine tumours : update on systematic review and meta-analysis
- 2013
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer. - 1619-7070 .- 1619-7089. ; 40:11, s. 1770-1780
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Forskningsöversikt (refereegranskat)abstract
- Purpose Neuroendocrine tumours (NET) are uncommon and may be localized in many different places in the body. Traditional imaging has mainly been performed with CT and somatostatin receptor scintigraphy (SRS). Recently, it has become possible to use somatostatin receptor PET/CT (SMSR PET) instead, which might improve diagnostic quality. To evaluate the diagnostic quality of SMSR PET we performed a meta-analysis as an update of a previous study published in 2012. A literature search was performed searching MEDLINE, Embase and five other databases with a combination of the expressions "PET", "positron emission tomography", "neuroendocrine" and "NET". The search was updated to 31 December 2012. Studies were selected which evaluated the sensitivity and specificity of SMSR PET for NET in the thorax or abdomen with a study size of at least eight patients. The methodological quality of the included studies was evaluated with QUADAS-2. Eight studies fulfilled the inclusion criteria and were selected for final analysis, and 14 articles from a previous meta-analysis were added for a total of 22 articles. A total of 2,105 patients were included in the studies, an increase from 567 in the previous meta-analysis. The pooled sensitivity was 93 % (95 % CI 91 - 94 %) and specificity 96 % (95 % CI 95 - 98 %). The area under the summary ROC curve was 0.98 (95 % CI 0.95 - 1.0). In the previous meta-analysis the pooled sensitivity was 93 % (95 % CI 91 - 95 %) and specificity 91 % (95 % CI 82 - 97 %). SMSR PET has good diagnostic performance for evaluation of NET in the thorax and abdomen, better than SRS which has been the previous standard method. This meta-analysis gives further support for switching to SMSR PET.
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| 36. |
- Giammarile, Francesco, et al.
(författare)
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EANM procedure guideline for the treatment of liver cancer and liver metastases with intra-arterial radioactive compounds
- 2011
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 38:7, s. 1393-1406
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Tidskriftsartikel (refereegranskat)abstract
- surgery (i.e. resection or liver transplantation), but only 10-20% of patients are candidates for this. In other patients, a variety of palliative treatments can be given, such as chemoembolization, radiofrequency ablation or recentlyPrimary liver cancers (i.e. hepatocellular carcinoma or cholangiocarcinoma) are worldwide some of the most frequent cancers, with rapidly fatal liver failure in a large majority of patients. Curative therapy consists of introduced tyrosine kinase inhibitors, e. g. sorafenib. Colorectal cancer is the second most lethal cancer in Europe and liver metastases are prevalent either at diagnosis or in follow-up. These patients are usually treated by a sequence of surgery, chemotherapy and antibody therapy [Okuda et al. (Cancer 56: 918-928, 1985); Schafer and Sorrell (Lancet 353: 1253-1257, 1999); Leong et al. (Arnold, London, 1999)]. Radioembolization is an innovative therapeutic approach defined as the injection of micron-sized embolic particles loaded with a radioisotope by use of percutaneous intra-arterial techniques. Advantages of the use of these intra-arterial radioactive compounds are the ability to deliver high doses of radiation to small target volumes, the relatively low toxicity profile, the possibility to treat the whole liver including microscopic disease and the feasibility of combination with other therapy modalities. Disadvantages are mainly due to radioprotection constraints mainly for I-131-labelled agents, logistics and the possibility of inadvertent delivery or shunting [Novell et al. (Br J Surg 78: 901-906, 1991)]. The Therapy, Oncology and Dosimetry Committees have worked together in order to revise the European Association of Nuclear Medicine (EANM) guidelines on the use of the radiopharmaceutical I-131-Lipiodol (Lipiocis (R), IBA, Brussels, Belgium) and include the newer medical devices with Y-90-microspheres. Y-90 is either bound to resin (SIR-Spheres (R), Sirtex Medical, Lane Cove, Australia) or embedded in a glass matrix (TheraSphere (R), MDS Nordion, Kanata, ON, Canada). Since Y-90-microspheres are not metabolized, they are not registered as unsealed sources. However, the microspheres are delivered in aqueous solution: radioactive contamination is a concern and microspheres should be handled, like other radiopharmaceuticals, as open sources. The purpose of this guideline is to assist the nuclear medicine physician in treating and managing patients undergoing such treatment. I-131-Lipiodol is a consolidated treatment option and the previous European Association of Nuclear Medicine (EANM) guidelines have been revised for its use. The newer Y-90-microsphere therapy is rapidly expanding throughout the nuclear medicine community. To date, published data on microspheres, particularly on dosimetry features and the characterization of the objective response, are still preliminary. Therefore, the aim of this part of the document is to set up a first basic procedure to guide nuclear medicine physicians in treatment with radiolabelled microspheres.
