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K Ott

Publications and source records attributed to K Ott.

At least 19 recordsLinked to original sources
PubMed2007

[18F-FDG-PET in therapy response of esophageal cancer].

PET imaging with the glucose analog fluorodeoxyglucose (FDG-PET) has been evaluated in several studies to monitor tumor response in patients undergoing chemo- and radiotherapy. The clinical value of FDG-PET for differentiation of residual tumor and therapy induced fibrosis has been documented for esophageal cancer. Furthermore, there are now several reports suggesting that quantitative assessment of therapy induced changes in tumor FDG-uptake may allow prediction of tumor response and patient outcome very early in the course of therapy. This suggests that FDG-PET may be used to identify non-responders early during neoadjuvant chemoradiotherapy allowing for early modifications of the treatment protocol.

Esophageal Neoplasms↗
PubMed2006

[Curative vs palliative strategies in locoregional recurrence of gastrointestinal malignancies].

Locoregional recurrence is a relevant problem in surgical oncology. Intraluminal local relapse only occurs when the primary resection is carried through with inappropriate safety margins. If possible, a second surgical resection with wider margins is the treatment of choice. When the primary resection was appropriately done, extraluminal relapse in the original tumor bed indicates the primary tumor was already in an advanced stage. The indication for a second resection must be considered carefully. A realistic prospect of long-term tumor control exists only when the second resection yields tumor-free margins and is combined with chemo- and radiotherapy. There is usually no curative treatment option for recurrences in the draining lymph node region, the so-called fourth dimension.

Combined Modality Therapy↗
PubMed2006

A rare case of primary rectal rhabdomyosarcoma in an adult.

We report an extremely rare case (1:200 000) of primary rectal rhabdomyosarcoma (RMS) in an adult. In the literature, this case report is the first one dealing with an adult patient. The diagnosis was assessed by computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), endoscopy and histological examination. Neoadjuvant systemic chemotherapy with adriamycin and isofosfamide followed by anterior rectum resection was performed. This article should implicate RMS as a rare differential diagnosis of atypical rectal tumours in adults.

Adult↗
PubMed2006

The importance of PET in the diagnosis and response evaluation of esophageal cancer.

The major aims of imaging in esophageal cancer are to distinguish between locoregional and systemic disease (M-stage), to determine local tumor extension (T- and N-stage), to assess response to chemo- or chemoradiotherapy and to identify recurrence of cancer. The sensitivity of computed tomography (CT) for detection of distant metastases ranges between < 50% and > 90%. In esophageal cancer, F-18-fluorodeoxyglucose positron emission tomography (FDG-PET) has been shown to detect metastatic disease in approximately 20% of patients who are considered as having only locoregional disease on CT. In locoregional pretherapeutic tumor staging, FDG-PET specificity of 80% is sufficient, but FDG-PET sensitivity of 50% is rather low. However, the initial staging of regional lymph nodes is less important because at the moment there is no pretherapeutic therapy stratification based on lymph node category. The accuracy for correct identification of recurrence in esophageal cancer is higher for FDG-PET than for CT scan. Unfortunately until today no reliable essays for prediction of response or prognosis exist for esophageal cancer in clinical practice for patients with neoadjuvant treatment. Thus the identification of parameters predicting response and/or prognosis is crucial for the future. Post-therapeutic assessment of tumor response by FDG-PET has been shown to correlate with histopathologic tumor regression and patient survival. Furthermore, quantitative measurements of tumor FDG-uptake may allow an early metabolic response evaluation after only 2 weeks of therapy. An association of metabolic response with histopathologic tumor regression and patient outcome 2 weeks after initiation of preoperative chemotherapy may be shown for esophageal cancer.

Esophageal Neoplasms↗
PubMed2005

[Prophylactic gastric surgery].

A premalignant condition with high risk of gastric cancer is the basis for prophylactic gastric surgery. The germline mutation carrier in the E-cadherin gene has a lifetime risk of 70-80% for diffuse-type gastric cancer, and high-grade intraepithelial neoplasia has a 60-70% gastric cancer risk. Other premalignant conditions such as HNPCC syndrome (5% gastric cancer) and low-grade intraepithelial neoplasia (10% risk) are moderate risk factors for developing gastric cancer. They do not justify prophylactic surgery, but surveillance is required. In case high-grade intraepithelial neoplasia or early gastric cancer is detected, an option is extended radicality with total gastrectomy instead of subtotal gastric resection. Positive family history and early-onset of gastric cancer are risk factors to consider when discussing prophylactic gastrectomy or extended radicality.

Adolescent↗
PubMed2005

FDG PET and CT in locally advanced adenocarcinomas of the distal oesophagus. Clinical relevance of a discordant PET finding.

