K. T. Moesta

Treatment of Thoracic Anastomotic Leaks After Esophagectomy With Self-expanding Plastic Stents

Objective:To evaluate the efficacy of a self-expanding plastic stent in the treatment of thoracic leaks after esophagectomy for cancer. Summary Background Data:Anastomotic leaks are a major cause of morbidity and mortality after esophageal resection. Treatment options range from aggressive surgery to conservative management, but there remains much controversy on the best treatment. Methods:Over a 6-year period (1998–2003), esophagogastric leaks were observed in 19 of 204 patients (9.3%) after esophagectomy. Between 1998 and 2000, anastomotic leaks were managed by reexploration (n = 7) or by conservative treatment (n = 3). Since 2001, insertion of self-expanding plastic stents was performed for all anastomotic leaks (n = 9). The short-term efficacy and long-term outcome of both treatments were analyzed. Results:Self-expanding plastic stents were successfully placed in all patients without procedure-related morbidity. Immediate leak occlusion was obtained in 8 of 9 patients. The mean healing time (time to stent removal) was 29 days. Compared with the conventional treatment group, patients who were treated with stents had earlier oral intake (11 days versus 23 days), a less extensive intensive care course (25 days versus 47 days), and shorter hospital stay (35 days versus 57 days). In-hospital mortality was 0% (0 of 9 patients) in the stent group and 20% (2 of 10 patients) in the other group. After a mean follow-up of 12 months, none of the patients developed a stricture after stenting, but a stricture occurred in 1 patient after conservative treatment. Conclusions:Self-expanding plastic stents can reduce leak-related morbidity and mortality after esophagectomy and may be considered a cost-effective treatment alternative.

Comparison of Two Tricarbocyanine-Based Dyes for Fluorescence Optical Imaging

Optical technologies are evolving in many biomedical areas including the biomedical imaging disciplines. Regarding the absorption properties of physiological molecules in living tissue, the optical window ranging from 700 to 900 nm allows to use fluorescent dyes for novel diagnostic solutions. Here we investigate the potential of two different carbocyanine-based dyes fluorescent in the near infrared as contrast agents for in vivoimaging of subcutaneously grown tumours in laboratory animals. The primary aim was to modify the physicochemical properties of the previously synthesized dye SIDAG to investigate the effect on the in vivoimaging properties.

Magnetic resonance-guided biopsy of suspicious breast lesions with a handheld vacuum biopsy device.

Purpose: To evaluate a handheld vacuum-assisted device system for magnetic resonance image (MRI)-guided breast lesion biopsy. Material and Methods: In 32 patients, a total of 42 suspicious breast lesions (mean diameter 7.5 mm for mass lesions, 11.6 mm for non-masslike diffuse lesions) seen with MRI (no suspicious changes in breast ultrasound or mammography) were biopsied (27 lateral, 15 medial) using a 10G vacuum-assisted breast biopsy device under MR guidance. Histology of biopsy specimens was compared with final histology after surgery or follow-up in benign lesions. Results: In all biopsies, technical success was achieved. Histology revealed 11 lesions with ductal carcinoma in situ (DCIS) or invasive cancer, three with intermediate lesions (LCIS) and 28 with benign breast lesions (adenosis, infected hematoma). In one patient with discordant results of MRI and histology, surgical excision revealed medullary cancer. In the follow-up (mean 18 months) of the histological benign lesions, no breast cancer development was observed. Besides minor complications (hematoma, n = 6), with no further therapeutic interventions, no complications occurred. Conclusion: MRI-guided breast lesion biopsy using a handheld vacuum-assisted device is a safe and effective method for the work-up of suspicious lesions seen with breast MRI without changes in mammography or ultrasound. In the case of discordant histology of vacuum biopsy and breast MRI appearance, surgical excision is recommended.

Detection and characterization of breast tumours by time-domain scanning optical mammography

The paper gives a short overview of various methods of optical mammography, emphasizing scanning time-domain mammography. The results of a clinical study on time-domain optical mammography are reviewed, comprising 154 patients carrying a total of 102 carcinomas validated by histology. A visibility score attributed to each carcinoma as qualitative measure of tumour detectability indicates acceptable sensitivity but poor specificity for discrimination between malignant and benign lesions. Likewise, a multi-variate statistical analysis yields sensitivity and specificity between 80% and 85% for tumour detection and discrimination with respect to normal (healthy) breast tissue, but values less than 70% for discrimination between malignant and benign breast lesions, being too low to be of clinical relevance. For 87 of the 88 tumours detected retrospectively in both projection optical mammograms, optical properties and tissue parameters were derived based on the diffraction of photon density waves by a spherical inhomogeneity as forward model. Following injection of a bolus of indocyanine green as non-targeted absorbing contrast agent, dynamic contrast-enhanced time-domain optical mammography was carried out on a small number of patients, but no differences in wash-out kinetics of indocyanine green between tumours and healthy breast tissue were observed.

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.

Histopathological correlation to MRI findings during and after laser-induced thermotherapy in a pig pancreas model.

