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Biomedical subjects

K Jentzsch

Publications and source records attributed to K Jentzsch.

At least 19 recordsLinked to original sources
PubMed1987

CT-assisted assessment of bladder and rectum dose in gynecological implants.

Eight patients who received gynecological implants with Fletcher-Suit type applicators were involved in this study. An orthogonal pair of films and computed tomographic scans were obtained for each patient. In the CT study, judicious use of contrast materials and selective window and level settings permitted clear delineation of the bladder and the rectum boundaries relative to the implanted applicators. In comparison to reference organ doses derived from the orthogonal film pair method, the maximum organ doses estimated from the CT-assisted evaluation were considerably higher, by approximately twofold on the average. The differences between the values estimated from the two methods vary from patient to patient, being highly dependent on the individual anatomy and the geometry of the implanted sources. These preliminary results point to the inaccuracy of the conventional method of estimating organ doses. CT-assisted evaluation may be necessary to accurately calculate organ doses in gynecological applications.

Brachytherapy↗
PubMed1981

Leg function after radiotherapy for Ewing's sarcoma.

Twenty-nine patients with Ewing's sarcoma of the lower extremity who survived for two or more years following therapy (5000 rad locally and systemic chemotherapy) were studied to assess functional status of the affected leg. Twenty-two of twenty-nine were alive and were reexamined; the deceased patients were evaluated by record review. Twenty-two of the twenty-nine had serial radiographs, which were reviewed to assess growth change induced by radiation. The living patients were divided on the basis of clinical examination into four functional groups with Group I comprising patients with minor functional limitations and leg length discrepancy 1.5 cm or less. Group II patients had moderate functional limitations with 2.5-cm leg-length discrepancy or less. Group III patients had severe functional limitations with up to 4-cm leg length discrepancy. Group IV patients had severe complications, sufficient enough to warrant amputation. Thirteen of twenty-two patients were classified as functional Group I, five as Group II, three as Group III, and one as Group IV. Radiographic changes in growing bone did not correlate with functional results. Although a femoral fracture and an age less than 16 years at diagnosis were found to be less favorable prognostic factors for the functional treatment result, these results show that neither femoral location nor young age justify primary amputation for Ewing's sarcoma of the lower leg extremity.

Adolescent↗
PubMed1978

Further clinical experiences of a phase I study with the hypoxic cell radiosensitizer misonidazole.

Since April 1976 we have performed clinical investigations with multiple doses of the hypoxic cell radiosensitizer misonidazole in 21 patients. A significant side effect of the drug was the development of peripheral sensory neuropathies in 13 patients (8 mild, 5 severe) and of a transient acute organic psychosyndrome in 2 of the 5 patients with a severe polyneuropathy. The severity of the polyneuropathies is related to the total dose of misonidazole and the overall time of drug administration. Treatment schedules designed to obtain the desired sensitizing effect without neurological side effects are under investigation.

Adolescent↗
PubMed1977

[Radiotherapy of Nephroblastoma (author's transl)].

The treatment methods for the differnt stages of the disease are discussed. The tumour is irradiated preoperatively. Intraoperatively, chemotherapy is commenced and, depending on the stage of the disease, radiotherapy is continued with chemotherapy. In stages III and IV and, if metastases occur, extended fields are irradiated, including the whole area of the body cavities. The abdomen is irradiated with 3000 rad, the lung with 1000-1200 rad and concomitant chemotherapy is given. Seven children were treated by us during 1969-1975 in conjunction with the Paediatric Department of Vienna University. All of them are still living. Severe radiation-induced side effects were observed in two of the cases.

Age Factors↗
PubMed1977

[Radiotherapy of neuroblastoma (author's transl)].

