Search PubMed⌕ Search

Biomedical subjects

M Hünerbein

Publications and source records attributed to M Hünerbein.

At least 19 recordsLinked to original sources
PubMed2005

Comparison of CT, MRI and FDG-PET in response prediction of patients with locally advanced rectal cancer after multimodal preoperative therapy: is there a benefit in using functional imaging?

The aim of this study was to compare CT, MRI and FDG-PET in the prediction of outcome of neoadjuvant radiochemotherapy in patients with locally advanced primary rectal cancer. A total of 23 patients with T3/4 rectal cancer underwent a preoperative radiochemotherapy combined with regional hyperthermia. Staging was performed using four-slice CT (n=23), 1.5-T MRI (n=10), and (18)F-FDG-PET (n=23) before and 2-4 weeks after completion of neoadjuvant treatment. Response criteria were a change in T category and tumour volume for CT and MRI and a change in glucose uptake (standard uptake value) within the tumour for FDG-PET. Imaging results were compared with those of pretherapy endorectal ultrasound and histopathological findings. Histopathology showed a response to neoadjuvant therapy in 13 patients whereas 10 patients were classified as nonresponders. The mean SUV reduction in responders (60+/-14%) was significantly higher than in nonresponders (37+/-31%; P=0.030). The sensitivity and specificity of FDG-PET in identifying response was 100% (CT 54%, MRI 71%) and 60% (CT 80%, MRT 67%). Positive and negative predictive values were 77% (CT 78%, MRI 83%) and 100% (CT 57%, MRI 50%) (PET P=0.002, CT P=0.197, MRI P=0.500). These results suggest that FDG-PET is superior to CT and MRI in predicting response to preoperative multimodal treatment of locally advanced primary rectal cancer.

Adenocarcinoma↗
PubMed2005

Prediction of gastric cancer lymph node status by sentinel lymph node biopsy and the Maruyama computer model.

AIMS: The extent of lymph node dissection in gastric cancer remains controversial. The Maruyama computer model and the sentinel lymph node biopsy (SLNB) are compared for their value to predict the nodal status and lead to stage-adapted surgery. METHODS: Thirty four patients with stage I-IV gastric cancer underwent both staging procedures. For SLNB, 15 patients underwent endoscopic, peri-tumoural injection of (99m)Tc-colloid, and 19 patients were injected of Patent blue V. All 'hot' or blue sentinel lymph nodes (SLNs) were separately excised and histopathologically assessed. If the SLN was negative after routine staining by H&E, it was processed completely and reanalysed after immunohistochemistry. RESULTS: At least, one SLN was detected by means of SLNB in 33/34 of the patients. The sensitivity to identify a positive nodal status was 22/33 and the specificity/positive predictive value was 10/10 and 22/22. Additional micrometastases or isolated tumour cells in the SLN led to 'upstaging' of 5/15, initially classified as nodal negative by H&E-staining. Using the Maruyama computer model, a sensitivity of 22/23 for the correct prediction of the lymph node involvement was associated with a specificity of 2/10 and a positive predictive value of 22/30. CONCLUSIONS: The clinical impact of the Maruyama computer model is limited due to low specificity and a low positive predictive value, rendering the method less useful as an indicator for individualised surgery.

Diagnosis, Computer-Assisted↗
PubMed2005

[CT-guided resection of pulmonary metastases].

PURPOSE: To evaluate the feasibility and potential use of intraoperative computed tomography (IOP CT) as guidance for video-assisted thoracic surgery (VATS). MATERIAL AND METHODS: Fifteen consecutive patients with peripheral intrapulmonary nodules underwent a thoracoscopy with IOP CT. Solitary lesions were known in 6/15 patients (40 %, group II) whereas 9/15 (60 %, group I) patients had multiple lesions (n >/= 2). IOP CT was performed with the mobile CT scanner Philips Tomoscan M. Radiologists intraoperatively placed percutaneous marks of lung lesions after unsuccessful VATS by use of a lung marker set (Somatex, Teltow, Germany). VATS was performed under general anaesthesia and with double lumen endotracheal intubation for single lung ventilation. Imaging quality and imaging of pulmonary nodules were rated. RESULTS: IOP CT was evaluated as feasible combined with VATS. Thoracotomy was avoided in 5/15 patients where lesions could not be detected by VATS. A CT-guided biopsy was performed in two patients after an unsuccessful attempt of thoracoscopy. There were no documented side effects. CONCLUSION: First clinical results suggest that a combination of VATS and IOP CT is feasible. Thus, the number of open thoracoscopies might be decreased. Intrapulmonary lesions not detectable with VATS could be marked under CT -- guidance intraoperatively and then resected by thoracoscopy.

