Andreas Dietz | Leipzig University (Universität Leipzig) (original) (raw)
Papers by Andreas Dietz
Laryngo-rhino-otologie, Nov 16, 2020
Laryngo-Rhino-Otologie
PROBLEM DEFINITION: The goal of this work is the integration of the information of the intraopera... more PROBLEM DEFINITION: The goal of this work is the integration of the information of the intraoperative EMG monitoring of the facial nerve into the radiological data of the petrous bone. The following hypotheses are to be examined: (I) the N. VII can be determined intraoperatively with a high reliability by the stimulation-probe. A computer program is able to discriminate true-positive EMG signals from false-positive artifacts. (II) The course of the facial nerve can be registered in a three-dimensional area by EMG signals at a nerve model in the lab test. The individual items of the nerve can be combined into a route model. The route model can be integrated into the data of digital volume tomography (DVT). (I) Intraoperative EMG signals of the facial nerve were classified at 128 measurements by an automatic software. The results were correlated with the actual intraoperative situation. (II) The nerve phantom was designed and a DVT data set was provided. Phantom was registered with a navigation system (Karl Storz NPU, Tuttlingen, Germany). The stimulation probe of the EMG-system was tracked by the navigation system. The navigation system was extended by a processing unit (MiMed, Technische Universität München, Germany). Thus the classified EMG parameters of the facial route can be received, processed and be generated to a model of the facial nerve route. The operability was examined at 120 (10 x 12) measuring points. The evaluation of the examined algorithm for classification EMG-signals of the facial nerve resulted as correct in all measuring events. In all 10 attempts it succeeded to visualize the nerve route as three-dimensional model. The different sizes of the individual measuring points reflect the appropriate values of Istim and UEMG correctly. This work proves the feasibility of an automatic classification of an intraoperative EMG signal of the facial nerve by a processing unit. Furthermore the work shows the feasibility of tracking of the position of the stimulation probe and its integration into amodel of the route of the facial nerve (e. g. DVT). The rediability, with which the position of the nerve can be seized by the stimulation probe, is also included into the resulting route model.
Laryngo-Rhino-Otologie
ABSTRACT
HNO
With the help of dynamic magnetic resonance tomography (dMRT) the status of tissue microcirculati... more With the help of dynamic magnetic resonance tomography (dMRT) the status of tissue microcirculation can be visualized. 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. 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. 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.
Laryngo-Rhino-Otologie, 2005
Zusammenfassung. Fortgeschrittene Plattenepithelkarzinome der Mundhöhle, des Oro-, Hypopharynx un... more Zusammenfassung. Fortgeschrittene Plattenepithelkarzinome der Mundhöhle, des Oro-, Hypopharynx und Larynx erweisen sich oft als nicht sinnvoll resektabel. In die komplexen Überlegungen zur Resektabilität flieûen morphologische, funktionelle und sozialethische Aspekte ein, die oft eine Therapieentscheidung deutlich erschweren. Im Falle einer Nicht-Resektabilität bieten sich die modernen kurativen Ansätze der multimodalen Therapieprotokolle an, die heute, nach in Studien abgesichertem Nachweis, als simultane Radiochemotherapie empfohlen werden. Als begleitende Chemotherapeutika kommen aktuell Cis-, Carboplatin, 5-Fluorouracil, Mitomycin C und die Gruppe der Taxane zur Anwendung. Ergänzend wird beispielsweise zur Vermeidung einer Glossektomie die interstitielle Brachytherapie empfohlen. Rettungschirurgische Maûnahmen (salvage surgery) konzentrieren sich erstrangig auf Residuen persistierender Halslymphknotenmetastasen nach erfolgter Radiochemotherapie. Der Stellenwert einer alleinigen Chemotherapie wird in ihrem rein palliativen Charakter gesehen. Schlüsselwörter: Radiochemotherapie´nicht resektable Kopf-Hals-Tumoren 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.
