PURPOSE: To study the factors affecting the risk of symptomatic temporal lobe necrosis after different fractionation schedules. METHODS AND MATERIALS: One thousand thirty-two patients with T1-2 nasopharyngeal carcinoma treated with radical radiotherapy in Hong Kong during 1990-1995 were studied. They were treated at four different centers with similar techniques but different fractionation schedules: 984 patients were given 1 fraction daily throughout (q.d.), and 48 patients were irradiated twice daily (b.i.d.) for part of the course. The median total dose was 62.5 Gy (range 50.4-71.2), dose per fraction was 2.5 Gy (range 1.6-4.2), and overall treatment time (OTT) was 44 days (range 29-70). In addition, 500 patients received supplementary doses for parapharyngeal extension, 113 received booster doses by brachytherapy, and 114 received sequential chemotherapy using cisplatin-based regimes. RESULTS: Altogether, 24 patients developed symptomatic temporal lobe necrosis: 18 from the q.d. group and 6 from the b.i.d. group. The 5-year actuarial incidence ranged from 0% (after 66 Gy in 33 fractions within 44 days) to 14% (after 71.2 Gy in 40 fractions within 35 days). Multivariate analyses showed that the risk was significantly affected by the fractional effect of the product of total dose and dose per fraction (hazard ratio [HR] = 1.04, 95% confidence interval [CI] 1.02-1.05), OTT (HR 0.88, 95% CI 0.80-0.97), and b.i.d. scheduling (HR 13, 95% CI 3-54). Repeating the analyses for patients treated with the q.d. schedules confirmed the independent significance of OTT in addition to the product of total dose and dose per fraction. CONCLUSION: The tentative results suggest that in addition to fractional dose, the OTT also had significant impact on the risk of temporal lobe necrosis, and b.i.d. scheduling increased the hazard further. 相似文献
Two cases of interhemispheric subdural haematoma are presented. None of the patients had any neurological deficit on admission. They developed progressive neurological deficits within a day or two. Surgical treatment was by a large convexity craniectomy and a wide opening of the dura. The dura was left open in one case and primary duroplasty was done in the other. No deliberate attempt was made to remove the interhemispheric clot. Both patients made a quick and complete recovery by this simple procedure. Cranioplasty was carried out subsequently. Chinese Abstract Figure Chinese Abstract Open in figure viewer PowerPoint
HYPOTHESIS: Endolymphatic hydrops in patients diagnosed with Ménière's disease causes changes in the response properties of the basilar membrane that lead to impaired high-pass noise masking of auditory brainstem responses to clicks. BACKGROUND: Ménière's disease is defined as the idiopathic syndrome of endolymphatic (cochlear) hydrops, which is an abnormal increase in the volume of cochlear fluid (endolymph) in the inner ear. Accurate detection and diagnosis are important but difficult because of the lack of sufficiently sensitive tests. METHODS: Two populations were compared: (1) 38 non-Ménière's normal-hearing subjects; and (2) 23 patients who, at the time of testing, continued to have at least three of the four hallmark symptoms (i.e., tinnitus, vertigo, fluctuating hearing loss, and fullness) used in the diagnosis of Ménière's disease. Auditory brainstem responses to clicks presented ipsilaterally with masking noise that was high-pass filtered at various frequencies were recorded. RESULTS: In the Ménière's patients, the masking noise is insufficient such that an undermasked Wave V is still present at a latency similar to that of Wave V in the response to the clicks alone. In the control non-Ménière's normal-hearing subjects, this undermasked component was either absent or significantly delayed because of the masking noise. The difference in the delays between these populations is such that the distributions do not overlap, resulting in 100% sensitivity and 100% specificity. CONCLUSION: This test is able to distinguish objectively active Ménière's disease in individuals and may show promise for tracking changes in the severity of the disease caused by progression or treatment. 相似文献
Theories of behavior change indicate that an analysis of barriers to change is helpful when trying to influence professional
practice. The aim of this study was to assess the perceived barriers to practice change by eliciting nurses' opinions with
regard to barriers to, and facilitators of, implementation of a Fall Prevention clinical practice guideline in five acute
care hospitals in Singapore. 相似文献
Interstitial deletion of the long arm of chromosome 9 (9q-) is an uncommon karyotypic abnormality in acute myeloid leukemia (AML). We report a case of acute myeloid leukemia, M6 according to the FAB criteria, in which 9q- was the sole karyotypic abnormality. From our own experience and that in the literature, interstitial 9q- seems to be associated with two specific morphologic/cytogenetic categories: AML M2 and t(8;21)(q22;q22)/trisomy 21; and as the sole karyotypic aberration in AML M1/M2(M6) with dyserythropoiesis. Examination of the published karyotypes shows that 9ql3 to 9q21 is the commonest deleted segment, suggesting that this region may carry genes important in leukemogenesis. 相似文献