PubMed Health⌕ Search

Biomedical subjects

K Turowski

Publications and source records attributed to K Turowski.

At least 19 recordsLinked to original sources
PubMed1992

[Factors affecting the quality of life of patients treated by a combined method for poorly differentiated supratentorial glioma].

The quality of life of patients treated for brain tumours and the length of survival are important factors making possible the evaluation of treatment effectiveness. Changes of life quality evaluated by the Karnofsky scale were analysed in a group of 56 patients who have received combined treatment for poorly differentiated supratentorial gliomas. Life quality changes were evaluated after completion of surgical and radiological treatment in relation to preoperative status. The influence of various clinical factors on life quality changes was evaluated. Surgical treatment and tumour site had a significant effect on the stabilization or slight improvement of life quality. The direction and extent of life quality changes were related to surgery, with further change after radiotherapy.

Adolescent↗
PubMed1992

[Brachytherapy of brain gliomas].

Radiotherapy is considered presently the most advantageous supplementary method after surgical treatment for gliomas. The limitations of classical teletherapy cause that interstitial radiation may become preferable. The authors present the theoretical principles and practical application of brachytherapy in 10 cases of glioma. Closed radioactive sources were used in form of I125 implanted stereotactically into brain tumours for a period sufficient for providing therapeutic radiation dose to the border of the tumour. The doses received by tumour borders ranged from 812 to 4560 cGy, and the mean dose was 2064 cGy. Five patients were given additionally 6000 cGy by teleradiotherapy.

Adolescent↗
PubMed1989

Quality of survival of patients with brain gliomas treated with postoperative CCNU and radiation therapy.

This prospective randomized clinical trial compared the effectiveness of combined treatment with CCNU and radiation therapy to the use of radiation therapy alone for the postoperative management of supratentorial brain gliomas (67% anaplastic) in 198 patients. The results were evaluated with the aid of a specially developed weighted neuropsychological test battery providing single-value estimation of "life quality" of patients, as well as with a clinical performance scale. Based on these methods, it was established that patients improved within 6 months following therapy. This improvement was maintained in surviving patients during the 2-year follow-up period. The patients led a relatively normal life, but when their condition deteriorated their decline was rapid. The median survival time of patients treated with radiotherapy did not differ significantly from that of patients receiving chemotherapy in addition. Nor did the analysis of life quality and of changes in clinical performance show any benefit in supplementing surgery and radiation therapy with CCNU chemotherapy at the dosage used.

Adolescent↗
PubMed1988

Postoperative radiotherapy and radiotherapy combined with CCNU chemotherapy for treatment of brain gliomas.

A prospective, randomized trial evaluates the effects of two postoperative treatment regimens on survival in 198 adult patients with supratentorial gliomas. All patients were irradiated with 6,000 rads after possibly radical removal of tumors. CCNU administration in the doses of 100 mg/sq m of body surface every 6-8 weeks following surgery proved to have no significant effect on the survival of patients. The median survival time in patients receiving radiation therapy alone was 61 +/- 7 weeks, while in those receiving additional chemotherapy was 56 +/- 4 weeks. Tumor histological malignancy and patients age were found to be the only important prognostic factors, irrespective of the treatment modality.

Adolescent↗
PubMed1988

Radiation dose response of normal brain.

Dose response relationships were determined after hemibrain x-irradiation of normal beagle dogs. Radiation doses of 11.5, 13.5, 14.3, and 17 Gy were delivered in a single dose and results were compared to previous studies using doses of 15 and 30 Gy. Brain injury was quantified using computed tomography (CT), with serial studies obtained monthly up to 1 year following irradiation. Quantitative endpoints included low density volume and contrast enhancement. Doses above 14.3 Gy resulted in high lethality 5-8 months following irradiation, and an LD50 of 14.9 Gy was calculated. At these lethal doses, low density volume representing edema, demyelination, and necrosis had a similar response with an ED50 of 14.6 Gy. Radiation-induced decreases in white matter density appeared 5-6 months after sublethal doses (less than or equal to 14.3 Gy) and the volume of tissue characterized by this low density increased with time and dose. This sublethal low density change had an ED50 of 12.8 Gy, and may reflect a loss or generalized atrophy of glial cells and/or myelin. These results show that: (a) the dose response curves obtained after hemibrain x-irradiation are extremely steep; and (b) at least two processes may be involved in the development of late radiation damage, one that is rapid upon onset (a "delayed acute" reaction) and the other which is a slower and more degenerative process.

Animals↗
PubMed1986

Contrast enhancement of brain tumors and irradiated normal brain: a comparison of iohexol and iothalamate.

