Over the last decades, the refinement of radiation therapy techniques has been associated with an increasing interest for individualized radiation therapy with the aim of increasing or maintaining tumor control and reducing radiation toxicity. Developments in artificial intelligence (AI), particularly machine learning and deep learning, in imaging sciences, including nuclear medecine, have led to significant enthusiasm for the concept of "rapid learning health system". AI combined with radiomics applied to (18F)-fluorodeoxyglucose positron emission tomography/computed tomography ([18F]-FDG PET/CT) offers a unique opportunity for the development of predictive models that can help stratify each patient's risk and guide treatment decisions for optimal outcomes and quality of life of patients treated with radiation therapy. Here we present an overview of the current contribution of AI and radiomics-based machine learning models applied to (18F)-FDG PET/CT in the management of cancer treated by radiation therapy.
Positron Emission Tomography Computed Tomography , Radiation Oncology , Humans , Fluorodeoxyglucose F18 , Artificial Intelligence , Quality of Life
Hereditary forms of Alzheimer's disease (AD) and early-onset forms have more brain damage than sporadic or late-onset forms at the time of diagnosis (1, 2). Data in the literature are contradictory concerning familial forms without known heredity or mutation. The aim of this study was to compare the brain distribution of FDG between two populations of patients with a clinical diagnosis of sporadic AD according to the presence or not of a first degree family history of dementia. We retrospectively included 243 patients with clinical diagnosis of AD who underwent brain FDG PET imaging between 2012 and 2017. SPM12 was used to compare the FDG brain distribution in 199 patients with AD and no familial history of dementia and 43 patients with AD and first degree familial history of dementia. Compared to a database of 22 healthy control subjects, both groups of AD patients showed a significant decrease of FDG distribution in temporo-parietal, posterior cingulate and posterior left frontal cortex with respect to the controls (p inferior to 0.05 corrected for the family-wise error, pFWE-corr). There were no significant differences between the two AD groups (pFWE-corr superior to 0.05 and p superior to 0.001 uncorrected for multiple comparisons) that present the same brain metabolic pathology.
Les formes héréditaires de la maladie d'Alzheimer (MA) et les formes à début précoce présentent une atteinte cérébrale plus importante que les formes sporadiques ou celles à début tardif au moment du diagnostic (1, 2). Les données de la littérature sont contradictoires en ce qui concerne les formes familiales sans hérédité ni mutation connue. L'objectif de cette étude était de comparer la distribution cérébrale du [18F]fluoro-2-deoxy-D-glucose ([18F]FDG) entre deux populations de patients présentant un diagnostic clinique de la MA sporadique selon la présence, ou non, d'une histoire familiale de démence au premier degré. Dans cette étude rétrospective, nous avons inclus 243 patients vus entre 2012 et 2017. Le logiciel SPM12 a été utilisé pour comparer la distribution cérébrale du FDG entre 199 patients souffrant de MA, sans histoire familiale et 43 patients souffrant de MA avec une histoire familiale de démence au premier degré. Comparés à une base de données de 22 sujets contrôles sains, chacun des deux groupes de patients présentait une réduction significative de la distribution du FDG au niveau du cortex temporo-pariétal, cingulaire postérieur et frontal postérieur gauche (p inf�rieur a 0,05 corrigé pour le family-wise error, pFWE-corr), caractéristique de la maladie. Il n'y avait pas de différence significative entre les deux groupes MA (pFWE-corr sup�rieur a 0,05 et p sup�rieur a 0,001 non corrigé, pour des comparaisons multiples) qui présentent donc la même altération métabolique cérébrale.
