Otitis media in adults with chlamydial conjunctivitis.

The aim of this study was to assess the prevalence of otological symptoms in patients with chlamydial conjunctivitis. We report four cases of chlamydial conjunctivitis, in association with otitis media, that were investigated by an otologist.

Symptomatic trichomoniasis, metronidazole allergic and pregnant--a management dilemma.

A case of persistent Trichomonas vaginalis (TV) in a pregnant, metronidazole-allergic woman is described. This case posed a management dilemma as untreated TV has been associated with adverse pregnancy outcomes but antibiotic desensitization is potentially dangerous during pregnancy.

Quality assurance in stereotactic radiosurgery/radiotherapy according to DIN 6875-1.

The new DIN ('Deutsche Industrie-Norm') 6875-1, which is currently being finalised, deals with quality assurance (QA) criteria and tests methods for linear accelerator and Gamma Knife stereotactic radiosurgery/radiotherapy including treatment planning, stereotactic frame and stereotactic imaging and a system test to check the whole chain of uncertainties. Our existing QA program, based on dedicated phantoms and test procedures, has been refined to fulfill the demands of this new DIN. The radiological and mechanical isocentre corresponded within 0.2 mm and the measured 50% isodose lines were in agreement with the calculated ones within less than 0.5 mm. The measured absorbed dose was within 3%. The resultant output factors measured for the 14-, 8- and 4-mm collimator helmet were 0.9870 +/- 0.0086, 0.9578 +/- 0.0057 and 0.8741 +/- 0.0202, respectively. For 170 consecutive tests, the mean geometrical accuracy was 0.48 +/- 0.23 mm. Besides QA phantoms and analysis software developed in-house, the use of commercially available tools facilitated the QA according to the DIN 6875-1 with which our results complied.

High precision radiosurgery and technical standards.

BACKGROUND: A high degree of precision and accuracy in radiosurgery is a fundamental requirement for therapeutic success. Small radiation fields and steep dose gradients are clinically applied thus necessitating a dedicated quality assurance program in order to guarantee dosimetric and geometric accuracy. MATERIAL AND METHODS: A detailed analysis of the course of treatment independent of the irradiation technique used results in the so-called chain of uncertainties in radiosurgery (immobilisation, imaging, treatment planning system, definition of regions of interest, mechanical accuracy, dose planning, dose verification). Each link in this chain is analysed for accuracy and the established quality assurance procedures are discussed. A "System Test" was used to check the whole chain of uncertainties simultaneously. RESULTS: The tests described are compatible with published reports on quality assurance in radiosurgery. In terms of accuracy the weakest link in the chain of uncertainties is stereotactic MR imaging. Geometric overall accuracy measured in the "System Test" is less than 0.7 mm. CONCLUSION: The established quality assurance routines have clinically been validated. MR imaging dominates geometric overall accuracy in radiosurgery, which can be limited to less than 1 mm by an adequate quality assurance protocol.

[Palliative treatment of brain metastases with gamma knife]. / Palliative Behandlung von Hirnmetastasen mit dem Gamma Knife.

The gamma knife is a stereotactic radiosurgery device which allows well defined, deep seated brain tumors or arteriovenous malformations with a maximal volume of about 25 ccm and a diameter not greater than 3.5 cm, to be treated in a single session under local anesthesia. The gamma knife offers an alternative treatment method to the classical approach of treating brain metastases by surgical excision and/or whole brain radiotherapy. The advantages of this technique are evident: the method is non-invasive, the treatment is carried out in a single session with a very short hospitalisation of two to three days, it is exempt from physical and psychical stress, the head does not need to be shaved and no hair loss occurs, a good quality of life is obtained for a reasonably prolonged survival time and it offers an economically favourable treatment method. Up to December 1999, over 30,000 patients suffering from brain metastases have been treated worldwide using the gamma knife. In Zürich, from September 1994 to December 2000 140 received this treatment. In the literature selection criteria may differ, and this may have determined some of differences in outcome. However, our results are comparable with those in the majority of publications with an average survival time of 263 days and a maximum survival of 1080 days. Good prognostic factors for survival and local control of brain metastases are a Karnofsky Performance Scale Score approaching 90 to 100, but not lower than 70, tumour volume, controlled primary cancer, and absence or stable extracranial metastases.