Search PubMed⌕ Search

Biomedical subjects

S Dische

Publications and source records attributed to S Dische.

At least 73 records · Page 4Linked to original sources
PubMed1988

Radiotherapy employing three fractions on each of twelve consecutive days.

In order to achieve the greatest advantage of accelerated hyperfractionated radiotherapy, treatment has been given 3 times each day for 12 consecutive days without a rest period. A total tumour dose of 50.4 Gy was well tolerated in a series of 38 patients with bronchial, head and neck and oesophageal carcinomas. A further 14 patients have now received an elevated dose of 54 Gy, again with satisfactory tolerance. The tumour responses at all these sites have been very promising and further work is proceeding.

Bronchial Neoplasms↗
PubMed1987

Comparison of lip function: surgery vs radiotherapy.

This work was undertaken to compare lip function after surgery and after radiotherapy. In all, 37 patients were studied, 19 post-surgery and 18 after radiotherapy. Both physical lip parameters, such as intercommissural distance and soft tissue gape, as well as sensation and functional outcome, were assessed. The cure rates were found to be comparable in both groups. Our study shows functional benefits when radiotherapy is used as opposed to extensive surgery. This is due primarily to the loss of sensation and elasticity which follows surgery.

Aged↗
PubMed1987

Radiotherapy using the hypoxic cell sensitizer Ro 03-8799 in malignant melanoma.

The hypoxic cell sensitizer Ro 03-8799 has been given with radiotherapy to achieve complete and sustained regression in 5 of 7 cases of recurrent malignant melanoma treated with the object of cure and in 1 of 3 treated palliatively. Particularly high tumour concentrations of this radiosensitizing drug have been found in 3 of 6 cases studied.

Adult↗
PubMed1986

Hemoglobin, radiation, morbidity and survival.

Analyses concerned with a group of patients treated by radiotherapy for carcinoma of the bronchus give evidence to support the view that oxygen tension at the time of radiation therapy is important both in determining tumor control and radiation morbidity.

Female↗
PubMed1986

Concentrations achieved in human tumors after administration of misonidazole, SR-2508 and Ro 03-8799.

Misonidazole, SR-2508 and Ro 03-8799 have been given in sequence to patients before tumor sampling. Tumor concentrations of the three drugs have been measured and it has been possible to make prediction as to the likely advantage of the newer drugs over misonidazole. Based upon the three cases described here and 13 others given two drug combination, we suggest that in multifraction radiotherapy, both are likely to prove more than five times more efficient than misonidazole.

Aged↗
PubMed1986

A comparison of the tumour concentrations obtainable with misonidazole and Ro 03-8799.

Both Ro 03-8799 and misonidazole were administered to six patients before tumour sampling. Using similar doses, tumour concentrations of Ro 03-8799 were approximately double those of misonidazole. Examination of the data with regard to the relative sensitising efficiencies of these two compounds gives us, as a conservative estimate, a factor of 1.6 in favour of Ro 03-8799. From these observations it is predicted that, when given with radiotherapy in a 25-fraction course Ro 03-8799, is likely to be at least five times more effective as a hypoxic cell sensitiser than misonidazole.

Adult↗
PubMed1986

A comparative study of Ro 03-8799: racemic mixture and enantiomers.

The maximum single dose of the 2-nitroimidazole hypoxic cell radiosensitiser Ro 03-8799 is limited to 1 g/m2 by the occurrence of a well characterised acute syndrome of sweating, nausea and mental changes. In an attempt to increase the tolerable dose, the clinical toxicity of the racemic mixture was compared with that of the R- and S-enantiomers of Ro 03-8799. Twelve patients received escalating alternate doses of racemic mixture and R- or S-enantiomer, the dose levels being 0.25 g/m2, 0.5 g/m2, 0.75 g/m2 and 1.0 g/m2. Careful monitoring of the acute syndrome failed to demonstrate any consistent differences between racemic mixture and either enantiomer. This would suggest that the toxicity is not mediated via any specific central nervous system receptor. It is concluded that separation of Ro 03-8799 into its enantiomers will not enable a clinically useful increase in dosage.

Dose-Response Relationship, Drug↗
PubMed1985

Chemical sensitizers for hypoxic cells: a decade of experience in clinical radiotherapy.