Alzheimer Disease , Fluorodeoxyglucose F18 , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Brain/diagnostic imaging , Fluorodeoxyglucose F18/metabolism , Humans , Positron-Emission Tomography/methods , Radiopharmaceuticals/metabolism , Retrospective Studies
Oncological imaging is a subspecialty of medical imaging and focuses on the workup and the follow-up of cancer. Oncological imaging takes into account all the specificities of cancer diseases, which is a constantly evolving field, especially in the era of precision medicine, and plays a key role in the care of cancer patients. It permits reliable diagnosis and gives precious information concerning disease extension at diagnosis, which is essential for the treatment planning. Oncological imaging allows also followup of patients under treatment, using response evaluation scores. Interventional imaging, which provides minimally invasive procedures, is useful in order to obtain a histological diagnosis, to treat some tumour or to improve quality of life of cancer patients. Finally, numerous perspectives, among them the advent of artificial intelligence (radiomics), will further strengthen the role of oncologic imaging in the near future.
L'imagerie oncologique, qui est une sous-discipline de l'imagerie médicale, s'intéresse spécifiquement à la mise au point et au suivi des cancers. Elle prend en compte toutes les spécificités de la maladie oncologique, dont les traitements évoluent constamment à l'ère de la médecine de précision. Elle joue un rôle primordial à toutes les étapes du trajet de soin du patient. Elle permet la réalisation de diagnostics fiables et donne des informations sur l'étendue de la maladie au moment du diagnostic, nécessaires à l'établissement d'un plan de traitement. L'imagerie oncologique s'intéresse également au suivi des patients sous traitement, grâce notamment à l'utilisation de score d'évaluation de la réponse thérapeutique. L'imagerie interventionnelle, à travers la réalisation de procédures faiblement invasives, joue un rôle dans l'obtention du diagnostic, dans le traitement de certaines tumeurs ou dans l'amélioration de la qualité de vie du patient. Enfin, de nombreuses perspectives, et notamment l'avènement de l'intelligence artificielle (radiomique), ne vont faire que renforcer le rôle central de l'imagerie oncologique dans les prochaines années.
Artificial Intelligence , Neoplasms , Diagnostic Imaging , Follow-Up Studies , Humans , Neoplasms/diagnostic imaging , Quality of Life
PURPOSE: [18F]FDG PET/CT may predict the absence of acute allograft rejection (AR) in kidney transplant recipients (KTRs) with acute kidney injury (AKI). Still, the proposed threshold of 1.6 of the mean of mean standardized uptake values (mSUVmean) in the renal parenchyma needs validation. METHODS: We prospectively performed 86 [18F]FDG PET/CT in 79 adult KTRs who underwent per-cause transplant biopsy for suspected AR. Biopsy-proven polyoma BK nephropathies (n = 7) were excluded. PET/CT was performed 192 ± 18 min after administration of 254.4 ± 30.4 MBq of [18F]FDG. The SUVmean was measured in both upper and lower poles of the renal allograft. One-way analysis of variance (ANOVA) and Tukey's studentized range test were sequentially performed. The receiver operating characteristic (ROC) curve was drawn to discriminate "AR" from non-pathological ("normal" + "borderline") conditions. RESULTS: The median age of the cohort was 55 [43; 63] years, with M/F gender ratio of 47/39. The mean eGFR was 31.9 ± 14.6 ml/min/1.73m2. Biopsies were categorized in 4 groups: "normal" (n = 54), "borderline" (n = 9), "AR" (n = 14), or "others" (n = 2). The median [min; max] mSUVmean reached 1.72 [1.02; 2.07], 1.97 [1.55; 2.11], 2.13 [1.65, 3.12], and 1.84 [1.57; 2.12] in "normal," "borderline," "AR," and "others" groups, respectively. ANOVA demonstrated a significant difference of mSUVmean among groups (F = 13.25, p < 0.0001). The ROC area under the curve was 0.86. Test sensitivity and specificity corresponding to the threshold value of 1.6 were 100% and 30%, respectively. CONCLUSION: [18F]FDG PET/CT may help noninvasively prevent inessential transplant biopsies in KTR with AKI.
