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Biomedical subjects

A Dietz

Publications and source records attributed to A Dietz.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Decision making in non resectable head and neck tumours].

Decision Making in Non Resectable Head and Neck Tumours. Advanced squamous cell carcinomas of the oral cavity, oro-, hypopharynx and larynx often have to be categorised as non resectable disease. Complex decision making for therapy is influenced by morphological, social and ethical aspects. In case of non resectability, simultaneous chemo radiation therapy is evident and recommended. Different substances for additional chemotherapy like Cis-, Carboplatine, 5-Fluorouracile, Mitomycin C and Taxans are in use. Alternatively for selected cases (to avoid total glossectomy for instance) brachytherapy is recommended. Salvage surgery after primary chemo radiation is predominantly common in residual neck disease. Sole chemotherapy is suggested for second or third line palliative treatment.

Antibiotics, Antineoplastic↗
PubMed2005

[Navigated control: a new concept in computer assisted ENT-surgery].

This work conceived and evaluates a mechatronical system for ORL-surgery by example of a Shaver for Functional Endoscopic Sinus Surgery controlled by navigation. The Shaver is automatically on/off-regulated depending on the current position in relation to the planned working space. This working space is defined on the basis of the individual CT data. Within this area the Shaver reacts to the signal of the surgeon (foot pedal). If the Shaver leaves the working space, an interruption of the drive regulation to the Shaver takes place. The evaluation of the planning software based on 32 patient CT-data sets. The registration accuracy in a anatomical model was examined on 451 measurements of endonasal attached titanium screws. The conversions of the working space were evaluated at 5 different technical models. The average time for segmenting the working space was found at 4.23 minutes per case. An average registration accuracy of the Shaver of 1.08 mm resulted. The pre-defined cavity was to be cleared away without restrictions. The preoperative determined work-space was converted by 3.1 mm over all levels. The study proves the feasibility of a mechatronical assistant system by the example of the navigate-controlled Shaver in paranasal sinus surgery. Contrary to conventional CAS solutions redundancy and cognitive discharge of the surgeon are considered in this conception. We see numerous applications according to the explained principle for power-control of instruments in ORL-surgery in the future such as drilling, high frequency surgery or laser.

Feasibility Studies↗
PubMed2004

[Diagnosis with (18)F-FDG PET scan after larynx preservation by primary radiochemotherapy].

PATIENTS AND METHODS: In a group of 20 patients undergoing chemoradiation for larynx organ preservation after diagnosis of laryngeal and hypopharyngeal carcinoma, (18)F-fluordeoxyglucose positron emission tomography ((18)F-FDG-PET) was performed before the start of therapy. After i.v. application of 240 MBq FDG, a dynamic PET in 3-D-mode was performed over 90 min (Siemens CTI ECAT EXACT HR(+)). Analysis was done visually and semiquantitatively (60-90 min p.i.) following iterative reconstruction. Additional (18)F-FDG-PET investigations were done and correlated with the clinical outcome in 16/20 patients at 3 months and in 14/20 patients at 6 months after the end of therapy. RESULTS: In 17/20 patients (85%), the preclinical (18)F-FDG-PET correlated well with the histologically confirmed primary tumor. Three cases were false negatives. In one case this was due to an increased glucose value (203 mg%). After 3 months, 8/13 (62%) patients showed a positive correlation between clinical and PET results (sensitivity 100%, specificity 70%). After 6 months, 9/11 (82%) patients presented clinically normal PET results. PET results were false negative in one case (sensitivity 67%, specificity 88%). CONCLUSION: The data of our trial slightly reduce the enthusiasm of early (18)F-FDG-PET detection of residual disease after chemoradiation in resectable laryngeal or hypopharyngeal cancer. Further trials should optimize the calculation integrating the exact quantification of glucose metabolism with the aim of improving sensitivity and specificity.

Aged↗
PubMed2004

Is there a role for chemosensitivity tests in head and neck cancer?

