Search PubMed⌕ Search

Biomedical subjects

V Strnad

Publications and source records attributed to V Strnad.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Hypoxic radiotherapy. The radioprotective effect of acute hypoxia in the radiotherapy of tumors in the abdominal area].

AIM: We tested, whether inhalation a of gas mixture containing 8.0 to 8.5% O2 reduces the radiosensitivity of healthy tissue in order to deliver higher tumor doses without increasing the side effects of radiation therapy. PATIENTS AND METHODS: In this study 165 patients were treated in the Clinic of Radiation Oncology Erlangen (Germany) and in the Institute of Oncology in Brno (Czech Republic) in the period of January 1986 to December 1993. In 108 patients external irradiation was applied using acute hypoxia (group A--hypoxyradiotherapy). This group was compared with a conventional therapy group of 57 patients (group B). The majority of the patients had advanced tumor of cervix uteri or of rectum. In 89% of patients of group A and in 61% patients of group B external irradiation was applied with portals > 20 x 15 cm2 (p < 0.01). The mean dose in the group A was increased about 30% compared to the mean dose of group B (55.2 Gy vs. 43.6 Gy; p < 0.01). RESULTS: Despite this increase in dose and large-field irradiation in most cases in group A no differences were found between group A and B concerning acute or late effects of radiation therapy. CONCLUSION: The aerogen acute hypoxia (hypoxyradiotherapy) is so far not only the simplest, but also one of the most effective selective radioprotective methods.

Abdominal Neoplasms↗
PubMed1994

[Hypoxia-radiotherapy: the changes in selected physiological parameters of healthy tissue during the breathing of a hypoxic gas mixture].

BACKGROUND: Chronic hypoxia in tumors is generally accepted to be one of the most important factors concerning sensibility to irradiation. The principle of hypoxyradiotherapy is to achieve a limited (maximal 30 min) radioresistance of the healthy (actually euoxic) tissue by acute aerogen hypoxia, without protecting effects in the average chronic hypoxic tissue of the tumor. This study investigates changes in selected physiological parameters in vivo during acute aerogen hypoxia. PATIENTS AND METHODS: In 31 persons (group A) we documented changes in blood-gas-analysis, ECG-parameters, blood pressure and pulse during acute hypoxia lasting 5 minutes. During 30 minutes of acute hypoxia we determined in another 10 persons (group B) the relations between different phosphoryl-metabolites by means of 31-phosphorus magnetic resonance spectroscopy (31P-MRS). The 31P-MRS of the Musculus triceps surae was performed on our 1.5 T imaging system (Magnetom, Siemens) using a 8 cm diameter surface coil. To achieve the hypoxic condition in the persons tested, a gas-mixture with 8.2% O2 was used. RESULTS: In group A the acute hypoxia led to significant changes in O2-pressure, the blood O2-saturation and pulse frequency. The pO2-values drop in the 5th minute to about 50% of the initial value. Concerning group B the relations of the phosphoryl metabolites show no significant changes during acute hypoxia. CONCLUSIONS: The results show an excellent tolerability of breathing of the hypoxic gas-mixture, and confirm that this mixture containing 8.2% of O2 ensures a decrease in the pO2-levels of more than 50%. This is necessary to achieve a dose modifying factor (DMF) of at least 1.15 to 1.2. The changes in relations of phosphoryl metabolites seem to reflect the ability of healthy tissue to adapt to hypoxic conditions starting after 10 minutes and leading to the loss of the radioprotective effect after 30 minutes.

Acute Disease↗
PubMed1994

[Radiochemotherapy in the liver metastases of cystosarcoma phyllodes].

BACKGROUND: Cystosarcoma phyllodes is a rare mesenchymal tumor in the breast with a quite different prognosis depending on its specific dignity. There are almost no data in the literature concerning therapeutic strategies of metastasized cystosarcoma phyllodes. PATIENTS AND METHODS: We report the unique case of a young female patient with advanced multiple liver metastases of a cystosarcoma phyllodes malignum. RESULTS: After irradiation of the total liver combined with simultaneous chemotherapy containing ifosfamide and adriamycin an impressing 12 months lasting remission and control of the liver metastases was achieved. No relevant treatment side effects were observed. CONCLUSION: Combined liver irradiation and simultaneous chemotherapy should be considered as effective treatment strategy for comparable situations in young patients with good physical conditions.

