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Biomedical subjects

R Kotz

Publications and source records attributed to R Kotz.

At least 127 records · Page 7Linked to original sources
PubMed1981

[Controlled ultra-high dosage methotrexate therapy in three patients with metastatic osteosarcoma (author's transl)].

9 HDMTX infusions with 30 to 55 g MTX and leucovorin rescue were given to 3 patients with multifocal osteosarcoma. Resistance to standard MTX infusions with up to 12 g/m2 body surface in 4 hours indicated the administration of these higher doses (27 g/m2 body surface on average) over a shorter period of time (160 min on average). MTX input was controlled by the increase in plasma MTX levels which were determined by EMIT enzyme assay within a few minutes of sampling. The plasma MTX levels were found to be up to 10 times (average 4 times) higher than those achieved by the standard infusion. All infusions proved to be relatively well tolerated in all 3 cases, although, thrice after 36 hours an increased leucovorin rescue had to be made for 12 hours, because of delayed renal methotrexate excretion; the usual leucovorin rescue (15 mg every 6 hours) was given for an average of five days. No therapeutic effects were seen either clinically, radiologically, or histologically. The resistance to HDMTX in these three patients could not be broken by HDMTX PLRD infusions.

Adolescent↗
PubMed1981

[Results of Primary chemotherapy and Delayed Surgical Resection in Osteosarcoma (author's transl)].

Primary systemic therapy with delayed surgical intervention has been employed for the treatment of malignant bone tumours since 1977 at the Universitäts-Kinderklinik and III. Medizinische Abteilung Graz. Improved therapeutic results, as originally reported on a large number of patients at the Memorial Sloan Kettering Cancer Center (MSKCC) seem to have been attained with a small group of patients (n = 5).

Adolescent↗
PubMed1981

Avascular necrosis of the femoral head: a review of the indications and results of Sugioka's transtrochanteric rotational osteotomy.

The results of Sugioka's trans-trochanteric anterior rotational osteotomy are reported. Seventeen cases of idiopathic avascular necrosis of the femoral head have been operated upon and followed-up for between 10 to 48 months, with an average of 25.2 months. Since 1975 the operative technique and complications are described and the clinical results were assessed according to Patterson's criteria. These results are compared with previous methods of treatment. The short term results of Sugioka's method are favorable in cases with a small to medium sized necrosis. This new method of re-orientation of the head provides an intact part of the femoral head for weight bearing and therefore would seem to be appropriate in cases without established osteo-arthritis.

Adolescent↗
PubMed1981

Treatment of osteosarcomata of the distal femur by rotation-plasty.

Rotation-plasty was carried out on fifteen patients--10 male and 5 female patients aged between 6 and 32--with an osteosarcoma of the distal femur following resection of the tumor. In the operation the lower leg was rotated through 180 degrees after resection of the distal femur and knee joint so that the ankle joint was effectively turned into a "knee joint". The indication for this operation was initially limited to children for whom the only possible therapeutic alternative was a high above-knee amputation. The surprisingly good functional rehabilitation justifies the indication of this method as an alternative to an endoprosthesis or arthrodesis even for young adults. In spite of the cosmetically very unusual position of the foot, none of the patients has so far experienced psychological problems thanks to suitable guidance. Both from an oncological and psychological point of view, this method represents an extremely responsible operation and should therefore only be carried out by hospital departments specializing in the therapy of bone tumors.

Adolescent↗
PubMed1979

[The angiographic diagnosis and differential diagnosis of inflammatory disease of bones and soft tissues (a report concerning 40 cases) (author's transl)].