Despite many advances in predictive testing of human malignancies, we are far from using it routinely in clinical practice. Investigating the responsiveness of solid tumors to cytostatic drugs is particularly challenging. Nevertheless, for head and neck cancer, chemosensitivity testing is an increasingly attractive option, since chemotherapy has proven to have curative potential in the therapy of head and neck cancer, in particular in combination with radiation. The significant need for predictive methods to identify patients responsive to therapy, first of all in organ preservation programs, which is an alternative to first-line surgery, had recently renewed the discussion on a possible role of chemosensitivity testing in head and neck cancer. In this review, we discuss the current state of chemosensitivity testing in head and neck cancer. Recent methodological developments, in particular elimination of photochemical artifacts and inclusion of stromal cell response studies, may soon augment the value of ex vivo chemosensitivity testing for the management of head and neck cancer.

Antineoplastic Agents↗
PubMed2004

Prognostic impact of EBV-related LMP-1, histologic type, and environmental factors in nasopharyngeal carcinoma in a German population.

INTRODUCTION: This retrospective study addressed the possible involvement of latent Epstein-Barr virus (EBV) infection, in particular LMP-1 expression, and further exogenous factors, i.e. tobacco, alcohol and occupational hazardous substances, in nasopharyngeal carcinoma (NPC) in a German population. PATIENTS AND METHODS: From 1980 to 2000, 44 patients suffering from histologically confirmed NPC were entered into the study. 33 specimens were available for immunostaining (IHC) to analyze LMP-1 expression. Information about environmental exposures were obtained employing a detailed standardized questionnaire. RESULTS: Outcome of patients with squamous cell NPC (SC-NPC) was significant worse than that of those with non-keratinizing NPC (NK-NPC). Age and tumor size correlated with response to therapy. The group with negative conventional LMP-1 staining showed better overall survival after 5 years compared to the group with positive or marginally positive LMP-1 detection (not significant). Nevertheless, after staining by tyramid-augmented IHC (TSA-IHC), nearly all specimens with negative LMP-1-staining in conventional IHC were found to be clearly positive. All patients with SC-NPC were smokers. The distribution of smokers and non-smokers in the group of NK-NPC was balanced. Comparable to the tobacco observation, there was also a correlation between high alcohol consumption and SC-NPC. CONCLUSION: Prognosis of NPC is mainly dependent on histologic type. Prognostic impact of LMP-1 is still unclear since LMP-1 was detected in all specimens using TSA-IHC. Therefore, TSA-IHC-LMP-1 detection might be interesting for diagnostic specification and development of new therapeutic strategies in NPC.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Approaches to preserve larynx function in locally advanced laryngeal and hypopharyngeal cancer.

Randomized controlled studies have shown that preservation of the larynx function in patients with advanced resectable laryngeal and hypopharyngeal cancer is possible without compromising survival compared to total laryngectomy (TL). Options for preserving the larynx include function-sparing surgery, radiotherapy alone, induction chemotherapy followed by radiotherapy of responders, and concomitant radiochemotherapy. The current data suggest that induction chemotherapy followed by radiotherapy of responders is an acceptable alternative to TL for patients desiring larynx preservation. Concomitant radiochemotherapy (platinum/5-FU) leads to superior local control and larynx preservation rates compared to induction chemotherapy followed by radiation. The optimal treatment sequence for newer cytotoxic agents is, however, unclear. Such cytotoxic agents and more effective fractionation regimens as well as more advanced surgical techniques are currently evaluated. Predictive tests to successfully stratify patients for the optimal treatment option and more effective systemic therapy are needed to improve therapeutic possibilities and survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

Interaction effects and population-attributable risks for smoking and alcohol on laryngeal cancer and its subsites. A case-control study from Germany.

