From Karl Wurm and Guy Scadding's staging to 18F-FDG PET/CT scan phenotyping and far beyond: perspective in the evading history of phenotyping in sarcoidosis

Sarcoidosis is an inflammatory granulomatous disease of unknown etiology involving any organ or tissue along with any combination of active sites, even the most silent ones clinically. The unpredictable nature of the sites involved in sarcoidosis dictates the highly variable natural history of the disease and the necessity to cluster cases at diagnosis based on clinical and/or imaging common characteristics in an attempt to classify patients based on their more homogeneous phenotypes, possibly with similar clinical behavior, prognosis, outcome, and therefore with therapeutic requirements. In the course of the disease's history, this attempt relates to the availability of a means of detection of the sites involved, from the Karl Wurm and Guy Scadding's chest x-ray staging through the ACCESS, the WASOG Sarcoidosis Organ Assessment Instruments, and the GenPhenReSa study to the 18F-FDG PET/CT scan phenotyping and far beyond to new technologies and/or the current "omics." The hybrid molecular imaging of the 18F-FDG PET/CT scan, by unveiling the glucose metabolism of inflammatory cells, can identify high sensitivity inflammatory active granulomas, the hallmark of sarcoidosis-even in clinically and physiologically silent sites-and, as recently shown, is successful in identifying an unexpected ordered stratification into four phenotypes: (I) hilar-mediastinal nodal, (II) lungs and hilar-mediastinal nodal, (III) an extended nodal supraclavicular, thoracic, abdominal, inguinal, and (IV) all the above in addition to systemic organs and tissues, which is therefore the ideal phenotyping instrument. During the "omics era," studies could provide significant, distinct, and exclusive insights into sarcoidosis phenotypes linking clinical, laboratory, imaging, and histologic characteristics with molecular signatures. In this context, the personalization of treatment for sarcoidosis patients might have reached its goal.

Current role of Nuclear Medicine in the diagnosis and therapy of gastroenteropancreatic neuroendocrine tumors (GEP-NETs)

Neuroendocrine tumors (NETs), are heterogenic neoplasms that arise from the disseminated endocrine cell system, primarily from gastroenteropancreatic (GEP) organs. Nuclear Medicine has a central role in both diagnosis and treatment of GEP-NETs. Somatostatin receptor scintigraphy (SRS) is still performed with SPECT/CT in case that PET/CT is not available but numerous studies have demonstrated the superior diagnostic accuracy of the latter for GEP-NETs. 68Ga -Dota peptide PET/CT (SSA-PET/CT) has high sensitivity, specificity and accuracy (86%-100%) and is recommended for the staging as also for the restaging of GEP-NETs.

Visceral adipose tissue phenotype and hypoadiponectinemia are associated with aortic Fluorine-18 fluorodeoxyglucose uptake in patients with familial dyslipidemias

BACKGROUND

The role of adipose tissue (AT) in arterial inflammation in familial dyslipidaemias is poorly studied. We investigated the relationship between AT and arterial inflammation in patients with heterozygous familial hypercholesterolemia (heFH) and familial combined hyperlipidemia (FCH).

METHODS AND RESULTS

A total of 40 patients (20 heFH/20 FCH) and a subgroup of 20 of non-heFH/FCH patients were enrolled. Participants underwent blood sampling for serum adipokine measurements and Fluorine-18 fluorodeoxyglucose (18F-FDG) PET/CT imaging. Abdominal visceral (VAT) and subcutaneous (SAT) AT volumes and AT and abdominal aorta 18F-FDG uptake were quantified. FCH patients had increased VAT (pANOVA = 0.004) and SAT volumes (pANOVA = 0.003), lower VAT metabolic activity (pANOVA = 0.0047), and lower adiponectin levels (pANOVA = 0.007) compared to heFH or the control group. Log(Serum adiponectin) levels were correlated with aortic TBR (b = - 0.118, P = 0.038). In mediation analysis, VAT volume was the major determinant of circulating adiponectin, an effect partly mediated via VAT TBR. Clustering of the population of heFH/FCH by VAT volume/TBR and serum adiponectin identified two distinct patient clusters with significant differences in aortic TBR levels (2.11 ± 0.06 vs 1.89 ± 0.05, P= 0.012).

CONCLUSIONS

VAT phenotype (increased VAT volume and/or high VAT TBR) and hypoadiponectinemia may account for the observed differences in arterial inflammation levels between heFH and FCH patients.

