SUMMARY A programme of increased physical activity and self treatment based on the forced expiration technique was introduced to 14 adolescent patients with cystic fibrosis, diagnosed since infancy or early childhood, who had gastrointestinal and pulmonary symptoms. Twelve patients who fulfilled the one year programme had unchanged clinical conditions, pulmonary function tests, and chest x ray films. There was a significant improvement in oxygen pressure correlated to the period of increased physical activity. Other blood gas variables, including pH, standard bicarbonate, and base excess, also indicated significant changes, mainly during exercise. The study shows that daily physical activity improves the pulmonary gas exchange and that self treatment combined with physical activity is as efficient as conventional physiotherapy.In cystic fibrosis the most serious symptoms come from the viscous secretions that cause plugging and bacterial colonisation of the small airways, leading to recurrent infections and pneumoniae. Previously, this disease meant death in early childhood, but with improved methods of treatment most children with this disease reach adulthood. Chest physiotherapy combined with appropriate antibiotics are the most important components in controlling pulmonary complications and maintaining a good pulmonary function.1 The time consuming chest physiotherapy -often 2-3 times a day-implies dependence on institutions or on other people, be they physiotherapists or parents. This great dependence causes special social problems during childhood and adolescence. Difficulties may occur both for the patients and their relatives in the choice of residence, place of study, holidays, and different activities. The general purpose of modern treatment is to enable these patients to be more independent of other people and thereby acquire a better quality of life.The aim of the present study was to evaluate if a method of self treatment2 was comparable in efficiency with conventional treatment with chest physiotherapy. As a part of the self treatment programme physical activity was increased, making a two step design of the study. PatientsFourteen patients, eight girls and six boys, aged 13-23 (mean 17-8 years), agreed to participate in the study after fulfilling the following criteria:(1) they had the motivation to cooperate in the whole study;(2) they were living within a reasonable distance from the hospital; (3) they had the interest and possibility, judged upon medical criteria, to take part in some sort of physical activity; (4) they were old enough to understand the intention of the study and to have a desire to be independent of other people for their own treatment.All the patients had normal height and weight. Mean height of the girls was 165-7 cm (range [158][159][160][161][162][163][164][165][166][167][168][169][170]

The aim of this study was to explore the possibilities of using multileaf-collimated electron beams for advanced radiation therapy with conventional scattering foil flattened beams. Monte Carlo simulations were performed with the aim to improve electron beam characteristics and enable isocentric multileaf collimation. The scattering foil positions, monitor chamber thickness, the MLC location and the amount of He in the treatment head were optimized for three common commercial accelerators. The performance of the three optimized treatment head designs was compared for different SSDs in air, at treatment depth in water and for some clinical cases. The effects of electron/photon beam matching including generalized random and static errors using Gaussian one-dimensional (1 D) error distributions, and also electron energy modulation, were studied at treatment depth in water. The modification of the treatment heads improved the electron beam characteristics and enabled the use of multileaf collimation in isocentric delivery of both electron and photon beams in a mixed beam IMRT procedure.

No abstract

Skin damage caused by radiation therapy (radiodermatitis) is a severe side effect of radiotherapy in cancer patients, and there is currently a lack of effective strategies to prevent or treat such skin damage. In this work, we show with several lines of evidence that plasminogen, a pro-inflammatory factor, is key for the development of radiodermatitis. After skin irradiation in wild-type (plg+/+) mice, the plasminogen level increased in the irradiated area, leading to severe skin damage such as ulcer formation. However, plasminogen-deficient (plg−/−) mice and mice lacking plasminogen activators were mostly resistant to radiodermatitis. Moreover, treatment with a plasminogen inhibitor, tranexamic acid, decreased radiodermatitis in plg+/+ mice and prevented radiodermatitis in plg+/− mice. Together with studies at the molecular level, we report that plasmin is required for the induction of inflammation after irradiation that leads to radiodermatitis, and we propose that inhibition of plasminogen activation can be a novel treatment strategy to reduce and prevent the occurrence of radiodermatitis in patients.

Some clinically relevant measurements of lung tissue/water equivalent interfaces have been performed for a 50 MV therapeutic x-ray beam. The purpose was to investigate the severity of dose perturbation effects in lung tissue and adjacent tissues using an energy well above the common clinical practice in thoracic irradiations. The phantoms were constructed of solid water, PMMA and white polystyrene as soft tissue (water) equivalents, and cork was used as the lung tissue equivalent. Measurements were performed using radiographic film and a cylindrical ionization chamber. The results show that the degradation of the 20/80% beam penumbra in the lung region is severe, up to 2.5 times the penumbra in water for a 10 cm thick lung with a density of 0.30 x 10(3) kg m(-3). The lack of electronic equilibrium in the low-density region can cause underdosage at the lung/tumour interface of up to 30% of maximum target dose, and the build-up depth to 95% of target dose in unit density tissue behind the lung may be as large as 22 mm. It is also shown that these figures strongly depend on patient anatomy and beam size and why a careful calculation of the individual dose distribution is needed for optimal choice of photon beam energy in thoracic treatments.