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R J Kau

Publications and source records attributed to R J Kau.

9 recordsLinked to original sources
PubMed1995

Comparison of fluorine-18-fluorodeoxyglucose PET, MRI and endoscopy for staging head and neck squamous-cell carcinomas.

UNLABELLED: Accurate, preoperative assessment of tumor extent and lymph node involvement is mandatory for individualized therapy in patients with squamous-cell carcinomas (SCCs) of the head and neck region. Metabolic imaging, [18F]fluorodeoxyglucose (FDG) PET and MRI were compared with postoperative, histologic tissue characterization. METHODS: Dynamic and static PET with 370 MBq [18F]FDG up to 60 min postinjection and MRI were compared prospectively in 22 patients with head and neck SCCs. PET results with and without attenuation correction were compared with postoperative T and N stages based on pathologic findings. RESULTS: Kinetic characteristics and tracer uptake intensity were similar in primary tumors and lymph node metastases. In both, FDG uptake did not reach a plateau phase 60 min postinjection. There was no statistically significant correlation of FDG uptake with plasma glucose level or histologic grading. All primary tumors were clearly demonstrated by PET, which tended to overestimate tumor size. The sensitivity and specificity for detecting individual lymph node involvement were 90% and 96%, respectively, for PET and, thus, significantly higher for MRI (78% and 71%, respectively; p < 0.05). N stages were correctly identified by MRI in only 4 patients; PET correctly staged lymph nodes in 15 of 17 patients. Based on "neck sides", the sensitivity and specificity were higher for PET, 89% and 100%, respectively, compared with MRI values of 72% and 56%, respectively. CONCLUSION: FDG-PET may be helpful in detecting occult primary tumors with positive lymph nodes.

Adult↗
PubMed1994

[Detection of somatostatin receptors in tumors in the area of the head and neck and their clinical importance].

The development of a radiolabelled somatostatin analogue Indium-111-Pentetreotide makes the detection of somatostatin receptor-bearing tumours by scintigraphic techniques possible. The existence of high-affinity binding sites for somatostatin has been described previously for most endocrine active tumours of the gastroenteropancreatic system (GEP), malignant lymphomas, small cell lung carcinomas, a subgroup of breast tumours and several types of neuroendocrine related human tumours. Using this new diagnostic tool we investigated some head and neck tumours of neuroendocrine origin (carcinoid of larynx, Merkel cell carcinoma, paragangliomas) with the newly developed radiolabelled somatostatin analogue Indium-111-Pentetreotide whether in vivo visualisation of somatostatin receptors might be possible. In cases not accessible for surgery but with a positive receptor status we started a specific therapy with the somatostatin analogue octreotide. The preliminary results suggest that this new isotopic scanning technique in a diagnostic tool and a predictive method for an effective therapy of those head and neck tumours which revealed highly specifically a positive receptor status. The therapeutical results using the somatostatin analogue octreotide indicate that this new concept is an ideal therapeutic strategy for those neuroendocrine head and neck tumours which cannot be controlled by surgical procedures.

Adult↗
PubMed1990

[Drainage of the middle ear].

Otitis media with effusion occurs very frequently in childhood and usually heals without therapy. The condition is thought to be due to a higher susceptibility to infections of the upper respiratory tract and the fact that the Eustachian tube is not yet functioning perfectly at that age. Many authors explain this astonishingly high rate of spontaneous recoveries by tube malfunction alone, never even considering a middle ear clearance system. It is known from the paranasal sinuses that the cavities are regularly and continually cleaned according to very precise rules. In in-vivo experiments with guinea pigs the author proved that there is an obvious similarity between the paranasal sinus and the middle ear as far as the clearance system is concerned. By applying tracer substances to the middle ear mucosa the usual drainage pathways out of the middle ear into the Eustachian tube, and the different rates of drainage were very precisely defined.

Animals↗
PubMed1990

[Otitis media].

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Brain Abscess↗
PubMed1989

[Initial results of immunotherapy approaches to tumor treatment in the animal model].

The possibilities of using immunocytes in cancer therapy have been increasing during the last few years. Contrary to the promising results gained by in vitro experiments, several clinical trials have shown that, on the one hand, it is difficult to preserve a quantity of cells big enough to inhibit tumours, and they have also shown that, on the other hand, antitumour lymphocytes do not get into the tumour. That is why we concentrated on improving the tumour selectivity of the antitumour lymphocytes. We carried this out practising two sets of experiments. First we incubated patient lymphocytes with tumour extract and vaccinated them in this manner. Secondly, by binding antitumour antibodies to lymphocytes, we could improve the ability of lymphocytes to bind with tumour cells. We tested these therapy models on human tumours and on tumour cell lines. Both were implanted in the renal capsule space of nude mice.

Adenocarcinoma↗
PubMed1987

[Latency of the acoustic evoked stapedius reflex and its clinical significance].

We measured the mean latency of the stapedius reflex by normal listeners. We observed a prolongation of the latency by patients with operative and histological confirmed neurinoma of the VIII. nerve. Even if the measured stapedius reflex latency considerably varies, this method represents, any way, an important support to BERA to discover tumours of the cerebello-pontine angle.

Adolescent↗
PubMed1987

[Sedation in ambulatory BERA (brainstem electric response audiometry) studies in childhood].

We use BERA to determine the hearing threshold of children. This examination is most of the time performed on outpatients and often combined with a minor surgery. That's the reason why a sedation has to fulfill following conditions: 1. a quick, non-traumatic induction of anaesthesia--normally--without premedication; 2. an anesthesia deep enough to enable us to carry out a minor surgery as well as to get the best reliable BERA results; 3. a short period of wake-up as the patient should leave the hospital as soon as possible. In short, we got the best results first using Halothane as inhalant for the minor surgery and continuing with Midazolam as i.v. sedative for BERA examination.

Anesthesia, General↗
PubMed1986

[Thorotrastoma--late damage following thorotrast arteriography].

We report two cases of cervical thorotrastoma. Thorotrast is no longer used as a radiographic contrast agent, so that the rare thorotrastoma is often forgotten in the differential diagnosis of hypopharyngeal tumours. Surgical treatment of a thorotrastoma is not recommenced.

Aged↗