Tumor Size Measurements for Predicting Hodgkin’s and Non-Hodgkin’s Lymphoma Response to Treatment

The purpose of this study was to investigate the value of tumor size measurements as prognostic indicators of treatment outcome of Hodgkin’s and Non-Hodgkin’s lymphomas. ¹⁸F-FDG PET/CT exams before and after treatment were analyzed and metabolic and anatomic parameters—tumor maximum diameter, tumor maximum area, tumor volume, and maximum standardized uptake value (SUVmax)—were determined manually by an expert and automatically by a computer algorithm on PET and CT images. Results showed that the computer algorithm measurements did not correlate well with the expert’s standard maximum tumor diameter measurements but yielded better three dimensional metrics that could have clinical value. SUVmax was the strongest prognostic indicator of the clinical outcome after treatment, followed by the automated metabolic tumor volume measurements and the expert’s metabolic maximum diameter measurements. Anatomic tumor measurements had poor prognostic value. Metabolic volume measurements, although promising, did not significantly surpass current standard of practice, but automated measurements offered a significant advantage in terms of time and effort and minimized biases and variances in the PET measurements. Overall, considering the limited value of tumor size in predicting response to treatment, a paradigm shift seems necessary in order to identify robust prognostic markers in PET/CT; radiomics, namely combinations of anatomy, metabolism, and imaging, may be an option.

Erdheim-Chester Disease and Acute Myeloid Leukemia with Mutated NPM1 in a Patient with Clonal Hematopoiesis: A Case Report

Background

Erdheim–Chester Disease (ECD) is a clonal non-Langerhans histiocytosis, classified as a macrophage-dendritic cell neoplasm in the 2016 WHO classification. The exact cell of origin of ECD is unknown, although some limited evidence suggests that it arises from myeloid progenitors.

Case Presentation

A 43-year-old patient, diagnosed with BRAF^V600E mutated ECD, developed NPM1⁺/FLT3⁺ acute myeloid leukemia (AML) with wild-type BRAF, 15 months after the initial ECD diagnosis. The patient received intensive chemotherapy plus midostaurin, followed by midostaurin maintenance. Six months into maintenance, the patient remains in complete remission with low-level measurable residual disease, whereas ECD shows a sustained partial metabolic response. Molecular karyotype at several distinct timepoints, namely ECD diagnosis, AML diagnosis, and following treatment of AML, highlighted a molecular signature, indicative of a persistent, underlying clonal hematopoiesis.

Conclusion

This case report suggests that ECD and AML might represent an expansion of two distinct clones in a background of clonal hematopoiesis, indicating their shared origin. Moreover, molecular karyotype might serve as a strong, inexpensive tool for revealing clonal hematopoiesis in cases of negative targeted next-generation sequencing. Finally, the moderate response of ECD to midostaurin suggests that kinase inhibition might have a potential role in ECD treatment.

The effects of chemotherapy on arterial inflammation assessed by 18 FDG PET-CT in patients with Lymphoma

Introduction

Anti-cancer treatment can lead to increased cardiovascular morbidity among lymphoma survivors. This may be the result of direct effect of treatment on heart function, or indirect acceleration of atherosclerosis. 18F-fluorodeoxyglucose (FDG) uptake is a sensitive and robust marker for assessment of atherosclerotic inflammation.

Purpose

To investigate the effects of chemotherapy on arterial inflammation using FDG-PET CT in patients with lymphoma.

Methods

Fifty nine (mean age 58±17 years) patients with Hodgkin (n=39) or non-Hodgkin lymphomas (n=20) underwent 18FDG PET-CT imaging at baseline, interim and after completion of chemotherapy as part of their routine protocol. Arterial inflammation was assessed by arterial target to background ratio (TBR) of the aortic wall along the entire aorta. The index vessel TBR (the vessel with the higher value at baseline) was used for assessment of arterial inflammation. Patients with Hodgkin Lymphomas (HL) underwent therapy with Doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD). The interim of their treatment was set at 1 to 3 days prior to initiating the 3rd chemotherapy cycle. Patients with non Hodgkin Lymphomas (NHL) underwent therapy with cyclophosphamide, doxorubicin, vincristine, and prednisone+rituximab (R-CHOP). The interim of their treatment was set at 2 weeks post the 4th chemotherapy cycle. All patients we reassessed 6 weeks after chemotherapy completion.

Results

There were no differences in age and atherosclerotic risk factors (hypertension, diabetes, dyslipidemia and smoking), between the two groups (all P>0.05). Similarly, there were no differences in mean (±SD) index vessel TBR between HL and NHL patients (2.4±0.7 vs 2.7±0.9, respectively, P=0.65). In the whole study population the index vessel TBR progressively decreased after the end of therapy (by 0.53±0.11, from baseline to 6 weeks following the end of therapies) (F=10.94, P<0.001, ANOVA). The index vessel TBR decreased in both HL and NHL patients at 6 weeks after therapy compared to baseline level (all P<0.01, ANOVA, figure). The decrease at the interim scan was more pronounced in NHL compared to HL patients, however at 6 weeks after chemotherapy completion the index vessel TBR decreased further in patients with HL, while it increased slightly compared to interim levels in NHL patients (figure 1).