Laryngo-Rhino-Otologie, 2008
Laryngo-Rhino-Otologie
In search of new targeted therapies for squamous cell carcinoma of the head neck (HNSCC), a bette... more In search of new targeted therapies for squamous cell carcinoma of the head neck (HNSCC), a better understanding of the carcinogenesis is of outmost importance. Recent studies show that not only genetic but also epigenetic alterations initiate the multistep process of tumordevelopment. Epigenetic changes lead to altered gene expression without alterations of the DNA sequence. The best characterized epigenetic change is the methylation of the promoter region of genes, especially of tumorsuppressor genes. The methylation of the promoter region blocks the promoter and therefore represses transcription. The loss of the gene products of tumorsuppressor genes leads to increased proliferation and decreased apoptosis. Methylation of tumorsuppressor genes was shown in precancerous lesions of HNSCC, which emphasizes the importance of methylation as an early biomarker. Several studies of tumor cell cultures show reactivated expression of proteins and as a result reduction of proliferation and induction of apoptosis after treatment with demethylating agentens. This presents a very promising new option for a targeted therapy.
Laryngo-Rhino-Otologie
Der mehrschrittige Prozess der Entstehung eines malignen Tumors wird im konventionellen Sinn vers... more Der mehrschrittige Prozess der Entstehung eines malignen Tumors wird im konventionellen Sinn verstanden als Akkumulation von Genveränderungen, den Mutationen, Amplifikationen oder Deletionen bestimmter DNA-Abschnitte. Es gilt als sicher, dass mehr als 10 6 Genmutationen "notwendig" sind, um ein Karzinom aus den Vorläuferläsionen entstehen zu lassen [1]. Anhand von genetischen Untersuchungen der Vorläuferläsionen, wie hyperplastischer Schleimhaut und niedrig-bzw. hochgradiger intraepithelialer Neoplasie, wurde ein Stufenschema der Karzinogenese von Plattenepithelkarzinomen entwickelt, das in den verschiedenen Entwicklungsstufen jeweils zusätzliche genetische Alterationen aufzeigt. Zahlreiche Alterationen betreffen hierbei Genlokationen, die für Tumorsuppressor-bzw. Onkogene kodieren. Die Fehlsteuerung bzw. Inaktivierung der Tumorsuppressor-Zusammenfassung !
Laryngo-Rhino-Otologie
ABSTRACT
HNO
Quality control is of special importance in head and neck oncology since the quality of medical c... more Quality control is of special importance in head and neck oncology since the quality of medical care constitutes a vital parameter for the diseased patient. In contrast to other medical specialties, no quality assurance program for head and neck cancer patients has yet been established in Germany. Therefore, a survey was conducted to assess the quality assurance instruments that are in use today in otorhinolaryngology-head and neck (ORL-HNS) centers. In a nationwide survey, questionnaires were sent out to 146 German ORL-HNS departments (the return rate was 75%). 56% of all departments apply dedicated quality assurance processes, and 38% have appointed a formal quality assurance officer. Interdisciplinary oncological conferences are held in the vast majority of all departments with the participation of radiation oncologists in 86 (78%), medical oncologists in 84 (76%), diagnostic radiologists in 82 (74%), and pathologists in 73 (66%). Morbidity-mortality conferences are held in seven departments (6%). A standardized follow-up of oncological patients is carried out in 95 units (86%), and 53 departments use computer-assisted data bases to organize their follow-up data (48%). A wide variety of documentation systems is in use throughout the country: 78 units (71%) offer formal follow-up to their oncological patients. This survey documents a wide-spread interest in quality assurance procedures. Many individual efforts are being undertaken. However, no uniform quality assurance or auditing system is currently in use in Germany nor is a commonly accepted data base available. The ability to offer oncological follow-up within the national social security system is generally considered indispensable for the maintenance of high-quality oncological care in ORL-HNS departments.
HNO
So far, only few studies exist that have investigated the influence of occupational exposure to p... more So far, only few studies exist that have investigated the influence of occupational exposure to paint and lacquer on the risk of cancer in the upper aerodigestive tract. Based on data from the Heidelberg case control study which enrolled 369 patients with carcinomas of the upper aerodigestive tract and 1476 randomized control subjects, the relative risk of head and neck cancer in patients exposed to paint, lacquer and varnish was analyzed. The relative risk (RR) of squamous cell cancer (after adjustment for possible alcohol and tobacco effects) was significantly increased for the larynx (RR = 2.3) and the oral cavity (RR = 3.6). However, this risk was not increased for the pharynx. Our findings and a critical analysis of the literature provide evidence that chronic exposure to paint, varnish and lacquer is a definite risk factor for cancer of the upper aerodigestive tract. Further studies are required to confirm these findings, and to identify more precisely toxic substances encountered in the workplace.
