Biomedical subjects

K Tverå

Publications and source records attributed to K Tverå.

8 recordsLinked to original sources

PubMed1999

Intracavity fractionated balloon brachytherapy in glioblastoma.

In order to reduce hospitalisation time for patients receiving postoperative radiotherapy a phase I-II study of intracavity balloon brachytherapy was instituted. An indwelling balloon catheter was implanted during the closing phase of the initial operation. Starting on the second or third postoperative day the catheter was afterloaded with a high dose rate isotope via a remotely controlled afterloading system. The treatment consisted of 10-12 fractions over a period of 5-6 days, with each treatment session requiring approximately 15 minutes. No external beam radiation was given. Forty-four newly diagnosed patients were treated. A total dose of either 60 Gy (33 patients) or 72 Gy (11 patients) was given. The overall median survival was 11.7 months, (range 2.7-50.9). The treatment was well tolerated and none of the applicators were removed prematurely. The total median hospital stay for this group of patients was significantly reduced compared to more conventional protocols. This study indicates that intracavity high dose rate balloon brachytherapy can achieve survival rates equivalent to those of conventional radiotherapy and is both cost and time efficient.

Adult↗

PubMed1996

[Prognosis in primary tumors of the central nervous system. A patient material from the Norwegian Radium Hospital 1960-94].

We present the results of a retrospective survey of 1,218 patients treated at the Norwegian Radium Hospital during the years 1980-94 for primary tumours of the central nervous system. Median survival for patients with glioblastoma (n = 492) was 12 months, for patients with anaplastic astrocytoma (n = 83) 25 months, astrocytoma (n = 260) 95 months, oligodendroglioma (n = 85) 74 months, mixed glioma (n = 68) 65 months, and medulloblastoma (n = 53) 109 months. Median survival for patients with brain stem tumours (n = 37) was nine months, while 74% of patients with tumours in the pineal region (n = 38) survived for five years. The histology and localisation of the tumour, as well as age and functional status, are important prognostic factors for survival in patients with primary CNS tumours.

Adolescent↗

PubMed1996

Noncritical soft tissues of the female pelvis: serial MR imaging before, during, and after radiation therapy.

PURPOSE: To present the findings of the irradiated noncritical soft tissues of the female pelvis at magnetic resonance (MR) imaging within 18 months after radiation therapy (RT). MATERIALS AND METHODS: The soft tissues of the pelvis of 24 women with advanced cervical carcinoma were studied in 240 MR examinations scheduled before, three times during, and 7 weeks and 3, 6, 9, 12 and 18 months after RT. Two radiologists visually evaluated the signal intensity (SI) of the subcutaneous fat, muscles, and presacral space (PS) on T1- and T2-weighted and short inversion time inversion-recovery images. RESULTS: SI compatible with edema appeared in the PS, pelvic muscles, and subcutaneous fat within 3 months after the end of RT and was observed in 23 (96%) of the 24 patients. During the observation period, the edema subsided. Eighteen months after treatment, edema in the PS was seen in 12 (50%) of the 24 patients. CONCLUSION: The soft tissues of the female pelvis showed a characteristic pattern of varying edema after irradiation.

Adipose Tissue↗

PubMed1995

External radiotherapy for circumscribed choroidal haemangiomas using a modified retinoblastoma technique.

This report describes two cases of circumscribed choroidal haemangiomas involving the fovea, complicated by serous retinal detachment. Laser photocoagulation, generally accepted as the treatment of choice for choroidal haemangioma, was considered either to be of no visual benefit or a risk for jeopardizing vision further due to the subfoveolar lesions. Fractionated radiotherapy using a lens-sparing, modified retinoblastoma technique, was given, using circular fields of 15 mm diameter. The dose was 24 Gy in 8 fractions. In both eyes the retina reattached completely. The visual acuity improved markedly in the first, and was restored to the prior level in the second. Normalization of a high intraocular pressure was also achieved in the second case. We believe this method to be a reasonable and effective therapy for some choroidal haemangiomas after careful individual consideration.

Adolescent↗

PubMed1995

Female pelvic bone marrow: serial MR imaging before, during, and after radiation therapy.