OBJECTIVES: To assess the joint effect of smoking and alcohol consumption on laryngeal risk on tumor subsites. METHODS: Population-based case-control study in South-West Germany with 257 histologically confirmed cases (236 males, 21 females), age 37 to 80 years, and 769 population controls (702 males, 67 females), 1:3 frequency matched by age and sex. RESULTS: Half of the tumors (50.6%) were glottic or subglottic, 17.5% were supraglottic. Due to advanced stage, the subsite of 31.9% of the tumors could not be determined clearly. There is a strong increase in risk with increasing tobacco consumption with an odds ratio (OR) of 59.8 (95% confidence interval (CI) 21.3-167.3) for heavy smoking (>80 packyears (py)), all cases combined. In comparison to current smokers, cancer risk is reduced for ex-smoking (>2 years) OR=0.36, 95% CI 0.24-0.53. The risks were higher for supraglottic than for glottic and subglottic tumors. The effect of alcohol is not as strong. A significantly increased odds ratio of 2.0, 95% CI (1.0-3.9) results for 75-100 g ethanol/day only for glottic and subglottic tumors. The OR rises from 2.2, 95% CI (1.1-4.3) for 100-150 g ethanol/day to 4.3, 95% CI (1.4-13.2) for more than 150 g ethanol/day (all models adjusted for education). The joint effect of smoking and alcohol results appears sub-multiplicative but super-additive. Almost 90% of the tumors can be attributed to both factors. CONCLUSION: Contrary to earlier investigations we observed a sub-multiplicative effect of smoking and alcohol. The risk for persons with both high alcohol and tobacco consumption is extremely high which indicates the importance of intervention.

Aged↗
PubMed2003

[Dynamic magnetic resonance tomography (dMRT). It's value in advanced head-neck tumors treated with radiochemotherapy].

PURPOSE: With the help of dynamic magnetic resonance tomography (dMRT) the status of tissue microcirculation can be visualized. METHODS: Dynamic MRI was performed in 13 patients with advanced, nonresectable oro- or hypopharynx carcinoma at the beginning and the end of therapy. Maximal signal intensity and exchange rate constant in the tissue of the tumor and the lymph node metastases were analyzed using a pharmacokinetic two-compartment model. RESULTS: In all six patients with clinical complete response (CR), the maximal signal intensity increased after therapy in the tissue of the primary tumor and the lymph node metastases. Furthermore, a high decrease in the parameter k(21) was associated with a better prognosis and could be observed especially after combined radiochemotherapy. CONCLUSION: Our first results indicate that contrast-enhanced dynamic MRI studies before and after radio- or combined radiochemotherapy offer important information about the changes of microcirculation in the tissue of the tumor and lymph node metastases. Furthermore, this information seems to be a promising predictor for clinical outcome of therapy.

Adult↗
PubMed2003

[Immunohistochemical determination of cell cycle regulatory proteins. No prognostic significance in advanced squamous epithelial carcinomas of the head-neck area].

BACKGROUND: In recent years, a number of molecular markers have been tested for their potential to predict the outcome after radiotherapy or radiochemotherapy in patients with advanced head and neck squamous cell carcinomas (HNSCC). These studies have produced controversial results. PATIENTS AND METHODS: The expression patterns of the proteins p53, pRb, cyclinD1, cdk4, p21(CIP1/WAF1), p16(INK4a), bcl-2, and mib-1/ki-67 were analyzed in pretreatment tumor biopsies of 53 patients with advanced nonresectable head and neck squamous cell carcinomas (mainly UICC IV). The patterns obtained were compared with clinical outcome after accelerated radiochemotherapy with carboplatin and 5-fluorouracil or accelerated fractionated radiotherapy alone, respectively. RESULTS: The expression patterns of the proteins examined did not correlate with response to therapy or with further clinical course. CONCLUSION: In patients with advanced head and neck squamous cell carcinomas, the prognostic relevance of pretreatment expression patterns of the proteins investigated in this study, particularly p53, cyclinD1, and cdk4, has to be questioned.

Adult↗
PubMed2003

[Brain abscesses after extracranial infections of the head and neck area].

