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F Vorbeck

Publications and source records attributed to F Vorbeck.

29 records · Page 2Linked to original sources
PubMed1998

Experiences in intraoperative computer-aided navigation in ENT sinus surgery with the Aesculap navigation system.

Five patients with chronic sinus pathology and an indication for sinus surgery were selected. For intraoperative navigation, we used Surgical Planning and Orientation Computer Systems (SPOCS) Aesculap navigation software (ISG Technologies, Mississauga, Ontario, Canada) and surgical instruments fitted with light-emitting diodes. Navigation procedures are described in detail in the article. The system's precision was measured by pointing at anatomical landmarks. The accuracy was measured as the distance in millimeters between the bony structures of the computed tomographic (CT) scan on screen and the cross-hair of the pointer tip displayed on the screen. Another parameter of the system's accuracy was calculated by the system itself as the root mean square error in millimeters between the markers' position as registered and their position in the CT data set. Axial 3/3/1-mm spiral CT provided sufficient resolution, and data transfer via optical disk was practicable. Positioning of the navigation equipment required some experience, and the registration of the patient's head position also needed attention, as the markers have to be pointed at precisely. During the operation, the position of the head-tracking system on the patient's head must remain unchanged to ensure a correct navigation display. The main advantage of the computed navigation system was the constant orientation provided during the sinus surgical procedure. Borders and critical anatomical structures could be identified in the corresponding CT data set, thus enabling the surgeon to decide on subsequent procedures. Use of the navigation system was found to increase the operation time by about 1 h, resulting in additional time under anesthesia. We found the SPOCS Aesculap computed navigation system to be an established technical aid, ready for use in ENT sinus surgery. In the cases reported here, a precision between 1 and 3 mm was obtained.

Humans↗
PubMed1998

123I-labelled vasoactive intestinal peptide receptor scintigraphy in patients with colorectal cancer.

Recent studies have shown that various gastrointestinal tumours express substantial amounts of vasoactive intestinal peptide (VIP) receptors. Based on these observations, we have developed a receptor scintigraphy using [123I]VIP as a radioligand. An initial series performed at our institution showed promising potential for visualization of various gastrointestinal adenocarcinomas by means of [123I]VIP. In this article, we now report the results obtained in 80 consecutive patients with colorectal adenocarcinoma. Eighty consecutive patients with histologically verified colorectal cancer underwent scanning by means of [123I]VIP (1 microg, approximately 150 MBq). Thirteen patients were free of tumour after complete resection of Dukes' C cancer, eight patients presented with primary and 14 with locally recurrent tumours but were free of metastases. Ten patients had locally recurrent disease and liver, lung or lymph node metastases. Disease confined to organ metastases (i.e. liver, lung or lymph nodes) was present in 35 patients. The size of the primary or recurrent tumours ranged between 3 and 6 cm, and the size of metastases was between 1 and 13 cm in diameter. Scan results were evaluated independently by two nuclear medicine physicians in a blinded way, and results were then compared with computerized tomography (CT)scans not older than 4 weeks. Seven out of eight primary (87%) and 21 out of 24 (82%) locally relapsing cancers were imaged with [123I]VIP. Negative VIP scans were obtained in all 13 patients in whom the cancers had been curatively resected. All patients with lymph node metastases showed positive VIP scans (four out of four), and positive scans were obtained in 25 out of 28 (89%) patients with liver metastases and in two out of three cases with lung metastases. In four patients with relapsing cancer, the VIP scan indicated the presence of disease before CT, and in two patients the diagnosis of scar tissue instead of a local recurrence of rectal cancer as suggested by CT could be established. We conclude that [123I]VIP receptor scanning is a sensitive method for radioimaging of colorectal cancer with the potential to provide valuable additional information to conventional radiological methods.

Adult↗
PubMed1998

Iodine-123-vasoactive intestinal peptide receptor scanning in patients with pancreatic cancer.