Fluorodeoxyglucose F18 , Kidney Transplantation , Adult , Allografts , Graft Rejection/diagnostic imaging , Humans , Kidney , Kidney Transplantation/adverse effects , Middle Aged , Positron Emission Tomography Computed Tomography , Radiopharmaceuticals
The advancement of artificial intelligence concurrent with the development of medical imaging techniques provided a unique opportunity to turn medical imaging from mostly qualitative, to further quantitative and mineable data that can be explored for the development of clinical decision support systems (cDSS). Radiomics, a method for the high throughput extraction of hand-crafted features from medical images, and deep learning -the data driven modeling techniques based on the principles of simplified brain neuron interactions, are the most researched quantitative imaging techniques. Many studies reported on the potential of such techniques in the context of cDSS. Such techniques could be highly appealing due to the reuse of existing data, automation of clinical workflows, minimal invasiveness, three-dimensional volumetric characterization, and the promise of high accuracy and reproducibility of results and cost-effectiveness. Nevertheless, there are several challenges that quantitative imaging techniques face, and need to be addressed before the translation to clinical use. These challenges include, but are not limited to, the explainability of the models, the reproducibility of the quantitative imaging features, and their sensitivity to variations in image acquisition and reconstruction parameters. In this narrative review, we report on the status of quantitative medical image analysis using radiomics and deep learning, the challenges the field is facing, propose a framework for robust radiomics analysis, and discuss future prospects.
Decision Support Systems, Clinical , Deep Learning , Image Processing, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Precision Medicine/methods , Humans , Reproducibility of Results
Ever since the initial description of the Milan criteria, used for selecting patients with hepatocellular carcinoma (HCC) for liver transplantation (LT), there has been a clear need to go further than solely morphological criteria. Tumours exceeding the Milan criteria, but presenting favourable biological behaviour, might still allow for comparable overall- and disease-free survivals after LT. As it is well established that the presence of microvascular invasion is a major factor that influences HCC recurrence after LT, several serum and tissue biomarkers in addition to imaging studies are attracting wider attention as more refined tools for selecting HCC patients for LT. A thorough review of the recent literature on the subject was conducted. In the future a combination of systemic inflammation markers, biomarkers and morphological criteria may be key to more accurate prediction of HCC recurrence after LT. This may allow LT in patients whose HCC tumours exceed the Milan criteria but have favourable biological behaviour. Further prospective studies are required in order to improve patient selection for transplantation in HCC and these could help a move towards more transparent and improved management.
Carcinoma, Hepatocellular/surgery , Liver Neoplasms/surgery , Liver Transplantation , Patient Selection , Humans
The article has been withdrawn at the request of the authors and editor because of incorrect authorship, which is considered a form of unethical publication. The Publisher apologizes for any inconvenience this may cause.
Alveolar echinococcosis is a zoonotic disease due to the tapeworm Echinococcus multilocularis. The definitive host is the red fox. Until recently, Belgium was considered a country at very low risk for alveolar echinococcosis. However, recent studies carried out in southern Belgium have revealed, through post-mortem examination, high prevalences (up to 62 %) in foxes. Cats and dogs can act as definitive hosts. Human are accidentally infected by ingestion of food contaminated by the feces. After a long incubation period, invasive hepatic lesions may appear, as well as extra-hepatic lesions. The disease may be fatal. The diagnosis is based on imaging techniques, serology and nucleic acid detection in tissues. Early diagnosis may allow surgical removal of the lesion associated with at least 2 years of albendazole postoperative treatment. In case of contraindication to surgery, a long term treatment with albendazole is necessary. Liver transplantation is sometimes necessary. This article presents the epidemiologic, clinical, diagnostic and therapeutics features of this zoonotic disease.