HNO
This work examines the application possibilities of the panoramic visualization system (HD-PVS) i... more This work examines the application possibilities of the panoramic visualization system (HD-PVS) in ENT surgery. The HD-PVS is a new optical system that is neither an endoscope nor a microscope. It has a focal length of 200 mm and a wide field of view. The analysis of the visualization quality took place under laboratory conditions at 4 close-to-surgery scenarios with a total of 40 result values. Furthermore, the system was used for 45 operative procedures on patients (tympanoplasty, parotidectomy, neck dissection, septumplasty, transfacial approaches). The results were analyzed following the ICCAS workflow-scheme and with standardized questionnaires. The analysis of the visualization quality of the PVS exhibited the best total evaluation in 2 out of 4 scenarios, in 1 scenario HD-PVS attained the maximum score possible, as did the microscope and the endoscope was better than HD-PVS in 1 scenario. The microscope was never evaluated as being better than HD-PVS. Apart from its use in middle ear surgery, the HD-PVS can be considered operational in 4 out of 5 clinical applications with only slight modifications. The advantages of HD-PVS over gold standards such as the surgical microscope are lower initial costs for the optical system with frequently already existing HD-video system, smaller space requirements, equal or sometimes better visualization quality, possibility of videoendoscopic representation of surgery and better ergonomic conditions.
European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery, Jan 18, 2015
The aim of this study is to investigate static and dynamic infrared (IR) thermography for intra- ... more The aim of this study is to investigate static and dynamic infrared (IR) thermography for intra- and postoperative free-flap monitoring following oropharyngeal reconstruction. Sixteen patients with oropharyngeal reconstruction by free radial forearm flap were included in this prospective, clinical study (05/2013-08/2014). Prior ("intraop_pre") and following ("intraop_post") completion of the microvascular anastomoses, IR thermography was performed for intraoperative flap monitoring. Further IR images were acquired one day ("postop_1") and 10 days ("postop_10") after surgery for postoperative flap monitoring. Of the 16, 15 transferred free radial forearm flaps did not show any perfusion failure. A significant decreasing mean temperature difference (∆T: temperature difference between the flap surface and the surrounding tissue in Kelvin) was measured at all investigation points in comparison with the temperature difference at "intraop_pre&q...
Journal of Neurological Surgery, Part B: Skull Base
Clinical Cancer Research
Second primary carcinoma is a peculiar feature of head and neck cancer and represents a form of t... more Second primary carcinoma is a peculiar feature of head and neck cancer and represents a form of treatment failure distinct from the recurrence of the primary tumor. Whether altered p53 expression in tumor-distant epithelia at the time of diagnosis is of clinical value as a biomarker for second primary carcinoma development has not been rigorously answered because of the lack of long-term follow-up studies involving a sufficiently large patient cohort. In this prospective study, we have investigated p53 expression in tumor-distant epithelia and in the corresponding primary tumors of 105 head and neck cancer patients by immunohistochemistry on frozen sections. After a median follow-up of 55 months, the clinical course of disease parameters, i.e., local recurrences, lymph node and distant metastasis, incidence of second primary carcinoma, and survival, was evaluated. Overexpression of p53 in tumor-distant epithelia was found in 49 patients (46.7%), and it was independent of the p53 pro...
HNO
Workers in the construction industry carry an increased risk for head and neck cancer due to the ... more Workers in the construction industry carry an increased risk for head and neck cancer due to the high consumption of alcohol and tobacco plus exposure to occupational carcinogenic or co-carcinogenic agents. These latter substances include asbestos, tar products, metal dust, wood dust, cement dust and paints. The Heidelberg case-control studies showed a statistically increased risk of pharyngeal cancer (RR=2.5 adjusted for tobacco and alcohol) and laryngeal cancer (RR=2.3 adjusted for tobacco and alcohol) in the construction workers (23.3%) when compared to controls (8.2%). A random sample analysis of patients with head and neck cancer referred by the largest health assurance company in Heidelberg (AOK), revealed that 21.2% were employed in the construction industry. Similar results have been obtained in a number of international epidemiological studies. Our findings show that male construction workers who regularly consume alcohol and tobacco represent an extreme risk group for head...
