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Biomedical subjects

C Lagergren

Publications and source records attributed to C Lagergren.

At least 19 recordsLinked to original sources
PubMed1991

Improved portal film image quality in radiation therapy with high energy photons.

Various metal screen-film combinations have been investigated in order to determine the best radiographic image. The quality of these different combinations has been evaluated by measuring the scattered to primary film dose ratio S/P. The S/P ratio increases with increasing atomic number of the front screen for 4 MV x-rays but shows no significant difference for 8 MV x-rays. For rear screens the S/P ratio is slightly increased for higher atomic numbers. A metal with an atomic number around 26-29 should be an optimal metal screen regarding quality aspects. A cassette of stainless steel has, in clinical use for portal and/or verification films, given very good images.

Humans↗
PubMed1986

Radiation therapy of ovarian carcinoma: presentation of a six-field technique.

A new technique for radiotherapy in ovarian carcinoma is presented. The aim was to deliver a homogeneous radiation dose to the entire abdominal cavity. The whole abdomen, except for 20% of the upper compartment, received a homogeneous dose of 40 Gy, while 2/3 of the kidneys and the posterior part of the liver received a dose ranging from 40 to 20 Gy. No clinically significant impairment of liver function was seen during follow-up.

Adult↗
PubMed1985

Interferon therapy in disseminated renal cell carcinoma.

Twenty patients with pulmonary metastases of renal cell carcinomas have been treated in a randomized study with either leucocyte interferon in daily doses of 3 x 10(6) I.U.i.m or irradiation of both lungs in a calculated mean central dose of 10 Gy in 4 weeks in combination with bleomycin and vincristine. Most patients had a short time to progression of their disease. Three patients in the interferon group had complete response (CR) and partial response (PR) and one patient in the other group had PR. The numbers of patients in both arms of the study are too small to allow any conclusions whether beneficial effects are more frequent in one group than in the other, but there is a more favourable tendency in the interferon group.

Adult↗
PubMed1984

A special cut-off gamma camera for high-resolution SPECT of the head.

A modern system for single photon emission computerized tomography has been modified in order to optimize examinations of the head. By cutting off part of the detector housing and collimators at one edge, it is possible to rotate the camera close to the skull while still covering the entire brain and the skull base. The minimum radius of revolution used in 32 patients was thereby reduced from about 20 cm to 12.7 +/- 0.8 cm. This, combined with an adjustment of the 64 X 64 matrix to a 26- by 26-cm field of view, resulted in an improvement of the spatial resolution from about 19 mm to 12.6 +/- 0.3 mm with a low-energy, all-purpose collimator, and to 10.4 +/- 0.3 mm (FWHM) with a low-energy, high-resolution collimator. The improved spatial resolution offers several clinical advantages in studies of the brain, the cerebrospinal fluid space, and the skull base.

Adult↗
PubMed1981

Role of bone scans in the initial assessment of operable patients with breast carcinoma.

The yield and the prognostic significance of initially performed bone scintigraphy in 387 patients with operable mammary carcinoma are reported. The mean follow-up time was 52 months. In 12 patients (3.1%) the scintigraphy was considered to indicate bone metastases but in only 3 of these bone metastases later developed. The low information obtained has resulted in exclusion of bone scintigraphy in the initial assessment of clinically operable patients with mammary carcinoma.

Adult↗
PubMed1978

Evaluation of tumour extension by whole body scanner.

Fifteen patients with urinary bladder carcinoma were examined by computerised tomography parallel with conventional urography before, during and after radiation therapy. Computer tomography gave better diagnostic information in the cases in which the tumour had encroached upon, or was growing outside the bladder wall, and was equally as valuable as urography when it was located wholly within the bladder. The scans were of great value as a guide in the planning of computer-aided radiation therapy.

Aged↗
PubMed1978

A method for determining bone mineral content using Fourier image reconstruction and dual source technique.

The basic principles of a quantitative tomographic technique for bone mineral determination are considered. The bone mineral content could be evaluated from a single reconstruction using projection data from two different energies. Beam hardening effects and photon counting statistics are studied by computer simulation and found to be the limiting factors in precision and accuracy.

Bone and Bones↗
PubMed1977

Xeroradiography in radiation therapy.

The xerographic technique has been introduced at Radiumhemmet for direct field control in therapy with high energy photon radiation (60Co-unit, 6 MV linear accelerator and 42 MeV betatron). The xerograms are of a sufficiently good quality for this purpose. The advantages and disadvantages connected with the xerographic facilities at present available are discussed.

Cobalt Radioisotopes↗
PubMed1976

Interferon therapy in Hodgkin's disease. A case report.

The treatment of a case of Hodgkin's disease (lymphocyte predominance, stage IV B) with exogenous i.m. interferon therapy is described. B symptoms disappeared, diseased nodes and pulmonary infiltrations decreased in size, and laboratory values normalized. Clinical improvement was associated with increased mitogenic responsiveness of the patient's lymphocytes towards various stimuli in vitro. After almost half a year's treatment tumour progression and a decreased mitogenic response were again observed. Interferon treatment was then abandoned and combined cytostatic courses were instituted. Partial remission was achieved after 6 months of cytostatic therapy, i.e. 1 year after the start of treatment.

Adult↗
PubMed1975

Radiation therapy for carcinoma of the urinary bladder. Radiologic planning and treatment techniques.

In radiation therapy for carcinoma of the bladder, various anatomic and physiologic factors affect the position of the target volume and introduce errors in the treatment technique. The radiologic procedures for planning and follow-up of the patients must consider these factors. The beam geometry is also of decisive importance for minimizing the effect of these factors and for avoiding injury to surrounding structures. The irradiation procedure of choice should be a four beam technique with supervoltage roentgen radiation.

Follow-Up Studies↗