L'échinococcose alvéolaire est une zoonose due à Echinococcus multilocaris, un cestode, dont l'hôte définitif est le renard roux (Vulpes vulpes). Jusqu'il y a peu, la Belgique était un pays considéré comme à très faible risque pour cette parasitose, mais de récentes autopsies de renards ont montré des prévalences élevées chez ceux-ci (pouvant dépasser les 60 %). Les chiens et les chats peuvent également être des hôtes définitifs. La transmission humaine (hôte accidentel) se fait principalement via la consommation d'aliments souillés par les déjections animales contaminées donnant, après une longue période d'incubation, des lésions hépatiques infiltrantes et, éventuellement, des atteintes extra-hépatiques pouvant être mortelles. Le diagnostic est fondé sur l'imagerie médicale couplée à des tests sérologiques et la PCR sur des tissus. La prise en charge curative est chirurgicale, lorsque la résection complète est possible. Elle est associée à un traitement de deux ans post-opératoire à base d'albendazole. En cas d'impossibilité de résection complète, un traitement au long cours par de l'albendazole est préconisé. Enfin, dans certains cas, une transplantation hépatique peut être envisagée. En raison de l'augmentation des cas autochtones rencontrés en Wallonie, un groupe spécialisé dans la prise en charge de l'échinococcose a été créé au sein de l'université de Liège. Cet article illustre les caractéristiques épidémiologiques, cliniques, diagnostiques et thérapeutiques de cette zoonose.
Echinococcosis/diagnosis , Echinococcosis/therapy , Albendazole/therapeutic use , Animals , Anthelmintics/therapeutic use , DNA, Protozoan , Diagnostic Imaging , Echinococcosis/transmission , Echinococcus multilocularis/genetics , Humans , Liver Transplantation , Patient Care Team , Polymerase Chain Reaction
BACKGROUND AND STUDY AIMS: The current standard of care for resectable pancreatic ductal adenocarcinoma (PDAC) is surgery-first followed by adjuvant chemotherapy. We review our single center experience in a PDAC cohort managed by the surgery-first strategy. We then compare our data to those of Belgian and international literature. PATIENTS METHODS: We reviewed a series of 83 consecutive resectable patients with PDAC, treated by the surgery-first approach in a Belgian Academic Hospital between 2007 and 2013. The outcomes were assessed with univariate and multivariate Cox regression analysis. Kaplan-Meier curves were drawn according to patient groups. RESULTS: For the entire population, the median survival (MS) was 18.4 months; the 1-year relapse-free survival was 56%, and the 5-year overall survival (OS) was 13%. The size of the primary tumor larger than 3 cm (OS, HR = 1.76, p = 0.033) and vascular resection (DFS, HR = 2.1, p = 0.024) were the single independent prognostic factors in the multivariate analysis of this cohort. Only 69% of the patients received adjuvant chemotherapy, and more than 75% of them demonstrated no chance of survival beyond 3 years because they harbored poor prognostic factors, recognized only postoperatively. CONCLUSIONS: Our results and those published in the literature brought to light the limited perspectives of the surgery-first strategy in a population of apparently resectable pancreatic cancers. In comparison, data from reported neo-adjuvant series deserve our interest to bring this strategy upfront in selected patients in the context of close observational monitoring and randomized trials. The actual standard of care for resectable PDAC is surgery-first followed by adjuvant chemotherapy. The performance of this strategy relies on the dedicated imaging that does not accurately recognize the limits of the tumor and the high prevalence of adverse prognostic factors. Moreover, pancreatectomy remains associated with high postoperative complication rates and the poor completion of adjuvant therapy. This translates into poor long-term survival figures. In our series the MS was 18.4 months and 5-year OS was 13%. The disease-free survival (DFS) was 15.6 months, 1 and 3-year DFS were 56 and 26%, respectively. The variables that significantly correlated with OS in univariate analysis are tumor size and lymph node involvement. Regarding DFS, vascular resection was the only significant factor. In the multivariate analysis, the only significant factor related to OS remained the tumor size >3 cm in greatest diameter. Vascular resection remained significant for DFS. 31% of the patients did not receive any chemotherapy at all before the 6-month period following resection. The rates of complete resections compared favorably with those of a surgery-first strategy with no excess of operative mortality, complications and early relapse rates. The advantages of a chemotherapy-first approach, eventually combined with chemo-radiotherapy, are to offer higher combined therapy completion rates and improve the level of free resection margins, lymph node involvement and patient selection. The advent of safe, more potent chemotherapy combinations has the potential to further improve survival when administered upfront.