AIM: The incidence of adenocarcinomas of the distal oesophagus (ADE) has dramatically increased in Western countries. The clinical importance of a FDG PET finding discordant with CT was determined in patients with locally advanced ADE. In addition, tumour standardized uptake values (SUV) were correlated with patient survival. PATIENTS, METHODS: 40 consecutive patients were analyzed retrospectively. All patients underwent an attenuation corrected FDG PET scan (neck, chest, abdomen) and contrast enhanced helical CT of the chest and abdomen. PET and CT scans were reviewed independently and concomitantly with respect to metastases in predefined lymph node sites and organs. Any discordance between PET and CT was assessed for clinical relevance. Clinical relevance was defined as a change in the overall therapeutic concept (curative vs. palliative). Follow-up imaging and histological evaluation served as the gold standard. Mean tumour SUVs were determined by 1.5 cm regions of interest placed over the tumour's maximum. RESULTS: When read independently from the CT scan FDG PET indicated a clinically relevant change in tumour stage in 9/40 patients (23%) and a non-relevant change in 11/40 patients (28%). PET was correct in 5/9 patients (56%) with clinically relevant discordances. In 4/9 patients PET was incorrect (3 false positive due to suspicion of M1-lymph nodes or lung metastases, 1 false negative in disseminated liver metastases). With concomitant reading, PET indicated a clinically relevant change in tumour stage in 6/40 patients (15%) and a non-relevant change in 5/40 patients (13%). PET was correct in 5/6 patients (83%) with clinically relevant discordances. The patient with disseminated liver disease remained the single false negative. Overall, the benefit from PET was based on its higher diagnostic accuracy at organ sites. Tumour SUV did not correlate with patient survival. CONCLUSION: About half of discordances between FDG PET and CT are clinically relevant. Concomitant reading of PET and CT is advisable as it reduces the overall rate of discordances and enhances the accuracy of PET in clinical relevant discordances (from 56% to 83%).

Adenocarcinoma↗
PubMed2004

Comparison of different SUV-based methods for monitoring cytotoxic therapy with FDG PET.

PURPOSE: Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) is a promising tool for monitoring cytotoxic therapy in tumours. Due to the limited data available, a standard imaging protocol for the prediction of tumour response has not yet been approved. The aim of this study was to compare commonly applied imaging protocols and calculations of the standardised uptake value (SUV) for the early prediction of histopathological response to chemotherapy. METHODS: Serial FDG PET scans of 43 patients with gastric carcinomas were retrospectively analysed. All patients received two consecutive scans (one bed position at 40 min p.i. and four bed positions at 90 min p.i.) at baseline and during the first cycle of cisplatinum-based chemotherapy. Reconstruction of the images was performed by filtered back-projection (FBP) and using an iterative algorithm (OSEM). SUVs were calculated with and without correction for the blood glucose level using normalisation by body weight, body surface area and lean body mass. Relative percentage changes between SUVs at baseline and follow-up were calculated and analysed for their potential to predict histopathological response to chemotherapy (ROC analysis). Response was defined as less than 10% viable tumour cells in the tumour specimen obtained by surgery 3-4 weeks after the completion of chemotherapy. RESULTS: Eight of 43 patients were histopathological responders to chemotherapy. The percentage changes in SUV(body weight) for responders and non-responders were -52.2 (+/-13.2) and -25.2 (+/-15.2), -54.7 (+/-18.2) and -24.5 (+/-16.1), -53.9 (+/-24.2) and -22.7 (+/-21.3), and -56.7 (+/-21.6) and -26.1 (+/-18.9) for serial scans at 40-min FBP, 40-min OSEM, 90-min FBP and 90-min OSEM, respectively (responders versus non-responders: p<0.01 in each case). According to ROC analysis, neither the scan protocol nor correction for blood glucose significantly influenced the accuracy (approx. 80%) or the cut-off value (approx. -40% change in tumour SUV) for the prediction of response. Normalisation of SUVs by body surface area or lean body mass instead of body weight yielded essentially identical results. CONCLUSION: In gastric carcinomas the prediction of response to chemotherapy on the basis of relative tumour SUV changes is not essentially influenced by any of the methodological variations investigated (time delay after FDG administration, acquisition protocol, reconstruction algorithm, normalisation of SUV). This demonstrates the robustness of FDG PET for therapeutic monitoring and facilitates the comparability of studies obtained at different institutions and with different protocols. However, whichever method is used for therapy monitoring with FDG PET, a highly standardised protocol must be observed to take the dynamics of tumour FDG uptake into account.

