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Zsolt Lengyel

Semmelweis University, Nuclear Medicine, Faculty Member

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Mária Gődény

Beáta Székely

Babes-Bolyai University Faculty of Psychology and Educational Sciences

Petrányi Ágota

László Czakó

Zsolt Dubravcsik

University of Szeged

University of Debrecen

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Papers by Zsolt Lengyel

A képalkotó vizsgálómódszerek alkalmazása az emlődaganatok korszerű szűrésében, diagnosztikájában és ellátásában – Szakmai útmutató a III. Emlőrák Konszenzus Konferencia alapján

by K. Borbély and Zsolt Lengyel

Breast radiologists and nuclear medical specialists have refreshed their previous statement text ... more Breast radiologists and nuclear medical specialists have refreshed their previous statement text during the 3rd Hungarian Breast Cancer Consensus Meeting. They suggest taking into consideration this actual protocol for the screening, diagnostics and treatment of breast tumors, from now on. This recommendation includes the description of the newest technologies, the recent results of scientific research,
as well as the role of imaging methods in the therapeutic processes and the followup. Suggestions for improvement of the Hungarian current practice and other related issues as forensic medicine, media connections, regulations, and reimbursement are also detailed. The statement text has been crosschecked with the related medical disciplines.
Forrai G, Ambrózay É, Bidlek M, Borbély K, Kovács E,
Lengyel Z, Ormándi K, Péntek Z, Riedl E, Sebő É, Szabó É;
Radiology/Nuclear Medicine Group. Use of imaging meth ods in the current screening, diagnostics and treatment of breast cancer – Professional guidelines. 3rd Breast Cancer Consensus Meeting. Hungarian Oncology 60:181–193, 2016

Complexity of Response Evaluation During Primary Systemic Therapy of Breast Cancer: Scoring Systems and Beyond-Preliminary Results

by Tímea Tőkés, Zsolt Lengyel, László Torgyík, Krisztián Somlai, Janina Kulka, and Magdolna Dank

Anticancer research, 2015

Precise and standardized response evaluation enables clinicians to tailor primary systemic therap... more Precise and standardized response evaluation enables clinicians to tailor primary systemic therapy (PST). Breast cancer patients underwent (18)F-fluoro-deoxy-glucose positron emission tomography and computerized tomography (FDG-PET/CT) before and after PST. Response was assessed by maximal Standardized Uptake Value (SUVmax); morphological changes and Ki-67 labeling index (LI). In parallel response assessment was performed by European Organization for Research and Treatment of Cancer (EORTC); PET Response Criteria in Solid Tumors (PERCIST); World Health Organization (WHO); Response Evaluation Criteria in Solid Tumors (RECIST); Chevallier and Sataloff classifications, and by a novel Ki-67 score. Accuracy of different scoring systems was evaluated. In the 42 enrolled patients, SUVmax, size, and Ki-67 LI decreased significantly on PST. Significant differences between patients with versus those without pathological complete response were observed for pre-treatment Ki-67 LI and SUVmax and...

[In vivo investigation of the A2A adenosine receptor distribution using the [11C]-CSC radioligand]

Orvosi Hetilap

A 11C labeled selective adenosine A2A antagonist, (E)-8-(3-chlorostyryl)-1,3-dimethyl-7-[11C]-met... more A 11C labeled selective adenosine A2A antagonist, (E)-8-(3-chlorostyryl)-1,3-dimethyl-7-[11C]-methylxanthine [(11C)-CSC] was prepared reacting (E)-8-(3-chlorostyryl)-1,3,-dimethylxanthine and [11C]-methyl iodide. A primary evaluation of [11C]-CSC as a potential tracer for mapping adenosine A2A receptors by positron emission tomography (PET) was also presented. Autoradiographic studies were carried out on Swiss mice. A high level accumulation of radioactivity was observed in the striatum and medulla oblongata in accordance with previous findings on the specific spatial distribution of A2A adenosine receptors. Dynamic PET studies on rabbits showed a fast brain uptake of CSC, reaching a maximum in less than 2 minutes. Competition experiments with the unlabeled ligand proved [11C]-CSC to bind specifically to the appropriate receptor.

[Salvage 125I brachytherapy of locally recurrent prostate cancer]

by Zsolt Lengyel, Péter Ágoston, and Mária Gődény

Magyar onkologia, 2014

The purpose of the study is to report a case of salvage low dose rate (LDR) prostate brachytherap... more The purpose of the study is to report a case of salvage low dose rate (LDR) prostate brachytherapy in a patient with locally recurrent prostate cancer, four years after his first treatment with combined external beam radiation therapy (EBRT) and high dose rate (HDR) brachytherapy. A 61-year-old man was treated with 1x10 Gy HDR brachytherapy and a total of 60 Gy EBRT for an organ confined intermediate risk carcinoma of the prostate in 2009. The patient's tumor had been in regression with the lowest PSA level of 0.09 ng/ml, till the end of 2013. After slow but continuous elevation, his PSA level had reached 1.46 ng/ml by February 2014. Pelvis MRI and whole body acetate PET/CT showed recurrent tumor in the dorsal-right region of the prostate. Bone scan was negative. After discussing the possible salvage treatment options with the patient, he chose LDR brachytherapy. In 2014, in spinal anesthesia 21 125I "seeds" were implanted with transrectal ultrasound guidance into the ...

[The [18F]-FNECA serves as a suitable radioligand for PET investigation of purinergic receptor expression]

Orvosi hetilap, Jan 26, 2002

The well known and widely used P1 adenosine agonist, 5'-N-ethyl-carboxamidoadenosine (NECA), ... more The well known and widely used P1 adenosine agonist, 5'-N-ethyl-carboxamidoadenosine (NECA), was labelled with 18F isotope for the in vivo PET investigation of A1, A2 and A3 adenosine receptor expression. The precursor 2-[18F]fluoroethylamine was reacted with 2',3'-O-isopropylideneadenosine-5'-uronic acid. Specific activity of the [18F]-FNECA was (2.3 +/- 1.1) TBq/mmol (60 Ci/mmol). Dynamic PET measurements were carried out in rabbits to study the in vivo kinetics of the receptor saturation with the labelled ligand. The time dependent accumulation was followed up in the heart, lungs, liver, brain and testis. The radiotracer uptake was rapid and reached its maximum in less than two minutes in the heart and testes after v. injection of the radiopharmaceutical, while it took about 6 minutes in the brain, lungs and liver. High [18F]-FNECA accumulation was detected in the intestines, too. The specific binding of the [18F]-FNECA was tested in competition experiments in bra...