Adenocarcinoma/surgery , Carcinoma, Pancreatic Ductal/surgery , Pancreatectomy/methods , Pancreatic Neoplasms/surgery , Adenocarcinoma/mortality , Adenocarcinoma/pathology , Belgium/epidemiology , Carcinoma, Pancreatic Ductal/mortality , Carcinoma, Pancreatic Ductal/pathology , Chemotherapy, Adjuvant , Combined Modality Therapy , Humans , Neoplasm Recurrence, Local , Pancreatic Neoplasms/mortality , Pancreatic Neoplasms/pathology , Prognosis , Survival Rate
A vast body of literature exists showing functional and structural dysfunction within the brains of patients with disorders of consciousness. However, the function (fluorodeoxyglucose FDG-PET metabolism)-structure (MRI-diffusion-weighted images; DWI) relationship and how it is affected in severely brain injured patients remains ill-defined. FDG-PET and MRI-DWI in 25 severely brain injured patients (19 Disorders of Consciousness of which 7 unresponsive wakefulness syndrome, 12 minimally conscious; 6 emergence from minimally conscious state) and 25 healthy control subjects were acquired here. Default mode network (DMN) function-structure connectivity was assessed by fractional anisotropy (FA) and metabolic standardized uptake value (SUV). As expected, a profound decline in regional metabolism and white matter integrity was found in patients as compared with healthy subjects. Furthermore, a function-structure relationship was present in brain-damaged patients between functional metabolism of inferior-parietal, precuneus, and frontal regions and structural integrity of the frontal-inferiorparietal, precuneus-inferiorparietal, thalamo-inferioparietal, and thalamofrontal tracts. When focusing on patients, a stronger relationship between structural integrity of thalamo-inferiorparietal tracts and thalamic metabolism in patients who have emerged from the minimally conscious state as compared with patients with disorders of consciousness was found. The latter finding was in line with the mesocircuit hypothesis for the emergence of consciousness. The findings showed a positive function-structure relationship within most regions of the DMN. Hum Brain Mapp 37:3707-3720, 2016. © 2016 Wiley Periodicals, Inc.
Brain Injury, Chronic/diagnostic imaging , Brain Injury, Chronic/physiopathology , Brain/diagnostic imaging , Brain/physiopathology , Diffusion Magnetic Resonance Imaging , Positron-Emission Tomography , Adult , Brain Injury, Chronic/complications , Consciousness Disorders/diagnostic imaging , Consciousness Disorders/etiology , Consciousness Disorders/physiopathology , Female , Fluorodeoxyglucose F18 , Humans , Male , Middle Aged , Neural Pathways/diagnostic imaging , Neural Pathways/physiopathology , Radiopharmaceuticals , Regression Analysis , Young Adult
BACKGROUND: Most peripheral T-cell lymphoma (PTCL) patients have a poor outcome and the identification of prognostic factors at diagnosis is needed. PATIENTS AND METHODS: The prognostic impact of total metabolic tumor volume (TMTV0), measured on baseline [(18)F]2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography, was evaluated in a retrospective study including 108 PTCL patients (27 PTCL not otherwise specified, 43 angioimmunoblastic T-cell lymphomas and 38 anaplastic large-cell lymphomas). All received anthracycline-based chemotherapy. TMTV0 