Algorithms↗
PubMed2003

[Surgical strategies in patients with inflammatory bowel disease].

Crohn's disease and ulcerative colitis are specific inflammatory bowel diseases. Quality of life can be considerably limited. It does not depend on the form of therapy that Crohn's disease is highly recurrent, whereas colitis ulcerosa is curable by proctocolectomy. For both forms of disease surgery is an important option. It has to be included early in the therapy concept and not as last choice. Quality of life in patients with Crohn's disease can be raised significantly by surgery. Meticulous selection of the patients are essential to the policy of surgery as well as a regular aftercare. Best profit for those patients are treatment with an interdisciplinary team, consisting of gastroenterologists, nutrition advisers, psychologists, surgeons and radiologists.

Acute Disease↗
PubMed2003

[Osteosynthesis of combined radius head and capitulum humeri fractures with mini-implants].

INTRODUCTION: Combined injuries of the capitellum humeri and the radial head are rare. Most of them show combined osteocartilaginous lesions and collateral ligament lesions. Recommendations for treatment of these fatal injuries of the elbow are missing. TYPE OF STUDY: Five cases were investigated in an retrospective analysis. The same approach was used for the osteocartilaginous lesion of the capitellum as well as the injury of the radial head. Internal fixation was done with mini-titanimplants, three of them combined with resorbable pins. PATIENTS AND METHODS: Between 1996-1999 five patients (four men, one woman) with combined injury of the radial head and the capitellum were stabilized. The average age was 34 years (31-40 years). All fractures were stabilized by a direct radial approach with 1.5 mm or 2.0 mm lag screws partly with resorbable pins. All patients were evaluated radiologically and clinically according to the Mayo-elbow-performance score. RESULTS: All patients were personally examined after an average period of 12.8 month (8-24 month) by an independent investigator. 4/5 patients were assessed for their satisfaction. No radiological signs of avascular necrosis of the capitellum or arthrosis were found. Three patients showed periarticular calcifications. The range of motion was averagely 124 degrees (extension 5-30 degrees, flexion 110-145 degrees), in three of five cases a secondary intervention for improvement of joint mobility was necessary. The Mayo-elbow-performance score rated for 85 points in average (range 70-100 points). CONCLUSION: Direct screw fixation with mini-implants, eventually combined with resorbable pins allows to use the same approach for anatomic reconstruction and fixation of the capitellum humeri and radial head. Transarticular fragment fixation of the capitellum allows for safe compression. Therefore early functional rehabilitation is possible postoperatively. Secondary interventions for improve joint motion were necessary in three of five cases.

Absorbable Implants↗
PubMed2002

[Neoadjuvant therapeutic principles guided by response prediction and evaluation].

Only patients with a clinical and pathohistological response to neoadjuvant therapy have a significantly improved survival. Therefore the identification of predictors for response and procedures for the early identification of nonresponders appear to be mandatory. Preliminary data of biochemical investigations of target enzymes for several cytostatics (e.g. TS, ERCC1) appear to be promising. Early changes of the tumor metabolism in the FDG-PET enable the identification of nonresponders with a negative predictive value of 88-95%. In near future these findings should lead to consequences in the design and realization of clinical studies.

Adenocarcinoma↗
PubMed2001

Prediction of response to preoperative chemotherapy in adenocarcinomas of the esophagogastric junction by metabolic imaging.

PURPOSE: Preoperative chemotherapy in patients with gastroesophageal cancer is hampered by the lack of reliable predictors of tumor response. This study evaluates whether positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (FDG) may predict response early in the course of therapy. PATIENTS AND METHODS: Forty consecutive patients with locally advanced adenocarcinomas of the esophagogastric junction were studied by FDG-PET at baseline and 14 days after initiation of cisplatin-based polychemotherapy. Clinical response (reduction of tumor length and wall thickness by > 50%) was evaluated after 3 months of therapy using endoscopy and standard imaging techniques. Patients with potentially resectable tumors underwent surgery, and tumor regression was assessed histopathologically. RESULTS: The reduction of tumor FDG uptake (mean +/- 1 SD) after 14 days of therapy was significantly different between responding (-54% +/- 17%) and nonresponding tumors (-15% +/- 21%). Optimal differentiation was achieved by a cutoff value of 35% reduction of initial FDG uptake. Applying this cutoff value as a criterion for a metabolic response predicted clinical response with a sensitivity and specificity of 93% (14 of 15 patients) and 95% (21 of 22), respectively. Histopathologically complete or subtotal tumor regression was achieved in 53% (eight of 15) of the patients with a metabolic response but only in 5% (one of 22) of the patients without a metabolic response. Patients without a metabolic response were also characterized by significantly shorter time to progression/recurrence (P =.01) and shorter overall survival (P =.04). CONCLUSION: PET imaging may differentiate responding and nonresponding tumors early in the course of therapy. By avoiding ineffective and potentially harmful treatment, this may markedly facilitate the use of preoperative therapy, especially in patients with potentially resectable tumors.

