Acta radiologica: therapy, physics, biology最新文献

Early radiation effects on the physiologic activity of ciliated cells during exposure have been investigated at 0.34Gy/s and 0.05 Gy/s. The results obtained indicate a more intense early biologic effect at a higher dose rate. The mechanisms of radiation injury are discussed.

A unique scheme for placing the most breast carcinoma patients into the least population includes newly developed systems to analyse 64 clinical and radiographic risk factors in combinations. The calibration sample consisted of 540 cancerous and 641 non-cancerous breasts. In an independent validation sample of 73 carcinoma and 462 non-carcinoma breasts, 90 percent of the potential malignant breasts were correctly classified with only 12 percent of the non-malignant breasts misclassified. Thus, the scope of prediction and delineation of malignant and non-malignant and non-malignant groups is extended.

Frozen mouse cadavers were exposed to 220 kV roentgen irradiation with the thymic area covered with a lead plate sized 18 mm X 24 mm X 4 mm oe 18 mm X 12 mm X 4 mm. Lif-Telfon rods were used for dose measurements. With larger plate the mean dose from scattered radiation, in percent of that in the uprotected abdomen, was 12.77 (thymic lobes) and 18.34 (vertebra). With the smaller shield the figures were markedly increased, 16.70 and 23.77, respectively. Since the percentage dose is relatively high, the amount of scattered radiation may have biologic significance.

Tumor control doses (TCD50) using single 60CO doses were determined on C3HBA adenocarcinoma and Dunn osteosaroma ranging in size from microscopic pulmonary colonies (3 X 13(-5) mm3) to palpable subcutaneous tumors (300 mm3) in the hind limb. The power function TCD50 =23.57 TV0.15, with TCD50 in GY and TV (tumor volume) in mm3, fits the data for both tumors over the entire range of tumor volumes used.

Lymphography of 123 newly diagnosed patients with lymphoma was followed by staging laparotomy without intra-operative abdominal roentgenography. These patients were retrospectively evaluated for residual abnormal nodes with postoperative abdominal roentgenography. Sixteen patients with pathologically normal nodes at laparotomy had residual lymphographically abnormal nodes at postoperative roentgenography. Nine patients received less extensive irradiation than they would have if the remaining abnormal nodes had been biopsied and found to contain tumor. Two had shortened survivals as an apparent consequence.

Five patients with carcinoma of the penis receiving radiation therapy and injections of Bleomycin were examined to determine whether Bleomycin affects the peripheral pool of lymphoid cells. Total lymphocyte counts were not decreased, but transient reduction of the frequency of thymus-dependent cells occurred in 3 patients. The responses of the lymphocytes to phytomitogens and PPD were temporarily decreased these 3 patients. In 2 subjects the phytomitogen reactivity of the lymphocytes was improved after treatment.

In 40 of 61 irradiated patients with Burkitt's lymphoma the long term results were evaluated. Five patients were primarily irradiated while the remaining patients had late recurrences or were chemotherapy failures. Seven patients were alive and free of recurrence after 6 months and 4 after 24 months.

Calcification at the site of lymph nodes previously affected by Hodgkin's disease and irradiated was found in 8 patients in a series of 481 consecutive cases. The patients were all women, young at the time of diagnosis, and had a long survival. The calcific deposits developed in the anterior mediastinum.

Extensive lymph node dissections have been performed in an attempt to increase survival after abdomino-perineal excision or anterior resection of the rectum for carcinoma. The lymph drainage from the upper and middle third of the rectum was demonstrated by means of 198Au which was injected into the submucosa. Less than one percent was drained to pelvic lymph nodes, giving little support for pelvic lymph node dissection for carcinoma in the upper and middle third of the rectum.

Irradiation of human peripheral lymphocytes in vitro reduces their capacity to be triggered to DNA-synthesis by PHA in a two-dose shaped fashion suggesting the presence of one relatively radiation sensitive and one relatively resistant cell population. Intracavitary and external radiation therapy for carcinoma of the uterus and vagina, which reduced the lymphocyte counts by approximately 66 per cent, did not significantly change the ratio of these subpopulations, indicating that PHA-reactive cells cannot be grouped into radiation sensitive and resistant subpopulations.