The clinical work with chemical agents to restore the radiosensitivity of hypoxic cells began in 1973 with metronidazole, misonidazole was first given in 1974. The results so far recorded of the clinical trials with misonidazole have been generally disappointing. Only in 5 of 32 studies analyzed have significant benefits been shown to suggest real advantage with the use of misonidazole. Hypoxic cells must exist in all human tumours presenting for treatment and it is, however, probable that the oxygen effect is an important one at all dose fractionation regimes employed in radiotherapy but, after conventional fractionated radiotherapy, hypoxia may be a reason for failure in only a proportion of cases. The most important factor underlying the failure of misonidazole to achieve useful advantage is undoubtedly the low radiosensitizing concentrations achievable with the permitted dose of this neurotoxic drug. New drugs are under development and some have different dose-limiting toxicity. Those showing promise at this time are the Stanford compound, SR-2508, which is being extensively studied in the United States and the Roche compound, Ro 03-8799, which is being studied in the United Kingdom. It is possible that the greatest sensitization with the greatest tolerance will be achieved by a combination of drugs.

Adrenal Cortex Hormones↗
PubMed1984

The pharmacokinetics of a new radiosensitiser, Ro 03-8799 in humans.

A new hypoxic cell radiosensitiser, Ro 03-8799 has been administered intravenously to human volunteers and its kinetic parameters derived from plasma and urine data. Good penetration of drug into tumour tissue is found, consistent with its large volume of distribution. The plasma clearance of this compound is rapid due to high metabolic and renal clearances. These parameters combine to produce an elimination half-life of 5.6 h, approximately half that of misonidazole, a well studied radiosensitiser. It is hoped that this decrease in total body exposure will also reduce the cumulative toxicity seen when misonidazole is administered repeatedly.

Adult↗
PubMed1984

Primary tumor control after radiotherapy for carcinoma of the bronchus.

The primary tumor control and the appearance of distant metastasis was observed closely in 62 patients entered into a randomized controlled trial of the radiosensitizing drug, misonidazole, in carcinoma of the bronchus. Sixty-one of the 62 patients are now dead; an autopsy examination was carried out in 42 (69%). Although survival was comparable to that observed in similar studies, tumor persisted or recurred at the primary site in 95% (58/61) while 39% (24/61) showed no evidence for distant metastasis. In these patients, improvement in the primary tumor control would be important in extending survival.

Bronchial Neoplasms↗
PubMed1984

The relationship between tumor response and survival following radiotherapy for carcinoma of the bronchus.

Tumor response was closely observed in a randomized controlled trial of a radiosensitizing drug in the radiotherapy of carcinoma of the bronchus. The persistence of tumor cells in the sputum after treatment and the degree of regression measured radiologically at two months did not correlate with the subsequent course. However, total regression of tumor and time to regrowth both assessed radiologically showed a highly significant correlation with survival (P less than 0.0005).

Bronchial Neoplasms↗
PubMed1984

Quality assurance in radiation therapy: European experience--present and future clinical efforts.

A high standard of radiotherapeutic practice must be sought in all phases of management of a patient with malignant disease. Radiation therapy must be appropriately chosen and integrated with surgery, cytotoxic chemotherapy and all other modes of treatment. The most suitable technique with a dose, fractionation and time regime must be devised and executed with technical and personal care. Follow-up to truly assess tumor control and morbidity is essential so as to guide the management of future patients. To achieve this in Europe great reliance is placed upon the training and qualification of the therapist and staff. In England a Fellowship of the Royal College of Radiologists in radiation therapy is regarded as essential for appointment as a permanent consultant within the Health Service. A high examination standard is set with pass rates ranging from 10 to 30%. High standards are applied to the professional qualifications for radiation physicists, nurses and technical staff. Most radiotherapy centers and departments have been visited by the Royal College in order to determine if the standard of staffing and equipment justifies inclusion in the list of training departments. There is, unfortunately, no control of continuing education of the consultant once appointed. In the countries belonging to the European economic union, a new Diploma in Radiation Therapy has been established to be a standard for consultant practice through all the countries included. In a few multi-center trials in the United Kingdom members of the central organization visit centers to look at the case notes and compare them with the material submitted from the trial center. This effort at monitoring clinical trials is only just beginning in the United Kingdom. The European Organization for Research and Treatment of Cancer has recently initiated a quality control study in some of the centers included in the Radiotherapy Group. A preliminary report has just appeared on the results of the clinical and dosimetric studies in 8 centers placed in 5 European countries. This first European effort appears to have been successful and further details will become available. These initiatives through research may well lead to wider studies of quality assurance in radiation therapy within Europe.

Accreditation↗