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Biomedical subjects

M Hünerbein

Publications and source records attributed to M Hünerbein.

At least 37 records · Page 2Linked to original sources
PubMed2003

[Flexible applicator systems for radiofrequency ablation (RFA) of hepatic tumors].

PURPOSE: To report our experience with flexible applicators in radiofrequency ablation (RFA) of hepatic tumors. MATERIALS AND METHODS: In 6 liver tumors in 6 patients, a flexible RFA-applicator system (RITA StarBurst FLEX, RITA Medical Systems, Mountain View, CA, USA) was placed under CT guidance. The Seldinger technique with an 11G access system (RITA StarBurst Access) was used to place the application system into the liver. Before and within a week after the ablation, all tumors were investigated with contrast-enhanced MRI. RESULTS: The Seldinger technique accommodated the placement of a thin 17.5-gauge needle for the initial puncture, enabling easy adjustment of the position of the needle. The flexible applicator of the RFA system could be placed in 4.5 (+/- 1.8) minutes on average. CONCLUSION: Flexible applicators facilitate CT-guided RFA and can be placed using the Seldinger technique.

Carcinoma, Hepatocellular↗
PubMed2002

[T4 rectal carcinoma. Surgical and multimodal therapy].

BACKGROUND: In locally advanced rectal cancer with infiltration of neighbouring organs (uT4), resectability and local control are difficult to achieve. Combined preoperative radiochemotherapy may result in increased resectability and reduced local recurrence rates. PATIENTS AND METHODS: Thirty-four patients with biopsy-proven locally advanced rectal cancer were treated by preoperative radiochemotherapy. All tumours had been staged as uT4 lesions by endorectal ultrasound or computed tomography. Radiotherapy was applied in standard blocks, 5 x 1.8 Gy up to 45 Gy. Chemotherapy consisted of two cycles of 5-fluorouracil (300-350 mg/m2/day) and leucovorin (50 mg). In 20 patients, additional thermotherapy was carried out using the Sigma 60 applicator BSD 2000 once a week prior to radiotherapy. Surgery was performed 4-6 weeks after radiochemotherapy. Postoperatively, all patients received four cycles of 5-fluorouracil and leucovorin. RESULTS: Treatment-induced toxicity occurred in 26% of the patients (WHO grade III (n = 6) and IV (n = 3)). The resectability rate was 76% (26/34 patients) (R0 resectability n = 21; 62%). The pathological complete response rate was 6% (n = 2) and the partial response rate was 47% (n = 16). A local failure was observed in six patients after median time of 16 months (range 7-36 months). Patients with R0 resection achieved a 5-year disease-free survival rate of 55% and a survival rate of 71%. The overall 5-year survival rate for all patients with advanced uT4 rectal cancer was 49%. CONCLUSIONS: Our data on preoperative combined treatment in locally advanced T4 rectal cancer revealed encouraging downstaging, local control, and survival rates.

Adult↗
PubMed2002

[Comparison between endorectal MRI (EMRTI) and endorectal sonography (ES) after surgery or therapy for rectal tumors to exclude recurrent or residual tumor].

PURPOSE: This study was designed to evaluate the accuracy and limitations for staging of contrast-enhanced endorectal MR imaging comparing with transrectal US for restaging of rectal lesions after surgery or after therapeutic radiation. Both methods were correlated with histologic findings. METHOD/MATERIALS: The efficacy of these both methods was evaluated in 30 patients with supposed residual or recurrent rectal neoplasms. Contrast enhanced (bolus injection of 0.1 mmol/kg b.w. Gd-DTPA) endorectal MR imaging was performed using a 1.5 Tesla Magnetom. In addition endosonography (7.5 x or 10-MHz transducer) was used. RESULTS: In 8 patients with rectal adenoma after electro-laser resection, 8 patients with rectal carcinoma stage pT1 after transanal resection, 8 patients with rectal carcinoma stage pT2 and 6 patients with rectal carcinoma stage pT3 after regional hyperthermia with radiochemo-therapy, the following results were obtained during the postsurgical or posttherapeutical follow-up with respect to histopathological evaluation: exact staging in 86.6 % with EMRI and 63.3 % in ES, overstaging in 8 % (EMRI) and 23 % (ES), understaging in 0 % (EMRI) and 7 % (ES). The highest diagnostic accuracy was shown in EMRT in patients with rectal adenoma and rectal carcinoma (pT1) and after electro-laser resection or transanal resection during follow-up. CONCLUSIONS: Contrast enhanced endorectal MR imaging appears to be very promising for accurate posttherapeutical staging of rectal cancer and helpful in the diagnosis of recurrence or the differentiation between scar tissue and residual rectal tumor.