Pattern of Increased Cerebral FDG Uptake in Down Syndrome Patients

Pediatric Neurology, 2006

Resting cerebral glucose metabolism was assessed by 18[F]-fluorodeoxyglucose in 11 Down syndrome ... more Resting cerebral glucose metabolism was assessed by 18[F]-fluorodeoxyglucose in 11 Down syndrome patients. Standardized uptake values were determined on a pixel-by-pixel basis from the measured tissue-activity data. The results revealed a mean overall 18[F]-fluorodeoxyglucose uptake in the Down syndrome patients close to that observed in the control group, consisting of children and young adults. However, the standard deviation of the standardized uptake values was much higher in the Down syndrome group in almost all voxels relating to the gray matter. The statistical parametric mapping method was applied to compare the cerebral 18[F]-fluorodeoxyglucose accumulation patterns of the Down syndrome and control groups. Six regions (clusters) were found for which the glucose uptake was higher in the Down syndrome patients than in the control group. The anatomic localization of these clusters was based on magnetic resonance investigations and a brain-atlas technique. The localization of the identified clusters with an increased glucose metabolism in the Down syndrome patients suggests that these subjects have an enhanced resting neuronal activity in cortical areas involved in reasoning, cognition, and speech as compared with normal subjects.

A számítógépes rétegvizsgálattal kombinált pozitronemissziós tomogrÁFIA (PET-CT) diagnosztikus értéke tüdőrákban (Tapasztalataink 408 beteg kapcsán)

by Zsolt Lengyel and K. Borbély

Magyar Onkológia, 2009

I S S N 0 0 2 5 -0 24 4 © A k a d é m i a i K i a d ó, B U DA PES T • M a g ya r O nko l ó gi a 5... more I S S N 0 0 2 5 -0 24 4 © A k a d é m i a i K i a d ó, B U DA PES T • M a g ya r O nko l ó gi a 5 3: 17-21, 2 0 0 9 • D O I: 10.15 5 6 / M O n ko l. 5 3 . 2 0 0 9.1. 3 Eredeti közlemény A szerzők 408 betegnél tüdőgyógyászati onkológiai indikációkban végze PET-CT-vizsgálataik értékét elemzik. Pulmonális kerekárnyék karakterizálásának céljából 154 PET-CT-t végeztek, amelyet 59 esetben műtét követe . A módszer malignitásra vonatkozó szenzitivitását 100%-nak, specifi citását 56%nak találták. A nyirokcsomó-érinte ség alapján történő staginget 17/54 esetben mediastinoscopia vagy thoracotomia köve e. Fenti indikációkban a PET-CT-pozitivitás szöve ani/citológiai megerősítése minden esetben szükséges. M-staginget 141, neoadjuváns kemoterápiát követő mediastinalis restaginget 24 betegnél végeztek. Utóbbi indikációt a PET-CT pontatlansága mia másodlagos jelentőségűnek gondolják. 175 beteg esetében a PET-CT műtéti indikációban játszo (sokszor) meghatározó szerepét elemezték. Tapasztalataik közreadásával segíteni szeretnék a PET-CT adta új lehetőségek jobb kihasználását, ill. gyorsítani ezek diagnosztikus protokollokba történő beillesztését. Magyar Onkológia 53: 17-21, 2009 Kulcsszavak: PET-CT, nem kissejtes tüdőrák, stádiumba sorolás, onkológia The authors analyzed the results of PET-CT scans made with oncological indications among 408 patients. One hundred and fi y-four PET-CTs were done to characterize pulmonary foci, a er which in 59 cases lung surgery was performed. The method's sensitivity in respect to malignancy was 100%, specifi city was 56%. Staging of aff ected lymph nodes resulted in 17 mediastinoscopies and 54 thoracotomies. In the former indications PET-CT-positive lymph nodes always need cytologic/histologic verifi cation. M-staging done with PET-CT was performed in 141 cases, mediastinal restaging of patients having received neoadjuvant chemotherapy was done in 24 cases. The la er indications we consider superfl uous because of the diagnostic inaccuracy of PET-CT. In 175 cases we analyzed the frequently determining factor of the PET-CT scan in the indication of lung surgery. The authors wish to share their experience for the be er use of this method and to accelerate the inclusion of PET-CT into the diagnostic protocol. Zsiray M, Markóczy Z, Magyar M, Lengyel Z, Fekésházy A, Borbély K. The advantage of Positron Emission Tomography combined with Computer Tomography (PET-CT) in the diagnosis of lung cancer, our own experience with 408 patients. Hungarian Oncology 53: 17-21, 2009