Aged↗
PubMed2004

Impact of miniprobe ultrasonography on planning of minimally invasive surgery for gastric and colonic tumors.

BACKGROUND: The use of minimally invasive procedures for the management of gastrointestinal cancer is increasing. The aim of this study was to investigate the role of high-frequency miniprobe endoscopic ultrasound (EUS) for therapeutic decisions making in patients with gastric or colonic tumors. METHODS: A total of 137 patients underwent EUS with a 12.5-MHz miniprobe for preoperative staging of tumors of the stomach ( n = 49) or colon ( n = 88). After resection, the surgical path was reviewed to analyze the role of preoperative staging with miniprobes. RESULTS: Miniprobe EUS enabled accurate assessment of the infiltration depth of gastric and colonic tumors. The overall accuracy rates were 88% and 87%, respectively. The lymph node status was predicted correctly in 82% of the patients (sensitivity, 61%, specificity, 94%). Based on the results of miniprobe EUS, patients with gastric cancer were accurately selected to undergo endoscopic mucosal resection, laparoscopic resection, or open surgery in 100%, 91%, and 86% of the cases, respectively. In patients with colonic tumors, the treatment decision analysis showed that the stratification was correct in 90% of the patients. CONCLUSIONS: Miniprobe EUS is a reliable method for validating treatment decisions for patients undergoing minimally invasive procedures for gastric and colonic tumors. This method is particularly valuable in the management of colon cancer, because endoscopic and laparoscopic resections can be offered to selected patients as an alternative to open surgery.

Adenocarcinoma↗
PubMed2004

[Imaging modalities in the preoperative staging of rectal carcinoma].

Thorough clinical examination, endorectal ultrasound, and magnetic resonance tomography (MRI) are decisive tools in the pretherapeutic work-up of patients with rectal cancer. Depth of infiltration to the rectal wall as well as involvement of perirectal lymph nodes by the tumor are the key questions to be answered. To receive adequate information from imaging procedures, the right questions need to be asked. The extent of invasion of the rectal wall and exact location of tumor infiltration to neighboring structures can be demonstrated by MRI very well, particularly if imaging planes are acquired at 90 degrees to the position of the rectum. Recent developments in computed tomography (CT) using isotrope voxels allow three-dimensional reconstructions of tumors without loss of imaging quality. Assessment of the primary tumor and its nodal metastases after preoperative radio-(chemo-)therapy is still seriously limited. Fusion of positron emission tomography and CT could be a step towards solving the problem of response assessment in the near future.

Contrast Media↗
PubMed2004

[Interdisciplinary surgery and telemedicine].

Surgical therapy is becoming increasingly complex. Besides new surgical techniques, sophisticated diagnostic methods and innovative interventional procedures must be integrated into the therapeutic concept to increase the efficacy of surgery. Accurate application of these techniques requires close cooperation between surgeons, other medical specialists, and technicians. Consequently, there is a significant need for structures promoting efficient communication, organization, and interaction in surgical departments. New techniques developed from telecommunication and information technology enable the transferal of complex medical data at any time to any place and are therefore the basis for telemedical applications. Telemedicine and other new techniques such as virtual operation planning, simulation, and intraoperative navigation promise to increase the efficacy of surgical therapy in the future. This paper provides an overview of the applications of telesurgery and currently available techniques.

Computer Communication Networks↗
PubMed2004

[Soft tissue sarcoma].

