Acta radiologica: oncology, radiation, physics, biology最新文献

The treatment of advanced base of tongue carcinoma with concurrent radiation therapy and 5-fluorouracil versus radiation therapy alone is compared. Although the results are inconclusive, it is noteworthy that all the 5-year survivors were patients given combined treatment. Important questions regarding optimization of time-dose relationships with combined therapy were generated. Accordingly, 18F-5 fluorouracil was synthesized in an attempt to answer some of these questions.

Patients with basal cell carcinoma of the skin were treated with combined MTDQ (6,6'-methylene-bis-(2,2,4-trimethyl-1,2-dihydroquinoline)) administration and irradiation. Significantly better results were obtained with a skin exposure of 2 000 R combined with MTDQ than with the same dose alone. The results were comparable to those obtained with an exposure of 4 000 R. MTDQ administration induced decrease of tissular malonaldehyde concentration and suggested the peroxide-decomposing action of the radiation sensitizer.

Hemopoietic tissues of mice contain cells capable of proliferation and differentiation to form endogenous spleen colonies (Endo-CFU-S) in irradiated animals. Hydroxyurea (HU) given before irradiation of C57BL mice for endogenous CFU assay increased the number of surviving CFU-S twofold. Either HU or HSATT given after the initial stimulus abolished this rise. In vivo and in vitro 'suicide' assays of spleen cells indicated that cells were stimulated by the HU or the initial stimulus to enter into DNA synthesis shortly after stimulation. The resting CFU cell population appeared to be positioned close to DNA-S phase and responded to the stimulus by entry into S phase. Whole body irradiation at intervals after HU revealed a changing radiation sensitivity of the endogenous CFU-S consistent with drug-induced progression with decreased radiation sensitivity of the S phase cohort of cells.

Brush border enzymes of proximal tubules, lysosomal activities and protein content of rat kidney were analysed after whole-body irradiation using two different experimental schedules. Maltase, alkaline phosphatase and beta-glucuronidase activities increased moderately during the first days after irradiation, whereas LAP, cathespsin D activities and protein content were not modified. No evident morphologic alterations were observed.

The vascular structure of experimental tumours was investigated by a resin cast technique. Six characteristic types of capillaries were found: club-like, wave-like, tortuous,sinusoid-like, disorderly running and tapering. The vascular structure was correlated to the tumour growth.

Treatment results in 31 patients with nephroblastoma are reported. Survival seemed superior in patients who received Actinomycin-D in addition to surgery and postoperative irradiation. Twelve long-term surviving children were evaluated for side-effects of the treatment. Although inhibition of growth and other abnormalities occurred in most survivors, little permanent disability and dysfunction appears to have resulted from the treatment.

Sixty postmenopausal patients with microscopically confirmed, progressive mammary carcinoma and local recurrence alone or in combination with distant metastases or with distant metastases only, not previously treated with cytostatics, were given tamoxifen (Nolvadex), 10 mg 3 times daily. The response rate in 37 evaluable patients was 48 per cent, with a median duration of the response of 26+ weeks. The effectiveness of the drug increased significantly with an increasing interval between primary treatment and the appearance of the first recurrence. No serious side effects occurred.

A randomized trial comparing Vincristine, Adriamycin, Cyclophosphamide (VAC) with or without Methotrexate with citrovorum factor rescue (VACM) was performed in 64 patients with metastatic postmenopausal mammary carcinoma. Previous treatment of metastases, dominant site of metastases and performance condition were similar in the patients. No significant difference was found in the response rates (complete remission + partial remission; VAC 21/31, VACM 25/33), in the duration of the remissions or in the survivals. The duration of remission in CR was significantly longer than in PR. No serious side effects were observed. The VAC regimen is preferable, particularly with respect to the costs and the simple procedure of administration.

Linear programming can be used to optimize intracavitary brachytherapy for carcinoma of the cervix. A method has been developed which gives meaningful output and is described. A set of reference points were necessary in addition to the standard reference points. Point A as well as an array of points for adjacent radiation sensitive normal structures were used in order to obtain isodose curves conforming to those commonly used for therapy. In addition, arbitrary upper and lower limits of dose at selected points were needed and were set to conform to systems commonly used clinically for intracavitary therapy. It was immediately evident that a wide variety of loadings can be used that deliver appropriate or improved doses to reference points while minimizing normal tissue dose. The loadings represent arrangements which are not commonly used in many clinics but offer potential for clinical use.

Rat brain was exposed to 30, 40 or 60 Gy of roentgen rays and different biochemical and physiologic parameters were assayed from one day to 2 years. The most important changes noted were an intermediate increase in DNA, an intermediate to late--dependent on dose--increase in collagen, a decrease in sialic acid, an early to intermediate increase in serotonin, an increase in cathepsin, an early depression, and intermediate enhancement and a late decrease in alpha amino isobutyrate uptake by brain, and an early reduction, an intermediate--and sometimes late--increase in blood flow. These changes suggest that all three principal systems 2n the brain, nerve cells, glia and vascular system, participate in late changes.