A PET study on the characterization of partially reversible radiogenic lower motor neurone disease

by Zsolt Lengyel and Péter Ágoston

Spinal Cord, 2002

Objective: To investigate the pathomechanism of the rare radiogenic lower motor neurone disease (... more Objective: To investigate the pathomechanism of the rare radiogenic lower motor neurone disease (LMND) on the basis of a case history involving a partial functional recovery. Patient: A 31-year-old seminoma patient received postoperative para-aortic and para-iliac telecobalt irradiation with a biologically eective dose of 88 Gy 2 (44 Gy in 2 Gy fractions/day, with an estimated a/b of 2 Gy) delivered to the spinal cord following a single cycle of chemotherapy. LMND developed 4 months after the completion of radiotherapy. The patient exhibited¯accid paraparesis of the lower extremities (without sensory or vegetative signs), followed by a worsening after further chemotherapy, due to pulmonary metastatization. A gradual spontaneous functional improvement commenced and led several years later to a stabilized state involving moderately severe symptoms. Methods: In the 15th year of the clinical course, magnetic resonance imaging (MRI) and positron emission tomography (PET) with [ 18 F]¯uorodeoxyglucose (FDG) and [ 11 C]methionine were conducted. Four lines of experiments (clonogenic assay using ®broblasts isolated from a skin biopsy sample of the patient, comet assay, micronucleus assay, and the testing of chromosome aberrations after in vitro irradiation of peripheral blood samples) were performed in a search for an increased individual radiosensitivity. Results: MRI investigations failed to reveal any pathological change. PET demonstrated an increased FDG accumulation, but a negligible [ 11 C]methionine uptake in the irradiated spinal cord segments. The radiobiological investigations did not indicate any sign of an increased individual radiosensitivity. Conclusions: We suggest that the observed partial functional recovery and stabilization of the symptoms of radiogenic LMND may be explained by the higher than normal density of sodium channels expressed along the demyelinated axons of the restored conduction. The increased energy demands of this type of conduction are proved by a higher metabolic rate (increased FDG uptake) of the irradiated spinal cord segments without a substantial regenerative process (lack of detectable protein synthesis).

Brain blood flow changes measured by positron emission tomography during an auditory cognitive task in healthy volunteers and in schizophrenic patients

Progress in Neuro-Psychopharmacology and Biological Psychiatry, 2006

Objective: Cognitive deficit is an essential feature of schizophrenia. One of the generally used ... more Objective: Cognitive deficit is an essential feature of schizophrenia. One of the generally used simple cognitive tasks to characterize specific cognitive dysfunctions is the auditory ''oddball'' paradigm. During this task, two different tones are presented with different repetition frequencies and the subject is asked to pay attention and to respond to the less frequent tone. The aim of the present study was to apply positron emission tomography (PET) to measure the regional brain blood flow changes induced by an auditory oddball task in healthy volunteers and in stable schizophrenic patients in order to detect activation differences between the two groups. Method: Eight healthy volunteers and 11 schizophrenic patients were studied. The subjects carried out a specific auditory oddball task, while cerebral activation measured via the regional distribution of [ 15 O]-butanol activity changes in the PET camera was recorded. Results and discussion: Task-related activation differed significantly across the patients and controls. The healthy volunteers displayed significant activation in the anterior cingulate area (Brodman Area -BA32), while in the schizophrenic patients the area was wider, including the mediofrontal regions (BA32 and BA10). The distance between the locations of maximal activation of the two populations were 33 mm and the cluster size was about twice as large in the patient group. Conclusions: The present results demonstrate that the perfusion changes induced in the schizophrenic patients by this cognitive task extends over a larger part of the mediofrontal cortex than in the healthy volunteers. The different pattern of activation observed during the auditory oddball task in the schizophrenic patients suggests that a larger cortical area -and consequently a larger variety of neuronal networks -is involved in the cognitive processes in these patients. The dispersion of stimulus processing during a cognitive task requiring sustained attention and stimulus discrimination may play an important role in the pathomechanism of the disorder. D

Pallidal Deep Brain Stimulation and L-Dopa Effect on PET Motor Activation in Advanced Parkinson's Disease

Journal of Neuroimaging, 2009

BACKGROUND AND PURPOSE The antiakinetic effect of internal Globus pallidus deep brain stimulation... more BACKGROUND AND PURPOSE The antiakinetic effect of internal Globus pallidus deep brain stimulation (Gpi-DBS) in Parkinson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease is not clear and not either how this effect is modulated by L-dopa. METHODS Left Gpi-DBS and/or L-dopa effect was studied with auditory paced right-handed sequential movements on (15)O-butanol positron emission tomography (PET) in five patients. Rest and for conditions during movements (DBS off/L-dopa off; DBS on/L-dopa off; DBS off/L-dopa on; DBS on/L-dopa on) were compared with statistical parametric mapping. RESULTS Gpi-DBS activated the right supplementary motor area/premotor (SMA/PMC), and right insular cortex (IC), and as L-dopa decreased the left sensorimotor cortex (M1/S1) activity. L-dopa increased the left ventrolateral thalamus (VLTH), and decreased the left superior parietal cortex (PC) activity. Gpi-DBS and L-dopa interaction showed right SMA/PMC, IC, and left PC activation, decrease of left VLTH, PMC, and dorsolateral prefrontal cortex (PFC) activity. CONCLUSIONS The improvement of bradykinesia with Gpi-DBS is secondary and contributed to the regress of M1/S1-related rigidity and compensatory SMA/PMC, and IC activation. L-dopa and Gpi-DBS alone each reduces M1/S1 overactivity. Interaction ignores this effect, moreover has akinetic effect in the left VLTH, PMC, and PFC. Motor improvement possibly related to left PC and compensatory right SMA/PMC, and IC activation.

Szükséges-e Hodgkin-limfóma primer stádium-megállapításához FDG-PET/CT mellett iv. ka. CT elvégzése is?

Orvosi Hetilap, 2014

Several study supported that 18F-Fluoro-deoxy-glucose (FDG) positron emission tomography/computer... more Several study supported that 18F-Fluoro-deoxy-glucose (FDG) positron emission tomography/computer tomography with low dose CT (standard PET/CT) is more accurate than contrast-enhanced CT (ceCT) in the primary staging of Hodgkin disease. The authors compared the accuracy of these examinations with this indication in their practice, and analysed the added value of ceCT which was performed as a supplement to standard PET/CT. Twenty-eight patients were categorized based on ceCT, single standard PET/CT and standard PET/CT with ceCT. Twenty-four patients were in the same disease-stage based on all methods. Disease was upstaged by standard PET/CT compared to ceCT in 4 patients. There was no change in stage when comparing standard PET/CT and standard PET/CT with ceCT. Standard PET/CT is more accurate than ceCT in the primary staging of Hodgkin disease. The authors established that it is not reasonable to supplement standard PET/CT with ceCT in this indication.