Adult↗
PubMed1994

[Radiotherapy of esthesioneuroblastoma].

AIM: To evaluate the radiocurability of esthesioneuroblastoma, we have retrospectively analyzed the results of radiation therapy in this tumor in our clinic. PATIENTS AND METHODS: From 1985 through 1990, twelve patients with esthesioneuroblastoma have been treated at the Department of Radiotherapy at the University of Erlangen. Two had Kadish stage A, one stage B, and nine stage C. There were seven males and five females with a mean age of 43 years. Eleven patients had combined transcranial-transbasal surgery prior to radiotherapy (five R0-, four R1-, and two patients R2-resections) and one received radiotherapy only. The dose was 12 to 60 Gy (mean 54 Gy) in 1.8 Gy to 2 Gy per fraction. RESULTS: 8/12 patients (67%) were locally controlled. One had progressive disease during radiotherapy after partial resection and died. Three had local recurrences, one in-field and two marginal. One patient with a local recurrence developed cervical lymph node metastases, and one locally controlled patient developed bone metastases but is alive eight years after chemotherapy plus radiotherapy for metastatic disease. The five-year-overall and recurrence-free survival was 72% and 55%, respectively. CONCLUSIONS: Sophisticated surgery plus radiotherapy may cure a reasonable number of patients with esthesioneuroblastoma.

Adolescent↗
PubMed1990

Tumor response and treatment complications in radiotherapy of localized prostate cancer.

The response of primary tumor to definitive radiation therapy and treatment related morbidity has been analysed in a group of 35 patients. All of them were treated with 20 MeV photon beam to a total dose of 67 to 71 Gy to the prostate. The effect of radiotherapy to a primary tumor were evaluated by means of repeated CT examination of the tumor volume. A statistically significant tumor regression was found to occur from the sixth month after finishing radiotherapy. The absolute majority of treatment complications was of the first grade. Neither moderate nor severe gastrointestinal or genitourinary complications were recorded. The follow-up data of our patients have confirmed that radiotherapy in localized prostatic carcinoma, when sophisticated techniques are employed, represents highly effective treatment modality which improved the quality of life in patients with prostate cancer.

Adenocarcinoma↗
PubMed1990

Hypoxyradiotherapy of uterine cervix cancer to decrease of acute side-effects and treatment complications.

The authors have reported on preliminary results of hypoxyradiotherapy in the course of external irradiation in patients with uterine cervix cancer from a view-point of the occurrence of acute reactions and treatment complications. A mixture of nitrogen and oxygen containing 8.0 to 8.5% of O2 was used to provoke acute hypoxia during irradiation. The applied doses of external irradiation was simultaneously increased by 40%. On the basis of a randomized study with 120 patients, acute hypoxia was found to protect healthy tissues against post-radiation damage. When the doses of 96 Gy in the paracervical space and that of 75 Gy in the pelvic wall were applied, acute side-effects decreased significantly if compared with a conventional radiotherapeutic procedure (p less than 0.01). Radiological preconditions for using acute hypoxia in radiotherapy are discussed.

Brachytherapy↗
PubMed1990

Calculation of radiation doses in critical organs compared with in vivo dosimetry during brachytherapy of carcinoma of the uterine cervix.

In a group of 38 patients with carcinoma of the uterine cervix, radiation doses were measured by thermoluminiscent dosimeters (TLDs) placed in catheters introduced into the urinary bladder and rectum during a 24 h uterovaginal application of 226Ra. The values of radiation doses registered by the TLDs were compared to those calculated from roentgenograms made after 24 h. To calculate the radiation doses, we used the program Brachy 9.3-C of the planning unit Evados (Siemens, FRG). Using nonparametric comparison tests, no statistically significant differences were found between the values of radiation doses registered by TLDs and those calculated after 24 h of uterovaginal application of 226Ra. Only in the oral part of the rectum, at a distance of 10 cm and above from the anal orifice, there were differences between doses measured by TLDs and those calculated from roentegenograms made after 24 h of brachytherapy. These differences were caused by the movement of the flexible catheters carrying the TLDs.

