18F-FDG PET/CT for detecting nodal metastases in patients with oral cancer staged N0 by clinical examination and CT/MRI.

(18)F-FDG PET has a high accuracy in staging head and neck cancer, but its role in patients with clinically and radiographically negative necks (N0) is less clear. In particular, the value of combined PET/CT has not been determined in this group of patients. METHODS: In a prospective study, 31 patients with oral cancer and no evidence of lymph node metastases by clinical examination or CT/MRI underwent (18)F-FDG PET/CT before elective neck dissection. PET/CT findings were recorded by neck side (left or right) and lymph node level. PET/CT findings were compared with histopathology of dissected nodes, which was the standard of reference. RESULTS: Elective neck dissections (26 unilateral, 5 bilateral; a total of 36 neck sides), involving 142 nodal levels, were performed. Only 13 of 765 dissected lymph nodes harbored metastases. Histopathology revealed nodal metastases in 9 of 36 neck sides and 9 of 142 nodal levels. PET was TP in 6 nodal levels (6 neck sides), false-negative in 3 levels (3 neck sides), true-negative in 127 levels (23 neck sides), and false-positive in 6 levels (4 neck sides). The 3 false-negative findings occurred in metastases smaller than 3 mm or because of inability to distinguish between primary tumor and adjacent metastasis. TP and false-positive nodes exhibited similar standardized uptakes (4.8 +/- 1.1 vs. 4.2 +/- 1.0; P = not significant). Sensitivity and specificity were 67% and 85% on the basis of neck sides and 67% and 95% on the basis of number of nodal levels, respectively. If a decision regarding the need for neck dissection had been based solely on PET/CT, 3 false-negative necks would have been undertreated, and 4 false-positive necks would have been overtreated. CONCLUSION: (18)F-FDG PET/CT can identify lymph node metastases in a segment of patients with oral cancer and N0 neck. A negative test can exclude metastatic deposits with high specificity. Despite reasonably high overall accuracy, however, the clinical application of PET/CT in the N0 neck may be limited by the combination of limited sensitivity for small metastatic deposits and a relatively high number of false-positive findings. The surgical management of the N0 neck should therefore not be based on PET/CT findings alone.     

Olfactory neuroblastoma mimicking primary intracranial neoplasm

A case of esthesioneuroblastoma with an unusual clinical and radiographic presentation is reported. The presenting symptoms as well as the computed tomographic examination were compatible with a primary intracranial mass.     

Improved estimates of discordance ratios in twin studies

In the study of monozygotic twins relative to disease and risk factors, particular interest focuses on the subset who are discordant for some suspected risk factor (for example, smoking), since such twins constitute a natural case-control pair. In such studies, questionnaires designed to identify the status of all twin pairs are sometimes error prone and can yield misleading estimates of the concordance-discordance ratios. Greater efforts to verify the characteristics of apparently discordant pairs than to verify those of apparently concordant pairs can result in the 'unequal ascertainment' fallacy. Using the results of a questionnaire with known error rates and the 'apparent' frequencies yielded, we present unbiased, maximum likelihood estimates of the 'true' proportions of concordant and discordant pairs. concordant and discordant pairs. We also present approximate covariances among these estimates.     

Local hemostasis in subarachnoid hemorrhage

Fibrinopeptide A (FPA), platelet-secreted protein, platelet factor 4 and beta-thromboglobulin were determined in the cerebrospinal fluid of patients who had suffered from subarachnoid hemorrhage and were treated with 6 g tranexamic acid or 4 million KIU aprotinin to prevent rebleeding. Platelet-secreted proteins and FPA were cleared from the cerebrospinal fluid within 3 days after bleeding. Their vasoactive and thrombotic capability is limited to the initiation period of vasospasm that usually comes to clinical observation 3-8 days after bleeding. Increased thrombotic activity of the cerebrospinal fluid, as reflected by high levels of FPA and platelet-secreted protein, seemed to promote the occurrence of neurological deficits.     

Outpatient management of chronic suppurative otitis media without cholesteatoma in children.

Prolonged antipseudomonal parenteral antibiotic therapy combined with daily aural toilet has been effective in resolving long standing ear discharge in children with chronic suppurative otitis media. However, such treatment suffered from the disadvantages of prolonged hospitalization. We conducted a prospective study to investigate the feasibility and efficacy of exclusive outpatient treatment of children with chronic suppurative otitis media without cholesteatoma who had failed ototopical/oral antimicrobial therapy. The treatment consisted of daily aural toilet (suction and debridement) and twice daily parenteral ceftazidime (50 mg/kg/dose). Thirty-seven children were included. The duration of discharge from the ear before treatment was 6 to 121 months (median, 30 months). Aerobic cultures yielded Pseudomonas aeruginosa in 97%, often with other organisms. The management and follow-up were performed jointly by otolaryngology and infectious diseases physicians using the hospital ambulatory services. The route of ceftazidime administration (intravenous or intramuscular) was chosen according to the parents' and patients' convenience. Discharge stopped within 3 to 20 days (median, 8 days) in all children but one. Seventy-six percent of the 29 children available for follow-up 12 months after treatment were still free of discharge. Our results demonstrate that a regiment combining daily aural toilet and twice daily parenteral ceftazidime is highly efficacious in resolving ear discharge in children with chronic suppurative otitis media without cholesteatoma and that such a regimen does not require hospitalization.     

Pressures on the fetal head during normal labor.

The pressure recordings from both parietal regions of the fetal head during the second stage of labor of 44 spontaneous deliveries with vertex presentation were evaluated and compared to the simultaneously recorded pressures in the amniotic cavity by calculating pressure parameters during and between uterine contractions. Analysis of the bearing down period revealed on the average higher values at the anterior side in comparison to the posterior side of the skull. This is explained by the complex anatomy of the curved birth canal. Overall, the head pressure values averaged from the recordings of both parietal regions were about twice as high as the corresponding amniotic pressure values. During the descend of the head through the birth canal, an increase of pressure on the fetal head was observed that is mainly due to the rising resistance of the narrowing pelvis and stretched tissue of the passageway. A marked interindividual deviation of head pressure was found that was independent from amniotic pressure variations thus preventing indirect deduction of head strain from internal togography.