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| 41. |
- Gordon, Isky, et al.
(författare)
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Guidelines for standard and diuretic renogram in children.
- 2011
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Ingår i: European journal of nuclear medicine and molecular imaging. - : Springer Science and Business Media LLC. - 1619-7089 .- 1619-7070. ; 38:6, s. 1175-88
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Tidskriftsartikel (refereegranskat)abstract
- Special consideration needs to be given to children who undergo dynamic renography. The Paediatric Committee of the European Association of Nuclear Medicine has updated the previous guidelines. Details are provided on how to manage the child, the equipment, and the acquisition and processing protocols. The pitfalls, difficulties and controversies that are encountered are also discussed, as well as the interpretation of the results.
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| 43. |
- Hindorf, Cecilia, et al.
(författare)
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EANM Dosimetry Committee guidelines for bone marrow and whole-body dosimetry
- 2010
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 37:6, s. 1238-1250
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Tidskriftsartikel (refereegranskat)abstract
- The level of administered activity in radionuclide therapy is often limited by haematological toxicity resulting from the absorbed dose delivered to the bone marrow. The purpose of these EANM guidelines is to provide advice to scientists and clinicians on data acquisition and data analysis related to bone-marrow and whole-body dosimetry. The guidelines are divided into sections "Data acquisition" and "Data analysis". The Data acquisition section provides advice on the measurements required for accurate dosimetry including blood samples, quantitative imaging and/or whole-body measurements with a single probe. Issues specific to given radiopharmaceuticals are considered. The Data analysis section provides advice on the calculation of absorbed doses to the whole body and the bone marrow. The total absorbed dose to the bone marrow consists of contributions from activity in the bone marrow itself (self-absorbed dose) and the cross-absorbed dose to the bone marrow from activity in bone, larger organs and the remainder of the body. As radionuclide therapy enters an era where patient-specific dosimetry is used to guide treatments, accurate bone-marrow and whole-body dosimetry will become an essential element of treatment planning. We hope that these guidelines will provide a basis for the optimization and standardization of the treatment of cancer with radiopharmaceuticals, which will facilitate single- and multi-centre radionuclide therapy studies.
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| 48. |
- Högberg, Jonas, 1976, et al.
(författare)
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On the dose heterogeneity in normal liver tissue due to treatment of liver tumors with yttrium-90 microspheres
- 2012
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Ingår i: 25th Annual Congress on European Association of Nuclear Medicine, Milano, Italy, October 27-31, 2012. European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 39:suppl 2
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Aim: When treating patients with primary or metastatic liver cancer, applying external radiotherapy, an absorbed dose of 30 - 35 Gy to the whole normal liver tissue volume is associated with a 5 % risk of radiation-induced hepatitis. If less than half of the normal liver volume is being exposed, the threshold for a 5 % risk of hepatitis is increased to above 60 Gy for both primary and metastatic liver cancer. Experience with patients treated with SIR-Spheres® (Sirtex Medical Ltd.), resin microspheres aggregated with yttrium-90, has shown that most patients tolerate an average absorbed dose to normal liver tissue higher than 60 Gy. The high tolerance for this treatment procedure can probably be explained by the resulting heterogenic distribution of radioactivity. It is of interest to study the degree of heterogeneity in the distribution of radioactivity in normal liver tissue, in order to explain or even predict the tolerance to radiation. The aim of this study was to describe the degree of heterogeneity by comparing the relative standard deviations of the radioactivity concentration for different sample mass categories. Materials and Methods: Two patients with cholangiocarcinoma were planned for a combined treatment with yttrium-90-aggregated SIR-Spheres followed by surgery 9 days after radiotherapy. According to standard protocol for treatments with SIR-Spheres, the therapies were preceded by Tc-99m-labled Macro aggregated albumin (Tc-99m-MAA) distribution studies for pre-therapeutic dosimetry and lung shunting evaluations. After surgery the resected tissue, containing both tumour and normal tissue, was studied regarding the distribution of radioactivity. Several small circular samples of normal liver tissue were punched out from 2 mm thick slices of resected tissue, deliberately varying the sizes, and thus the masses of the tissue samples (from 6 to 102 mg). The samples were weighed and categorized in two (first patient) and three (second patient) groups, depending on sample mass. After this the radioactivity was measured with a NaI(Tl) detector. The relative standard deviations (SD/Median) for the radioactivity concentration for each sample mass group were determined and compared. Results: The relative standard deviation for the radioactivity concentration was decreasing rapidly with increasing sample mass. Conclusion: The results indicate a considerable degree of heterogeneity in the distribution of microspheres. One probable explanation for this heterogeneity is clustering of microspheres in the blood vessels.