Brachytherapy↗
PubMed1990

Complications of radiotherapy of uterine cervix carcinoma.

The retrospective analysis of 242 patients treated for uterine cervix cancer at VUKEO Brno within 1977-1982 has been realized. The patients being only treated with radiotherapy alone using the external 42 MeV X-ray betatron beam irradiation of the pelvis, and the vaginal and intrauterine application of 226Ra, were included in this study. The complications of therapy were evaluated in accordance with the grade of severity, location and time of their source. The radiotherapeutical complications of the 2nd stage appeared for 27 patients (11.2%), and the complications of the 3rd stage appeared for 8 patients (3.3%). The total five-years' survival rate is 71%, 92% for 37 patients in the Ib stage, 78% for 105 patients in the IIa, b stages, and 54% for 100 patients in the IIIa, b stages.

Female↗
PubMed1989

Variations in dose distributions by the use of independent asymmetric jaws. A new technique for irradiation of localized carcinoma of the prostate.

The use of independent jaws set asymmetrically in the moving field technique with bilateral arcs allows the entirely new dose distributions be obtained. The basic principle of this technique is that, with the use of moving field technique with bilateral arcs, the independent jaw more proximate to the central ray (axis) of beam must always be on the side of the critical organ. In this area the characteristic deformation of isodoses and the formation of very steep dose slope occur. We consider as optimum technique for the target irradiation of the prostatic carcinoma the moving field technique with bilateral 105 degrees arcs with 20 MeV X-ray beam of linear accelerator and with independent jaws set asymmetrically, when the independent jaw more proximate to the central ray is always + 1.5 cm from the central ray of the beam.

Carcinoma↗
PubMed1989

Effect of small doses of 252Cf on the tumour regression in cervix uteri during combined radiotherapy.

The results of a randomized study on the regression rate of the cervix uteri tumour for a group of 56 patients, investigated during and after radiotherapy with 2 Gy dose of the 252Cf neutron component applied by means of intracavitary therapy at the beginning of the therapeutic cure are presented and compared with the conventional 226Ra therapy. It was found that the tumour regression curve after 252Cf irradiation is significantly steeper than the curve of the control group. The quantitative evaluation of the results regarding the time required for a 50% regression of the original tumour shows that a group of patients treated by 252Cf needs a 27 days' cure in comparison with 40 days' cure for patients treated only by gamma radiation. The regression rate of the irradiated tumours shows a difference of approximately 30% for the treatment using small doses of 252Cf.

Adult↗
PubMed1989

[Radiotherapy of carcinoma of the prostate--5 years' experience].

Forty three patients were treated for cancer of prostate by irradiation at the Radiotherapeutic Ward of the Research Institute of Clinical and Experimental Oncology in the years 1976 to 1981. The five-year period of survival in patients with a localized tumorous disease was 45%. The authors analyzed causes of unsuccessful therapy and evaluated complications of the therapy, the latter being mostly early postirradiation reactions. Possibilities of improving the results of treatment in optimizing the radiotherapy of the localized prostate cancer are outlined.

Carcinoma↗
PubMed1989

[The importance of the gammagraphic examination of the skeleton in the diagnostic and therapeutic strategy in carcinoma of the prostate].

One hundred and sixty patients with the diagnosis of prostate cancer have been treated at the Research Institute of Clinical and Experimental Oncology in Brno over the last 10 years. The present paper has been devoted to the diagnostics of skeleton by scintigraphy as compared with X-ray examination of bones. Scintiscanning of skeleton was performed on a gamma-graph Picker 500 i, 99mTc pyrophosphate was used and scintiscanning was performed in the usual examination regimen. The highest importance of this examination resides in the fact that the demonstration of bone metastases results, in most cases, in changing therapeutic procedure and thus significantly influences the course of the disease and the patient's fate. In the group of patients the authors detected metastases in the skeleton in 40% during the first examination of skeleton, sometime even after introducing the therapy. The results confirm the necessity of a complex skeleton examination before the onset of therapy in each patient with this kind of diagnosis.

Bone Neoplasms↗