The indication for radiotherapy in neuroblastoma depends on the stage of the disease; the irradiation dosage depends on the age of the child. The tumour is radiosensitive, but tends to recur if the irradiation dosage is inadequate. Irradiation of the tumour may induce coversion to a more differentiated tumor pattern. Radiotherapy can reduce the tumour volume, thereby rendering previously inoperable tumours resectable. Since 1959 11 out of 16 children with neuroblastoma undergoing treatment at the Paediatric Department of the University of Vienna were subjected to radiotherapy. Out of 9 children with suprarenal origin of the tumour only one child is still alive (survival time to date-26 months since diagnosis). Out of 7 children with extraadrenal tumour localization 70% have survived for more than 2 years. The side effects of radiotherapy survived for more than 2 years. The side effects of radiotherapy were: 1 case of quadripelgia, 1 case of symmetric growth delay of the pelvis and 1 case of scoliosis.

Adolescent↗
PubMed1977

Initial clinical experience with the radiosensitizing nitroimidazole Ro 07-0582.

The 2-nitroimidazole derivate Ro 07-0582 is known from experimental studies to be a very efficient radiosensitizer of hypoxic cells. Experiences with its clinical use are very limited so far. This study reports the side effects observed in the use of this drug in 12 patients. Nine of these patients were suffering from brain tumors, 3 from extracerebral tumors. In 8 of our 12 patients a sensoric polyneuropathy occurred which was strongly related to the total dose of the drug administered. Polyneuropathy was observed on the average after a total dose of 26 grams, but was already noticed at doses as low as 22 grams. It showed a good tendency for remission after termination of the drug treatment and was reversible in all patients within 4 weeks. In one patient with a brain tumor a severe organic psychosyndrome occurred which is possibly related to the drug. This side effect was also reversible. In this small group of patients the critical dose limit seems to be 29 grams. This dose can be divided into 6 fractions of 60-80 mg/kg. Up to the present knowledge this single dose is likely to give an enhancement ratio of 1,5, which would be extremly valuable for the treatment of hypoxic tumor cells.

Adolescent↗
PubMed1976

[Improved demonstration of normal lymph nodes in lymphangiograms (author's transl)].

Lymphography with Lipiodol ultra fluid was carried out in eight domestic pigs. The purpose of the experiment was to obtain even distribution of the oil in normal lymph nodes in order to improve its diagnostic value. This was attempted by changes in pressure, temperature and by the addition of benzopyrone. By increasing injection pressure from 0.4 to 0.8 atmospheres, using a pump, it was possible to show more of the lymphatic tissue. Whether this would be possible in man is still not certain. The use of a benzopyrone preparation also improved contrast distribution in lymph nodes. Additional pelvic lymphatics were also seen. The improved distribution of oil is indicated by the altered pattern, strikingly even filling of the vacuoles and 10% incfreased filling rate.

Animals↗
PubMed1975

[Cystostatic drug sensitivity testing of primary cultures of human tumours (author's transl)].

One to eight week-old primary tissue cultures of human tumours (1 rhabomysarcoma, 1 renal adenocarcinoma, 1 hymphogranuloma, 2 melanomas) and cultures of chicken embryo cells and HeLa-cells were tested for their sensitivity to chemotherapeutic agents. The drugs tested were: vincristine, actinomycin D, adriblastine, bleomycin. The drug effect was recorded by registration of morphological changes and, in some cultures by a change in the 3-H-thymidine incorporation. The cultures showed a variable reaction to vincristine, a good response to actinomycin D and adriblastine and were uniformly resistant to bleomycin. Two cultures were pulse labelled with 3-H-thymidine to obtain some data in regard to their growth characteristics.

Antibiotics, Antineoplastic↗
PubMed1975

Lymphoblastic extramedullary spinal tumor during remission of acute lymphoblastic leukaemie.

An unusual case history of a girl with ALL is presented. The diagnosis was established at the age of 7. At the age of 11, 5 years and 3 months after remission due to treatment an extramedullary tumour of a lumbar vertebra produced a transverse lesion of the spinal cord and meningeal leukaemia. The tumour consisted mainly of connective tissue with small foci of lymphoblastic cells, identical with those originally seen in the peripheral blood stream. After laminectomy, irradiation and chemotherapy the girl is still in her first haematological remission, lasting nearly 7 years.