HNO
The requirements of ENT (ear, nose and throat) surgery, i. e. operating theatre, have changed dra... more The requirements of ENT (ear, nose and throat) surgery, i. e. operating theatre, have changed dramatically in recent years, e. g. by high definition video endoscopy, navigation, neuromonitoring, intraoperative imaging, navigated and navigation-controlled instruments and intraoperative imaging and video documentation. For this reason a specialized operating theatre is necessary for ENT. The aim of this work was to compare this operating theatre with the previous standard. The scientific basis of this work represents a surgical workflow analysis. Over 200 completely documented operations in conventional operating theatres were available for comparison. In addition the log files of the medical technical devices, software analysis modules of the clinical documentation and ergonomics questionnaires (NASA TLX standard) were available. In the period from 1(st) June 2009 to 31(st) September 2009 a total of 139 standard procedures (9 different ENT surgeons) were analyzed in the new ly integr...
HNO
At present no procedure exists to measure distances or volumes in endoscopic or otherwise limited... more At present no procedure exists to measure distances or volumes in endoscopic or otherwise limited surgical approaches directly and with high accuracy. Here a laser measuring system is evaluated for the first time as a clinical application in ENT surgery. The volume control system (VCS) measures with the help of automatic recognition of laser measuring points in the surgical situs. A lab test examines the accuracy and the precision at anatomically accurate paranasal sinus and tympanic cavity models under flexible endoscopic visualization. The true values are known in each case as calibrated distances. Thus 90 values were available for evaluation. The clinical trial serves as proof of the intraoperative applicability and includes 32 patients. The measurements in the lab test resulted in an average deviation from the true value at a maximum of 7.1%. The precision was between 0.2 and 0.5 mm. In the clinical setting the system could be used in all 32 patients. Altogether 97 measured valu...
Laryngo-rhino-otologie, Nov 16, 2020
Laryngo-Rhino-Otologie
PROBLEM DEFINITION: The goal of this work is the integration of the information of the intraopera... more PROBLEM DEFINITION: The goal of this work is the integration of the information of the intraoperative EMG monitoring of the facial nerve into the radiological data of the petrous bone. The following hypotheses are to be examined: (I) the N. VII can be determined intraoperatively with a high reliability by the stimulation-probe. A computer program is able to discriminate true-positive EMG signals from false-positive artifacts. (II) The course of the facial nerve can be registered in a three-dimensional area by EMG signals at a nerve model in the lab test. The individual items of the nerve can be combined into a route model. The route model can be integrated into the data of digital volume tomography (DVT). (I) Intraoperative EMG signals of the facial nerve were classified at 128 measurements by an automatic software. The results were correlated with the actual intraoperative situation. (II) The nerve phantom was designed and a DVT data set was provided. Phantom was registered with a navigation system (Karl Storz NPU, Tuttlingen, Germany). The stimulation probe of the EMG-system was tracked by the navigation system. The navigation system was extended by a processing unit (MiMed, Technische Universität München, Germany). Thus the classified EMG parameters of the facial route can be received, processed and be generated to a model of the facial nerve route. The operability was examined at 120 (10 x 12) measuring points. The evaluation of the examined algorithm for classification EMG-signals of the facial nerve resulted as correct in all measuring events. In all 10 attempts it succeeded to visualize the nerve route as three-dimensional model. The different sizes of the individual measuring points reflect the appropriate values of Istim and UEMG correctly. This work proves the feasibility of an automatic classification of an intraoperative EMG signal of the facial nerve by a processing unit. Furthermore the work shows the feasibility of tracking of the position of the stimulation probe and its integration into amodel of the route of the facial nerve (e. g. DVT). The rediability, with which the position of the nerve can be seized by the stimulation probe, is also included into the resulting route model.