The angiographic appearances of inflammatory disease of bones and soft tissues was analysed in 40 patients. The angiographic findings in inflammation of bone (28 patients) differed greatly, from normal findings (14.2%), moderate angiographic changes corresponding to the severity of the inflammatory process (32.1%), marked changes in the arterial, capillary and venous beds (42.9%) and significant local staining with little peripheral reaction (10.7%). Soft tissue inflammation on the other hand showed increased vascularity in all cases. A typical angiogram was found in 50% of cases and shows the following characteristics: vascularity as compared with the surroundings is usually increased and may be extensive, far more so than is found surrounding vascular bone foci; the contrast staining is usually ill-defined and the veins in the late phase are increased in calibre. Early venous filling is common and should not be regarded as a sign of malignancy. In 17.5% of patients the angiogram simulated a tumour; in four patients (10%) a false positive diagnosis of tumour was made, in two (5%) a tumour could not be excluded and in one case a benign tumour was diagnosed because of localised staining. None of the angiograms which had been interpreted incorrectly showed typical pathological vessels, which are the most important tumour criteria.

Adolescent↗
PubMed1979

[(Management of acute toxicity after high dose methotrexate therapy)].

A 13-year-old girl with osteosarcoma and pulmonary metastases developed life-threatening renal toxicity, encephalopathy, and bone marrow failure following high dose methotrexate therapy. After successful treatment, high dose methotrexate therapy was continued without further problems. Recommendations for the prevention and the current management of methotrexate toxicity are discussed.

Adolescent↗
PubMed1979

[Endoprosthetic replacement following resections of malignant tumors of the extremities (author's transl)].

Due to advances in chemotherapy and endoprothetics, amputation is increasingly being replaced by local resectioning in malignant tumors. While suitable implantations for bridging defects in the proximal humerus and proximal femur are available, prostheses for resectioned tumors in the knee area have not yet been fully developed. From 1966 to 1978, 77 endoprostheses were implanted in 29 primary bone tumors, 3 malignant soft-tissue tumors and 45 bone metastases. There were 43 endoprostheses of the proximal femur, 31 endoprostheses of the proximal humerus and 3 special endoprostheses of the knee region. In most cases, eliminating the tumor radically was successful and a functional extremity was retained.

Bone Neoplasms↗
PubMed1978

[Osteosarcoma 1978 a turning point in prognosis through adjuvant chemotherapy following adequate surgery (author's transl)].

Results of surgery and chemotherapy in osteosarcoma are based on a retrospective investigation of 122 patients from 1930 till 1978 treated at the Orthopaedic Department of Vienna University and documented at the Viennese Bone Tumour Registry. Adequate surgery is considered to be the radical elimination of the tumour in an oncological sense, e.g. amputation or resection. Our own patients were examined in this light and different forms of chemotherapy are compared and their efficacy as adjuvant treatment is evaluated. The turning point in the prognosis of osteosarcoma came with the introduction of high-dose methotrexate therapy (HDMTX) in 1972 and which has been employed at the Orthopaedic Department of Vienna University since 1975. So far, HDMTX has been used in the management of 18 patients and the short-term results confirm the excellent results reported in the literature. The consequent change in policy with regard to the current surgical approach to osteosarcoma is discussed in detail.

Adolescent↗
PubMed1978

[The problem of angiographic diagnosis of giant cell tumors (author's transl)].

The value of angiography in the diagnosis of giant cell tumors of the bone was investigated in 12 patients listed in the Viennese bone tumor register. It could be shown that angiographic criteria of malignancy can frequently be found in grade II cell tumors. Therefore angiography does not seem to be helpful in differentiation and prediction of benign and malignant course of giant cell tumors.

Adolescent↗
PubMed1977

[Cellular immunity during and after high-dose methotrexate therapy in patients with osteosarcoma (author's transl)].

Nine patients with osteogenic sarcoma and one patient with epitheloid sarcoma of bone undergoing treatment with high-dose methotrexate (MTX) therapy were studied immunologically. The following peripheral blood lymphocyte parameters were evaluated: 1-8 days after the intravenous infusion of 7.5 g MTX followed by leucovorin rescue: absolute count/mm3, the stimulatory response to the mitogens, phythemagglutinin (PHA) and pokeweed (PW) and the reactivity in the mixed lymphocyte culture (MLC). The response to PHA remained unaffected during the observation period, whereas the response to PW decreased on the 2nd and 4th day after treatment. The MLC response was inhibited between the 1st and the 4th day. The inhibition manifested itself first in the patients plasma and was demonstrable 48 hours later in the lymphocyte itself. The responsiveness regained normal or even reacted supranormal values about 7 days after treatment. Lymphocyte function remained essentially unaltered after several cycles of treatment. Absolute lymphocyte counts, however, tended to decrease. The MTX sensitive period in vitro lasts from the 2nd to the 6th day of the MLC, which is the period of intense RNA and DNA synthesis. We conclude that high-dose MTX therapy for osteogenic sarcoma leaves the patient without major permanent damage to cellular immune function.

