Gábor Bajzik

Angiography effectively supports the diagnosis of hepatic metastases in medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) belongs in the group of neuroendocrine tumors with early lymphatic and hepatic dissemination. A high rate of undetectable metastases is hypothesized to be responsible for the frequent mismatch between the apparent relatively small tumor burden and the elevated plasma tumor marker level.

Increased Metabolic Activity in the Spinal Cord of Patients with Long-Standing Lhermitte’s Sign

Purpose:To investigate the pathophysiology of the radiation-induced, chronic Lhermitte’s sign (LS) on the basis of long-standing case histories with partial functional recovery.Patients and Methods:As radiotherapy in two nasopharyngeal cancer patients, a biologically effective dose (BED) of 103.8 Gy2 (case 1) and 94.8 Gy2 (case 2) was delivered to the cervical spinal cord. Neurologic signs relating to the irradiated spinal cord segments developed after 2 months (case 1) and 5 years (case 2), with radiation-induced damage equivalent to grade 3 (case 1) and grade 2 (case 2) toxicity (Common Toxicity Criteria, Version 2.0). The clinical status improved to grade 2 (case 1) and grade 1 (case 2). Positron emission tomography (PET) and fibroblast clonogen assay were applied 25 and 7 years postirradiation, respectively, to characterize this rare clinical picture.Results:PET demonstrated increased [18F]fluorodeoxyglucose (FDG) accumulation and [15O]butanol perfusion, but negligible [11C]methionine uptake in the irradiated spinal cord segments in both patients. In clonogenic assays, fibroblasts from case 1 displayed much higher radiation sensitivity than in healthy controls, while in case 2 the fibroblasts sensitivity was normal.Conclusions:These data suggests a close direct relationship between regional perfusion and metabolism of the spinal cord, similarly as in the brain. The postirradiation recovery may be related to energy-demanding conduction, explaining the increased metabolism and perfusion. The increased radiosensitivity and higher spinal cord BED may have contributed to the more severe sequelae in case 1.Ziel:Untersuchung der Pathophysiologie des strahleninduzierten chronischen Lhermitte-Zeichens auf der Basis der Langzeitbeobachtung von zwei Patienten mit partieller funktioneller Erholung.Patienten und Methodik:Bei zwei Patienten mit Nasopharynxkarzinom wurde die Halswirbelsäule mit einer biologisch effektiven Dosis (BED) von 103,8 Gy2 (Patient 1) bzw. 94,8 Gy2 (Patient 2) bestrahlt. Neurologische Symptome, die auf die bestrahlten Segmente des Zervikalmarks zurückzuführen waren, traten nach 2 Monaten (Patient 1) bzw. nach 5 Jahren (Patient 2) auf, wobei die strahleninduzierte Schädigung einer Grad-3- (Patient 1) bzw. Grad-2-Toxizität (Patient 2) entsprach (Common Toxicity Criteria, Version 2.0). Der klinische Status ging auf Grad 2 (Patient 1) bzw. Grad 1 (Patient 2) zurück. Positronenemissionstomographie (PET) und der Fibroblastenklonogenitätsassay wurden 25 bzw. 7 Jahre nach der Strahlentherapie eingesetzt, um dieses seltene Krankheitsbild zu charakterisieren.Ergebnisse:Im PET zeigten sich bei beiden Patienten eine erhöhte [18F-]Fluorodesoxyglucose-(FDG-)Aufnahme und [15O-] Butanol-Perfusion, jedoch eine vernachlässigbar geringe [11C-]Methionin-Aufnahme in den bestrahlten Segmenten. In den Klonogenitätsassays hatten die Fibroblasten des Patienten 1 eine höhere Strahlungsempfindlichkeit als bei gesunden Kontrollen, während die Fibroblastensensitivität bei Patient 2 normal war.Schlussfolgerungen:Diese Befunde sprechen für eine—ähnlich wie im Gehirn—enge direkte Beziehung zwischen regionaler Perfusion und Metabolismus des Rückenmarks. Die Erholung nach der Strahlentherapie dürfte mit Energie verbrauchenden Prozessen einhergehen, was die Steigerung von Metabolismus und Perfusion erklärt. Die erhöhte Strahlenempfindlichkeit und die höhere BED am Rückenmark können zu den gravierenderen Folgeerscheinungen bei Patient 1 beigetragen haben.