UNLABELLED: Recent data demonstrated a high sensitivity (>90%) in the visualization of primary/recurrent pancreatic cancer as well as metastases by means of 123I-labeled vasoactive intestinal peptide (VIP). The aim of this study was to investigate the diagnostic value of radioiodinated VIP in patients suffering from adenocarcinoma of the exocrine pancreas. METHODS: Sixty consecutive patients (26 women, 34 men; mean age 59 yr) with histologically verified pancreatic cancer were investigated in this study. Twenty-one patients presented with organ-confined malignancy (19 at study entry and 2 during follow-up after initial surgery developed tumor recurrence), while 25 patients had distant metastases along with the local malignancy, and 7 patients had liver metastases after resection of the primary lesion (6 on study entry and 1 during follow-up showed tumor development). In 5 of these patients, abdominal lymph node metastases were present at the time of scanning. Of 10 patients, who had undergone potentially curative surgery for their cancer, 7 remained free of disease during follow-up until death or for at least 6 mo. Iodine-123-VIP (150-200 MBq; approximately 1 microg VIP) was administered to all patients. Scintigraphic results were evaluated as compared to conventional radiologic imaging methods and surgical exploration. RESULTS: Primary pancreatic tumors were visualized by 123I-VIP in 19/21 patients (90%) with disease confined to the pancreas and in 8/25 patients (32%) suffering both from locoregional and disease metastatic to the liver. The overall 123I-VIP scan sensitivity for primary pancreatic adenocarcinomas was 58% (27/46 scans). Liver metastases were imaged in 29/32 patients (scan sensitivity 90%) and abdominal lymph node metastases in 4/5 patients. In 5 patients, the VIP receptor scan indicated the malignant lesion before CT. In vitro results confirmed specific binding of 123I-VIP to primary pancreatic tumor cells as well as to PANC1 adenocarcinoma cells. CONCLUSION: Iodine-123-VIP receptor scanning has the potential to offer additional information to augment diagnostic standard methods and could influence the decision-making process in the treatment of pancreatic cancer.

Adenocarcinoma↗
PubMed1998

Indium-111-DOTA-lanreotide: biodistribution, safety and radiation absorbed dose in tumor patients.

UNLABELLED: Imaging with radiolabeled somatostatin/vasoactive intestinal peptide analogs has recently been established for the localization diagnosis of a variety of human tumors including neuroendocrine tumors, intestinal adenocarcinomas and lymphomas. This study reports on the biodistribution, safety and radiation absorbed dose of 111In-1,4,7,10-tetraazacyclododecane-N,N',N",N'''-tetraacetic acid (DOTA)-lanreotide, a novel peptide tracer, which identifies hSST receptor (R) subtypes 2 through 5 with high affinity, and hSSTR1 with low affinity. METHODS: The tumor localizing capacity of 111In-DOTA-lanreotide was initially investigated in 10 patients (3 lymphomas, 5 carcinoids and 2 intestinal adenocarcinomas). Indium-111 -DOTA-lanreotide was then administered to 14 cancer patients evaluated for possible radiotherapy with 90Y-DOTA-lanreotide (8 neuroendocrine tumors, 4 intestinal adenocarcinomas, 1 Hodgkin lymphoma and 1 prostate cancer). After intravenous administration of 111In-DOTA-lanreotide (approximately = 150 MBq; 10 nmol/patient), sequential images over one-known tumor site were recorded during the initial 30 min after peptide application. Thereafter, whole-body images were acquired in anterior and posterior views up to 72 hr postinjection. Dosimetry calculations were performed on the basis of scintigraphic data, urine, feces and blood activities. A comparison with 111In-DTPA-D-Phe1-octreotide (111In-OCT) scintigraphy was performed in 8 of the patients. RESULTS: After an initial rapid blood clearance [results of biexponential fits: T(eff1) 0.4 min (fraction a1 80%) and T(eff2) 13 min (fraction a2 14%)], the radioactivity was excreted into the urine and amounted to 42% +/- 3% of the injected dose (%ID) within 24 hr and 62% +/- 6%ID within 72 hr after injection of 111In-DOTA-lanreotide. In all patients, tumor sites were visualized during the initial minutes after injection of 111In-DOTA-lanreotide. The mean radiation absorbed dose amounted to 1.2 (range 0.21-5.8) mGy/MBq for primary tumors and/or metastases. The effective half-lives of 111In-DOTA-lanreotide in the tumors were T(eff1) 4.9 +/- 2.2 and T(eff2) 37.6 +/- 6.6 hr, and the mean residence time tau was 1.8 hr. The highest radiation absorbed doses were calculated for the spleen (0.39 +/- 0.13 mGy/MBq), kidneys (0.34 +/- 0.08 mGy/MBq), urinary bladder (0.21 +/- 0.03 mGy/MBq) and liver (0.16 +/- 0.04 mGy/MBq). The effective dose was 0.11 +/- 0.01 (range 0.09-0.12) mSv/MBq. During the observation period of 72 hr, no side effects were noted after 111In-DOTA-lanreotide application. The 111In-DOTA-lanreotide radiation absorbed tumor dose was significantly higher (ratio 2.25 +/- 0.60, p < 0.01) when directly compared with 111In-OCT. CONCLUSION: Indium-111 -DOTA-lanreotide shows a high tumor uptake for a variety of different human tumor types, has a favorable dosimetry over 111In-OCT and is clinically safe.