Conclusion

Arterial inflammation is reduced during and post-chemotherapy in patients with lymphoma. The index vessel TBR changes at the interim phase and 6 weeks after therapy completion indicate a different effect of specific treatment regimes in arterial inflammation between HL and NHL patients.

Figure 1

Funding Acknowledgement

Type of funding source: None

Prevalence, distribution and clinical significance of joints, muscles and bones in sarcoidosis: an 18F-FDG-PET/CT study

OBJECTIVES

In Sarcoidosis joints-muscles-bones (JMBs) localizations are of the least common. ¹⁸F-FDG-PET/CT imaging revolutionized detection of JMBs involvement by adding metabolic activity information and allowing for a comprehensive, whole-body mapping of the disease.

AIM AND METHODS

This study investigated prevalence, distribution, and clinical significance of JMBs sarcoidosis in 195 consecutive patients that underwent ¹⁸F-FDG PET/CT examination.

RESULTS

Joint and bone involvement were encountered in 15% of patients with a mean of the maximum-standardized-uptake-value (SUV_max) of 6.1. Most common location was the axial skeleton. Hypercalciuria was significantly more frequent in patients with osseous involvement (p = 0.003). Muscle activity (SUVmax = 2.4) was encountered in 20% of the patients, most frequently in treatment-naïve (p = 0.02). The muscles of the lower extremities were affected the most. Muscle and bone localization coexist in 50% of the cases. JMBs disease was almost asymptomatic, not related to chronicity but to pulmonary, nodal, and systemic disease. Long-term follow-up and treatment response of affected patients confirmed sarcoidosis.

CONCLUSION

¹⁸F-FDG-PET/CT revealed JMBs localizations and coexistence with other organ sites supporting the concept that sarcoidosis is a systemic disease. By allowing an integrative interpretation of multi-organ involvement in the context of a pattern highly suggestive of sarcoidosis, it strongly keeps-off the diagnosis of malignancy.

Human white-fat thermogenesis: Experimental and meta-analytic findings

White adipose tissue (WAT) thermogenic activity may play a role in whole-body energy balance and two of its main regulators are thought to be environmental temperature (T_env) and exercise. Low T_env may increase uncoupling protein one (UCP1; the main biomarker of thermogenic activity) in WAT to regulate body temperature. On the other hand, exercise may stimulate UCP1 in WAT, which is thought to alter body weight regulation. However, our understanding of the roles (if any) of T_env and exercise in WAT thermogenic activity remains incomplete. Our aim was to examine the impacts of low T_env and exercise on WAT thermogenic activity, which may alter energy homeostasis and body weight regulation. We conducted a series of four experimental studies, supported by two systematic reviews and meta-analyses. We found increased UCP1 mRNA (p = 0.03; but not protein level) in human WAT biopsy samples collected during the cold part of the year, a finding supported by a systematic review and meta-analysis (PROSPERO review protocol: CRD42019120116). Additional clinical trials (NCT04037371; NCT04037410) using Positron Emission Tomography/Computed Tomography (PET/CT) revealed no impact of low T_env on human WAT thermogenic activity (p > 0.05). Furthermore, we found no effects of exercise on UCP1 mRNA or protein levels (p > 0.05) in WAT biopsy samples from a human randomized controlled trial (Clinical trial: NCT04039685), a finding supported by systematic review and meta-analytic data (PROSPERO review protocol: CRD42019120213). Taken together, the present experimental and meta-analytic findings of UCP1 and SUV_max, demonstrate that cold and exercise may play insignificant roles in human WAT thermogenic activity. Abbreviations: WAT:White adipose tissue; T_env: Environmental temperature; UCP1: Uncoupling protein one; BAT: Brown adipose tissue; BMI:Body mass index; mRNA: Messenger ribonucleic acid; RCT: Randomized controlled trial; WHR: Waist-to-hip ratio; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-analyses; PET/CT: Positron Emission Tomography and Computed Tomography; REE: Resting energy expenditure; ¹⁸F-FDG: F¹⁸ fludeoxyglucose; VO₂peak:Peak oxygen consumption; 1RM: One repetition maximum; SUV_max: Maximum standardized uptake value; Std: Standardized mean difference.