Adenocarcinoma↗
PubMed2001

[Monitoring of response to neoadjuvant therapy by positron emission tomography (PET)].

Neoadjuvant therapy is frequently hampered by the lack of reliable non-invasive techniques for prediction and assessment of response. Positron emission tomography using the glucose analogue 18F-fluorodeoxyglucose (FDG-PET) provides a unique means of non-invasive assessment of tumor metabolism. Several recent studies have indicated that a reduction of tumor metabolic activity after neoadjuvant therapy is closely correlated with the degree of histopathological tumor regression. The reduction of metabolic activity may also allow one to predict subsequent response early during the course of therapy. Therefore FDG-PET may permit individualized therapy management. However, there is a requirement for larger-scale trials to assess this technique.

Female↗
PubMed2001

High concentrations of fluoride and boron in drinking water wells in the Muenster region--results of a preliminary investigation.

In 1998, two cases of severe dental fluorosis in schoolchildren occurred in the Muenster region. These cases took place in one household, where fluoridated toothpaste, fluoridated salt, and fluoride tablets were consumed. Furthermore, the family used drinking water from its private well only. Analyses of the well water ordered by local health officials revealed very high amounts of fluoride, boron, and other electrolytes. This unusual combination of high amounts of fluoride and boron could also be found in the water of a great number of other private wells that are the only source for drinking water in this rural region of the Muensterland. Anthropogenic sources could be excluded. Because of this, the results of the water samples were collated to the specific geological situation in this area. In the Muenster region there are marl layers of the chalk era covered with quarternary sediments. The quarternary sediments are up to 10 to 20 metres thick and they usually conduct the groundwater. The marl contains high concentrations of fluoride and boron. In some places the groundwater has contact with these layers. To check the amount of fluoride and boron in the groundwater, indicator values were sought, which can give a hint of high contents of these trace elements. In this study the conductivity and acidity were identified as possible indicators of a high amount of fluoride and boron in the drinking water in this specific region. To work economically and efficiently, the drinking water should be checked for fluoride and boron on a regular basis only when these values are extraordinarily high. In the case of high concentrations, especially of fluoride, in the drinking water the persons concerned should be informed about their potential health risk, giving them the opportunity to optimise the total daily intake of fluoride.

Boron↗
PubMed2001

Surveillance of antibiotic resistance in invasive isolates of Neisseria meningitidis in Australia 1994-1999.

A total of 1434 strains of Neisseria meningitidis isolated from cases of invasive meningococcal disease (IMD) in Australia between 1994 and 1999 were examined by standard methods for susceptibility to antibiotics used for treatment and prophylaxis. The proportion of isolates fully susceptible to penicillin decreased from 45% in 1994 to 26% in 1999 (P<0.001). All the other isolates were less sensitive to penicillin except for two meningococci with a penicillin MIC of 1 mg/l. The geometric mean penicillin MIC increased from 0.045 to 0.065 mg/l from 1994 to 1999. There was no significant difference in the geometric mean penicillin MICs of serogroup B and serogroup C meningococci. Penicillin susceptibility was significantly associated with a poorer outcome. Isolates from survivors of IMD had a higher geometric mean penicillin MIC (0.06 mg/l) than those from fatal cases (0.048 mg/l) (P< 0.001). This suggests that factors other than the decrease in susceptibility to penicillin observed were more relevant to outcome in IMD. All isolates were fully susceptible to ceftriaxone. Rifampicin resistance was infrequent (eight isolates in 6 years) and sporadic. A single isolate had decreased quinolone susceptibility. Despite the significant shift in susceptibility to penicillin recorded, this group of antibiotics remains a suitable treatment for IMD in Australia.

4-Quinolones↗
PubMed2001

New technologies in the assessment of hemodynamic parameters.

Pulmonary artery catheter (PAC) use has led to major advances in the assessment of hemodynamics. Since its introduction three decades ago, features have been added to the PAC to enhance its hemodynamic monitoring capabilities. In addition, newer technologies have been proposed to replace the PAC. This article discusses three features that enhance the PAC--measures of mixed venous oxyhemoglobin, right ventricular ejection fraction, and continuous cardiac output--and two newer technologies--esophageal Doppler and exhaled carbon dioxide measurements. The article describes current and future applications of hemodynamic monitoring.

Blood Gas Analysis↗