Adenocarcinoma↗
PubMed1998

Response to treatment with yttrium 90-DOTA-lanreotide of a patient with metastatic gastrinoma.

1,4,7,10-tetraazacyclododecane-N,N',N",N'''-tetraacetic acid (DOTA)-lanreotide is a universal somatostatin (SST) receptor subtype ligand that binds to a large variety of human tumors. We report the case of a patient with metastatic gastrinoma who was treated with 90Y-DOTA-lanreotide. Before treatment, dosimetry with 111In-DOTA-lanreotide (150 MBq, 10 nmol) indicated a dose of 5.8 mGy/MBq for the recurrent abdominal gastrinoma, and a mean dose of approximately 1.0 mGy/MBq for liver metastases (i.e., 56 and approximately 10 mGy/MBq for 90Y-DOTA-lanreotide, respectively). After four infusions of 90Y-DOTA-lanreotide (each 1 GBq, approximately 30 nmol) over a 6-mo period, the 111In-DOTA-lanreotide scintigraphy of the liver had returned to a nearly normal condition and a remarkably decreased uptake by the recurrent gastrinoma was calculated (approximately 5 mGy/MBq for 90Y-DOTA-lanreotide). The imaging results were well-correlated with a 25% regression of the liver metastases as indicated by CT. Blood, urine and whole-body clearances of 111In-DOTA-lanreotide and 90Y-DOTA-lanreotide were very similar. The DOTA-lanreotide promises to be useful for functional tumor diagnosis (111In-DOTA-lanreotide) and receptor-mediated tumor radiotherapy (90Y-DOTA-lanreotide).

Gastrinoma↗
PubMed1997

Treatment of advanced pancreatic cancer with epirubicin, 5-fluorouracil and 1-leucovorin: a phase II study.

BACKGROUND: Preclinical data suggest that the levorotatory isomer of leucovorin (1-LV) can augment the cytotoxic effects of 5-fluorouracil (5-FU) more effectively than racemic LV. A phase II study was initiated to evaluate the effect of a combination of the pure L-isomer of LV and 5-FU along with epirubicin in patients with advanced pancreatic cancer. PATIENTS AND METHODS: Twenty-eight consecutive, previously untreated patients with measurable metastatic adenocarcinoma of the pancreas were enrolled in this study. Treatment consisted of epirubicin 50 mg/m2 on day 1 and 5-FU 400 mg/m2 plus 1-LV 100 mg/m2 both administered on days 1 to 5. Treatment cycles were repeated every four weeks for a total of six months unless progressive disease was documented earlier. The study endpoints were survival, toxicity, objective response as well as palliative beneficial effects of the regimen in terms of performance status, body weight and pain. RESULTS: Six patients had a partial response (21%; 95% CI, 8% to 44%) and 10 (36%) stable disease (35%), while the remaining 12 patients (43%) progressed during treatment. The median time to treatment failure was 2.9 months (range 1.2-13.7 months), and the median survival time was six months (range 1.8-19 months), with three patients (11%) being alive after one year. Beneficial palliative effects in terms of performance status, body weight and/or pain were seen in 12 of 28 patients (43%): an improvement in performance status was recorded in four patients, pain was attenuated and/or analgetic consumption reduced by > or = 50% in eight patients, and five patients had weight gain of > 5% of their pretreatment body weight. Treatment-associated side effects were generally mild to moderate. Severe adverse reactions included (asymptomatic) granulocytopenia in five, mucositis and/or diarrhea WHO grade 3 in four patients. CONCLUSION: Our data suggest that epirubicin plus 5-FU and 1-LV is a tolerable regimen that has some positive effects in the treatment of pancreatic cancer. Since this regimen, however, is unlikely to offer any major therapeutic advantage compared to monochemotherapy or other combination regimens, the search for novel and more effective cytotoxic agents must continue.

