Acta radiologica: therapy, physics, biology最新文献

From the central part of the labium majus the lymphatic transport of 198Au is invariably bilateral to inguinal and pelvic lymph nodes. Thus, bilateral inguinal and low pelvic lymph-adenectomy is logical in the treatment of carcinoma of the vulva. 198Au injected subcutaneously and Lipiodol injected intralymphatically in the dorsum of the foot were transported exclusively to ipsilateral inguinal and pelvic lymph nodes. Thus, there is no need for contralateral lymphadenectomy in malignancies on the dorsum of the foot.

The modulation transfer function of radiologic imaging systems is commonly obtained by determining the line spread function (LSF) of the system and computing its Fourier transform. Ideally, LSF should be obtained with infinitesimally narrow slits. The use of finite slits for obtaining the LSF is analyzed theoretically. An expression for the MTF of a finite rectangular slit is derived. Slit width correction of observed MTF is discussed as well as the correction for any generalized slit configuration.

Twenty-two patients with Burkitt's lymphoma in complete remission induced by either cyclophosphamide or a combination of cyclophosphamide, oncovin and methotrexate were randomized to receive or not to receive prophylactic cerebrospinal irradiation. Six of 11 irradiated patients relapsed with tumour of the central nervous system as compared to 4 of 11 controls. Relapse frequency appeared to be related to stage of disease on admission. It is concluded that irradiation does not prevent relapse.

In hairless mice, dorsal skin flaps were exposed to 15 kV roentgen radiation. Thin metal wires were stretched across the field. At eight different intervals, up to 6 days, and following Colcemid injection, the number and location of mitoses in the epidermis were recorded. The regeneration observed in the irradiated parts of the epidermis seems to be due to migration of cells from shielded areas, the rate during the first 6 days being about 1/6 mm per day. Migration takes place along the basal membrane of the epidermis before any increased loss of cells in superficial layers has occurred.

Human tumors grown subcutaneously in the thymus deficient nude mice are used as a model system to compare the effectiveness of clinically relevant irradiation regimes. Procedures for local irradiation of the tumors with 60Co radiation are described in detail. A preliminary test of the regression of two malignant melanomas, following three clinically relevant fractionation schedules, is performed. The overall treatment time and the nominal standard dose (NSD) are kept equal for the irradiation regimes chosen.

The time course of 3H-TDR labelling index of osteoprogenitor cells and the doses in endosteum of lumbar vertebra and distal femoral epiphysis were autoradiographically determined in young female mice after single injections of 19.7 and 55.9 micronCi/kg body weight of 226Ra. The selected bone areas were examined in animals killed 2 hours to 28 days after the injection of nuclide. It was ascertained that changes in the relative labelling index are depending on the absorbed doses of alpha radiation. The possible relevance of these experimental findings for the explanation of the osteosarcoma induction and localization is discussed.

The graft in 178 renal transplant patients was irradiated in an effort to halt acute rejection phenomena. Of the patients, 61 per cent received their transplant from either a sibling, parent or child and 38 per cent received cadaveric kidneys. Of the irradiated kidneys 61 per cent were functioning at 6 months, 58 per cent at 12 months and 49 per cent at 18 months. The rational for irradiation of transplanted kidneys with acute rejection is discussed.

Isotope nephrography was performed in 90 cases of carcinoma of the uterine cervix stage I B before radical hysterectomy with pelvic lymph node dissection. Ureteric involvement was indicated in 15 patients, 10 of these had metastases to the pelvic lymph nodes. The overall metastases detection rate was 55 per cent.

The effect of cysteamine and 2-mercapto-propionyl-glycine on the induction and repair of single-strand breaks in the DNA of Chinese hamster cells by irradiation in vitro in the presence of oxygen or in anoxia was investigated. The substances protected against the formation of breaks by irradiation both under oxic and anoxic conditions. The substances also exhibited a toxic effect which resulted in degradation of DNA. Cysteamine inhibited the rejoining of breaks after radiation exposure.

The value of 75Se-selenite scintigraphy in clinical staging was investigated in 45 patients with Hodgkin's disease and in 28 patients with non-Hodgkin's lymphoma. Of these, 9 patients had recurrence of previously treated lymphomas. The scintigraphic results were compared with clinical, cytologic, histologic and radiographic findings in different anatomic regions. 75Se-selenite scintigraphy resulted in 6 to 20 per cent false negative findings, 15 to 43 per cent false positive and 12 to 20 per cent equivocal evaluations, the accuracy being least in the abdominal region. The relatively high rediation dose delivered by 75Se-selenite, furthermore, makes it less attractive for use in the primary diagnosis of malignant lymphomas.