Soft tissue sarcomas are characterized by their heterogeneity. With new diagnostic imaging techniques, low- and high-grade components of the tumor can be differentiated. Thus biopsies should be guided by imaging to assure representative specimens. Besides histopathology, the advent of chromosomal and gene expression analysis may allow more accurate classification in the near future. Gene expression profiling has already proven its value by finding new subclassifications in other tumor types. Furthermore, this technique is a promissing tool to predict the response of a tumor to neoadjuvant and adjuvant therapy. Up to now, response evaluation in neoadjuvant therapy is based on tumor size and not on vital tumor cells. Newer techniques (i.e., Magnetic-resonance-Spectroscopy, Molecular Imaging) can show the change of metabolism in neoadjuvant therapy and allow objective, comparative measurement of biological activity. The diagnostic of soft tissue sarcomas implies primarily a multidisciplinary approach for a stage associated therapy.

Biopsy↗
PubMed2004

Endoscopic and surgical palliation of gastrointestinal tumors.

Approximately 40-50% of patients with gastrointestinal tumors are not candidates for curative surgery because of locally advanced tumors or metastatic disease. In the course of the disease most of these patients will require palliative treatment because of obstruction, fistula, pain or hemorrhage. Various endoscopic and surgical procedures can be offered to these patients to alleviate the symptoms of the disease, to improve quality of life and to increase their survival time. However, the potential risk of each treatment must be balanced carefully with the expected benefits and the prognosis of the individual patient. Consequently, minimally invasive procedures, i.e. endoscopic and laparoscopic procedures, have been increasingly used for palliation in recent years. This article provides an overview on endoscopic and surgical palliation of gastrointestinal tumors on the basis of our own experience and a review of the literature.

Endoscopy, Gastrointestinal↗
PubMed2004

New concepts of staging in gastrointestinal tumors as a basis of diagnosis and multimodal therapy.

The therapy of gastrointestinal tumors is becoming more and more sophisticated and complex. This is due to an improved understanding of the pathogenesis of tumors, a more detailed classification and increasing therapeutic options. The basis of optimized therapeutic concepts is the exact evaluation of tumor spread and exact staging. The following review describes some of the most recent staging concepts in gastrointestinal tumors. Multislice computed tomography (CT), positron emission tomography (PET) and new supraparamagnetic iron oxide contrast agents for magnetic resonance imaging enable an increasing quality of the visualization of tumors and metastases. 3D imaging will be used for planning of surgical interventions in the future. Optical coherence tomography may contribute to an improved tumor staging and, thus, to the safety of limited interventions in early oesophageal- and gastric cancer patients. Laparoscopy and laparoscopic ultrasound become increasingly important for the identification of small metastases in the peritoneum, in lymph nodes and in the liver. The sentinel lymph node concept will contribute to an improved staging and individualized therapy as well.

Combined Modality Therapy↗
PubMed2003

Endosonography of upper gastrointestinal tract cancer on demand using miniprobes or endoscopic ultrasound.

BACKGROUND: The aim of this study was to investigate whether endosonography on demand with miniprobes and conventional endoscopic ultrasound improves the accuracy of endosonographic staging of upper gastrointestinal tract cancer. METHODS: Altogether, 173 patients underwent endoscopic ultrasonography for preoperative staging of esophageal (n = 63) or gastric cancer (n = 110). Depending on the endoscopic appearance (i.e., size and growth pattern), tumors were examined with a linear-array echoendoscope (7.5 MHz) or with high-resolution miniprobes (12.5 MHz). The results of preoperative staging were correlated with histopathology of the resection specimen. RESULTS: The overall accuracy of miniprobe ultrasonography and endoscopic ultrasound in assessing the infiltration depth of upper gastrointestinal cancer was 87% and 81%, respectively. Miniprobe ultrasonography was superior to conventional endoscopic ultrasound in the staging of early cancers, particularly T1 tumors (accuracy, 81% vs 56%). The combined accuracy of both techniques for all tumor stages was 82%. Correct diagnosis of lymph node involvement was obtained with miniprobe ultrasonography or endoscopic ultrasound in 76% and 71% of the cases, respectively. The combined accuracy in assessing the lymph node status was 73% (sensitivity, 68%; specificity, 81%). CONCLUSIONS: Endosonography on demand using either miniprobes or conventional endoscopic ultrasound may result in more effective and less invasive staging of esophageal and gastric cancer. Selective use of high-resolution miniprobes and conventional endoscopic ultrasound offers accurate staging of all tumor stages.