Adolescent↗
PubMed1977

[Clinical observations on the use of high-dose methotrexate treatment in osteogenic sarcoma (author's transl)].

Since January 1976 high-dose methotrexate (HDMTX) therapy has been used in the management of patients with osteogenic sarcoma at the Orthopaedic Department, University of Vienna. 7500 mg MTX/sqm body surface is administrated in a four-hour infusion with citrovorum factor rescue. This therapy is combined with dactinomycin, adriamycin, bleomycin, cyclophosphamide and vincristine in a multi-drug chemotherapeutic program as a prophylactic regimen after surgical treatment of the primary tumour, as well as in the management of metastases. So far, 12 patients have received a total of 46 infusions with HDMTX at montly intervals (6 patients already had widespread metastases). The use of several precautions such as adequate hydration 3 l/sqm body surface fluid), systematic alkalinization of the urine and regular control of the serum MTX level renders HDMTX therapy less hazardous. Five out of the 46 infusions were followed by mild toxic reactions consisting of mouth ulceration, fever and/or bone marrow depression. One out of the 6 patients with metastases and 5 out of the 6 patients receiving HDMTX as a prophylactic measure are without evidence of disease at present. In view of the short observation period, this report is limited to clinical observations only.

Adolescent↗
PubMed1977

Tumor-specific immunity in sarcoma patients.

Stimulatory responses of 40 patients with bone [33] and soft tissue [7] sarcomas to autologous tumor cells were correlated with clinical data and prognosis. Although conclusive judgments for individual patients cannot be made, some genral features emerge: patients with stimulation indices greater than 1.5 have a 50 percent relapse-free interval after surgery of 22 months, patients with indices, below 1.5 have a 50 percent relapse-free interval of 5 months. 7 out of 10 responder patients are tumor-free 1 year after surgery as compared to 5 out of 19 (26 percent of non-responder pateints (p less than 0.05). Removal of the tumor is followed by an increase in the stimulatory response and by the dissappearance of blocking serum factors in patients with favourable prognosis. Responses return to baseline levels in tumor free patients 9-12 months after surgery. The results suggest that tumor-associated immune responses play a role in the development of human sarcomas. In addition, 47 lymphocyte samples of 25 patients were tested for stimulation by autologous tumor cells and for cell-mediated cytotoxicity against allogeneic sarcoma cell lines. Similar results were obtained in both test systems when pre-therapy lymphocytes were used. Discordant results were frequently seen at times after surgery. Both test systems may complement each other and may help clarify the tumor-specificity of certain lymphocytotoxic activities.

Adolescent↗
PubMed1977

Problems of local recurrence in patients with Ewing's sarcoma.

With the increasing longevity of patients with Ewing's sarcoma not only the long term tissue effects of local treatment are important, but also the management of patients who develop local recurrent disease. Of our 42 patients with Ewing's sarcoma, 33 were treated by irradiation and 7 of them developed a recurrence. The reasons of failure to control the primary tumor are analysed in the light of present experience and guidelines for the management of the recurrence are discussed. With optimal combination therapy it is hoped, that a proportion of patients with recurrent disease can be salvaged.

Adolescent↗
PubMed1976

The immune-status in patients with bone and soft-tissue sarcomas.

The immunologic status of 50 sarcoma patients was established. It was possible to apply the DNCB test and the recall antigen test in most cases during the course of the illness. The PHA stimulation of the lymphocytes and their cytotoxicity on homologous sarcoma cell lines were also correlated with the course of the illness. Nonspecific tests related neither to each other nor to the development of the illness while the tumor-specific cytotoxicity test correlated closely with the course of the disease.

Adolescent↗