Emerging phenotypes of sarcoidosis based on 18F-FDG PET/CT: a hierarchical cluster analysis

Objectives: In sarcoidosis, the definition of organ involvement with traditional means appears laborious and somewhat controversial, and phenotyping by the above overlapping. ¹⁸F-FDG PET/CT defines disease extent by activity more precisely, and may result in a better understanding of sarcoidosis disease behavior and phenotypes expression. We hypothesized that ¹⁸F-FDG PET/CT could add in the phenotyping of sarcoidosis patients by unveiling in detail sites of involvement even in clinically and physiologically silent disease.Methods: This study was designed to investigate the role of ¹⁸F-FDG PET/CT in phenotyping sarcoidosis using cluster analysis by adding this new means in the routine work-up of 195 sarcoidosis patients of a single academic center.Results: ¹⁸F-FDG PET/CT succeeded to identify despite the random distribution of the disease, an ordered stratification into 4 phenotypes: I) thoracic nodal hilar-mediastinal, II) thoracic nodal hilar-mediastinal and lungs, III) an extended thoracic and extra-thoracic only nodal phenotype including inguinal-abdominal-supraclavicular stations, and IV) all the above plus systemic organs and tissues such as muscles-bones-spleen and skin.Conclusion: Though further studies are necessary to confirm findings as patterns of disease behavior; the proposed phenotypes may prove useful in the design of future studies with homogeneous cohorts facilitating in sarcoidosis patients a personalized medicine approach.

P3363Severity of lymphoma is associated with aortic FDG uptake assessed by FDG PET/CT imaging

Introduction

There is increasing evidence that metabolic disease burden in lymphoma modifies patients' outcome. However, the impact of disease severity on cardiovascular system remains unknown.

Purpose

To investigate whether lymphoma is associated with arterial inflammation by examining the relationship between disease burden and arterial F-18 Fluorodeoxyglucose (FDG) uptake assessed by positron emission tomography/computed tomography (PET/CT) in Hodgkin and non-Hodgkin sub-types.

Methods

Sixty-two patients (43 male, mean age 58±18 years) with Hodgkin (n=29) or non-Hodgkin lymphoma (n=33) underwent FDG PET/CT imaging before chemotherapy. Disease severity was quantified by total metabolic tumor volume (TMTV) that represents the volume exhibiting standard uptake values (SUV) ≥41% or ≥2.5 of maximum SUV within lymphoma regions, while aortic FDG uptake assessment was based on target-to-background ratio (TBR). Serum high sensitivity-C-reactive protein (hs-CRP), white blood count (WBC), ratio of neutrophils to lymphocytes (N/L), albumin and lactic acid dehydrogenase (LDH) values were recorded in all the patients.

Results

TMTV measurements correlated significantly with hs-CRP, WBC, N/L ratio, albumin and LDH. (Table) Patients with advanced stage disease (III-IV) had higher aortic TBR values compared to those with stage I-II disease (median 2.19 interquartile range (1.96–2.54) vs. 2.04 (1.83–2.15) p=0.046 respectively). Aortic TBR was related with N/L ratio (R=0.370, p=0.009), while no significant correlation was observed with either WBC or hs-CRP values (p=0.930 and p=0.296, respectively). There were significant associations between aortic TBR uptake and TMTV values even after adjustment for age, sex, LDH, albumin, N/L ratio, as well as for the number of cardiovascular risk factors of each patient (β=0.353, p=0.001, adjusted R2=0.318 for TMTV41%, β=0.442, p=0.001, adjusted R2=0.269 for TMTV2.5).

Table 1. Pearson correlation between indices of lymphomas' severity and serum biomarkers PET derived measurements Hs-CRP P-value Neutrophils to lymphocytes ratio P-value MTV41% 0.306 0.016 0.317 0.026 MTV2.5 0.312 0.013 0.389 0.006 Albumin LDH MTV41% −0.281 0.044 0.465 <0.001 MTV2.5 −0.419 0.002 0.616 <0.001

Conclusions

Aortic wall FDG uptake is related with disease severity and subtype of lymphoma indicating a vascular effect of lymphoma, as well as a new potential role of molecular imaging in cardio-oncology by evaluation of disease severity and its consequences to vascular beds with a single examination.

P5302Significant correlation of visceral adiposity and adipocytokines with arterial inflammation in genetic dyslipidaemias

Background

The adipose tissue is now established as a major regulator of cardiovascular status, mediated by the secretion of several bioactive molecules, including adipocytokines. Individuals with genetic dyslipidaemias of either familial combined hyperlipidemia (FCH) or heterozygous familial hypercholesterolemia (heFH) subtype are characterized by accelerated atherosclerosis. Nonetheless, limited data exists on the relationship between adiposity and arterial inflammation, a marker of cardiovascular risk, in this setting.

Purpose

To investigate the relationship between adiposity indices and arterial inflammation evaluated by 18F fluorodeoxyglycose positron emission tomography (PET/CT) in patients with hereditary lipid metabolism disorders.

Methods

Consecutive patients with either FCH or heFH, free of statin therapy, and normolipidaemic individuals underwent PET/CT imaging. Arterial FDG uptake was estimated as the average value of target-to-background ratio (TBR) within aortic and carotid wall. Volumes of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were measured from CT images between the proximal (cephalic) end of the L1 and distal (caudal) end of the L3 vertebrae by selecting all voxels with attenuation between −190 and −30 Hounsfield Units (HU). Serum adiponectin and leptin levels were measured with ELISA by available commercial kits. For comparisons with arterial TBR, adiponectin and leptin concentrations above and below the 25th percentile, were stratified as high and low, respectively.

