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Biomedical subjects

O Esik

Publications and source records attributed to O Esik.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Malignant thyroid tumors in Hungary: morbidity and mortality].

In 1993, 181 new cases (36 men and 145 women) of thyroid cancer were diagnosed pathologically in Hungary, i.e. a morbidity of 1.8/100,000 for the total population, and of 0.7/100,000 and 2.7/100,000 for men and women, respectively. The distribution of the histological diagnoses: 61% papillary, 25% follicular, 5% medullary and 3% anaplastic carcinomas, and 6% others. In the same year, 125 patients (31 men and 94 women) died from thyroid cancer, i.e. a mortality rate of 1.2/100,000 for the total population, and of 0.6/100,000 and 1.8/100,000 for men and women, respectively. The relatively low morbidity reflects the fact that no new strong aetiological factor is operative in Hungary. The substantial mortality rate, however, is influenced by the geographically determined aggressivity of the disease, the inadequacy of the diagnostic procedures and therapeutic measures, and lack of the active follow-up. The latter facts are especially prominent in centres with a low patient turnover. In the field of health care, various measures must be introduced to prevent an increase in the morbidity and to diminish the mortality. Reduction of the iodine deficiency, rationalization of the medical use of ionizing irradiation, and implementation of the necessary hormonal medication for all patients operated by resection for thyroid diseases are needed for tumour prophylaxis. Before any medical decision-making, the achievement of complete diagnostic information, including the pathological revision of clinically questionable cases, is of paramount importance. The fundamental goals as concerns the treatment modalities are as follows: increased surgical skill and level of performance of external irradiation, the availability of radionuclide therapy, and guidance of all types of thyroxine medication by endocrine experts.

Adult↗
PubMed1996

[Positron emission tomography: foundations and applications].

Positron emission tomography (PET) is a non-invasive biomedical imaging technique whereby the distribution of biological tracer molecules, labelled by positron emitting isotopes, in the living body can be studied quantitatively. As theoretically an metabolically active molecule can be labelled, the technique is applicable to the measurement of any biochemical or physiological process in proper anatomical context. The introduction of PET has revolutionised the exploration of normal physiological functions. With the help of technique, among others, anatomical structures underlying mental functions can be localised in the human brain, the receptor architecture of the nervous system can be mapped, or the kinetics of pharmacons can be properly measured and modelled. In the clinical practice, PET has proven to be a uniquely useful diagnostic technique in neurology, psychiatry, cardiology, and oncology in establishing primary diagnosis and differential diagnosis, designing therapeutic interventions as well as assessing their efficacy. Hungary's and Central European region's first PET center has been established at the University Medical School in Debrecen.

Humans↗
PubMed1996

A retrospective analysis of different modalities for treatment of primary orbital non-Hodgkin's lymphomas.

We have reviewed 37 patients with primary orbital lymphoma, using the Ann Arbor criteria and the Working Formulation and its modification. Thirty-one patients had stage I disease, four stage II, one stage III and one stage IV. The male to female ratio was 2.7:1. There were 34 low-grade tumours (including 24 mantle zone) and three intermediate-grade. Patients were divided into three groups according to their primary treatment. Group 1: radiotherapy (17 cases); Group 2: surgery alone (13 cases); Group 3: chemotherapy (seven cases). Patients were followed up from 5 months to 24.3 years, with a mean and median of 7.6 and 6.2 years, respectively. The BMDP software package was used for survival estimation (Kaplan-Meier) and determination of prognostic variable (univariate Cox regression). Local relapse-free survival at 10 years was 100% in Group 1, 0% in Group 2 and 42% in Group 3 with a statistically significant difference (p < 0.01) in favour of radiotherapy. Statistically significant good prognostic features were: complete remission (CR) in response to initial treatment, primary radiotherapy and older age. For stage I cases, there was no difference in distant relapse-free survival in the three groups. The overall cause-specific survival for stage I patients at 10 years was 100% for each group and at 20 years was 100, 67 and 0% for Groups 1, 2 and 3. The difference between the primary radiotherapy and chemotherapy-treated groups was significant at the p = 0.08 level. Statistically significant prognostic factors were early stage, low-grade histology and primary radiotherapy. In one patient, ptosis and diplopia appeared after surgery. One case of glaucoma required enucleation, one patient suffered severe dry eye syndrome. All patients (11/11) in whom the lens received direct radiation developed cataracts of different degrees if follow-up was long enough. Cataract formation was prevented by adequate lens shielding. One patient in CR from a stage I low-grade tumour died from chemotherapy-induced marrow aplasia. Primary orbital lymphoma is an indolent, usually stage I disease, showing low to intermediate-grade histology. After biopsy the best treatment is 30 (low-grade) to 40 Gy (intermediate-grade) carefully planned, lens-sparing megavoltage radiation without adjuvant chemotherapy.