was computed with the 41% maximum standardized uptake value threshold method and an optimal cut-off point for binary outcomes was determined and compared with others prognostic factors. RESULTS: With a median follow-up of 23 months, 2-year progression-free survival (PFS) was 49% and 2-year overall survival (OS) was 67%. High TMTV0 was significantly associated with a worse prognosis. At 2 years, PFS was 26% in patients with a high TMTV0 (>230 cm(3), n = 53) versus 71% for those with a low TMTV0, [P < 0.0001, hazard ratio (HR) = 4], whereas OS was 50% versus 80%, respectively, (P = 0.0005, HR = 3.1). In multivariate analysis, TMTV0 was the only significant independent parameter for both PFS and OS. TMTV0, combined with PIT, discriminated even better than TMTV0 alone, patients with an adverse outcome (TMTV0 >230 cm(3) and PIT >1, n = 33,) from those with good prognosis (TMTV0 ≤230 cm(3) and PIT ≤1, n = 40): 19% versus 73% 2-year PFS (P < 0.0001) and 43% versus 81% 2-year OS, respectively (P = 0.0002). Thirty-one patients (other TMTV0-PIT combinations) had an intermediate outcome, 50% 2-year PFS and 68% 2-year OS. CONCLUSION: TMTV0 appears as an independent predictor of PTCL outcome. Combined with PIT, it could identify different risk categories at diagnosis and warrants further validation as a prognostic marker.
Lymphoma, T-Cell, Peripheral/diagnostic imaging , Lymphoma, T-Cell, Peripheral/drug therapy , Prognosis , Tumor Burden , Adult , Aged , Aged, 80 and over , Anthracyclines/administration & dosage , Disease-Free Survival , Female , Fluorodeoxyglucose F18 , Humans , Lymphoma, T-Cell, Peripheral/pathology , Male , Middle Aged , Positron Emission Tomography Computed Tomography
Management of kidney transplant recipients (KTRs) with suspected acute rejection (AR) ultimately relies on kidney biopsy; however, noninvasive tests predicting nonrejection would help avoid unnecessary biopsy. AR involves recruitment of leukocytes avid for fluorodeoxyglucose F(18) ((18) F-FDG), thus (18) F-FDG positron emission tomography (PET) coupled with computed tomography (CT) may noninvasively distinguish nonrejection from AR. From January 2013 to February 2015, we prospectively performed 32 (18) F-FDG PET/CT scans in 31 adult KTRs with suspected AR who underwent transplant biopsy. Biopsies were categorized into four groups: normal (n = 8), borderline (n = 10), AR (n = 8), or other (n = 6, including 3 with polyoma BK nephropathy). Estimated GFR was comparable in all groups. PET/CT was performed 201 ± 18 minutes after administration of 3.2 ± 0.2 MBq/kg of (18) F-FDG, before any immunosuppression change. Mean standard uptake values (SUVs) of both upper and lower renal poles were measured. Mean SUVs reached 1.5 ± 0.2, 1.6 ± 0.3, 2.9 ± 0.8, and 2.2 ± 1.2 for the normal, borderline, AR, and other groups, respectively. One-way analysis of variance demonstrated a significant difference of mean SUVs among groups. A positive correlation between mean SUV and acute composite Banff score was found, with r(2) = 0.49. The area under the receiver operating characteristic curve was 0.93, with 100% sensitivity and 50% specificity using a mean SUV threshold of 1.6. In conclusion, (18) F-FDG PET/CT may help noninvasively prevent avoidable transplant biopsies in KTRs with suspected AR.