Laryngo-Rhino-Otologie
ABSTRACT
HNO
With the help of dynamic magnetic resonance tomography (dMRT) the status of tissue microcirculati... more With the help of dynamic magnetic resonance tomography (dMRT) the status of tissue microcirculation can be visualized. 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. 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. 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.
Laryngo-Rhino-Otologie, 2005
Zusammenfassung. Fortgeschrittene Plattenepithelkarzinome der Mundhöhle, des Oro-, Hypopharynx un... more Zusammenfassung. Fortgeschrittene Plattenepithelkarzinome der Mundhöhle, des Oro-, Hypopharynx und Larynx erweisen sich oft als nicht sinnvoll resektabel. In die komplexen Überlegungen zur Resektabilität flieûen morphologische, funktionelle und sozialethische Aspekte ein, die oft eine Therapieentscheidung deutlich erschweren. Im Falle einer Nicht-Resektabilität bieten sich die modernen kurativen Ansätze der multimodalen Therapieprotokolle an, die heute, nach in Studien abgesichertem Nachweis, als simultane Radiochemotherapie empfohlen werden. Als begleitende Chemotherapeutika kommen aktuell Cis-, Carboplatin, 5-Fluorouracil, Mitomycin C und die Gruppe der Taxane zur Anwendung. Ergänzend wird beispielsweise zur Vermeidung einer Glossektomie die interstitielle Brachytherapie empfohlen. Rettungschirurgische Maûnahmen (salvage surgery) konzentrieren sich erstrangig auf Residuen persistierender Halslymphknotenmetastasen nach erfolgter Radiochemotherapie. Der Stellenwert einer alleinigen Chemotherapie wird in ihrem rein palliativen Charakter gesehen. Schlüsselwörter: Radiochemotherapie´nicht resektable Kopf-Hals-Tumoren 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.
Laryngo-Rhino-Otologie, 2008
Laryngo-Rhino-Otologie
In search of new targeted therapies for squamous cell carcinoma of the head neck (HNSCC), a bette... more In search of new targeted therapies for squamous cell carcinoma of the head neck (HNSCC), a better understanding of the carcinogenesis is of outmost importance. Recent studies show that not only genetic but also epigenetic alterations initiate the multistep process of tumordevelopment. Epigenetic changes lead to altered gene expression without alterations of the DNA sequence. The best characterized epigenetic change is the methylation of the promoter region of genes, especially of tumorsuppressor genes. The methylation of the promoter region blocks the promoter and therefore represses transcription. The loss of the gene products of tumorsuppressor genes leads to increased proliferation and decreased apoptosis. Methylation of tumorsuppressor genes was shown in precancerous lesions of HNSCC, which emphasizes the importance of methylation as an early biomarker. Several studies of tumor cell cultures show reactivated expression of proteins and as a result reduction of proliferation and induction of apoptosis after treatment with demethylating agentens. This presents a very promising new option for a targeted therapy.
Laryngo-Rhino-Otologie
Der mehrschrittige Prozess der Entstehung eines malignen Tumors wird im konventionellen Sinn vers... more Der mehrschrittige Prozess der Entstehung eines malignen Tumors wird im konventionellen Sinn verstanden als Akkumulation von Genveränderungen, den Mutationen, Amplifikationen oder Deletionen bestimmter DNA-Abschnitte. Es gilt als sicher, dass mehr als 10 6 Genmutationen "notwendig" sind, um ein Karzinom aus den Vorläuferläsionen entstehen zu lassen [1]. Anhand von genetischen Untersuchungen der Vorläuferläsionen, wie hyperplastischer Schleimhaut und niedrig-bzw. hochgradiger intraepithelialer Neoplasie, wurde ein Stufenschema der Karzinogenese von Plattenepithelkarzinomen entwickelt, das in den verschiedenen Entwicklungsstufen jeweils zusätzliche genetische Alterationen aufzeigt. Zahlreiche Alterationen betreffen hierbei Genlokationen, die für Tumorsuppressor-bzw. Onkogene kodieren. Die Fehlsteuerung bzw. Inaktivierung der Tumorsuppressor-Zusammenfassung !