Results

In total, 60 individuals (20 FCH, 20 heFH and 20 controls) were included. A modest but significant correlation between SAT volume and arterial TBR (R=0.386, p=0.004) was detected. This relationship did not remain significant after controlling for VAT volume (p=0.303). A strong correlation between VAT volume and arterial TBR (R=0.621, p=0.001) was observed. This relationship remained significant after controlling for SAT volume (R=0.541, p<0.001). Arterial TBR values were higher in individuals with low plasma adiponectin levels (p=0.010). In addition, patients with higher leptin levels exhibited increased arterial FDG uptake compared to subjects with low serum leptin concentrations (p=0.05)

Conclusions

Abdominal adipose tissue imaging markers and serum adipocytokines correlate with arterial inflammation as assessed by PET/CT in patients with familial dyslipidaemias highlighting the role of abdominal adipose tissue for atherosclerosis progression in this population.

P730Decreased adiponectin levels and FDG uptake in visceral adipose tissue in familial combined hyperlipidemia compared to heterozygous familial hypercholesterolemia and normolipidemics

Background

Adipose tissue regulates energy balance and glucose homeostasis via the secretion of circulating molecules, termed adipokines, such as leptin and adiponectin. Excess adiposity and adipose tissue dysfunction have been involved in the pathogenesis of dyslipidemias. Positron emission tomography/computed tomography (PET/CT) with F-18-Fluorodeoxyglycose (FDG) has been used for the assessment of adiposity.

Purpose

To compare abdominal adipose tissue function assessed by FDG uptake with serum indices, such as plasma adipokines' levels in individuals with different subtypes of dyslipidemia and normolipidemics.

Methods

Seventy individuals (mean age 44±13 years, range 21–75, 43 men) with a clinical diagnosis of either heterozygous familial hypercholesterolemia (heFH) (n=38) or familial combined hyperlipidemia (FCH) (n=32), not under statins for at least one year, and 20 age and sex matched controls, were enrolled. Visceral (VAT) and subcutaneous adipose tissue metabolic activity (SAT) was assessed with FDG-PET/CT imaging and was quantified by calculating the target-to-background ratios (TBR) in consecutive axial fat images between the proximal (cephalic) end of the L1 and distal (caudal) end of the L3 vertebrae by dividing the average of the mean standard uptake value (SUV) to the mean SUV of the vena cava. Leptin and adiponectin were measured in all the subjects.

Results

There was no significant difference of plasma leptin values between FCH, heFH and non dyslipidemics subjects (p=0.204). FCH had reduced adiponectin values compared to heFH patients and controls [median 5.7 IQR (3.9–7.6) vs. 13.1 (9.2–23.3) vs. 10.9 (6.1–19.1) μg/mL, respectively, p<0.001]. There was no difference in FDG uptake in subcutaneous adipocytes (SATTBR) between FCH, heFH and controls (p=0.161). In contrast, patients with FCH had reduced VATTBR values compared to heFH patients and controls (0.63±0.14 versus 0.81±0.17 versus 0.86±0.28, p=0.005). This difference remained significant even after adjustment for age, sex and cardiovascular risk factors (b=-0.428, p=0.001, adjusted R2=0.219). SATTBR was inversely correlated to leptin levels (r=−0.484, p<0.001), while no significant association was observed with adiponectin values (p=0.167). No significant associations were observed between VATTBR and either serum leptin (p=0.066) or adiponectin levels (p=0.254).

Conclusions

Visceral adipose tissue FDG uptake is reduced in patients with FCH compared to those with heFH and normolipidemics. In addition, serum adiponectin levels are lower in patients with FCH. These findings highlight the different pathophysiological role of visceral fat function in the two most common types of familial dyslipidemia and suggest that visceral fat could be an attractive target for the treatment of FCH.

Central nervous system disorders affecting the heart-insights from radionuclide imaging

There is a growing research activity focusing on the brain heart cross-talk. A great variety of brain disorders affect the heart and recent developments in neurosciences have revealed the particular role of specific neuroanatomic sites on heart rhythm and rate, myocardial function and vascular tone. Cardiac radionuclide imaging plays a pivotal role in this setting, since not only helps elucidating underlying pathobiological mechanisms but in addition, it promises exciting possibilities for early identification of patients at risk of developing cardiovascular manifestations of certain neurological diseases.