Iodine-125 Brachytherapy of Brain Stem Tumors

Purpose:To report on iodine-125 (125I) interstitial irradiation in the treatment of brain stem tumors.Patients and Methods:Two patients with brain stem tumors were treated with CT- and image fusion-guided 125I stereotactic brachytherapy.Results:By March 2003, the patients had been followed up for 47 and 13 months, respectively. In case 1, the tumor volume was 1.98 cm3 on the control CT, indicating a 65.5% shrinkage as compared to a target volume of 5.73 cm3 at the time of brachytherapy. In case 2, shrinkage was more distinct. After irradiation, the cyst volume was 0.16 cm3 on the control MRI, indicating a 97.4% shrinkage as compared to a target volume of 6.05 cm3 at the time of brachytherapy, i. e., the metastasis had virtually disappeared.Conclusion:CT- and image fusion-guided 125I stereotactic brachytherapy can be performed during the biopsy session. The procedure can be well planned dosimetrically and is surgically precise.Ziel:Beschreibung der interstitiellen Jod-125-(125I-)Brachytherapie bei der Behandlung von Hirnstammtumoren.Patienten und Methodik:Bei zwei Patienten mit Hirnstammtumoren wurde eine durch CT und Fusionsbild gesteuerte interstitielle 125I-Brachytherapie durchgeführt.Ergebnisse:Bis März 2003 betrugen die Nachuntersuchungszeiten der beiden Patienten 47 bzw. 13 Monate. Im ersten Fall lag das Tumorvolumen auf dem Kontroll-CT bei 1,98 cm3, was eine Schrumpfung um 65,5% anzeigte. Im zweiten Fall fiel diese Änderung deutlicher aus. Das Kontroll-MRT ergab eine Schrumpfung von 97,4%, d. h., die Metastase war praktisch verschwunden.Schlussfolgerung:Die durch CT und Fusionsbild gesteuerte interstitielle 125I-Brachytherapie lässt sich dosimetrisch gut planen, und die Methode ist chirurgisch präzise.

Integrating Functional MRI Information into Radiotherapy Planning of CNS Tumors-Early Experiences

The purpose of our study was to examine the integration of functional MRI (fMRI) information into 3D based planning process of the central nervous system (CNS) malignancies. Between 01.01.2008 and 01.12.2008 four patients with astrocytoma were enrolled to this study. Before the planning process conventional planning CT, postoperative MR and individual functional MRI examinations were delivered. For the functional MRI examination the following four types of stimulus were applied: acoustic, visual, somatosensory and numeral. Three different theoretical planning situations were applied and compared: 3D conformal plan without fMRI information, 3D conformal plan with fMRI information and IMRT plan with fMRI information. For plan comparison DVH analysis, and NTCP model were used. fMRI based OR definition resulted in 4 additional OR’s in the contouring process. As these cases demonstrate, an average of 50% dose reduction was achieved in OR, OR2 and OR3 with IMRT and fMRI based 3D planning, especially in case of midline localization and big tumor extent. IMRT provides additional sparing effect in the optic tract and brainstem, especially for localizations close to the midline. Our results demonstrated that using fMRI information in conventional 3D based treatment planning potentially benefits significant dose reduction in critical organs, with no compromise in PTV coverage. fMRI can be widely used even in low grade cases (long life expectancies, lower acute and late toxicity in radiotherapy) and in cases with high grade astrocytomas or metastases (higher dose to PTV with better risk organ sparing in radiotherapy).

Quantitative brain proton MR spectroscopy based on measurement of the relaxation time T1 of water

To provide a straightforward method for metabolite quantitation in the brain. Tissue water concentration can be determined in a voxel by measuring T1 and it may provide an internal reference for the calculation of the metabolite concentrations.

Novel approach to magnetic resonance imaging of epileptic dogs — T2 relaxometry of the brain with emphasised hippocampus

Hippocampal sclerosis is the most common imaging finding of intractable human epilepsy, and it may play an important role in canine and feline epileptogenesis and seizure semiology, too. The magnetic resonance imaging (MRI) criteria of hippocampal sclerosis are T2 hyperintensity, shrinkage and loss of internal structure. The detection of these changes is often challenging by subjective visual assessment of qualitative magnetic resonance (MR) images. The recognition is more reliable with quantitative MR methods, such as T2 relaxometry. In the present prospective study including 31 dogs with idiopathic epilepsy and 15 control dogs showing no seizure activity, we compared the T2 relaxation times of different brain areas. Furthermore, we studied correlations between the hippocampal T2 values and age, gender and skull formation. We found higher hippocampal T2 values in the epileptic group than in the control; however, these findings were not statistically significant. No correlations were found with age, gender or skull formation. In the individual analysis six epileptic dogs presented higher hippocampal T2 relaxation times than the cut-off value. Two of these dogs were also evaluated as abnormal in the visual assessment. Individual analysis of hippocampal T2 relaxation times may be a helpful method to understand hippocampal involvement in canine epilepsy.

[Preliminary experiences with low-dose computed tomography for lung cancer screening in Hungary].