Cholinotoxic effects of β-amyloid(1–42) peptide on cortical projections of the rat nucleus basalis magnocellularis

Brain Research, 1995

The Role of Disulfide Bond C191-C220 in Trypsin and Chymotrypsin

Biochemical and Biophysical Research Communications, 1997

charge of residue 189. However, replacement of Asp189 Serine proteases of the chymotrypsin family... more charge of residue 189. However, replacement of Asp189 Serine proteases of the chymotrypsin family contain of trypsin with the analogous Ser189 of chymotrypsin fails three conserved disulfide bonds: C42-C58, C168-C182, and to convert specificity and resulted in a poor, non-specific C191-C220. C191-C220 connects the loops around the subprotease (4). Conversion of trypsin to a chymotrypsinstrate binding pocket. Using site directed mutagenesis, like protease requires substitution of non conservative cysteines of this disulfide bridge were replaced by alaresidues in the S1 site together with the exchange of two nines in trypsin, in chymotrypsin, and in TrrChadjacent surface loops, which do not directly contact the [S1/L1/L2/Y172W], a mutant trypsin with high chymosubstrate (5). This mutant, TrrCh[S1/L1/L2], has been trypsin like activity. The functional role of this ''active improved to a protease with about 20% of the activity of site'' disulfide was assessed by comparing the catalytic chymotrypsin by mutating Tyr172 to Trp (6) . In properties of wild-type and mutant enzymes. Its removal addition to these primary effects, it has been proposed from all three proteases caused a decrease in k cat /K M of

A novel titration technique for the analysis of streamed samples—the triangle-programmed titration technique

Analytica Chimica Acta, 1978

An apparatus is described for canyicg out triangleprogrammed titrations with coulometric reagent ... more An apparatus is described for canyicg out triangleprogrammed titrations with coulometric reagent generation. Different halides and pseudohalides can be determined by titration with silver(I). Both voltammetric and potentiometric detection systems are discussed, but emphasis is placed on potentiometric detection with ion-selective electrodes. 'Ihe proposed technique can be used for accurate determinations of flowing samples of halides and pseudohalides at low concentrations. The simultaneous determination of two-component mixtures is discus+ed.

HYPOGLYCEMIA ACTIVATES COMPENSATORY MECHANISM OF GLUCOSE METABOLISM OF BRAIN

Acta Biologica Hungarica, 2001

articoli italiani CHEST BPCO Scopo dello studio: È stato studiato il ruolo dei due recettori del ... more articoli italiani CHEST BPCO Scopo dello studio: È stato studiato il ruolo dei due recettori del leukotriene B4 (LTB4), il recettore di membrana BLT1 e il recettore nucleare peroxisome proliferator-activated receptor (PPAR)-α, sulla suscettibilità dei fumatori a sviluppare BPCO. Infatti, le attività pro-infiammatorie del LTB4 sono mediate dal recettore BLT1, mentre il PPARα promuove l'inattivazione del mediatore lipidico. Soggetti e metodi: L'espressione di BLT1 e PPARα è stata quantificata mediante tecniche di immunoistochimica in campioni di parenchima polmonare ottenuti chirurgicamente da 19 fumatori con e senza BPCO e da 7 soggetti non fumatori. Risultati: Nei soggetti con BPCO è stato osservato un aumento significativo della percentuale di macrofagi alveolari positivi al PPARα e del numero di cellule nella parete alveolare positive al PPARα rispetto ai soggetti di controllo. Inoltre, i pazienti con BPCO presentavano un aumento significativo dei macrofagi alveolari positivi al BLT1 rispetto ai non fumatori e un incremento del numero di cellule nella parete alveolare positive al BLT1 rispetto ai fumatori sani. In contrasto, l'immunoreattività per BLT1 e PPARα non mostrava differenze significative nel confronto tra i soggetti non fumatori e i fumatori sani. La maggior parte delle cellule positive al BLT1 nella parete alveolare erano neutrofili e linfociti T CD8. Fra queste cellule infiltranti il parenchima polmonare il numero di neutrofili risultava simile nei tre gruppi, mentre il numero di linfociti T CD8 era aumentato nei soggetti con BPCO, anche se non vi erano evidenze che il BLT1 fosse sovraespressso in queste cellule. Conclusioni: I risultati hanno dimostrato che i recettori BLT1 e PPARα sono identificabili nel tessuto polmonare umano prevalentemente nei macrofagi alveolari e nei linfociti T CD8 e che l'espressione di questo doppio sistema recettoriale per il LTB4 è accresciuta nel polmone periferico dei fumatori suscettibili a sviluppare BPCO. Questo sistema recettoriale potrebbe rappresentare un nuovo target per l'intervento terapeutico nei pazienti con BPCO.

[Role of 18FDG-PET/CT in the management and gross tumor volume definition for radiotherapy of head and neck cancer; single institution experiences based on long-term follow-up]

by Erika Szántó, Szilvia Gaál, Zsófia Együd, Ágnes Dobi, and Zsolt Lengyel

Magyar onkologia, 2015

célThe purpose of our work is evaluation of the impact of 18FDG-PET/CT on the complex management ... more célThe purpose of our work is evaluation of the impact of 18FDG-PET/CT on the complex management of locoregionally advanced (T3-4N1-3) head and neck squamous cell cancer (LAHNSC), and on the target definiton for 3D conformal (3DCRT) and intensity-modulated radiotherapy (IMRT). 18FDG-PET/CT were performed on 185 patients with LAHNSC prior to radiotherapy/chemoradiation in the treatment position between 2006 and 2011. Prior to it 91 patients recieved induction chemotherapy (in 20 cases of these, baseline PET/CT was also available). The independently delineated CT-based gross tumor volume (GTVct) and PET/CT based ones (GTVpet) were compared. Impact of PET/CT on the treatment strategy, on tumor response evaluation to ICT, on GTV definition furthermore on overall and disease-specific survival (OS, DSS) was analysed. PET/CT revealed 10 head and neck, 2 lung cancers for 15 patients with carcinoma of unknown primary (CUP) while 3 remained unknown. Second tumors were detected in 8 (4.4%), di...