18-Fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography scan for monitoring the therapeutic response in experimental Staphylococcus aureus foreign-body osteomyelitis

Background

18-Fluoro-2-deoxy-d-glucose positron emission tomography combined with computed tomography (¹⁸F-FDG PET/CT) scan is useful for diagnosis of osteoarticular infections. Whether ¹⁸F-FDG PET/CT scanning may be used for therapeutic monitoring is not clear. The objective of this study was to develop ¹⁸F-FDG PET/CT scanning for monitoring therapeutic response to antimicrobials in experimental Staphylococcus aureus osteomyelitis.

Methods

A total of 22 rabbits were studied. In 20 animals, the right tibia was inoculated intraoperatively with S. aureus. Two control animals were inoculated with normal saline. A needle was placed in the tibia as a foreign body. Infection was allowed to develop for 21 days when ¹⁸F-FDG PET/CT was performed, the needle was removed, and bone specimens were cultured to confirm infection. Antimicrobial therapy with daptomycin was initiated in all successfully infected animals for 1, 3, or 6 weeks. Following completion of treatment, a second ¹⁸F-FDG PET/CT was performed, animals were euthanized, and infected tibias were harvested for quantitative cultures and histology. A positive scan was defined as ¹⁸F-FDG signal activity greater in the infected tibia than that of the contralateral non-infected control tibia. Therapeutic response was measured by the change of ¹⁸F-FDG signal activity in the infected tibia.

Results

All successfully infected animals (n = 14), with microbiologically and/or histologically confirmed osteomyelitis, had positive ¹⁸F-FDG PET/CT scans, while the two control animals had negative scans despite the presence of the foreign body [mean maximum standardized uptake value (SUVmax) (±SD) values 2.96 (±0.80) vs. 1 (±1.10), respectively, P = 0.04]. In the 14 successfully infected animals, the mean SUVmax was significantly higher in the infected compared to the uninfected tibia (P < 0.0001). A SUVmax of 1.4, when used as a cutoff for infection, yielded a diagnostic accuracy of 93 %. At the end of treatment, successfully treated animals and saline controls had a negative ¹⁸F-FDG PET/CT scan (n = 4), while animals with persistent infection despite treatment (n = 12) had a positive ¹⁸F-FDG PET/CT scan (SUVmax 1.0–3.0) (p < 0.001). SUVmax values were significantly reduced after 42 days of treatment from 3.15 ± 0.5 (day 7) to 1.71 ± 0.37 (day 42) (p = 0.05).

Conclusions

¹⁸F-FDG PET/CT scan is a sensitive and specific tool in therapeutic monitoring of experimental foreign-body osteomyelitis.

Positron emission tomography in spinal infections

Magnetic resonance imaging is the imaging method of choice for diagnosing infection of the spine in unoperated cases. 2-[(18)F]-fluoro-2deoxy-d-glucose positron emission tomography/computed tomography study is recommended to distinguish between spinal infection and common Modic change in patients with metallic implants and prosthetic replacements and for differentiating tuberculous from pyogenic spondylitis in ambiguous cases, reflecting the activity of the infection. Also, it seems to have a strong clinical impact in more than half of patients with infectious spondylitis, while it is superior to other imaging techniques in revealing residual disease after treatment and early response to therapy. New tracers as well as new hybrid modalities are under investigation.

Assessment of myocardial perfusion and viability by positron emission tomography

An important evolution has taken place recently in the field of cardiovascular Positron Emission Tomography (PET) imaging. Being originally a highly versatile research tool that has contributed significantly to advance our understanding of cardiovascular physiology and pathophysiology, PET has gradually been incorporated into the clinical cardiac imaging portfolio contributing to diagnosis and management of patients investigated for coronary artery disease (CAD). PET myocardial perfusion imaging (MPI) has an average sensitivity and specificity around 90% for the detection of angiographically significant CAD and it is also a very accurate technique for prognostication of patients with suspected or known CAD. In clinical practice, Rubidium-82 ((82)Rb) is the most widely used radiopharmaceutical for MPI that affords also accurate and reproducible quantification in absolute terms (ml/min/g) comparable to that obtained by cyclotron produced tracers such as Nitrogen-13 ammonia ((13)N-ammonia) and Oxygen-15 labeled water ((15)O-water). Quantification increases sensitivity for detection of multivessel CAD and it may also be helpful for detection of early stages of atherosclerosis or microvascular dysfunction. PET imaging combining perfusion with myocardial metabolism using (18)F-Fluorodeoxyglucose ((18)F FDG), a glucose analog, is an accurate standard for assessment of myocardial hibernation and risk stratification of patients with left ventricular dysfunction of ischemic etiology. It is helpful for guiding management decisions regarding revascularization or medical treatment and predicting improvement of symptoms, exercise capacity and quality of life post-revascularization. The strengths of PET can be increased further with the introduction of hybrid scanners, which combine PET with computed tomography (PET/CT) or with magnetic resonance imaging (PET/MRI) offering integrated morphological, biological and physiological information and hence, comprehensive evaluation of the consequences of atherosclerosis in the coronary arteries and the myocardium.