Adenoma↗
PubMed2002

Sentinel lymphonodectomy in gastrointestinal cancer--where are we now?

Up to now, no reliable methods for the pre- or intraoperative prediction of the nodal status are available in gastrointestinal cancer patients. Therefore, after the successful application of the sentinel lymph node concept in melanoma and breast cancer, ongoing research on this field is extended to gastrointestinal tumor entities. According to recent experiences, the most promising tumor entities are colon, gastric and anal cancer. First results with these patients indicate that the method could be a reliable predictor of the nodal status and, thus, may have important future implications for adjuvant therapy and the extent of surgery. The dye method for colon cancer and the combined method (dye and radiocolloid) for gastric cancer seem to be appropriate approaches, even when the general experience is still low. In rectal cancer, however, current experience failed yet to yield satisfying results. Up to now, anal cancer has not been a focus of publication, even when the concept seems to be very attractive for the evaluation of the inguinal lymph node status.

Gastrointestinal Neoplasms↗
PubMed2001

[Minimal invasive surgery. Aspects of surgical oncology of the gastrointestinal tract].

The general potential and current position of minimally invasive surgery for the surgical treatment of malignant tumours of the gastrointestinal tract are discussed. A reliable validation of these procedures for tumour surgery is still impossible due to the lack of long-term results, the selective experience, and the ongoing process of learning and development. However, it seems clear that minimally invasive procedures will have an important position within surgical oncology. This is especially true with respect to improved staging of gastrointestinal tumours by laparoscopy and various palliative procedures that may be performed laparoscopically. Minimally invasive procedures may suffice for the treatment of certain, highly selected cases of preneoplastic and early cancerous lesions. The definitive acceptance of minimally invasive procedures in the future will require further clinical, preferably randomised trials, comparing the advantages of the minimally invasive access route to possible long-term disadvantages with regard to recurrence-free and overall survival.

Gastrointestinal Neoplasms↗
PubMed2001

[Value of laparoscopic ultrasound for staging of gastrointestinal tumors].

BACKGROUND: The objective of this study was to evaluate the impact of laparoscopic ultrasound on the staging of gastrointestinal tumors prospectively. METHODS: Between 1993 and 2000 staging laparoscopy was performed on 668 patients with various neoplasms. Laparoscopy provided adequate information regarding resectability in 366 patients. Laparoscopic ultrasonography was performed in 302 patients (45%) using an intraoperative ultrasound unit (B & K) and a semiflexible ultrasound probe (5-7.5 MHz). The results of staging laparoscopy were compared to the preoperative staging and histopathology. RESULTS: Compared to preoperative staging laparoscopic ultrasound provided additional information of therapeutic relevance in 46 of 302 cases (15%). In a group of 384 patients with tumors of the upper gastrointestinal tract, laparoscopic ultrasound was performed in 186 cases and showed occult liver metastases, M1-lymph nodes, or nonresectable disease in 26 patients. Overall, this technique improved the staging of esophageal, gastric and pancreatic cancer in 12%, 3%, and 12% of the patients, respectively. Laparoscopic ultrasound proved to be most useful in esophageal and pancreatic cancer with a rate of 52% and 20% information additional to laparoscopy. The relative contribution of laparoscopic ultrasound to the staging of gastric cancer was only 10%. CONCLUSION: Laparoscopic ultrasound improves the diagnostic accuracy of staging laparoscopy. However, routine use of this technique is only justified, if neoadjuvant therapy--particularly in controlled trials--is considered in patients with advanced gastrointestinal cancer.

