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Biomedical subjects

U Fink

Publications and source records attributed to U Fink.

At least 91 records · Page 5Linked to original sources
PubMed1996

[Digital luminescence radiography in comparison with the conventional film-screen technique in diagnosis of fractures].

PURPOSE: The accuracy of digital luminescence radiography was compared with that of conventional film/screen techniques, using animal preparations and clinical examinations. MATERIAL AND METHOD: Fine fissures were made in 8 animal bones and these were examined radiologically. The digital examinations were carried out with and without edge enhancement. 208 patients were examined in a similar way. Film quality and assessment of the fractures were evaluated quantitatively. RESULTS: In no instance did either of the digital methods provide inferior quality when compared with conventional films. ROC analysis for evaluation of fractures in patients, using an experienced radiologist, showed no significant difference between the various methods (ROC areas: conventional 0.947, digital 0.958, digital with edge enhancement 0.943). With a less experienced observer there were significant advantages for both digital methods (ROC areas: 0.851, 0.886, 0.908). CONCLUSION: Our investigation has proved that fractures which are difficult to see can be reliably demonstrated by digital luminescence radiography.

Animals↗
PubMed1996

The full-scale PACS archive. A prerequisite for the filmless hospital.

PURPOSE: Increasing percentages of digital modalities in radiology, in particular of digital image acquisition in conventional radiography, call for digital reporting, communication, and archiving techniques. These techniques are prerequisites for the "filmless" hospital. The first 2 have been covered extensively in the literature and by vendors. However, as regards online digital image archives there are still no satisfactory concepts available in the medical field. The present paper puts forward some suggestions as to how this situation could be improved. MATERIAL AND METHODS: Analyses of radiology operations consider the prevailing PACS (picture archiving and communication system) archive concepts that use optical discs to be too small, too slow and too cumbersome to manage and therefore unable to function as comprehensive image archives for filmless hospitals. We suggest borrowing and adapting the well tested archive technologies from space research and the oil and broadcasting industries which have much higher capacities and speeds and better software interfacing possibilities. With such technologies the needs of filmless hospital operations can be met. RESULTS: A feasible concept for a transition strategy from conventional analog to digital archives is presented. Model calculations of the necessary investments and potential savings, including generous placement of viewing stations in the entire hospital, indicate amortization periods of 3.8-4.8 years. CONCLUSION: Alternative technologies for digital image archives already today make full-scale PACS for filmless hospitals technologically and conceptually feasible and financially mandatory.

Computer Systems↗
PubMed1996

Combined preoperative chemotherapy and radiotherapy in patients with locally advanced esophageal cancer. Interim analysis of a phase II trial.

PURPOSE: The prognosis of patients with locally advanced esophageal cancer (LAEC) remains poor when treated with local modalities. An intensive preoperative program with chemoradiotherapy was used to evaluate the curative resection rate, pathologic response, and survival of patients with LAEC. PATIENTS AND METHODS: Ninety patients with LAEC were treated preoperatively with chemotherapy (three courses of fluorouracil, leucovorin, etoposide, and cisplatin [FLEP]) followed by concurrent chemoradiotherapy (one course of cisplatin plus etoposide in combination with 40 Gy of radiation). Transthoracic esophagectomy was performed 4 weeks after the end of radiation. RESULTS: Seventy-two patients were included in this evaluation. Forty-four (61%) underwent a complete tumor resection, and 16 (22%) had no tumor in the resected specimen (pathologic complete response [PCR]). The operative mortality rate was 15%. At a median follow-up time of 22 months (range, 12 to 41), the median survival duration of all 72 patients was 17 months (range, 1 to 41+). The calculated survival rates at 3 years were 33%, 42%, and 68% for all patients, patients after complete resection, and patients with PCR, respectively. CONCLUSION: This combined treatment modality is active in LAEC, with a PCR in 33% of the patients undergoing surgery. The results appear improved compared with those reported with surgery alone, by approximately doubling the 3-year survival rate. The high efficacy of preoperative chemoradiation warrants evaluation of the role of surgery in LAEC.

Adenocarcinoma↗
PubMed1996

Multimodality Therapy for Esophageal Cancer.