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| 49. |
- Jakobson Mo, Susanna, et al.
(författare)
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Pre- and postsynaptic dopamine SPECT in the early phase of idiopathic parkinsonism : a population-based study
- 2010
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 37:11, s. 2154-2164
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to assess the diagnostic contribution of pre- and postsynaptic dopamine SPECT in drug-naïve patients with early idiopathic parkinsonism and to investigate possible differences between idiopathic Parkinson's disease (PD) and atypical parkinsonian syndromes (APS) and possible differences in motor subtypes of parkinsonism.METHODS: A group of 128 newly diagnosed idiopathic parkinsonian patients and 48 healthy controls was studied. Presynaptic baseline SPECT with (123)I-FP-CIT was performed in all patients and in 120 patients also a baseline postsynaptic SPECT with (123)I-IBZM. Clinical diagnoses were reassessed after 12 months.RESULTS: Presynaptic uptake in the putamen and caudate was significantly reduced in patients compared to controls. Presynaptic uptake ratios were not different between PD patients and patients with APS, and postsynaptic uptake in APS was not significantly reduced compared to PD or controls. In half of the APS patients both pre- and postsynaptic uptake ratios were reduced on the same side in the striatum. Impaired motor performance was associated with decreased presynaptic uptake in the putamen in PD. The postural instability and gait difficulty (PIGD) subtype of PD had lower presynaptic uptake ratios than patients with tremor-dominated (TD) symptoms.CONCLUSION: Not only presynaptic putamen uptake ratios, but also caudate ratios were reduced in a majority of the patients in our study. At baseline scan, i.e. in an early stage of the disease, the accuracy of excluding APS in the whole study population was 85% using a combination of pre- and postsynaptic SPECT. Already at baseline, lower presynaptic SPECT ratios were seen in PD with PIGD at onset compared to those with TD subtype.
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| 50. |
- Jögi, Jonas, et al.
(författare)
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Ventilation/perfusion SPECT in chronic obstructive pulmonary disease: an evaluation by reference to symptoms, spirometric lung function and emphysema, as assessed with HRCT.
- 2011
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 38, s. 1344-1352
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation which is not fully reversible. Despite the heterogeneity of COPD, its diagnosis and staging is currently based solely on forced expiratory volume in 1 s (FEV(1)). FEV(1) does not explain the underlying pathophysiology of airflow limitation. The relationship between FEV(1), symptoms and emphysema extent is weak. Better diagnostic tools are needed to define COPD. Tomographic lung scintigraphy [ventilation/perfusion single photon emission tomography (V/P SPECT)] visualizes regional V and P. In COPD, relations between V/P SPECT, spirometry, high-resolution computed tomography (HRCT) and symptoms have been insufficiently studied. The aim of this study was to investigate how lung function imaging and obstructive disease grading undertaken using V/P SPECT correlate with symptoms, spirometric lung function and degree of emphysema assessed with HRCT in patients with COPD. METHODS: Thirty patients with stable COPD were evaluated with the Medical Research Council dyspnoea questionnaire (MRC) and the clinical COPD questionnaire (CCQ). Spirometry was performed. The extent of emphysema was assessed using HRCT. V/P SPECT was used to assess V/P patterns, total reduction in lung function and degree of obstructive disease. RESULTS: The total reduction in lung function and degree of obstructive disease, assessed with V/P SPECT, significantly correlated with emphysema extent (r = 0.66-0.69, p < 0.0001) and spirometric lung function (r = 0.62-0.74, p < 0.0005). The correlation between emphysema extent and spirometric lung function was weaker. No correlation between MRC, CCQ and objective measurements was found. CONCLUSION: V/P SPECT is sensitive to early changes in COPD. V/P SPECT also has the possibility to identify comorbid disease. V/P SPECT findings show a significant correlation with emphysema extent and spirometric lung function. We therefore recommend that scintigraphic signs of COPD, whenever found, should be reported. V/P SPECT can also be used to categorize the severity of functional changes in COPD as mild, moderate or severe.
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