Carcinoma, Squamous Cell↗
PubMed2001

Three-dimensional ultrasonography of bone and soft tissue lesions.

BACKGROUND: The aim of this study was to investigate feasibility and potential applications of three-dimensional (3D) ultrasonography in the evaluation of musculoskeletal disorders. METHODS: 3D ultrasonography was performed in 83 patients with bone (n = 50) or soft tissue lesions (n = 33). Volume data were obtained using two volume probes (1-8.5 and 8.5-12 MHz) and a 3D ultrasound unit. The results of 3D ultrasonography were compared to two-dimensional ultrasound and radiological imaging. RESULTS: The system enabled acquisition of 3D ultrasound data in diagnostic quality. 3D image-processing permits to analyse ultrasound data interactively in three orthogonal planes (section mode) or in realistic 3D views (rendering mode). Compared to conventional ultrasonography 3D image analysis improved assessment of details, provided better spatial orientation and facilitated image interpretation in 23, 44 and 49 cases, respectively. Additional findings that had significant influence on patient management were obtained in 16 of 83 patients (19%). Multiplanar reformating provided additional scan planes and increased the comparability of follow up examinations by standardized display and measurement. 3D surface reconstructions were very helpful to understand the morphology of bone lesions e.g. tortuous fracture lines. CONCLUSION: Our preliminary experience shows that 3D ultrasonography of musculoskeletal disorders is feasible. The ability to assess previously unattainable scan planes and lifelike surface projections may be particularly valuable for imaging of bone lesions. Further studies will be required to assess the exact role of this new technique for the evaluation of musculoskeletal disorders.

Adult↗
PubMed2001

Regression of high-grade gastric B-cell lymphoma after eradication of Helicobacter pylori.

Regression of high-grade gastric B-cell lymphoma after eradication of Helicobacter pylori with antibiotic therapy has recently been shown in a very small number of patients. We describe here a patient with a 5-cm polypoid gastric lymphoma, who received a 7-day course of triple therapy when the histopathology was unknown. A second endoscopic examination 4 weeks later showed partial tumor regression without biopsy evidence of malignancy. Endoscopic mucosectomy was performed 8 weeks after the initial diagnosis. Again, in the histological analysis of the specimen, no evidence of B-cell lymphoma could be found. To confirm that the original biopsies were from the same patient, DNA analyses were carried out which gave identical results. This case suggests that a subgroup of primary gastric B-cell lymphomas responds to eradication of H. pylori with antibiotic therapy.

Anti-Bacterial Agents↗
PubMed2001

The role of transrectal ultrasound-guided biopsy in the postoperative follow-up of patients with rectal cancer.