INTRODUCTION Lung cancer has the highest mortality rate of all types of cancers both in developed countries and Hungary. AIM To obtain experience and facilitate the application of low-dose computed tomography-based lung cancer screening as a targeted public health screening procedure. METHOD Volunteers without thoracic complaints above the age of 40 years (n = 963) were screened for lung cancer using digital chest radiography and low-dose computed tomography. RESULTS Two lung cancers were found among the participants screened with digital chest radiography (0.2%). After informed consent, 173 individuals with normal chest radiography findings (n = 943) took the opportunity to voluntarily participate in low-dose computed tomography screening for lung cancer. After 3 or 12 months, 65 individuals had follow up control examinations based on the size and characteristics of the detected lesions. Among them, one participant was found to have lung cancer using low-dose computed tomography. CONCLUSIONS These results indicate that low-dose computed tomography-based lung cancer screening as a public health screening procedure can enhance the success of screening with 50% (from 0.2% to 0.3%). The cost-benefit ratio can be raised if chest radiography is performed prior to the low-dose computed tomography examination.

First result of differentiated communication—to smokers and non-smokers—in order to increase the voluntary participation rate in lung screening

BackgroundLung cancer is the most common fatal malignacy and also the primary cause of cancer mortality. Participation in lung screening is an important step in diagnosing patient in early stage and it can promise better outcomes. The aim of this preliminary study was to determinate the differences in the participation rate of smokers and non-smokers in lung cancer screening and to determine the communication strategies to increase the participation rate.MethodsIn the given period of time (from May to August 2012) out of 1426 people who participated in the lung screening program 1,060 adult volunteers (331 males and 729 females, average age 54.0±9.3 years), completed fully and anonymously author’s questionnaire that contained 28 questions. 25.7% of the respondents were smokers (n=272), 64.6% have never smoked, while 9.7% were former smokers.ResultsMostly former smokers considered lung screening as an effective method for early detection of pulmonary diseases (86.4%). The most important source (41.0%) of information was the general practitioner. The participation rate of non-smokers is higher in lung screening than the ratio of non-smokers in the population. The unclear data suggest that smokers need distinct, concise messages to know why they should regularly undergo lung screening and doctors have a major role in this.ConclusionsWe found that smokers significantly more frequently took part in lung screening annually. It is positive that the participation rate of former smokers is higher than non-smokers, it is just a bit lower than the participation rate of smokers—both in annual and biannual participation. The participation rate of non-smokers is higher in lung screening than the rate of non-smokers in the population.

A PET/CT szerepe a sugárkezelésre kerülő betegek N és M klinikai stagingjében, a terápia meghatározásában. Intézeti tapasztalatok

INTRODUCTION AND AIM: The aim of our study was to investigate changes in clinical staging N (lymph node) and M (distant metastasis) in patients who receive PET/CT-based 3D radiotherapy within complex oncological treatment, and compare to conventional cross-sectional imaging staging technique. We also investigated the presence of PET/CT-detected second tumors and the effect of PET/CT on therapeutic decisions. METHOD: From the 1st of January 2015 to the 30th of November 2016, 192 patients (n = 192) were treated with PET/CT-based radiation (109 head, 44 lung, 28 rectum and 11 cervical localization) in the Oncoradiology Institute of the Health Center of the University of Kaposvar. All patients received conventional cross-sectional and PET/CT imaging in accordance with the valid investigation protocol. The average time interval between the two cross-sectional investigations was 5.2 weeks. Clinical N and M staging was performed on the basis of the classification of the American Joint Committee on Cancer (AJCC) and the Union of International Cancer Control (UICC). RESULTS: By analyzing the clinical stages N and M separately, based on the results of the PET/CT studies, the N stage was changed in 77 cases and the M stage changed in 31 cases. Overall, the PET/CT study resulted in higher clinical stages in 68 (35.4%) patients and lower clinical stages in 14 (7.3%) patients. The treatment plan was changed in 9% of the patients (n = 18) (definitive versus palliative treatment) and the extension of radiotherapy treatment target volume (PTV) was indicated in 20% of the patients (n = 39) due to the change in clinical lymph node status. PET/CT also detected secondary tumors in 15 (8%) patients. CONCLUSION: Based on our results, the addition of PET/CT to conventional cross-sectional staging imaging permits a more accurate clinical classification of N and M stages and significantly influences therapeutic decisions. PET/CT imaging also provides a great help in detecting occult second tumors. The results of our Institute harmonize with the international data available in the literature. Orv Hetil. 2018; 159(39): 1593-1601.

A PET/MR képalkotás magyarországi klinikai alkalmazásának lehetőségei, első tapasztalatai

Hungarys first and still only multimodality PET/MR device is operating in the Health Center of Kaposvar University. The aim of our review article is to present the current Hungarian PET/MR imaging application opportunities, our available initial experiences with this novel multimodality imaging technique in malignant and non-malignant diseases and further potential targeted clinical fields of use are also addressed. Orv Hetil. 2018; 159(34): 1375-1384.