Neurofibromatosis type 1 and renal artery aneurysms: an uncommon entity of severe hypertension

Neurofibromatosis (NF1) is a relatively common autosomal dominant disorder. Secondary causes of hypertension, such as renovascular disease, coarctation of the abdominal aorta or phaeochromocytoma, may be identified in up to 1% of patients with NF1. Usually, renal angiography, which is always used to confirm the diagnosis of renovascular hypertension, reveals stenoses and rarely bilateral or unilateral renal artery aneurysms. We present the first description of a percutaneous transluminal renal angioplasty performed in an adult female patient with NF1, severe hypertensive disease and renal artery aneurysms, in order to restore renal artery anatomy and treat renovascular hypertension.

Molecular indicators for pollution source identification in marine and terrestrial water of the industrial area of Kavala city, North Greece

Eight terrestrial and four marine water samples were collected from the industrial section of the city of Kavala in northern Greece to determine the occurrence and distribution of organic contaminants, as well as to identify the molecular markers of different emission sources. The samples were analyzed by means of non-target screening analyses. The analytical procedure included a sequential extraction of the samples, GC-FID, GC/MS analyses, and additional quantitative analyses of selected pollutants. The results show a wide variety of compounds including halogenated compounds, technical additives and metabolites, phosphates, phthalates, benzothiazoles, etc. A close relationship between many of the contaminants and their emission sources was determined based on their molecular structures and information on technical applications.

Optimization of nitrogen removal and start-up of Psyttalia sewage treatment works

Bench scale experiments were conducted in order to finalize the design of the secondary treatment stage of Psyttalia Sewage Treatment Works that serves the Greater Athens area with a population equivalent of 3.5 million. Carbon and nitrogen removal efficiencies and activated sludge settling characteristics were determined through continuous flow experiments and determination of the maximum specific utilization rates of ammonia (AUR) and nitrate (NUR). According to the results of the pilot experiments the need arose for a significant increase in the initial design's anoxic volume to ensure a 70% average annual nitrogen removal. AUR experiments showed an insignificant inhibition to the nitrification process in the order of 0-30%, representative of typical domestic sewage. The findings of the pilot study were in good agreement with full scale data obtained during the start up of Psyttalia biological treatment plant. According to full scale data and AUR tests a very satisfactory nitrogen removal efficiency was obtained during start up. Finally both lab scale and full scale data indicated that the activated sludge plant operating on Psyttalia primary effluent that has a high oil and grease content, is prompt to experience foaming problems due to the excessive growth of filamentous microorganisms M. parvicella and Gordona amarae - like microorganisms.

Is there a role of whole body bone scan in early stages of non small cell lung cancer patients

PURPOSE

The aim of our study was to re-evaluate the role of whole-body bone scanning (WBBS) in detecting bone metastases in apparently operable stages of non small cell lung cancer (NSCLC) patients.

PATIENTS AND METHODS

We made a retrospective analysis of 60 patients (53 males, 7 females, aged 47-87 years, mean 68+/-4) between 2004-2006. All patients had a full series of imaging staging procedures including WBBS. Their medical records were reviewed with respect to how often bone metastases were detected and whether or not the patients showed any symptoms or laboratory abnormalities indicating bone involvement.

RESULTS

Skeletal metastases (confirmed afterwards by x-ray, computed tomography or biopsy) were found in 11 (18.3%) patients. All of them had normal serum alkaline phosphatase and calcium concentrations. Eleven patients had symptoms suggesting bone metastases and 49 were asymptomatic. Bone metastases were detected in 3 (27.2%) of 11 clinically symptom-positive patients and in 8 (16.3%) of 49 clinically symptom-negative patients.

CONCLUSION

The present study indicates that if bones scans were done only in patients reporting skeletal symptoms an important number of patients (16.3%) would have been misstaged due to asymptomatic bone metastases. We conclude that in patients with apparently operable NSCLC preoperative staging using WBBS is useful to avoid under-staging and futile surgery.

Investigation of the uptake ability of fly ashes produced after lignite combustion

Fly ash samples from the five steam electric power stations of the Lignite Center of Western Macedonia were used in this study. They consisted mainly of anhydrite, lime, quartz and amorphous material as well as feldspars, calcite, micas + clays, portlandite and gehlenite which were all present in minor amounts. Anhydrite, lime and portlandite in the fly ash samples diminished upon treatment with ammonium acetate aqueous solution, whereas quartz, feldspars, gehlenite and amorphous material were enriched. The uptake ability of the fly ash samples ranged from 89 to 101 mequ./100g. The uptake ability of the samples was mainly attributed to the amorphous material and the microporous minerals, micas + clays. The amorphous material content was estimated at between 17 and 20 wt% in the treated fly ashes and may be unburned organic matter and amorphous inorganic material that resulted during the combustion of the lignite. A positive correlation was observed between the uptake ability and the total percentage of amorphous material and micas + clays. The relatively high uptake ability of the fly ash samples could lead to additional industrial and environmental uses of the fly ashes. The environmental advantage of fly ash exploitation will be particularly important for large electric power centers, such as the LCWM.

