Sinonasal pathology in nonallergic asthma and COPD: 'united airway disease' beyond the scope of allergy.

BACKGROUND: In contrast to the epidemiological and clinical association between allergic rhinitis and asthma, upper airway inflammation is less characterized in patients with nonatopic asthma and virtually unexplored in chronic obstructive pulmonary disease (COPD). Here, sinonasal pathology is studied in patients with allergic asthma, nonallergic asthma and COPD. METHODS: Ninety patients with stable bronchial disease were included in the study, of which 35 were diagnosed with allergic asthma, 24 with nonallergic asthma and 31 with COPD. Concurrently, 61 control subjects without pulmonary disease were included and matched for age and smoking habits respectively with the asthma and the COPD group. Sinonasal symptoms were evaluated on a visual analogue scale and rhinosinusitis-related impairment of quality of life was assessed with the sino-nasal outcome test-22 (SNOT-22) questionnaire. Nasal mucosal abnormalities were quantified with nasal endoscopy and nasal secretions collected for measuring inflammatory mediators. RESULTS: Allergic asthmatics, nonallergic asthmatics and COPD patients reported more nasal symptoms than their respective control subjects, had a higher SNOT-22 score and presented more mucosal abnormalities in the nose. Nasal secretions of both allergic and nonallergic asthmatics contained higher levels of eotaxin, G-CSF, IFN-gamma and MCP-1 than controls. Allergic asthmatics had higher nasal IP-10 levels as well. COPD-patients had higher nasal levels of eotaxin, G-CSF and IFN-gamma than controls. CONCLUSION: Patients with allergic and nonallergic asthma and COPD show increased nasal symptoms and more nasal inflammation. Hence, our data confirm the 'united airways' concept to be beyond the scope of allergic asthma.

Verification of absolute dose rates for intravascular brachytherapy beta sources.

The absolute dose rate around beta sources for intravascular brachytherapy was measured with thin thermoluminescent (TL) dosimeters and radiochromic film. The calibration of these dosimeters was performed at the dose maximum in a 6 MeV electron beam of a linear accelerator. Compared to the values given by the manufacturers, higher dose rates of about 20% for 90Sr/90Y source trains and 20 to 40% for 90Y line sources were found. We also measured the dose rate for a planar 90Sr/90Y source, which was calibrated at NIST (National Institute of Standards and Technology). This source serves as a reference for the determination of the dose rates by the supplier of the 90Y sources. For this source we measured a 13% higher dose rate compared to the value given in the calibration report by NIST. Our observation can have important consequences for the interpretation and comparison of the dose-related clinical results of intravascular brachytherapy with these and other beta sources. Also the comparison of the clinical results obtained with beta sources and gamma sources, i.e. 192Ir, depends largely on the accuracy of the absolute dosimetry of the beta sources.

Comparison of measured and calculated dose distributions in lung after electron beam treatment of the chest wall.

In this paper a comparison of measured and calculated absorbed dose distributions due to 6 and 8 MeV electron irradiation of a thorax phantom consisting of layers of tissue equivalent materials and infinite cylindrical rib inhomogeneities are presented. Dose measurements, carried out in lung equivalent tissue using thermoluminescent dosimeters for the phantom with and without the rib inhomogeneities, are compared with calculations using a typical two-dimensional (2-D) treatment planning system and EGS4 Monte Carlo calculations. The results show that the used 2-D planning system generally reproduces the dose distribution for the phantom without the cylindrical inhomogeneities. As results from the calculations of ratios of the doses in the phantom with ribs to the doses in the phantom without ribs, the dose perturbations are well reproduced by the EGS4 Monte Carlo calculations, but seriously underestimated by the planning system. The deviations are in the same direction for both energies, but are more pronounced for 6 MeV electrons. The disagreement between the results of the planning system on one hand and the Monte Carlo calculations and experiments on the other hand for the multirib system used is examined further by calculating dose distributions for a phantom containing only one infinite rib. The calculations show that the 2-D treatment planning system generally yields broader and less profound minima in the dose distribution directly beneath the inhomogeneities, with deviations more prominent at lower energies. In addition to the limitation of the central ray approximation, it is suggested that these discrepancies may be due to a too large electron pencil beam spread resulting from the implementation of a range straggling modification function of limited validity at the depths beyond dose maximum for these energies and these tissues.

Stereotactic radiosurgery of vestibular schwannomas with a linear accelerator.

The authors describe their initial experience with stereotactic radiosurgery of 22 cases with vestibular schwannomas using a linear accelerator. 14 of them with a follow-up of at least one year were studied. 6-9 months after treatment 86% had central tumour necrosis, 71% tumour shrinkage and none of them evidence of tumour growth 3 patients developed reversible facial nerve impairment, 2 had permanent facial numbness. Hearing diminished in one case out of three with normal hearing and in two out of three with already diminished hearing. Although there is a general consensus that microsurgery is the treatment of choice for these benign tumours, stereotactic radiosurgery challenges this opinion. Stereotactic radiosurgery not only proves to be a valuable alternative for selected cases not suitable for microsurgery, but it is conceivable that it will become the treatment of choice for small vestibular tumours. Tumour control can be obtained in the majority of treated patients with fewer complications and with a higher rate of cranial nerve sparing. This series indicates that linear accelerators can achieve results similar to the Gamma Unit in the treatment of vestibular schwannomas.

Decreased haptoglobin levels in respiratory allergy.

As unusually high frequency of decreased haptoglobin levels in patients with asthma and/or rhinitis is described. The condition is significantly associated with haptoglobin 2-2 phenotype. Decreased haptoglobin levels are more frequently associated with young age, atopic antecedents, positive skin tests for pollens, higher IgE and higher RAST activity for pollens and housedust mite. Whether the association of decreased haptoglobin levels and IgE-mediated respiratory disease has a physiopathological significance or is solely the expression of a common genetic determinate remains to be investigated.