Laryngo-Rhino-Otologie
ABSTRACT
HNO
Quality control is of special importance in head and neck oncology since the quality of medical c... more Quality control is of special importance in head and neck oncology since the quality of medical care constitutes a vital parameter for the diseased patient. In contrast to other medical specialties, no quality assurance program for head and neck cancer patients has yet been established in Germany. Therefore, a survey was conducted to assess the quality assurance instruments that are in use today in otorhinolaryngology-head and neck (ORL-HNS) centers. In a nationwide survey, questionnaires were sent out to 146 German ORL-HNS departments (the return rate was 75%). 56% of all departments apply dedicated quality assurance processes, and 38% have appointed a formal quality assurance officer. Interdisciplinary oncological conferences are held in the vast majority of all departments with the participation of radiation oncologists in 86 (78%), medical oncologists in 84 (76%), diagnostic radiologists in 82 (74%), and pathologists in 73 (66%). Morbidity-mortality conferences are held in seven departments (6%). A standardized follow-up of oncological patients is carried out in 95 units (86%), and 53 departments use computer-assisted data bases to organize their follow-up data (48%). A wide variety of documentation systems is in use throughout the country: 78 units (71%) offer formal follow-up to their oncological patients. This survey documents a wide-spread interest in quality assurance procedures. Many individual efforts are being undertaken. However, no uniform quality assurance or auditing system is currently in use in Germany nor is a commonly accepted data base available. The ability to offer oncological follow-up within the national social security system is generally considered indispensable for the maintenance of high-quality oncological care in ORL-HNS departments.
HNO
So far, only few studies exist that have investigated the influence of occupational exposure to p... more So far, only few studies exist that have investigated the influence of occupational exposure to paint and lacquer on the risk of cancer in the upper aerodigestive tract. Based on data from the Heidelberg case control study which enrolled 369 patients with carcinomas of the upper aerodigestive tract and 1476 randomized control subjects, the relative risk of head and neck cancer in patients exposed to paint, lacquer and varnish was analyzed. The relative risk (RR) of squamous cell cancer (after adjustment for possible alcohol and tobacco effects) was significantly increased for the larynx (RR = 2.3) and the oral cavity (RR = 3.6). However, this risk was not increased for the pharynx. Our findings and a critical analysis of the literature provide evidence that chronic exposure to paint, varnish and lacquer is a definite risk factor for cancer of the upper aerodigestive tract. Further studies are required to confirm these findings, and to identify more precisely toxic substances encountered in the workplace.
HNO
This work examines the application possibilities of the panoramic visualization system (HD-PVS) i... more This work examines the application possibilities of the panoramic visualization system (HD-PVS) in ENT surgery. The HD-PVS is a new optical system that is neither an endoscope nor a microscope. It has a focal length of 200 mm and a wide field of view. The analysis of the visualization quality took place under laboratory conditions at 4 close-to-surgery scenarios with a total of 40 result values. Furthermore, the system was used for 45 operative procedures on patients (tympanoplasty, parotidectomy, neck dissection, septumplasty, transfacial approaches). The results were analyzed following the ICCAS workflow-scheme and with standardized questionnaires. The analysis of the visualization quality of the PVS exhibited the best total evaluation in 2 out of 4 scenarios, in 1 scenario HD-PVS attained the maximum score possible, as did the microscope and the endoscope was better than HD-PVS in 1 scenario. The microscope was never evaluated as being better than HD-PVS. Apart from its use in middle ear surgery, the HD-PVS can be considered operational in 4 out of 5 clinical applications with only slight modifications. The advantages of HD-PVS over gold standards such as the surgical microscope are lower initial costs for the optical system with frequently already existing HD-video system, smaller space requirements, equal or sometimes better visualization quality, possibility of videoendoscopic representation of surgery and better ergonomic conditions.
European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery, Jan 18, 2015
The aim of this study is to investigate static and dynamic infrared (IR) thermography for intra- ... more The aim of this study is to investigate static and dynamic infrared (IR) thermography for intra- and postoperative free-flap monitoring following oropharyngeal reconstruction. Sixteen patients with oropharyngeal reconstruction by free radial forearm flap were included in this prospective, clinical study (05/2013-08/2014). Prior ("intraop_pre") and following ("intraop_post") completion of the microvascular anastomoses, IR thermography was performed for intraoperative flap monitoring. Further IR images were acquired one day ("postop_1") and 10 days ("postop_10") after surgery for postoperative flap monitoring. Of the 16, 15 transferred free radial forearm flaps did not show any perfusion failure. A significant decreasing mean temperature difference (∆T: temperature difference between the flap surface and the surrounding tissue in Kelvin) was measured at all investigation points in comparison with the temperature difference at "intraop_pre&q...