PURPOSE: To study early changes in irradiated pelvic and adjacent nonirradiated bone marrow with T1-weighted magnetic resonance (MR) and short inversion time inversion-recovery (STIR) imaging. MATERIALS AND METHODS: The bone marrow of 31 women with advanced cervical carcinoma was studied in 161 MR examinations before, during, and 7 weeks after radiation therapy. Two radiologists visually evaluated the marrow signal intensity (MSI) on T1-weighted and STIR images. RESULTS: Changes in irradiated and adjacent nonirradiated marrow were shown on T1-weighted images in 31 (100%) and 18 (58%) of the 31 patients, respectively. MSI changes on images were observed as early as 8 days after the start of radiation therapy and occurred more frequently in irradiated than in adjacent nonirradiated marrow. In the irradiated regions, a complete fatty marrow was seen on T1-weighted images obtained 6-8 weeks after the start of radiation therapy in 28 (90%) of the 31 patients. CONCLUSION: T1-weighted and STIR images obtained during and soon after radiation therapy complement each other in showing changes in bone marrow.

Adult↗

PubMed1992

Deoxyribonucleic acid cytometry and histological findings before and after 125iodine implantation of primary prostate cancer.

Deoxyribonucleic acid (DNA) flow cytometry and light microscopy were performed in pre-radiotherapy and post-radiotherapy biopsies obtained from the primary tumor in 31 patients with prostate cancer. Radiotherapy was applied by means of transperineal 125iodine (125I) implantation. Of the patients 21 had pretreatment biopsies and in 19 of these biopsies also were performed 1 and/or 1 1/2 years after the 125I implantation. Posttreatment biopsies were available for DNA flow cytometry in 12 additional patients without pretreatment DNA flow cytometry assessment. Of the 21 pretreatment biopsies 7 were diploid, 6 tetraploid and 8 aneuploid. All 31 posttreatment biopsies were either tetraploid (21) or aneuploid (10). All 6 pretreatment diploid tumors became tetraploid after radiotherapy. At 1 and/or 1 1/2 years after 125I implantation residual tumors were found in 28 of 31 prostatic glands. The high frequency of nondiploid DNA stemlines 1 or more years after 125I implantation and the high rate of residual tumor leave some doubt about the radiocurability of prostate cancer by the chosen radiotherapy technique.

Biopsy↗

PubMed1989

[Intracranial stereotaxic external radiation using a linear accelerator].

The article describes a method making it possible to give high radiation doses to a localized volume of the brain while sparing normal surrounding brain tissue. The treatment consists of sending multiple narrow radiation beams from different directions to the volume of tissue to be treated by rotating the radiation source and the patient table in relation to each other. Mega-voltage radiation from a linear accelerator is used. A non-invasive stereotactic frame is mounted on the patient and a CT scan of the brain is performed to localize the center and extent of the tissue to be treated. The radiation treatment is then given by using the coordinates on the frame to assure that the center of rotation of the treatment table and the linear accelerator pass through the center of the volume of tissue. The method has been used to give radiation boosts after external radiation to brain tumours, and to treat patients with recurrent tumours. Small localized benign intracranial tumours and AV-malformations have also been treated.

Brain Neoplasms↗

PubMed1985

Some short-term cell kinetic effects of ionizing radiation on mouse bladder urothelium.

Early morphological changes and the pattern of reactive proliferation of the hairless mouse urinary bladder urothelium after irradiation are reported. Groups of female hairless mice were anaesthetized with sodium pentobarbital and irradiated over the bladder region with 0, 10, 20 and 30 Gy. Control groups were sham-treated. Short-term cell kinetic changes were monitored using incorporation of tritiated thymidine and flow cytometry. Only minor radiation-induced alterations in the cell kinetic pattern were recorded, and no significant histomorphological changes were seen. However, a marked increase in the thymidine incorporation was seen in the control animals on the first day after anaesthesia. Radiation proctitis induced early deaths in the 30 Gy irradiated animals. The present results are in accordance with commonly accepted radiobiological theories, but not in agreement with results previously published by others.

Animals↗