Adjuvant and neoadjuvant therapeutic principles have in recent years received increasing attention in the management of patients with esophageal cancer. A series of randomized prospective trials has convincingly demonstrated that adjuvant postoperative radiation or chemotherapy does not result in a survival advantage after a complete tumor resection. The available data on the role of neoadjuvant preoperative therapy in patients with adenocarcinoma or squamous cell carcinoma of the esophagus are not yet conclusive. While neoadjuvant therapy may undoubtedly reduce the tumor mass in a substantial portion of patients, a series of randomized controlled trials has shown that compared with primary resection, a multimodal approach does not result in a survival benefit in patients with locoregional, i.e., potentially resectable, tumors. In contrast, in patients with locally advanced tumors, i.e., tumors in which a complete tumor removal with primary surgery appears unlikely, neoadjuvant therapy allows a marked downstaging of the primary tumor and thus significantly increases the chance for complete tumor removal on subsequent surgery. However, only patients with objective clinical or histopathological response to preoperative therapy appear to benefit from this approach. Compared with preoperative chemotherapy alone, combined radiochemotherapy increases the rate of response but may also increase postoperative morbidity and mortality. Neoadjuvant therapy should therefore currently be performed only in experienced centers within the context of clinical trials. The identification of factors which would facilitate prediction of the response to neoadjuvant therapy is currently the focus of several studies. Furthermore, more effective and less toxic preoperative therapy regimens are required to increase the response rates and combat systemic recurrences.

Journal Article↗
PubMed1996

[Early squamous epithelial carcinoma of the esophagus--multicentricity, metastatic pattern and prognosis].

The results of surgical treatment of 65 patients with pT1 squamous cell carcinoma of the esophagus and the histologic workup of the specimens were analyzed. The treatment of choice was transthoracic enbloc esophagectomy (n = 45); in 16 patients with very distal carcinoma and restrained lung function transhiatal esophagectomy was performed. Two patients with concomitant early gastric carcinoma or lymphoma had total esophagogastrectomy, and in 2 other patients cervical esophagectomy was performed. The postoperative 30-day mortality was 6.1%. 74% of the cases had an infiltration of the submucosa, whereas in 26% the carcinoma was limited to the mucosa. No patients with mucosal carcinoma had lymph node metastases, whereas 23% of the patients with submucosal infiltration showed lymph node involvement. Tumors of other organs, especially stomach and hypopharynx, were found in 15.4% of the patients. The 5-year survival rate of the total group of 65 patients was 61.3%. As 3 patients with mucosal carcinoma died during long-term follow-up due to recurrence or second cancer, no significant prognostic difference was found between patients with mucosal or submucosal infiltration. The survival curves of patients with pN0 and those with pN1 tumors were not significantly different.

Adult↗
PubMed1996

Weekly infusional 5-fluorouracil plus/minus other drugs for the treatment of advanced gastric cancer.

Based on preclinical data and the promising results being achieved with infusional 5-FU in colorectal and breast cancer, we investigated a weekly schedule of a 24-hour infusion of 5-FU plus folinic acid (HD-FU/FA) in patients failing to first-line chemotherapy and HD-FU/FA plus cisplatin (C) or plus cisplatin/epidoxorubicin (C/E) in chemo-naive patients with advanced gastric cancer. In all three trials the results achieved with the tested chemotherapy regimens indicated high activity and good tolerability. All three protocols were administered as outpatient treatment. With HD-FU/FA and overall response rate of 24% and a median survival time of 5 months was observed in 17 patients refractory to or relapsing after first-line chemotherapy. HD-FU/FA/C induced an overall response rate of 66% and a median survival time of 13 months. Of note was the high activity of this regimen in patients with malignant ascites. HD-FU/FA/C/E also proved to be an interesting regimen similar active as HD-FU/FA/C but it was subjectively less well tolerated. In patients with locally advanced disease the response rate was 90% (10/11), and in patients with distant metastases 50% (8/16).

Adult↗
PubMed1995

Preoperative chemotherapy for stage III-IV gastric carcinoma: feasibility, response and outcome after complete resection.