A képalkotó vizsgálómódszerek alkalmazása az emlődaganatok korszerű szűrésében, diagnosztikájában és ellátásában – Szakmai útmutató a III. Emlőrák Konszenzus Konferencia alapján

by K. Borbély and Zsolt Lengyel

Breast radiologists and nuclear medical specialists have refreshed their previous statement text ... more Breast radiologists and nuclear medical specialists have refreshed their previous statement text during the 3rd Hungarian Breast Cancer Consensus Meeting. They suggest taking into consideration this actual protocol for the screening, diagnostics and treatment of breast tumors, from now on. This recommendation includes the description of the newest technologies, the recent results of scientific research,
as well as the role of imaging methods in the therapeutic processes and the followup. Suggestions for improvement of the Hungarian current practice and other related issues as forensic medicine, media connections, regulations, and reimbursement are also detailed. The statement text has been crosschecked with the related medical disciplines.
Forrai G, Ambrózay É, Bidlek M, Borbély K, Kovács E,
Lengyel Z, Ormándi K, Péntek Z, Riedl E, Sebő É, Szabó É;
Radiology/Nuclear Medicine Group. Use of imaging meth ods in the current screening, diagnostics and treatment of breast cancer – Professional guidelines. 3rd Breast Cancer Consensus Meeting. Hungarian Oncology 60:181–193, 2016

Complexity of Response Evaluation During Primary Systemic Therapy of Breast Cancer: Scoring Systems and Beyond-Preliminary Results

by Tímea Tőkés, Zsolt Lengyel, László Torgyík, Krisztián Somlai, Janina Kulka, and Magdolna Dank

Anticancer research, 2015

Precise and standardized response evaluation enables clinicians to tailor primary systemic therap... more Precise and standardized response evaluation enables clinicians to tailor primary systemic therapy (PST). Breast cancer patients underwent (18)F-fluoro-deoxy-glucose positron emission tomography and computerized tomography (FDG-PET/CT) before and after PST. Response was assessed by maximal Standardized Uptake Value (SUVmax); morphological changes and Ki-67 labeling index (LI). In parallel response assessment was performed by European Organization for Research and Treatment of Cancer (EORTC); PET Response Criteria in Solid Tumors (PERCIST); World Health Organization (WHO); Response Evaluation Criteria in Solid Tumors (RECIST); Chevallier and Sataloff classifications, and by a novel Ki-67 score. Accuracy of different scoring systems was evaluated. In the 42 enrolled patients, SUVmax, size, and Ki-67 LI decreased significantly on PST. Significant differences between patients with versus those without pathological complete response were observed for pre-treatment Ki-67 LI and SUVmax and...

[In vivo investigation of the A2A adenosine receptor distribution using the [11C]-CSC radioligand]

Orvosi Hetilap

A 11C labeled selective adenosine A2A antagonist, (E)-8-(3-chlorostyryl)-1,3-dimethyl-7-[11C]-met... more A 11C labeled selective adenosine A2A antagonist, (E)-8-(3-chlorostyryl)-1,3-dimethyl-7-[11C]-methylxanthine [(11C)-CSC] was prepared reacting (E)-8-(3-chlorostyryl)-1,3,-dimethylxanthine and [11C]-methyl iodide. A primary evaluation of [11C]-CSC as a potential tracer for mapping adenosine A2A receptors by positron emission tomography (PET) was also presented. Autoradiographic studies were carried out on Swiss mice. A high level accumulation of radioactivity was observed in the striatum and medulla oblongata in accordance with previous findings on the specific spatial distribution of A2A adenosine receptors. Dynamic PET studies on rabbits showed a fast brain uptake of CSC, reaching a maximum in less than 2 minutes. Competition experiments with the unlabeled ligand proved [11C]-CSC to bind specifically to the appropriate receptor.

[Salvage 125I brachytherapy of locally recurrent prostate cancer]

by Zsolt Lengyel, Péter Ágoston, and Mária Gődény

Magyar onkologia, 2014

The purpose of the study is to report a case of salvage low dose rate (LDR) prostate brachytherap... more The purpose of the study is to report a case of salvage low dose rate (LDR) prostate brachytherapy in a patient with locally recurrent prostate cancer, four years after his first treatment with combined external beam radiation therapy (EBRT) and high dose rate (HDR) brachytherapy. A 61-year-old man was treated with 1x10 Gy HDR brachytherapy and a total of 60 Gy EBRT for an organ confined intermediate risk carcinoma of the prostate in 2009. The patient's tumor had been in regression with the lowest PSA level of 0.09 ng/ml, till the end of 2013. After slow but continuous elevation, his PSA level had reached 1.46 ng/ml by February 2014. Pelvis MRI and whole body acetate PET/CT showed recurrent tumor in the dorsal-right region of the prostate. Bone scan was negative. After discussing the possible salvage treatment options with the patient, he chose LDR brachytherapy. In 2014, in spinal anesthesia 21 125I "seeds" were implanted with transrectal ultrasound guidance into the ...

[The [18F]-FNECA serves as a suitable radioligand for PET investigation of purinergic receptor expression]

Orvosi hetilap, Jan 26, 2002

The well known and widely used P1 adenosine agonist, 5'-N-ethyl-carboxamidoadenosine (NECA), ... more The well known and widely used P1 adenosine agonist, 5'-N-ethyl-carboxamidoadenosine (NECA), was labelled with 18F isotope for the in vivo PET investigation of A1, A2 and A3 adenosine receptor expression. The precursor 2-[18F]fluoroethylamine was reacted with 2',3'-O-isopropylideneadenosine-5'-uronic acid. Specific activity of the [18F]-FNECA was (2.3 +/- 1.1) TBq/mmol (60 Ci/mmol). Dynamic PET measurements were carried out in rabbits to study the in vivo kinetics of the receptor saturation with the labelled ligand. The time dependent accumulation was followed up in the heart, lungs, liver, brain and testis. The radiotracer uptake was rapid and reached its maximum in less than two minutes in the heart and testes after v. injection of the radiopharmaceutical, while it took about 6 minutes in the brain, lungs and liver. High [18F]-FNECA accumulation was detected in the intestines, too. The specific binding of the [18F]-FNECA was tested in competition experiments in bra...