BACKGROUND: The value of endorectal ultrasound (EUS) in the diagnosis of recurrent rectal cancer is limited by the inability to differentiate between malignant and benign lesions. We have prospectively investigated the role of EUS with transrectal ultrasound-guided biopsy in the postoperative follow-up of rectal cancer. METHODS: Since 1995, patients who had undergone a sphincter-saving operation for rectal cancer (n = 312) were followed-up by a standard program including rectal palpation, carcinoembryonic antigen monitoring, computed tomography, and EUS. Transrectal EUS-guided biopsy of perirectal lesions was performed in 68 patients with perirectal lesions by using a rigid endoprobe with a 10 MHZ multiplane transducer and special targeting device. RESULTS: Overall local recurrence was observed in 36 patients. Intraluminal recurrence was diagnosed by proctoscopy in 12 patients. Transrectal EUS-guided biopsy showed pelvic recurrence in 22 of 68 patients with perirectal lesions. Biopsy specimens with benign histology were obtained from 41 patients, and the procedure failed in 5 cases (accuracy, 92%). There was a strong agreement between transrectal biopsy results and the final diagnosis (kappa = 0.84), the sensitivity and specificity being 91% and 93%, respectively. In contrast, clinical examination (kappa = 0.27), computed tomography (kappa = 0.47), or EUS (kappa = 0.42) showed only a moderate level of agreement with the histopathologic diagnosis, mainly because of the limited specificity of all 3 methods (65% vs 46% vs 57%). EUS-guided biopsy was significantly more accurate than computed tomography and EUS (P <.01). The biopsy results had a considerable impact on the management in 18 of 68 patients (26%). CONCLUSIONS: Transrectal EUS-guided biopsy is a safe and efficient method for tissue sampling of perirectal lesions. This minimally invasive and inexpensive technique improves the accuracy of endorectal ultrasound in the diagnosis of recurrent rectal cancer.

Biopsy↗
PubMed2000

Prospective comparison of endorectal ultrasound, three-dimensional endorectal ultrasound, and endorectal MRI in the preoperative evaluation of rectal tumors. Preliminary results.

BACKGROUND: The aim of this study was to compare the value of endorectal ultrasound (EUS), three-dimensional (3D) EUS, and endorectal MRI in the preoperative staging of rectal neoplasms. METHODS: Thirty consecutive patients with rectal tumors were assessed by EUS and endorectal MRI. Additionally, three-dimensional ultrasound was performed in a subgroup of 25 patients. EUS data were obtained with a bifocal multiplane transducer (10 MHz) and processed on a 3D ultrasound workstation. MR imaging was carried out with a 1. 5 T superconducting unit using an endorectal surface coil. RESULTS: EUS was carried out successfully in all 30 patients, whereas endorectal MRI was not feasible in two patients. Compared with the histopathological classification, EUS and endorectal MRI correctly determined the tumor infiltration depth in 25 of 30 and 28 patients, respectively. The comparative accuracy of EUS, 3D EUS, and endorectal MRI in predicting tumor invasion was 84%, 88%, and 91%, respectively. EUS, three-dimensional EUS, and endorectal MRI enabled us to assess the lymph node status correctly in 25, 25, and 24 patients, respectively. Both three-dimensional EUS and endorectal MRI combined high-resolution imaging and multiplanar display options. Assessment of additional scan planes facilitated the interpretation of the findings and improved the understanding of the three-dimensional anatomy. CONCLUSION: The accuracy of three-dimensional EUS and endorectal MRI in the assessment of the infiltration depth of rectal cancer is comparable to conventional EUS. One advantage of both methods is the ability to obtain multiplanar images, which may be helpful for the planning of surgery in the future.

Adult↗
PubMed2000

Preoperative evaluation of colorectal neoplasms by colonoscopic miniprobe ultrasonography.

OBJECTIVE: To investigate the value of colonoscopic miniprobe ultrasonography for preoperative staging of colorectal neoplasms. SUMMARY BACKGROUND DATA: Endoscopic ultrasonography is the most accurate technique for staging colorectal cancer. However, limitations of this technique include the inability to examine stenotic tumors and the difficulty of reaching tumors proximal to the rectum. METHODS: Miniprobe ultrasonography (12.5 MHz) was performed in 63 patients with tumors of the colon or rectum. The results of imaging were compared with endoscopic assessment of the lesions and histopathologic findings of the resected specimens. RESULTS: Miniprobe ultrasonography allowed high-resolution imaging of colorectal tumors during routine colonoscopy. The infiltration depth was correctly classified in 22 adenoma, 3 T1, 10 T2, and 22 T3 or T4 tumors. The accuracy for tumors of the rectum and colon was 86% and 92%, respectively (overall accuracy 90%). The small diameter of the probe allowed examination of 21 stenotic tumors with an accuracy of 86%. Miniprobe ultrasonography revealed carcinoma in 5 of 30 broad-based polyps, although adenomas were diagnosed by endoscopy. Correct assessment of lymph node involvement was obtained in 47 of 55 patients. Based on the findings of miniprobe ultrasonography, management was modified in 7 of the 63 patients. CONCLUSIONS: These preliminary results show that miniprobe ultrasonography improves preoperative staging of stenotic rectal cancer and colonic tumors. This technique can be easily performed during routine colonoscopy and may have considerable impact on surgical therapy.