Despite extensive resection and systematic lymphadenectomy the prognosis of patients with locally advanced gastric carcinoma remains poor. The effect of preoperative outpatient chemotherapy with etoposide, doxorubicin and cisplatin was evaluated prospectively in 30 patients who had been shown by preoperative staging (including endosonography and surgical laparoscopy) to have gastric carcinoma stages IIIA, IIIB or IV. Haematological side-effects were common and necessitated hospitalization in 13 of 30 patients. Complete clinical response to neoadjuvant therapy was observed in eight of 27 evaluable patients. Resection was performed in 27 of 30 patients, with complete macroscopic and microscopic tumour removal in 24. There were no deaths and no major morbidity following operation. On multivariate analysis complete clinical response (P < 0.01) and complete tumour resection (P < 0.01) were the major independent predictors of long-term survival after neoadjuvant chemotherapy. Actuarial survival after complete tumour removal was superior with neoadjuvant therapy compared with results in an age-, sex- and tumour stage-matched control population who had primary resection (P = 0.07). Recurrence occurred in 17 of 23 evaluable patients who had complete tumour removal, with relapse in the tumour bed or area of lymphatic drainage in 11. These data show that neoadjuvant therapy in patients with locally advanced gastric carcinoma is feasible and appears to increase the rate of complete tumour removal. More powerful and less toxic regimens are, however, required to improve the response rate and to delay or avoid recurrence after neoadjuvant chemotherapy.

Adult↗
PubMed1995

[Comparison of input grey values and contrast profiles: a contribution to the discussion on optimization of evaluation parameters in storage phosphorus radiography].

On comparing the individual imaging stages in conventional and digital image radiography it becomes evident that a significant advantage of the digital method is the possibility to adapt the image character and exposure dose individually to various problems requiring an answer. To take advantage of this it is imperative to optimise image processing with care, especially contrast processing. No systematic procedure based on objective criteria had existed to date. This paper describes a method of taking into account both the diagnostic significance of the structures to be imaged and their distribution within the relevant density range, in order to arrive at the best possible contrast conversion. A prerequisite is to know for every kind of imaging which distribution of grey values pertaining to the relevant structures can be expected before digital image processing (initial grey values). This distribution determines the most favourable contrast conversion. The processing parameters for several types of imaging were optimised by this method. The method is demonstrated via thoracic images of newborn and children.

Child, Preschool↗
PubMed1995

[The diagnostic value of digital and conventional imaging in intravenous urography].

PURPOSE: To compare image quality of digital luminescence radiography with conventional film-screen techniques during excretion urography. Four field tests and ROC analysis for determining diagnostic value. MATERIAL AND METHOD: 135 patients were included in a prospective study. Three independent observers judged the five minute (59 cases) or ten minute (76 cases) films after contrast injection using digital images as well as corresponding conventional images (five minutes-76 cases, ten minutes-59 cases). RESULTS: The digital technique provided better information concerning the renal parenchyma, the soft tissues and bone structures. Contrast enhanced detail was demonstrated equally well by both systems. The two systems had similar sensitivity but digital radiography showed higher specificity.

Adolescent↗
PubMed1995

Staging concepts for gastrointestinal malignancies: the importance of preoperative locoregional T- and N-staging.

Preoperative locoregional staging of gastrointestinal tumors is of special significance for evaluation of resectability that means complete tumor removal without residual tumor (R0-resection). This is especially important within a multimodal therapeutic concept including neoadjuvant therapy of nonresectable tumors. In esophageal cancer above the bifurcation, tumors that are staged T3 or T4 should have neoadjuvant radiochemotherapy in order to achieve a down-staging and increase the chance for a complete tumor resection. Preoperative chemotherapy is further established in esophageal carcinomas below the bifurcation and gastric carcinomas in stage T4. As in pancreatic carcinoma, neoadjuvant treatment has no proven indication. Preoperative locoregional staging mainly concerns the infiltration of retroperitoneal veins, which represents the crucial point for resectability. Concerning carcinomas of the lower GI tract the T- and N-staging is of special relevance for rectal cancer because preoperative radiochemotherapy in T4-stage is an accepted indication. The T- and N-staging of gastrointestinal tumors has important clinical consequences; the demands for accuracy of endosonographic examinations are therefore very high.

Combined Modality Therapy↗
PubMed1995

[3-phase spiral CT--a new noninvasive procedure for the differentiation of multifocal liver lesions].

Dynamic CT is an established method for the differentiation of focal liver lesions by monitoring the contrast enhancement. It is especially restricted in the assessment of small and multiple lesions due to respiratory organ movements. Spiral-CT allows the examination of large volumes in the breathhold technique. Spiral-CT with controlled i.v. contrast media administration can be used for the assessment of the entire liver in distinct phases of perfusion. We describe the use of this new technique in a patient with multifocal nodular hyperplasia (FNH), for whom assessment with dynamic CT was not suitable. The lesions were first located with a conventional contrast-enhanced CT-scan. The impossibility to assess all the lesions with dynamic CT led to the decision to perform a three-phase spiral-CT with three sequential scans (native, arterial, and portal perfusion phase). The entire liver was scanned after power injector-controlled i.v. administration of contrast media with the following parameters: 1) arterial phase: 70 ml contrast media, 2 ml/s, start delay 18 s; 2) portal phase: 80 ml contrast media, 2 ml/s, start delay 60 s; slice 8 mm, table feed 8 mm, increment 4 mm; 24 s of breathhold data acquisition.