Pattern of Increased Cerebral FDG Uptake in Down Syndrome Patients

Pediatric Neurology, 2006

Resting cerebral glucose metabolism was assessed by 18[F]-fluorodeoxyglucose in 11 Down syndrome ... more Resting cerebral glucose metabolism was assessed by 18[F]-fluorodeoxyglucose in 11 Down syndrome patients. Standardized uptake values were determined on a pixel-by-pixel basis from the measured tissue-activity data. The results revealed a mean overall 18[F]-fluorodeoxyglucose uptake in the Down syndrome patients close to that observed in the control group, consisting of children and young adults. However, the standard deviation of the standardized uptake values was much higher in the Down syndrome group in almost all voxels relating to the gray matter. The statistical parametric mapping method was applied to compare the cerebral 18[F]-fluorodeoxyglucose accumulation patterns of the Down syndrome and control groups. Six regions (clusters) were found for which the glucose uptake was higher in the Down syndrome patients than in the control group. The anatomic localization of these clusters was based on magnetic resonance investigations and a brain-atlas technique. The localization of the identified clusters with an increased glucose metabolism in the Down syndrome patients suggests that these subjects have an enhanced resting neuronal activity in cortical areas involved in reasoning, cognition, and speech as compared with normal subjects.

A számítógépes rétegvizsgálattal kombinált pozitronemissziós tomogrÁFIA (PET-CT) diagnosztikus értéke tüdőrákban (Tapasztalataink 408 beteg kapcsán)

by Zsolt Lengyel and K. Borbély

Magyar Onkológia, 2009

I S S N 0 0 2 5 -0 24 4 © A k a d é m i a i K i a d ó, B U DA PES T • M a g ya r O nko l ó gi a 5... more I S S N 0 0 2 5 -0 24 4 © A k a d é m i a i K i a d ó, B U DA PES T • M a g ya r O nko l ó gi a 5 3: 17-21, 2 0 0 9 • D O I: 10.15 5 6 / M O n ko l. 5 3 . 2 0 0 9.1. 3 Eredeti közlemény A szerzők 408 betegnél tüdőgyógyászati onkológiai indikációkban végze PET-CT-vizsgálataik értékét elemzik. Pulmonális kerekárnyék karakterizálásának céljából 154 PET-CT-t végeztek, amelyet 59 esetben műtét követe . A módszer malignitásra vonatkozó szenzitivitását 100%-nak, specifi citását 56%nak találták. A nyirokcsomó-érinte ség alapján történő staginget 17/54 esetben mediastinoscopia vagy thoracotomia köve e. Fenti indikációkban a PET-CT-pozitivitás szöve ani/citológiai megerősítése minden esetben szükséges. M-staginget 141, neoadjuváns kemoterápiát követő mediastinalis restaginget 24 betegnél végeztek. Utóbbi indikációt a PET-CT pontatlansága mia másodlagos jelentőségűnek gondolják. 175 beteg esetében a PET-CT műtéti indikációban játszo (sokszor) meghatározó szerepét elemezték. Tapasztalataik közreadásával segíteni szeretnék a PET-CT adta új lehetőségek jobb kihasználását, ill. gyorsítani ezek diagnosztikus protokollokba történő beillesztését. Magyar Onkológia 53: 17-21, 2009 Kulcsszavak: PET-CT, nem kissejtes tüdőrák, stádiumba sorolás, onkológia The authors analyzed the results of PET-CT scans made with oncological indications among 408 patients. One hundred and fi y-four PET-CTs were done to characterize pulmonary foci, a er which in 59 cases lung surgery was performed. The method's sensitivity in respect to malignancy was 100%, specifi city was 56%. Staging of aff ected lymph nodes resulted in 17 mediastinoscopies and 54 thoracotomies. In the former indications PET-CT-positive lymph nodes always need cytologic/histologic verifi cation. M-staging done with PET-CT was performed in 141 cases, mediastinal restaging of patients having received neoadjuvant chemotherapy was done in 24 cases. The la er indications we consider superfl uous because of the diagnostic inaccuracy of PET-CT. In 175 cases we analyzed the frequently determining factor of the PET-CT scan in the indication of lung surgery. The authors wish to share their experience for the be er use of this method and to accelerate the inclusion of PET-CT into the diagnostic protocol. Zsiray M, Markóczy Z, Magyar M, Lengyel Z, Fekésházy A, Borbély K. The advantage of Positron Emission Tomography combined with Computer Tomography (PET-CT) in the diagnosis of lung cancer, our own experience with 408 patients. Hungarian Oncology 53: 17-21, 2009

A PET study on the characterization of partially reversible radiogenic lower motor neurone disease