Journal of Neurological Surgery, Part B: Skull Base
Clinical Cancer Research
Second primary carcinoma is a peculiar feature of head and neck cancer and represents a form of t... more Second primary carcinoma is a peculiar feature of head and neck cancer and represents a form of treatment failure distinct from the recurrence of the primary tumor. Whether altered p53 expression in tumor-distant epithelia at the time of diagnosis is of clinical value as a biomarker for second primary carcinoma development has not been rigorously answered because of the lack of long-term follow-up studies involving a sufficiently large patient cohort. In this prospective study, we have investigated p53 expression in tumor-distant epithelia and in the corresponding primary tumors of 105 head and neck cancer patients by immunohistochemistry on frozen sections. After a median follow-up of 55 months, the clinical course of disease parameters, i.e., local recurrences, lymph node and distant metastasis, incidence of second primary carcinoma, and survival, was evaluated. Overexpression of p53 in tumor-distant epithelia was found in 49 patients (46.7%), and it was independent of the p53 pro...
HNO
Workers in the construction industry carry an increased risk for head and neck cancer due to the ... more Workers in the construction industry carry an increased risk for head and neck cancer due to the high consumption of alcohol and tobacco plus exposure to occupational carcinogenic or co-carcinogenic agents. These latter substances include asbestos, tar products, metal dust, wood dust, cement dust and paints. The Heidelberg case-control studies showed a statistically increased risk of pharyngeal cancer (RR=2.5 adjusted for tobacco and alcohol) and laryngeal cancer (RR=2.3 adjusted for tobacco and alcohol) in the construction workers (23.3%) when compared to controls (8.2%). A random sample analysis of patients with head and neck cancer referred by the largest health assurance company in Heidelberg (AOK), revealed that 21.2% were employed in the construction industry. Similar results have been obtained in a number of international epidemiological studies. Our findings show that male construction workers who regularly consume alcohol and tobacco represent an extreme risk group for head...
HNO
The requirements of ENT (ear, nose and throat) surgery, i. e. operating theatre, have changed dra... more The requirements of ENT (ear, nose and throat) surgery, i. e. operating theatre, have changed dramatically in recent years, e. g. by high definition video endoscopy, navigation, neuromonitoring, intraoperative imaging, navigated and navigation-controlled instruments and intraoperative imaging and video documentation. For this reason a specialized operating theatre is necessary for ENT. The aim of this work was to compare this operating theatre with the previous standard. The scientific basis of this work represents a surgical workflow analysis. Over 200 completely documented operations in conventional operating theatres were available for comparison. In addition the log files of the medical technical devices, software analysis modules of the clinical documentation and ergonomics questionnaires (NASA TLX standard) were available. In the period from 1(st) June 2009 to 31(st) September 2009 a total of 139 standard procedures (9 different ENT surgeons) were analyzed in the new ly integr...
HNO
At present no procedure exists to measure distances or volumes in endoscopic or otherwise limited... more At present no procedure exists to measure distances or volumes in endoscopic or otherwise limited surgical approaches directly and with high accuracy. Here a laser measuring system is evaluated for the first time as a clinical application in ENT surgery. The volume control system (VCS) measures with the help of automatic recognition of laser measuring points in the surgical situs. A lab test examines the accuracy and the precision at anatomically accurate paranasal sinus and tympanic cavity models under flexible endoscopic visualization. The true values are known in each case as calibrated distances. Thus 90 values were available for evaluation. The clinical trial serves as proof of the intraoperative applicability and includes 32 patients. The measurements in the lab test resulted in an average deviation from the true value at a maximum of 7.1%. The precision was between 0.2 and 0.5 mm. In the clinical setting the system could be used in all 32 patients. Altogether 97 measured valu...