Fluorodeoxyglucose F18/administration & dosage , Graft Rejection/diagnostic imaging , Kidney Transplantation , Multimodal Imaging/methods , Radiopharmaceuticals/administration & dosage , Acute Disease , Adolescent , Adult , Aged , Female , Follow-Up Studies , Glomerular Filtration Rate , Graft Rejection/pathology , Graft Survival , Humans , Kidney Failure, Chronic/surgery , Kidney Function Tests , Male , Middle Aged , Pilot Projects , Positron-Emission Tomography/methods , Postoperative Complications , Prognosis , Prospective Studies , ROC Curve , Risk Factors , Tomography, X-Ray Computed/methods , Transplantation, Homologous , Young Adult
PURPOSE: [(18)F]UCB-H is a novel radiotracer with a high affinity for synaptic vesicle glycoprotein 2A (SV2A), a protein expressed in synaptic vesicles. SV2A is the binding site of levetiracetam, a "first-in-class" antiepileptic drug with a distinct but still poorly understood mechanism of action. The objective of this study was to determine the biodistribution and radiation dosimetry of [(18)F]UCB-H in a human clinical trial and to establish injection limits according to biomedical research guidelines. Additionally, the clinical radiation dosimetry results were compared to estimations in previously published preclinical data. PROCEDURES: Dynamic whole body positron emission tomography/X-ray computed tomography (PET/CT) imaging was performed over approximately 110 min on five healthy male volunteers after injection of 144.5 ± 7.1 MBq (range, 139.1-156.5 MBq) of [(18)F]UCB-H. Major organs were delineated on CT images, and time-activity curves were obtained from co-registered dynamic PET emission scans. The bladder could only be delineated on PET images. Time-integrated activity coefficients were calculated as area under the curve using trapezoidal numerical integration. Urinary excretion data based on PET activities including voiding was also simulated using the dynamic bladder module of OLINDA/EXM. The radiation dosimetry was calculated using OLINDA/EXM. RESULTS: The effective dose to the OLINDA/EXM 70-kg standard male was 1.54 × 10(-2) ± 6.84 × 10(-4) millisieverts (mSv)/MBq, with urinary bladder wall, gallbladder wall, and the liver receiving the highest absorbed dose. The brain, the tracer's main organ of interest, received an absorbed dose of 1.89 × 10(-2) ± 2.32 × 10(-3) mGy/MBq. CONCLUSIONS: This first human dosimetry study of [(18)F]UCB-H indicated that the tracer shows similar radiation burdens to widely used common clinical tracers. Single injections of at maximum 672 MBq for US practice and 649 MBq for European practice keep radiation exposure below recommended limits. Recently published preclinical dosimetry data extrapolated from mice provided satisfactory prediction of total body and effective dose but showed significant differences in organ absorbed doses compared to human data.
Fluorine Radioisotopes/pharmacokinetics , Positron-Emission Tomography/methods , Pyridines/pharmacokinetics , Pyrrolidinones/pharmacokinetics , Radiopharmaceuticals/pharmacokinetics , Animals , Humans , Male , Membrane Glycoproteins/metabolism , Mice , Middle Aged , Nerve Tissue Proteins/metabolism , Radiometry , Tissue Distribution , Tomography, X-Ray Computed , Whole Body Imaging/methods
Medical imaging plays a crucial role in the diagnosis, staging and therapeutic strategy of oncologic patients. The development of medical imaging over the last decade has allowed significant progresses in radiotherapy. Indeed, medical imaging is now considered the corner stone of radiotherapy. The main challenge for the radiation oncologist consists in the tumour identification with a view to irradiate the tumour at a curative dose while avoiding healthy tissues. To achieve these goals, the radiotherapist daily uses anatomical imaging such as computed tomography (CT) or magnetic resonance imaging (MRI). Since several years now, the development of functional imaging such as positron emission tomography (PET) combined with CT or functional MRI has opened new perspectives in the management of oncologic diseases. Indeed, these imaging techniques offer new information on tumour metabolism that may be taken into account to plan the radiotherapy treatment. This article illustrates the different imaging techniques used in radiotherapy and the role of functional imaging for establishing new therapeutic strategies in radiation oncology.