HEAVY METALS AND TOXIC TRACE ELEMENTS CONTENTS IN SOILS OF SELECTED AREAS OF THE KAVALA PREFECTURE, NORTHERN GREECE

In the present study a total of sixteen samples (3 surrounding rocks and 13 uncultivated topsoils) from the industrial zone east of the city of Kavala, Northern Greece, was collected and analyzed for their content in 41 elements. The extraction of the elements was based on the digestion of 0.1 g of each sample with 2 ml HNO3 and the soil fraction used was the < 20Όμιη. The analytical methods used were ICP-OES for the elements Ca, Mg, Κ, Β, Sr, Fe, Na, Si, S, Ρ, and ΑΙ and ICPMS for the elements Mn, Zn, Cu, Ti, V, Cr, Rb, Ba, Th, La, Ce, As, Sn, Co, Se, Y, Zr, Mo, Cd, Cs, W, Sb, Li, U, Ag, Ni, Hg, Ga, Ge and Pb. The mean element concentrations of the thirteen topsoil samples were compared with the mean values for soil types Fluvisols and Leptosols. The results showed that they are enriched for the elements Ag, As and Pb by 21, 15 and 3 times, respectively. Moreover, the topsoils were compared with the three surrounding rock samples. The results showed that the concentrations of Ca, Mg, Κ, Fe, Si, S, AI, Ρ Na, Β, Ce, Co, Cs, Ga, Ge, Hg, La, Li, Mo, Ni, Rb, Se, Sn, Sr, Th, U and W in the topsoils are mainly influenced by their concentrations in the surrounding rocks. The elements Ag, As, Ba, Cd, Cr, Cu, Mn, Pb, Sb, Ti, Y, V, Zn, and Zr are enriched in the topsoils. The enrichment of Ag, As, Cd, Cr, Cu, Mn, Pb, Sb, and Zn is mainly due to the widespread presence of PBG sulphides, Mn, Cd, and As in the surrounding mineralizations. The enrichment took place, quite possibly, during the formation of Drama and Nestos basins, during Tertiary, and is possibly being continued until today. However, the human activities that take place in the area are also, at least partially, responsible for this enrichment.

ORGANIC POLLUTANTS IN THE INDUSTRIAL AREA EAST OF KAVALA, NORTHERN GREECE

The occurrence and distribution of organic pollutants were studied at in an industrial area situated at the coastal zone east of Kavala, Northeastern Greece. The study focused especially on the area, where the oil facilities of Kavala Oil Co. are located. Three surface water samples were collected and investigated by means of non-target screening analyses to evaluate the level of organic pollution, as well as to reveal molecular markers representing the industrial emissions. The analytical procedure included a sequential extraction of the samples, GC-FID as well as GC/MS analyses (Franke et al., 1995). In the three water samples halogenated compounds, technical additives and synthetic fragrances, phosphates, phthalates, benzothiazoles, esters, ketones, phenols, ethers and PAH's were detected. Quantitative analyses of selected pollutants were additionally performed. Source-specific marker compounds were identified and used to trace different types of emissions throughout the affected environment

Presenilin-1 binds cytoplasmic epithelial cadherin, inhibits cadherin/p120 association, and regulates stability and function of the cadherin/catenin adhesion complex

Here we show that presenilin-1 (PS1), a protein involved in Alzheimer's disease, binds directly to epithelial cadherin (E-cadherin). This binding is mediated by the large cytoplasmic loop of PS1 and requires the membrane-proximal cytoplasmic sequence 604-615 of mature E-cadherin. This sequence is also required for E-cadherin binding of protein p120, a known regulator of cadherin-mediated cell adhesion. Using wild-type and PS1 knockout cells, we found that increasing PS1 levels suppresses p120/E-cadherin binding, and increasing p120 levels suppresses PS1/E-cadherin binding. Thus PS1 and p120 bind to and mutually compete for cellular E-cadherin. Furthermore, PS1 stimulates E-cadherin binding to beta- and gamma-catenin, promotes cytoskeletal association of the cadherin/catenin complexes, and increases Ca(2+)-dependent cell-cell aggregation. Remarkably, PS1 familial Alzheimer disease mutant DeltaE9 increased neither the levels of cadherin/catenin complexes nor cell aggregation, suggesting that this familial Alzheimer disease mutation interferes with cadherin-based cell-cell adhesion. These data identify PS1 as an E-cadherin-binding protein and a regulator of E-cadherin function in vivo.