Adult↗
PubMed2003

[Lymphatic mapping and sentinel lymph node biopsy in gastric cancer].

INTRODUCTION: Lymphatic mapping and the sentinel lymph node (SLN) concept has been validated in malignant melanoma and breast cancer.However, the application for other solid tumors is still controversial. One of the most promising approaches is selective lymph node staging in gastric cancer.The presented pilot study evaluated the feasibility of the radiocolloid technique in gastric cancer patients and its value in predicting a positive nodal status. PATIENTS AND METHODS: Fifteen patients with gastric cancer (u T(1-3)) underwent endoscopic submucosal injection of 0.4 ml 60 MBq (99m)Tc-Nanocis around the tumor 17 (+/-3) h prior to surgery. After laparotomy the activity of all 16 (JGCA) lymph node stations was measured by a handheld probe. All patients underwent standard gastrectomy with systematic D2 lymphadenectomy. After resection the site was scanned for residual activity. All sentinel lymph nodes (SLN's) were removed ex vivo from the resected specimen and processed for intensified histopathologic assessment including serial sections and immunohistochemistry. RESULTS: In 14 of 15 patients at least one or more SLN's were obtained (93%), the median number of SLN's was 3 (1-5). Of the 14 patients, 9 revealed lymph node metastases. In eight of the nine patients the sentinel node(s) correctly predicted metastatic lymph node invasion. In five cases the lymph node station with positive sentinel node(s) was the only positive node station resulting in a sensitivity of 8/9 (89%). In one case immunohistochemical staining revealed micrometastases leading to an upstaging in 1/6 of the initially nodal-negative patients. CONCLUSION: Lymphatic mapping and sentinel node biopsy using the radiocolloid technique is feasible in gastric cancer. Limited results indicate a correct prediction of the nodal status and the potential of upstaging.Further studies seem to be justified to evaluate the clinical impact of the method.

Aged↗
PubMed2003

[Reducing trauma with minimally invasive surgery. Evidence and new strategies].

Minimally invasive surgery has become a viable alternative to conventional surgery. The technical advantages of minimally invasive surgery can be translated into clinical benefits for the patients, i.e., less postoperative pain and impairment of lung function, better cosmetic results, shorter hospitalization, and earlier convalescence. Laparoscopic operations have replaced a significant proportion of open surgical procedures and are now routinely used. While the role of laparoscopic surgery has been generally accepted for the management of benign disorders, there is ongoing debate regarding the adequacy of this technique in surgical oncology. There is evidence that minimally invasive surgery can reduce perioperative morbidity in cancer patients. However, definite validation of these procedures for tumor surgery is not yet available due to the lack of prospective randomized trials providing reliable long-term data on disease-free survival and overall survival. It seems likely that minimally invasive procedures will play an important role for the treatment of preneoplastic lesions and tumors of limited size.

Evidence-Based Medicine↗
PubMed2003

Endorectal ultrasound in rectal cancer.

Accurate staging of rectal carcinoma is crucial for planning surgery and the indication for adjuvant therapy. Although computed tomography and magnetic resonance imaging are very sensitive in the detection metastastic disease, local staging of rectal cancer with these techniques has been disappointing. Endorectal ultrasound (EUS) remains the most accurate method for staging of rectal cancer. High accuracy rates in the assessment of the depth of infiltration (T stage) (80-90%) and in the determination of the lymph node status (70-80%) have been confirmed in several studies. Continued research and development has made the instrumentation for EUS more accurate and user-friendly. New techniques that have contributed significantly to the evolution of EUS include three-dimensional EUS, high-frequency miniprobes and transrectal ultrasound-guided biopsy techniques. Further improvement can be expected by contrast enhancement with microbubbles and colour Doppler imaging.

Biopsy↗
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↗