Adult↗
PubMed1995

[Abdominal recurrence after interventions on the intestines].

Local recurrences (LR) of intestinal tumors have to be divided into intra- and extraluminal LR since operative reintervention is more frequently possible in intraluminal tumor recurrences. Esophageal cancer most frequently recurs in the posterior mediastine and in the neck. In our own patients we found 16% LR following curative esophagectomy. Curative reresection is normally not possible. Palliative treatment aims to maintain the passage of food. In gastric cancer LR is most frequently seen following resection of a diffuse type carcinoma. The incidence of 7,8% in our series is low. Curative reresection was possible in 19% of extraluminal LR and in 75% of intraluminal LR. Colon carcinoma usually recurs in the abdomen. 12% of left sided primary tumors recur in the pelvis. Quite frequently extended multivisceral resections are necessary to deal with the LR. In 69% reresection was possible and in 41.5% R0-resection was achieved. As in gastric cancer intraluminal LR tend to have a better prognosis. The decision for operative reintervention has to take individual risk factors into consideration.

Abdominal Neoplasms↗
PubMed1995

[Volumetry of abdominal tumors. Problems--feasibility].

If multimodal tumor therapy in the abdomen is to be effective, exact staging is required for which one needs precise planimetric and volumetric data. The most important indication for clinically reliable volumetric determination of tumor size in the abdominal region is monitoring liver metastases during chemotherapy. Determination of volume can be effectively realized using 3D reconstruction. Therefore, the primary data set must be complete and contiguous. The mass should be depicted strongly enhanced and free of artifacts. At present, this prerequisite can only be complied with using thin-slice spiral CT. Phantom studies have proven that a semiautomatic reconstruction algorithm is recommendable. The basic difficulties involved in volumetric determination of tumor size are the problems in differentiating active malignant mass and changes in the surrounding tissue, as well as the lack of histomorphological correlation. Possible indications for volumetry of gastrointestinal masses in the assessment of neoadjuvant therapeutic concepts are under scientific evaluation.

Abdominal Neoplasms↗
PubMed1994

Prognostic impact of urokinase-type plasminogen activator and its inhibitor PAI-1 in completely resected gastric cancer.

The prognostic impact of the proteolytic factors urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) was evaluated in 76 completely resected gastric cancer patients enrolled in a prospective study. All patients underwent macroscopically and microscopically residual tumor-free resection (category R0, Union International Contre Cancer, 1987). uPA and PAI-1 levels were quantified in detergent-extracted (Triton X-100) specimens of primary gastric tumors by enzyme-linked immunosorbent assays. Median values of 1.57 ng uPA/mg protein were determined in tumor tissue extracts compared to 0.14 ng uPA/mg protein in normal mucosa. For PAI-1, 0.93 ng PAI-1/mg protein versus 0.09 ng PAI-1/mg protein was calculated. uPA levels in tumor tissue extracts were significantly correlated with vascular invasion, Laurén classification, and WHO classification, whereas PAI-1 levels showed a significant correlation with advanced lymph node involvement, depth of invasion, tumor stage, site of tumor, and the Laurén, Borrmann, and WHO classifications. Elevated uPA and PAI-1 levels were found to be associated with poor prognosis. The optimal cutoff values indicating a group of patients with shorter survival were 1.5 ng uPA/mg protein and 1.25 ng PAI-1/mg protein, respectively (Classification and Regression Tree analysis). Patients with either high uPA or PAI-1 values were significantly associated with decreased survival (median time of survival was 23 months (high) versus 44 months (low). By univariate Cox regression analysis, it was shown that TNM categories, WHO classification, size of tumor, uPA and PAI-1 levels were all significantly associated with survival. However, in multivariate Cox regression analysis of these grouped variables, nodal status, PAI-1 levels, and WHO classification were the only independent prognostic factors. The relative risks of failure were 5-, 2.9-, and 2.4-fold, respectively. We conclude that PAI-1 and uPA positivity may serve as new prognostic factors in gastric cancer, predicting shorter survival even in clinically important subgroups of patients.

Adult↗