Adult↗
PubMed1995

[Quality assurance, audit and quality control of radiotherapy at radiology departments in Hungary].

The first quality assurance, audit and control system in the Hungarian "'health" care industry" is described for the medical specialty of radiotherapy. The prerequisites of the elaboration of the programme were an exact knowledge of the current Hungarian infrastructural and staffing conditions, and the radiotherapeutic activities. The recommendations cover the 5 medical universities including the national institute (the Debrecen, Pécs, Semmelweis, Szent-Györgyk Albert Medical Universities, and Haynal Imre University of Health Sciences) and the 5 regional oncological centres in hospitals (Jósa András, Markusovszky, Petz Aladár, Szentpéteri kapu and Uzsoki Hospitals). The departmental functions (patient care, teaching-education, research work and scientific organizing activity) and the structure (organization, infrastructure, staffing conditions, etc.) are described first, followed by the therapeutic principles and clinical process (patient referral and selection, decision-making, priorities in therapy initiation, treatment preparation and execution, etc.). The informal daily/weekly quality assurance programme long applied in the routine patient care has been formalized and supplemented with a weekly audit conference. In the course of the medical audit, all relevant clinical data are reviewed and scored by an internal or an external expert (not participating directly in the treatment process), e.g. for the adequacy of the medical decision preparative process, conformation to the institutional treatment protocol, equipment selection, treatment planning, simulation and portal film, etc. If a major deviation is detected, an immediate correction is initiated; minor deviations need analysis and then preventive and correcting action. As concern the audit of the other activities of the departments, the important indicators and their minimally desirable level are defined. The final goal of the implementation of this programme is high-precision radiotherapy with the best achievable treatment result.

Dose-Response Relationship, Radiation↗
PubMed1994

[Tridimensional radiation treatment planning].

The effectiveness of radiotherapy and the possibility that the patient will be cured are basically determined by the accuracy of the therapy planning and the treatment. The tumour with its environment is a three-dimensional (3D) phenomenon, and therefore 3D radiation treatment planning and performance are needed for adequate coverage of the target volume (tumour+safety zone). The prerequisities of the elaboration of the 3D radiotherapy planning were as follows: the availability of high-performance hardware, the establishment of interactive computer graphics, and the development and direct integration into the therapy planning process of the digitalized information derived from diagnostic imaging, and especially computer tomography. The introduction of 3D treatment planning will mean the modernization of the radiotherapy, the accuracy of which may permit more cures, i. e. more patients will recover their ability to work.

Dose-Response Relationship, Radiation↗
PubMed1994

Calcitonin-secreting ovarian strumal carcinoid.

A 3-mm strumal carcinoid was found incidentally in a mature ovarian cystic teratoma of a 38-year-old woman followed up for more than 9 years. Although the thyroid component disclosed a typical normal light microscopic appearance, no thyroglobulin and thyroxine were detected immunohistochemically. Immunoreactive calcitonin was demonstrated within the tumour cells. The close relationship between functionally imperfect thyroid tissue and a neuroendocrine marker-secreting tumour seems to be concordant with the theory of the existence of a pluripotential stem cell capable of differentiating multidirectionally.

Adult↗
PubMed1994

Significance of three-dimensional radiation treatment planning.

A tumour and its environment constitute a three-dimensional (3D) phenomenon. Consequently, adequate management of the target volume (tumour + safety zone) is feasible only with a 30 treatment planning and irradiating system. The more precise planning and dose delivery involved in such a 30 treatment lead to an improved therapeutic effectiveness.

Humans↗
PubMed1992

[External irradiation of differentiated thyroid cancer: 30 follow up].

UNLABELLED: Following surgery which left no macroscopic residue 114 patients with differentiated thyroid cancer (58 papillary, 56 follicular) were subgrouped on the basis of the dose of prophylactic postoperative external radiation applied: group I--an adequate dose of radiation (greater than or equal to 4500 cGy of telecobalt, greater than or equal to 4000 R of orthovolt therapy); group II--an inadequate dose of radiation (including non-irradiated patients). Local/regional relapse-free survival (LRRFS), distant metastatic relapse-free survival (DMRFS) and total cause-specific survival (TCSS) were calculated by means of life-table analysis for both histologic types separately. Results. 1. TCSS and LRRFS were significantly (p less than 0.001) better for group I in papillary cancer. No difference was found in DMRFS. 2. LRRFS was significantly (p less than 0.001) better for group I in follicular cancer. No differences were found in TCSS and DMRFS. CONCLUSIONS: 1. The prophylactic postoperative external irradiation is an effective method for survival prolongation in papillary cancer, the local/regional recurrences thereby being reduced. 2. External irradiation, in conjunction with radioiodine treatment, should be considered in the postoperative management of follicular cancer to diminish local/regional relapse.