Adult↗
PubMed1999

Accuracy of endorectal ultrasound after preoperative radiochemotherapy in locally advanced rectal cancer.

OBJECTIVES: Factors limiting the accuracy of endorectal ultrasound in staging, locally advanced primary rectal cancer after preoperative neoadjuvant radiochemotherapy (RCT) were evaluated. METHODS: Patients (n = 84) with initial locally advanced rectal cancer (uT3/uT4) undergoing R0 resection were investigated after preoperative treatment that combined radiotherapy up to 45 Gy with two cycles of chemotherapy (5-FU and leucovorin on d 1-5 and 22-28). At 4 to 6 weeks after completion of RCT and before tumor resection, preoperative endoluminal ultrasound was performed. RESULTS: The accuracy to predict the depth of tumor infiltration (T-category) was found to correlate with downstaging. The T-category was correctly staged before surgery in 15 of the 51 responders (29%) and in 27 of 33 nonresponders (82%), whereas misinterpretation occurred in 36 of the responders (71%) and in 6 of the nonresponders (18%) (p < 0.001). Neither tumor distance from anal verge nor tumor location correlated with the staging accuracy. Lymph node involvement was correctly assessed in 48 patients (57%). Wall invasion was correctly ascertained in 42 patients (50%), with under estimation in 11 patients (13%) and overestimation in 31 patients (37%). CONCLUSIONS: After radiochemotherapy, endosonography does not provide a satisfactory accuracy for preoperative staging of rectal cancer. New interpretation and diagnostic criteria are needed for the prediction of treatment response.

Adenocarcinoma↗
PubMed1999

EUS-guided fine needle biopsy: minimally invasive access to metastatic or recurrent cancer.

OBJECTIVE: Endoscopic ultrasound (EUS) is a sensitive technique for preoperative staging of gastrointestinal tumors. However, the value of this technique in the diagnosis of metastatic or recurrent disease is limited by the inability to differentiate malignant and benign lesions. We have prospectively investigated the role of EUS-guided biopsy in the evaluation of peri-intestinal tumors. METHODS: EUS-guided biopsy was performed in 167 patients with thoracic, intra-abdominal or pelvic lesions. The upper gastrointestinal tract was examined with a flexible echoendoscope equipped with a 7.5 MHz curved array transducer. For transrectal EUS a rigid endoprobe with a bifocal multiplane transducer (10 MHz) was used. Both instruments allowed to observe the biopsy procedure exactly in the longitudinal scan plane. RESULTS: Real time ultrasonography guidance of the biopsy needle enabled precise tissue sampling even of small lesions with a diameter of 1 cm. Overall EUS-guided fine needle biopsy yielded tissue samples for histopathologic or cytologic analysis in of 151 of 167 patients. Histology demonstrated benign lesions in 71 of 74 patients and malignant tumors in 68 of 93 patients. EUS-guided fine needle biopsy failed to provide the correct diagnosis in 28 cases. The overall sensitivity and specificity of EUS-guided biopsy in the diagnosis of malignancy were 73 and 96%, respectively. The histopathological results changed the clinical and endosonographic diagnosis in 49 patients. No complications were observed related to the biopsy. CONCLUSIONS: EUS-guided needle biopsy is a safe and efficient method for tissue sampling of peri-intestinal lesions. This minimally invasive technique provides adequate biopsies and improves the diagnostic value of endoscopic ultrasonography considerably.

Biopsy, Needle↗