The authors report on 20 immunocompetent patients with brain abscess after 12 cases of middle ear, seven tooth and a single frontal sinus infection. The clinical aspects, hematochemical and microbiological data, the role of imaging diagnostics (CT, MR) and the type of treatment are analysed. Neurosurgery was performed on 17 patients (85%), eight of whom subsequently underwent evacuation of the primary source of infection (four mastoidectomies, two timpanoplasties, two tooth extractions). Mastoidectomy was eventually carried out on one of the three patients who did not undergo neurosurgery. Microbiological diagnosis was possible in nine patients through culture examination: Proteus mirabilis in three cases, Peptostreptococcus sp. in two, Micrococcus varians, Proteus vulgaris, Streptococcus sanguis and Streptococcus viridans not typed in single cases. The pus was sterile in eight patients (47.1% of those operated). An association of two antimicrobial agents was used in 18 patients, while in two cases monotherapy was preferred, based on the isolated bacteria. Treatment lasted on average 38 days. The most frequently used therapy regimen (75%) was the association of a beta-lactam drug with chloramphenicol or metronidazole. Therapy was successful in 19/20 patients; one patient died. There was no significant difference in prognostic terms with regard to sex, age, duration of symptoms prior to diagnosis, clinical picture at onset, number and size of abscesses or type of treatment. Recognising the first clinical signs and symptoms (headache, fever, alterations in consciousness, focal neurological deficit, epileptic seizures) is extremely important for prompt diagnosis of brain abscess.

Adolescent↗
PubMed2002

A phase III placebo-controlled study in advanced head and neck cancer using intratumoural cisplatin/epinephrine gel.

Patients with recurrent or refractory head and neck squamous cell carcinoma received cisplatin/epinephrine injectable gel or placebo gel injected directly into the clinically dominant tumour. The double-blind phase III trial comprised of up to 6 weekly treatments over 8 weeks, 4 weekly evaluation visits, and then monthly follow-up; open-label dosing began as needed after three blinded treatments. Tumour response was defined as complete (100% regression) or partial (50-99% regression) sustained for > or =28 day, and patient benefit as attainment of palliative or preventive goals prospectively selected by investigators and patients. With cisplatin/epinephrine gel, 25% (14 out of 57) of tumours responded (16% complete regression, 9% partial regression), vs 3% (one out of 35, complete regression) with placebo (P=0.007). Patient benefit was positively associated with target tumour response in the blinded period among cisplatin/epinephrine gel recipients (P=0.024): 43% (six out of 14) of responders benefited, vs 12% (five out of 43) of non-responders. The most frequent adverse event was pain during injection and the next most frequent was local cytotoxic effects consistent with the gel's mode of action. Systemic adverse events typical of intravenous cisplatin were uncommon. Intratumoural therapy with cisplatin/epinephrine gel provided safe, well-tolerated, effective palliative treatment for patients with locally advanced head and neck squamous cell carcinoma, who lack other satisfactory treatment options.

Adrenergic Agonists↗
PubMed2002

[Organ preservation in advanced laryngeal and hypopharyngeal carcinoma by primary radiochemotherapy. Results of a multicenter phase II study].

INTRODUCTION: Regarding the promising results of international trials we conducted the first German prospective multicentre phase II trial for organ preservation with primary simultaneous chemoradiation in advanced laryngeal and hypopharyngeal cancer. PATIENTS AND METHODS: 28 of 30 recruited patients suffering from stage II and III (UICC) laryngeal and hypopharyngeal cancer were treated with primary simultaneous chemoradiation within an organ preservation program and monitored in follow-up of one year. Exclusion criteria included tumor infiltration of the laryngeal cartilage, bilateral neck nodes (N2c) and need for flap reconstruction in case of laryngectomy. The protocol included an accelerated concomitant boost chemoradiation (66 Gy) with Carboplatinum (70 mg/m2 1st and 5th week) and a restaging procedure one month after therapy. In case of residual disease, salvage laryngectomy and/or neck dissection were performed. RESULTS: After follow-up of one year 20 of 28 patients (71%) were presented with stable complete remission and functionally preserved larynx. Of these 20 patients 3 developed pulmonary metastases, 1 secondary primary carcinoma of the lung and 3 neck metastases which needed neck dissections. The other patients showed in 4 cases relapsing tumor which was indicated for laryngectomy. One patient needed tracheotomy because of persisting edema and 2 patients died due to tumor progress. One patient died after complications due to salvage surgery. CONCLUSION: The organ preservation protocol was feasible with well tolerated early toxicity. Problems of screening for recurrent disease, salvage surgery and late toxicity should be noted and pronounced in patient information. Further studies should focus on the improvement of patient selection which could be realized by induction Chemotherapy (using new components like taxan) and/or use of prediction factors such as tumor volume and hemoglobin levels.

Adult↗