Adolescent↗
PubMed1975

Radiotherapy of malignant lymphomas.

Radiotherapy of non-Hodgkin's lymphomas situated in the central nervous system is basically similar to the treatment applied to any other part of the body. There are two requirements: the first is the prophylactic irradiation of the CNS in a systemic disease of the reticuloendothelial system mainly in acute lymphatic leukemia; the second is the treatment of solitary tumors in the CNS. Radiotherapy can improve dramatically the results obtained with intrathecal chemotherapy, particularly in leukemic involvement of the CNS in childhood. The fractionated single radiation dose should be increased slowly and total doses of 2 500 rd should not be exceeded. Prophylactic radiotherapy of the CNS in acute leukemia has to include the entire subarachnoid space. It is therefore necessary to irradiate the entire skull and spinal cord. This treatment schedule and its results will be discussed. There is a tendency to sue prophylactic radiotherapy in other systemic diseases of the RES as well. The indications and contraindications for this will be discussed. The methods and results of treatment of focal lesions with regard to the morphologic tumor pattern are discussed. Rare primary tumors of the CNS which have the histological features of lymphoma-sarcoma or reticulosarcoma have the best prognosis as far as radiotherapy is concerned.

Brain Neoplasms↗
PubMed1975

Prevention of meningeal leukaemia and relapses by cranial irradiation and intrathecal MTX in acute lymphatic leukaemia.

Experience with CNS prophylaxis in 35 children with acute lymphatic leukaemia is reported. Before prophylactic irradiation of the skull was given the average survival time in 36 children was 2,8 (2,7) years. Menigeal leukaemia preceeded bone marrow relapse in 9 cases and followed relapse in a further 5 cases (39%). Between 1971 and 1973 Pinkel's treatment scheme VII was given to 35 children. This included prophylactic skull irradiation and intraspinal MTX injections. 29 children are still in their first remissions which range from 10 - 35 months in length. Meningeal leukaemia has not so far been observed, in this latter group.

Child↗
PubMed1975

[The value and limitation of echotomography in the diagnosis of abdominal lymphomas in malignant diseases(author's transl)].

The indication for ultrasonic examination in addition to endolymphatic methods is discussed. In 23 histologically proved advanced cases the accuracy of lymphography was 77% and in echotomography 74%. In the diagnosis of lymphonodal enlargements in the area of the liver and spleen hilium echotomography proved to be a valuable diagnostic method independent from endolymphatic methods. In X-ray treatments echotomography enables us to estimate the therapeutic result and to evaluate the lymphonodal status. The controls are performed in an out-patient manner.

Abdominal Neoplasms↗
PubMed1975

[Effect of 5-fluorouracil and irradiation of the cell kinetics of Walker carcinoma and the small intestine in rats].

A therapeutic schedule of synchronizing cytostatical-radiological treatment often used in human medicine is applied to rats carrying a Walker tumor. The effect of this treatment on the kinetics of tumor cells and epithelium of small intestine is investigated. 1. 5-Fluorouracil, i.p. during 18 and 12 hours, brings about no changes in the mitotic index; however, in the curve of marked mitoses a small fraction of cells is represented which is considered to be a consequence of the synchronization of a very small portion of tumor cells. 2. If ten hours after 5-FU-injection the cells are irradiated with a single dose of 300 rd, there occurs a distinct G2-block and a lengthening of the S-phase. These changes are found both in the 5-FU ground and in the controls. 3. 5-FU-injection thrice alternated with irradiation likewise causes a G2-block. After solution of the block a delayed increase of mitoses in the controls is going on which cannot be detected in the 5-FU group. These findings are interpreted as an effect of 5-FU on the proliferation rate of tumor tissues.

Animals↗