Adenocarcinoma↗
PubMed1996

[Infectious spondylitis in adults].

In adults, infectious spondylitis is a rare but severe disease, caused by a bacterial thrombus in tissue of reduced resistance. In conventional radiographs initial findings are a narrowing of the intervertebral space, local osteoporosis and poorly defined erosive borders of the vertebral endplates. These changes can be found at least three to six weeks after the onset of disease. However, in Szintigraphy and MRT pathologic alterations are evident after ten to twelve days. Thus, early diagnosis and treatment becomes possible. In early stages of the disease a localized lysis surrounded by a reactive sclerosis appears in predisposed areas of the vertebral body (subchondral, anterobasal, ventral, central). Apparently, a soft tissue tumor is associated. Sclerosis and reduction of the soft tissue tumor are the first signs of repair processes. After at least 12 weeks, computed tomography can reveal typical sintering of the vertebral body and occasionally the development of a bony sequester. In addition, MRT as well as CT can be helpful in the detection and localization of complications as abscesses or affection of the vertebral canal. The tuberculous spondylitis can sometimes cause difficulties in differential diagnosis. Clinical findings, affection of several vertebral bodies, large soft tissue tumors with appearance of calcification as well as not typical locations are strongly suggestive of tuberculous spondylitis, but these findings are not specific of the disease. Degenerative disorders such as erosive osteochondrosis or changing due to chronic dialysis (e.g. amyloid or crystal arthropathies) may cause even more problems in differential diagnosis. Typical for a blastomatous process is the integrity of the interverebral disc space, which is a rare finding in spondylitis.

Adult↗
PubMed1994

Prognostic factors in primary fallopian tube carcinoma. Austrian Cooperative Study Group for Fallopian Tube Carcinoma.

A retrospective nationwide evaluation of primary fallopian tube carcinomas for a period of 10 years (1980-1990) was performed to evaluate the prognostic impact of various factors. Sixty-six cases were investigated for the prognostic influence of estrogen (ER) and progesterone (PgR) status, mitotic activity, degree of nuclear anaplasia, and inflammatory reaction. ER and PgR receptors were detected by immunohistochemistry from paraffin sections. Forty-two percent were PgR-positive and 26% were ER-positive. However, no correlation of steroid receptors with survival could be found. Ninety-two percent of all tumors showed a moderate and high degree of nuclear anaplasia and only 8% showed a low degree of nuclear anaplasia. Thirty-four (52%) samples from all patients revealed low mitotic activity compared to 32 (48%) with an intermediate and high mitotic rate. Twenty-four (37%) tissue samples showed a positive inflammatory reaction which correlated with a significantly better outcome compared with tumors without this feature. This finding was also confirmed in multivariate analysis as an independent prognostic factor.

Fallopian Tube Neoplasms↗
PubMed1990

Risk of vocal chord dysplasia in relation to smoking, alcohol intake and occupation.

The significance of tobacco smoking, alcohol consumption and occupation as risk factors for the development of vocal chord dysplasia was evaluated in a case-control study. Twenty-seven male patients with dysplasia of the vocal chords were chosen from the I. ENT-University Clinic in Vienna (1985-1988) and compared with 54 controls. The main results are: The relative risk (RR) of a smoker compared to that of a non-smoker for vocal chord dysplasia is 7.27 (6.81-7.73); the RR adjusted for occupation is 3.58 (2.31-4.84). The most important risk factor, however, is occupational exposure. The relative risk of a blue collar worker compared to that of a white collar worker is 11.04 (10.61-11.46), which is reduced only to 10.02 (10.61-11.46) after stratification according to smoking habits.

Adult↗
PubMed1990

[What happens to vocal cord dysplasias in variable smoking behavior?].

UNLABELLED: The influence of smoking with regard to the development and course of laryngeal dysplasias was examined. The case histories of 63 patients with histologically proven dysplasias of the larynx were evaluated in the light of their answers to a questionnaire covering their lifetime smoking habits. RESULTS: 1. The percentage of smokers in the patient group significantly exceeds the percentage of smokers in the general population. 2. The disease is more likely to lead to deteriorated histological findings in smokers. 3. A change in smoking habits at the time of diagnosis has no significant effect on the further course of disease. 4. Non-smokers have higher levels of dysplasia at first biopsy, but the disease is less likely to progress. The development of malignancy was not observed in the non-smoker group.

Humans↗