The nonionic contrast agent iohexol was compared with the ionic agent iothalamate for contrast enhancement of brain tumors and radiation brain damage in dogs. Tissue enhancement during infusion of contrast and 5, 10, 15 and 30 min later was measured using quantitative computed tomography. Blood iodine was measured using x-ray fluorescence. Peak contrast enhancement occurred during infusion in tumors and after 5 min in irradiated normal brain for both contrast agents. Absolute uptake of contrast in each lesion was the same for both agents when normalized to total grams of iodine administered. Blood iodine levels were slightly but not significantly higher using iohexol. The reduced osmotic load and similar contrast enhancement of lesions suggest that the nonionic contrast medium iohexol may be a useful agent for routine CT of the brain.

Animals↗
PubMed1986

Normal brain iodine-125 radiation damage: effect of dose and irradiated volume in a canine model.

High-activity iodine-125 sources in plastic catheters were surgically placed in the cerebral white matter of healthy beagle dogs and later removed. Reference doses, calculated at a point 0.75 mm from the source, ranged from 10 to 40 Gy. Necrosis, vascular-related damage, and edema were quantified by computed tomography. Volumetric analyses were used to derive the relationship of dose and dose rate to necrosis and contrast enhancement. The extent of necrosis was related to irradiated volume; a minimum effective dose averaging 180-200 Gy was required to induce this type of damage. Contrast enhancement was less dependent on irradiated volume or total dose. The extent of radiation-induced edema was directly related to the volumes of necrosis plus contrast enhancement. Noninvasive serial studies in a well-characterized in vivo model can address specific clinically related questions on damage to normal tissue after interstitial irradiation.

Animals↗
PubMed1986

Computerized tomography in the prognosis of malignant cerebral gliomas.

Ninety-seven patients with supratentorial malignant gliomas who received postoperative radiation therapy and chemotherapy at the University of California, San Francisco, from 1977 through 1984 showed improvement in their follow-up computerized tomography (CT) scans. Twenty-one of these 97 "CT responders" were designated "complete responders" because on serial CT scans they had complete disappearance of the tumor mass and contrast enhancement, which had been present postoperatively. In the remaining 76 patients, CT scans showed reduction in the size, but not disappearance, of the lesions, and these were designated "partial responders." Fifty-eight partial responders had glioblastoma multiforme (GM); their median survival time was 72 weeks. The median survival time for the 11 complete responders with GM has not yet been achieved, but survival at the 53rd percentile is 172 weeks. Among patients with highly anaplastic astrocytoma, the median survival time was 211 weeks for the 10 complete responders and 125 weeks for the 18 partial responders. Eleven of the 21 complete responders are alive at a median postoperative follow-up time of 163 weeks (range 114 to 470 weeks). Eighteen of these patients had subtotal resection of tumor; three patients had gross total tumor resections, but postoperative CT scans showed evidence of residual or possibly recurrent tumor within 1.5 to 4.5 months. Resolution of the tumor mass and contrast enhancement took 9 to 151 weeks; the time to resolution did not depend upon the configuration of the remaining tumor mass and contrast enhancement after surgery. In this study, patients with malignant gliomas whose CT scans eventually showed sustained complete disappearance of the tumor mass and contrast enhancement had a more favorable prognosis than did patients whose CT scans showed improvement, but not complete disappearance, of the tumor. These CT findings may prove useful in determining the prognosis of patients with malignant gliomas.

Adolescent↗
PubMed1985

Radiation brain damage induced by interstitial 125I sources: a canine model evaluated by quantitative computed tomography.

The canine brain is a good model of the human brain for studying radiation damage after megavoltage x-irradiation for brain tumors. We have further developed this model to study radiation damage induced by high activity interstitial 125I sources. Removable 125I sources were implanted in normal canine brains, and doses of 1,000 to 10,000 rads were delivered to a reference point at a 10-mm radius from the source; dose rates were 35 to 40 rads/hour at the reference point. Serial quantitative analysis of tissue damage (tissue density and contrast enhancement) was done using computed tomographic scanning up to 6 months after implantation and was compared to histopathological findings after the animals were killed. At doses greater than 19,000 rads (i.e., inside the reference point), frank coagulation necrosis was observed. Pronounced vessel-related changes, manifest as areas of contrast enhancement, corresponded to tissues receiving a minimum of 6,000 rads and a maximum of 19,000 rads. These results indicate that this model can be used in serial noninvasive studies to quantify the development of damage induced by interstitial irradiation and to provide dose-response information in individual animals.

Animals↗