Adenocarcinoma↗
PubMed1991

[Clinical observations on breast cancer in males].

The analysis of clinical parameters of seventeen male breast cancer patients clearly demonstrate the correlation between prognosis and size of primary tumour as well as regional spread. The localization of the tumour in the breast is not correlated to survival. Intelligent hormonal therapy contributes to improving of survival. Detections of plasma FSH, LH, testosterone, 17 beta estradiol levels are useful in examining of pathomechanism, revealing relapse, and monitoring hormonal therapy.

Aged↗
PubMed1991

Three-dimensional photon radiotherapy planning for laryngeal and hypopharyngeal cancers. 1. Conventional rotational technique.

Three-dimensional dose distributions have been computed for the photon radiation therapy of laryngeal and hypopharyngeal cancers, using biaxial and eccentric rotatory techniques. Treatment plans obtained under various conditions of irradiation with a 15 MV linear accelarator (MEVATRON 77, Siemens) are analysed and compared. Dose delivery to the tumour and the degree of spinal cord protection are evaluated for both treatment techniques. The eccentric plan is somewhat superior to the biaxial one, suggesting a justifiable preference to use this method in the radiation treatment of these tumours. Simulations show that extreme care is needed in positioning the axis: an accuracy of +/- 3 mm is required in the sagittal plane.

Humans↗
PubMed1991

Three-dimensional photon radiotherapy planning for laryngeal and hypopharyngeal cancers. 2. Conformation treatment planning using a multileaf collimator.

Three-dimension dose distributions have been computed for 15 MV X-ray radiation therapy (MEVATRON 77, Siemens) of laryngeal and hypopharyngeal cancers using isocentric rotational technique with multileaf collimator. Using a new concave contour tracing algorithm, satisfactory dose delivery to the target volume and efficient protection of the normal tissues can be achieved.

Humans↗
PubMed1990

[Bone scintigraphy in breast cancer: a ten-year follow up study].

The value of bone scanning in the primary staging and clinical course of breast cancer was studied in a 10-years follow-up. Bone metastases (BM) were detected at the time of primary diagnosis in 6.8% of the patients. After primary therapy, the skeleton was the first site of the relapse in 42% of the cases. During the follow-up, BM were revealed in 25% of 623 patients a mean of 22.3 months after the operation. BM were manifested in 17% of the cases with small primary (pT1) tumors and negative axillae. Forty-three percent of the patients had no symptoms at the time of BM diagnosis. The mean survival after the appearance of BM in 163 patients was 18.2 months. Thirteen patients survived more than 5 years after the diagnosis of BM. The routine use of bone scanning is suggested at the time of primary diagnosis, and then yearly in a minimum 5-years period, independently of the symptoms.

Bone Neoplasms↗
PubMed1990

[Internal mammary lymphoscintigraphy in breast cancer].

Clinical importance of the internal mammary radionuclid lymphoscintigraphy (IM RNLS) have been studied in 203 breast cancer patients at the primer staging in 94 unilateral, 7 bilateral independent breast tumor, 13 inflammatory breast cancer, and in the frame of the clinical follow-up in 41 local/regional recurrence, 9 soliter sternal lesion and 2 metastatic bilateral breast tumor. Based on the results the routine use of the IM RNLS is suggested beyond the primer staging in the course of the clinical follow-up at the appearance of the above mentioned entities related to the lymphogen tumor spread.

Breast Neoplasms↗
PubMed1990

Three-dimensional photon radiotherapy planning for laryngeal and hypopharyngeal tumours.

Three-dimensional absorbed dose distributions have been computed for high-energy photon radiation therapy of laryngeal and hypopharyngeal cancers, using a coaxial pair of opposing lateral beams in fixed positions. Treatment plans obtained under various conditions of irradiation are analyzed and compared for a cobalt-60 gamma unit (GAMMATRON S80, Siemens), photon beams from a 6 MV (CLINAC 1800, VARIAN), an 8 MV (SATURNE, CGR) and a 15 MV (MEVATRON 77, Siemens) linear accelerator. Using open fields a somewhat non-uniform and partly insufficient dose in target volume of interest is obtained with all treatment units if sufficient protection of the spinal cord is provided. The x-ray plans are somewhat superior to the cobalt-60 ones. Depending on the quantum energy and wedge isodose angle, wedging only slightly improves or sometimes moderately decreases the homogeneity of the dose in the target volume. According to these small and/or controversial effects of wedges their application seems unnecessary and/or non-convenient. Simulations show that extreme care is needed in positioning the isocentre: an accuracy of +/- 3 mm is required in the median sagittal plane.

Cobalt Radioisotopes↗