by Zsolt Lengyel and Péter Ágoston

Spinal Cord, 2002

Objective: To investigate the pathomechanism of the rare radiogenic lower motor neurone disease (... more Objective: To investigate the pathomechanism of the rare radiogenic lower motor neurone disease (LMND) on the basis of a case history involving a partial functional recovery. Patient: A 31-year-old seminoma patient received postoperative para-aortic and para-iliac telecobalt irradiation with a biologically eective dose of 88 Gy 2 (44 Gy in 2 Gy fractions/day, with an estimated a/b of 2 Gy) delivered to the spinal cord following a single cycle of chemotherapy. LMND developed 4 months after the completion of radiotherapy. The patient exhibited¯accid paraparesis of the lower extremities (without sensory or vegetative signs), followed by a worsening after further chemotherapy, due to pulmonary metastatization. A gradual spontaneous functional improvement commenced and led several years later to a stabilized state involving moderately severe symptoms. Methods: In the 15th year of the clinical course, magnetic resonance imaging (MRI) and positron emission tomography (PET) with [ 18 F]¯uorodeoxyglucose (FDG) and [ 11 C]methionine were conducted. Four lines of experiments (clonogenic assay using ®broblasts isolated from a skin biopsy sample of the patient, comet assay, micronucleus assay, and the testing of chromosome aberrations after in vitro irradiation of peripheral blood samples) were performed in a search for an increased individual radiosensitivity. Results: MRI investigations failed to reveal any pathological change. PET demonstrated an increased FDG accumulation, but a negligible [ 11 C]methionine uptake in the irradiated spinal cord segments. The radiobiological investigations did not indicate any sign of an increased individual radiosensitivity. Conclusions: We suggest that the observed partial functional recovery and stabilization of the symptoms of radiogenic LMND may be explained by the higher than normal density of sodium channels expressed along the demyelinated axons of the restored conduction. The increased energy demands of this type of conduction are proved by a higher metabolic rate (increased FDG uptake) of the irradiated spinal cord segments without a substantial regenerative process (lack of detectable protein synthesis).

Brain blood flow changes measured by positron emission tomography during an auditory cognitive task in healthy volunteers and in schizophrenic patients

Progress in Neuro-Psychopharmacology and Biological Psychiatry, 2006

Objective: Cognitive deficit is an essential feature of schizophrenia. One of the generally used ... more Objective: Cognitive deficit is an essential feature of schizophrenia. One of the generally used simple cognitive tasks to characterize specific cognitive dysfunctions is the auditory ''oddball'' paradigm. During this task, two different tones are presented with different repetition frequencies and the subject is asked to pay attention and to respond to the less frequent tone. The aim of the present study was to apply positron emission tomography (PET) to measure the regional brain blood flow changes induced by an auditory oddball task in healthy volunteers and in stable schizophrenic patients in order to detect activation differences between the two groups. Method: Eight healthy volunteers and 11 schizophrenic patients were studied. The subjects carried out a specific auditory oddball task, while cerebral activation measured via the regional distribution of [ 15 O]-butanol activity changes in the PET camera was recorded. Results and discussion: Task-related activation differed significantly across the patients and controls. The healthy volunteers displayed significant activation in the anterior cingulate area (Brodman Area -BA32), while in the schizophrenic patients the area was wider, including the mediofrontal regions (BA32 and BA10). The distance between the locations of maximal activation of the two populations were 33 mm and the cluster size was about twice as large in the patient group. Conclusions: The present results demonstrate that the perfusion changes induced in the schizophrenic patients by this cognitive task extends over a larger part of the mediofrontal cortex than in the healthy volunteers. The different pattern of activation observed during the auditory oddball task in the schizophrenic patients suggests that a larger cortical area -and consequently a larger variety of neuronal networks -is involved in the cognitive processes in these patients. The dispersion of stimulus processing during a cognitive task requiring sustained attention and stimulus discrimination may play an important role in the pathomechanism of the disorder. D

Pallidal Deep Brain Stimulation and L-Dopa Effect on PET Motor Activation in Advanced Parkinson's Disease

Journal of Neuroimaging, 2009

BACKGROUND AND PURPOSE The antiakinetic effect of internal Globus pallidus deep brain stimulation... more BACKGROUND AND PURPOSE The antiakinetic effect of internal Globus pallidus deep brain stimulation (Gpi-DBS) in Parkinson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease is not clear and not either how this effect is modulated by L-dopa. METHODS Left Gpi-DBS and/or L-dopa effect was studied with auditory paced right-handed sequential movements on (15)O-butanol positron emission tomography (PET) in five patients. Rest and for conditions during movements (DBS off/L-dopa off; DBS on/L-dopa off; DBS off/L-dopa on; DBS on/L-dopa on) were compared with statistical parametric mapping. RESULTS Gpi-DBS activated the right supplementary motor area/premotor (SMA/PMC), and right insular cortex (IC), and as L-dopa decreased the left sensorimotor cortex (M1/S1) activity. L-dopa increased the left ventrolateral thalamus (VLTH), and decreased the left superior parietal cortex (PC) activity. Gpi-DBS and L-dopa interaction showed right SMA/PMC, IC, and left PC activation, decrease of left VLTH, PMC, and dorsolateral prefrontal cortex (PFC) activity. CONCLUSIONS The improvement of bradykinesia with Gpi-DBS is secondary and contributed to the regress of M1/S1-related rigidity and compensatory SMA/PMC, and IC activation. L-dopa and Gpi-DBS alone each reduces M1/S1 overactivity. Interaction ignores this effect, moreover has akinetic effect in the left VLTH, PMC, and PFC. Motor improvement possibly related to left PC and compensatory right SMA/PMC, and IC activation.

Szükséges-e Hodgkin-limfóma primer stádium-megállapításához FDG-PET/CT mellett iv. ka. CT elvégzése is?

Orvosi Hetilap, 2014

Several study supported that 18F-Fluoro-deoxy-glucose (FDG) positron emission tomography/computer... more Several study supported that 18F-Fluoro-deoxy-glucose (FDG) positron emission tomography/computer tomography with low dose CT (standard PET/CT) is more accurate than contrast-enhanced CT (ceCT) in the primary staging of Hodgkin disease. The authors compared the accuracy of these examinations with this indication in their practice, and analysed the added value of ceCT which was performed as a supplement to standard PET/CT. Twenty-eight patients were categorized based on ceCT, single standard PET/CT and standard PET/CT with ceCT. Twenty-four patients were in the same disease-stage based on all methods. Disease was upstaged by standard PET/CT compared to ceCT in 4 patients. There was no change in stage when comparing standard PET/CT and standard PET/CT with ceCT. Standard PET/CT is more accurate than ceCT in the primary staging of Hodgkin disease. The authors established that it is not reasonable to supplement standard PET/CT with ceCT in this indication.