Diagnostic Imaging/methods , Neoplasms/radiotherapy , Radiotherapy/methods , Humans , Magnetic Resonance Imaging/methods , Neoplasm Staging , Neoplasms/pathology , Positron-Emission Tomography/methods , Tomography, X-Ray Computed/methods
Adenoma/metabolism , Hyperparathyroidism/diagnostic imaging , Mediastinal Neoplasms/metabolism , Paraneoplastic Endocrine Syndromes/diagnostic imaging , Parathyroid Hormone/metabolism , Adenoma/surgery , Adult , Female , Hormones, Ectopic , Humans , Hyperparathyroidism/etiology , Hyperparathyroidism/surgery , Mediastinal Neoplasms/diagnostic imaging , Mediastinal Neoplasms/surgery , Neoplasms, Multiple Primary/diagnostic imaging , Neoplasms, Multiple Primary/surgery , Paraneoplastic Endocrine Syndromes/surgery , Parathyroid Neoplasms/metabolism , Parathyroid Neoplasms/surgery , Radionuclide Imaging
Rupture of abdominal aortic aneurysm (AAA) remains a major cause of death in the elderly. Its prediction is a serious challenge for public health. Despite its regular use to identify patients requiring surgical treatment, the diameter of AAA is not a sufficiently precise and reliable parameter for discriminating aneurysms at high risk of rupture. A better targeting of high risk patients needs understanding in deep the processes and mechanisms directing wall rupture. Inflammation is a significant element in the progression ofAAA and can be visualized using medical imaging techniques such as positron emission tomography (PET) using a glucose derivative (FDG) as radiotracer. Studies conducted in our department have established a relationship between PET positivity and the presence of symptoms such as accelerated growth of the aneurysm or pain, signs generally considered as predictive of rupture. Moreover, activation of leukocytes coupled to cellular and molecular alterations of the aneurysmal wall in the sites of FDG uptake may lead to its instability and incompetence to resist blood pressure and rupture. PET therefore represents a new original exploration method to characterize the severity of AAA progression allowing to assess the need for a surgical treatment much better than does the AAA diameter.
Aortic Aneurysm, Abdominal/diagnostic imaging , Positron-Emission Tomography , Aortic Aneurysm, Abdominal/diagnosis , Humans , Prognosis
PET/CT imaging of 15F-FPRGD2 allows the visualization and quantification of integrin αVß3 in tissues. This imaging technique was developed with the purpose of quantifying tumor angiogenesis and of assessing the efficacy of antiangiogenic treatments. However, the PET signal of 18F-FPRGD2 appears more complex as various tumor cell types, inflammatory cells and osteoclasts express the integrin αVß3 regulating cell interactions with the extracellular matrix. This article provides data of clinical studies evaluating 18F-FPRGD2 PET/CT imaging in patients with a renal mass or a locally advanced rectal carcinoma and finally reports on the incidental discovery of 18F-FPRGD2 uptake in osteoarticular processes such as osteoarthritis.
Fluorodeoxyglucose F18 , Integrin alphaVbeta3/analysis , Multimodal Imaging , Positron-Emission Tomography , Radiopharmaceuticals , Tomography, X-Ray Computed , Humans
In this article, we will discuss about hypophosphatemia due to tumor-induced osteomalacia. This disease is characterized by severe muscular and articular tenderness inducing profound walking limitation. Clinical chemistry results show severe hypophosphatemia due to hyperphosphaturia. Fibroblast growth factor 23 (FGF-23) is abnormally high. Physiological role of FGF-23 is examined. We also consider the pathophysiology of tumor induced osteomalacia, the use of different investigations to localize the tumor and therapies available to treat this rare disease.
Hypophosphatemia/complications , Neoplasms/complications , Osteomalacia/etiology , Fibroblast Growth Factor-23 , Fibroblast Growth Factors/blood , Fibroblast Growth Factors/physiology , Humans , Hypophosphatemia/etiology , Hypophosphatemia/therapy , Osteomalacia/therapy
