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

Sixty-seven patients with nodular sclerosis (Hodgkin's disease stages I and II) have been subclassified according to the cellular composition and the amount of fibrosis. Predominance of mature lymphocytes and rarity of Reed Sternberg cells were associated with less extensive disease at presentation and more favourable outcome. A less definite correlation to the amount of fibrosis was found.

Skin reaction in the rat's foot was used as an experimental method to evaluate the protective potential of profound temporary hypoxia against roentgen radiation produced by a linear accelerator. Hypoxia was induced by intraarterial injection of degradable starch microspheres. The irradiation dose needed to evoke a certain reaction in the hypoxic feet was 2.0 times the dose giving the same reaction in a control group. The results point towards a new technique of inducing local hypoxia in healthy tissues which need to be protected in an irradiation field.

A review of 82 cases of adenoid cystic carcinoma in the head and neck is given. Radical surgery was carried out in 33 patients and yielded the best long-term results. Radiation therapy was given to 43 patients for inoperable tumour, local recurrence or, postoperatively, for sub-clinical disease. It proved especially valuable in obtaining remissions from local recurrence.

Patients with unresectable or inoperable bronchial carcinoma were treated with en-bloc irradiation of the tumour and the mediastinal lymph nodes to a total target absorbed dose of 40 Gy in 20 fractions. The first 52 patients were treated in one series and the last 45 patients in two series (split-course). Radiation adverse effects were only mild. The two regimens gave the same palliative results. The median survival was the same for the 2 groups (8 months). Most patients died in disseminated disease.

The hematologic effects of combined chemotherapy and irradiation were analyzed in 70 patients with Hodgkin's disease stage I and II. The schedule used was as follows: one cycle of 15--21 days of chemotherapy immediately followed by irradiation, including mantle and lumboaortic fields. After a rest of one month, another cycle of the same chemotherapy was applied. The erythrocytes varied slightly; the leukocytes decreased during chemotherapy and were stable or increased slightly during irradiation. Platelets decreased slightly during chemotherapy and more markedly during irradiation. No major side effects were observed, and the regimen appeared well tolerated.

Recently a new method was described, the 67Ga subtraction scanning method. 67Ga accumulates in neoplastic and inflammatory tissue. The subtraction method was applied for evaluating 38 patients with Hodgkin's disease and non-Hodgkin's lymphoma. The preliminary experiences are described. It was found that the diagnostic accuracy is comparable to that of 67Ga scanning. The subtraction method offers potential improvement of the accuracy for equivocal scans, but further technological refinement is needed before the method can be widely applicable.

This report describes now a set of applicators, convering fields with dimensions of 4 to 20 cm, for the 6 to 20 MeV electron beams of a MEL SL75-20 linear accelerator was developed. The electron scatter contribution of the applicator walls to the treatment field was investigated, varying the applicator entrance opening and the scattering foil, with the aim of optimizing the resulting field flatness, with a minimum loss of depth dose. Experiments with field defining end frames and additional perspex scatterers for large field sizes are also reported.

The results and side effects of en-bloc irradiation of ear, nose and throat tumours and their lymphatics showed that the technique had been successful in nasopharyngeal carcinoma, but poor in carcinoma of the hypopharynx. Marked early and late radiation side effects were relatively common in high age and with certain tumour sites, whereas no correlation could be demonstrated with total absorbed dose, fractionation, cumulative radiation effect or major surgery.

Eight children with histiocytosis X were investigated with reference to immunologic reactivity in vitro (PHA, PWM, Con-A and MLC testing). No significant impairment of immune function was detected, but a subnormal (statistically insignificant) response in the MLC test may suggest some abnormality of the T lymphocytes reacting against allogeneic cells. In a patient who relapsed a marked, but insignificant, increase in lymphocyte reactivity in vitro was observed.

Collected data on radiation-induced lesions of the brachial plexus were analyzed on the assumption that this reaction arises from depletion of some unidentified cell population in the irradiated tissues. A multi-probit search program was used to derive best-fitting cell kinetic parameters in a composite multi-target model for cellular radiation lethality and repopulation. From these parameters, a comprehensive iso-effect table, for a wide range of treatment schedules including daily treatment as well as fractionation at shorter and longer intervals, was constructed. The table provides a useful set of tolerance dosage limits for late effects in irradiated peripheral nerve.