Cholinotoxic effects of β-amyloid(1–42) peptide on cortical projections of the rat nucleus basalis magnocellularis

Brain Research, 1995

The Role of Disulfide Bond C191-C220 in Trypsin and Chymotrypsin

Biochemical and Biophysical Research Communications, 1997

charge of residue 189. However, replacement of Asp189 Serine proteases of the chymotrypsin family... more charge of residue 189. However, replacement of Asp189 Serine proteases of the chymotrypsin family contain of trypsin with the analogous Ser189 of chymotrypsin fails three conserved disulfide bonds: C42-C58, C168-C182, and to convert specificity and resulted in a poor, non-specific C191-C220. C191-C220 connects the loops around the subprotease (4). Conversion of trypsin to a chymotrypsinstrate binding pocket. Using site directed mutagenesis, like protease requires substitution of non conservative cysteines of this disulfide bridge were replaced by alaresidues in the S1 site together with the exchange of two nines in trypsin, in chymotrypsin, and in TrrChadjacent surface loops, which do not directly contact the [S1/L1/L2/Y172W], a mutant trypsin with high chymosubstrate (5). This mutant, TrrCh[S1/L1/L2], has been trypsin like activity. The functional role of this ''active improved to a protease with about 20% of the activity of site'' disulfide was assessed by comparing the catalytic chymotrypsin by mutating Tyr172 to Trp (6) . In properties of wild-type and mutant enzymes. Its removal addition to these primary effects, it has been proposed from all three proteases caused a decrease in k cat /K M of

A novel titration technique for the analysis of streamed samples—the triangle-programmed titration technique

Analytica Chimica Acta, 1978

An apparatus is described for canyicg out triangleprogrammed titrations with coulometric reagent ... more An apparatus is described for canyicg out triangleprogrammed titrations with coulometric reagent generation. Different halides and pseudohalides can be determined by titration with silver(I). Both voltammetric and potentiometric detection systems are discussed, but emphasis is placed on potentiometric detection with ion-selective electrodes. 'Ihe proposed technique can be used for accurate determinations of flowing samples of halides and pseudohalides at low concentrations. The simultaneous determination of two-component mixtures is discus+ed.

HYPOGLYCEMIA ACTIVATES COMPENSATORY MECHANISM OF GLUCOSE METABOLISM OF BRAIN

Acta Biologica Hungarica, 2001

articoli italiani CHEST BPCO Scopo dello studio: È stato studiato il ruolo dei due recettori del ... more articoli italiani CHEST BPCO Scopo dello studio: È stato studiato il ruolo dei due recettori del leukotriene B4 (LTB4), il recettore di membrana BLT1 e il recettore nucleare peroxisome proliferator-activated receptor (PPAR)-α, sulla suscettibilità dei fumatori a sviluppare BPCO. Infatti, le attività pro-infiammatorie del LTB4 sono mediate dal recettore BLT1, mentre il PPARα promuove l'inattivazione del mediatore lipidico. Soggetti e metodi: L'espressione di BLT1 e PPARα è stata quantificata mediante tecniche di immunoistochimica in campioni di parenchima polmonare ottenuti chirurgicamente da 19 fumatori con e senza BPCO e da 7 soggetti non fumatori. Risultati: Nei soggetti con BPCO è stato osservato un aumento significativo della percentuale di macrofagi alveolari positivi al PPARα e del numero di cellule nella parete alveolare positive al PPARα rispetto ai soggetti di controllo. Inoltre, i pazienti con BPCO presentavano un aumento significativo dei macrofagi alveolari positivi al BLT1 rispetto ai non fumatori e un incremento del numero di cellule nella parete alveolare positive al BLT1 rispetto ai fumatori sani. In contrasto, l'immunoreattività per BLT1 e PPARα non mostrava differenze significative nel confronto tra i soggetti non fumatori e i fumatori sani. La maggior parte delle cellule positive al BLT1 nella parete alveolare erano neutrofili e linfociti T CD8. Fra queste cellule infiltranti il parenchima polmonare il numero di neutrofili risultava simile nei tre gruppi, mentre il numero di linfociti T CD8 era aumentato nei soggetti con BPCO, anche se non vi erano evidenze che il BLT1 fosse sovraespressso in queste cellule. Conclusioni: I risultati hanno dimostrato che i recettori BLT1 e PPARα sono identificabili nel tessuto polmonare umano prevalentemente nei macrofagi alveolari e nei linfociti T CD8 e che l'espressione di questo doppio sistema recettoriale per il LTB4 è accresciuta nel polmone periferico dei fumatori suscettibili a sviluppare BPCO. Questo sistema recettoriale potrebbe rappresentare un nuovo target per l'intervento terapeutico nei pazienti con BPCO.

[Role of 18FDG-PET/CT in the management and gross tumor volume definition for radiotherapy of head and neck cancer; single institution experiences based on long-term follow-up]

by Erika Szántó, Szilvia Gaál, Zsófia Együd, Ágnes Dobi, and Zsolt Lengyel

Magyar onkologia, 2015

célThe purpose of our work is evaluation of the impact of 18FDG-PET/CT on the complex management ... more célThe purpose of our work is evaluation of the impact of 18FDG-PET/CT on the complex management of locoregionally advanced (T3-4N1-3) head and neck squamous cell cancer (LAHNSC), and on the target definiton for 3D conformal (3DCRT) and intensity-modulated radiotherapy (IMRT). 18FDG-PET/CT were performed on 185 patients with LAHNSC prior to radiotherapy/chemoradiation in the treatment position between 2006 and 2011. Prior to it 91 patients recieved induction chemotherapy (in 20 cases of these, baseline PET/CT was also available). The independently delineated CT-based gross tumor volume (GTVct) and PET/CT based ones (GTVpet) were compared. Impact of PET/CT on the treatment strategy, on tumor response evaluation to ICT, on GTV definition furthermore on overall and disease-specific survival (OS, DSS) was analysed. PET/CT revealed 10 head and neck, 2 lung cancers for 15 patients with carcinoma of unknown primary (CUP) while 3 remained unknown. Second tumors were detected in 8 (4.4%), di...