Stroszczynski C, Hosten N, Puls R, et al. Histopathological correlation to MRI findings during and after laser-induced thermotherapy in a pig pancreas model. Invest Radiol 2001;36:413–420. rationale and objectives. To investigate whether percutaneous laser-induced thermotherapy (LITT) with continuous magnetic resonance (MR) monitoring of thermal effects within the pancreas is feasible in a porcine model. methods.Laser applicators were placed in the pancreas of 15 female pigs. A temperature-sensitive (thermo–fast low-angle shot) sequence was used for continuous monitoring of thermal effects during LITT at 1.5 T. Follow-up MR images were acquired, the pigs were observed for 7 days, and then a pathological examination was performed after sacrifice. results.Continuous MR monitoring visualized thermal effects in pancreatic tissue and thermal damage of the spleen (n = 1), the left kidney (n = 1), and peripancreatic fat (n = 4) but missed the thermal damage of the duodenum (n = 2). Thermal-induced lesions (10–32-mm diameter) were clearly visualized on contrast-enhanced T1-weighted images. conclusions.Laser-induced thermotherapy of pancreatic tissue was feasible in this porcine model, and online monitoring was practicable. Further studies are necessary to increase the accuracy of online MR imaging of thermal effects.

Characteristic porphyrin-like autofluorescence in primary colon tumors and lymph nodes

Fluorescence spectra of primary colon tumors, normal colonic tissue and lymph nodes were recorded ex vivo, following pulsed laser excitation at lambda equals 505 nm. Fluorescence was detected at zero delay and at a delay of 20 ns between the optical pulse and the opening of the intensified diode array detector. Generally, the spectra consist of a broad unspecific background (unspecific autofluorescence) and two characteristic fluorescence bands at lambda approximately equals 630 nm and lambda approximately equals 700 nm (specific autofluorescence). By delayed observation the intensity of the specific fluorescence diminishes less than the intensity of the unspecific background indicating a longer fluorescence decay time of the specific compared to the unspecific fluorescence. The fluorescence excitation and the fluorescence emission spectra of the specific autofluorescence as well as the fluorescence decay time are similar to those of porphyrins. Assuming that the relative amount of specific autofluorescence can be used to discriminate between primary tumors and normal colonic tissue or involved and non-involved lymph nodes, we have analyzed undelayed and delayed fluorescence spectra quantitatively to derive characteristic quantities for discrimination. We have investigated 18 primary colon tumors and associated normal colonic tissue as well as 174 lymph nodes. Out of 18 primary tumors classified by routine pathology we have correctly identified 16 by fluorescence analysis. Because of the rather weak specific autofluorescence in lymph nodes only 22 metastatically involved lymph nodes were detected out of 34 identified by routine pathology. Although the sensitivity of 65% is rather low a discrimination between involved and non-involved lymph nodes is of particular medical importance.

In-vivo tissue optical properties derived by linear perturbation theory for edge-corrected time-domain mammograms.

A valuable method is described to analyze time-domain optical mammograms measured in the slab-like geometry of the slightly compressed female breast with a method based on linear perturbation theory including edge correction. Perturbations in scattering and absorption coefficients were mapped applying a computationally efficient point model.

Treatment procedures for adenocarcinoma of the esophagogastric junction

Die Inzidenz des Adenokarzinoms des ösophagogastralen Übergangs ist weltweit steigend, insbesondere im Verhältnis zur Inzidenz der Plattenepithelkarzinome der Speiseröhre. Die Lokalisation der Adenokarzinome betrifft vorwiegend den distalen Ösophagus.Da diese Karzinome häufig die Kardia mit einbeziehen und es in der Regel schwierig ist festzulegen, inwieweit ein proximales Magenkarzinom den Ösophagus infiltriert bzw. ein distales Ösophaguskarzinom in den Magen infiltriert, wurde eine Nomenklatur für die Adenokarzinome des distalen Ösophagus, des proximalen Magens und der eigentlichen Kardia vorgeschlagen,wonach diese Tumoren einheitlich als Adenokarzinom des ösophagogastralen Übergangs bezeichnet werden sollen [1]. Die Eigenständigkeit dieser Krankheitsentität wird inzwischen weltweit zunehmend anerkannt [2, 3]. Alters- und Geschlechtsverteilung sind different sowohl im Vergleich zum Plattenepithelkarzinom des Ösophagus als auch im Vergleich zum Magenkarzinom.Das mediane Erkrankungsalter beträgt je nach Untersuchung zwischen 60 und 63 Jahren,wobei die Erkrankung das männliche Geschlecht stark bevorzugt.

Staging and neoadjuvant therapy for esophageal cancer

Once the diagnosis of esophageal cancer is established, the decision on treatment will depend on the stage of the disease. Since improvement of prognosis can only be expected in patients with complete removal of their tumor, preoperative staging plays a pivotal role in the decision-making process. Preoperative diagnostic procedures should define the tumor in its relation to the tracheal bifurcation (site), determine the depth of tumor invasion (T status), evaluate regional lymph node metastases (N1 disease) and exclude distant metastases (M1 disease). Endosonography represents currently the most accurate imaging technique for detecting the correct T stage over the correct N stage. A higher accuracy rate may be achieved by combining endosonography with other staging modalities such as computed tomography. Chest x-ray, and percutaneous ultrasonography (abdominal, neck) form the diagnostic basis in staging M1 disease. Computed tomography (neck, chest and abdomen) is currently the best method to detect metastases in the liver and in celiac nodes. Staging laparoscopy when combined with laparoscopic ultrasonography shows a higher sensitivity than ultrasonography and computed tomography in the diagnosis of smaller metastases and peritoneal seedings. En bloc esophagectomy together with the regional lymph nodes remains the treatment of choice in medically fit patients with localized esophageal carcinoma (Stage I-IIB, T1-T2/N0-N1/M0). Due to early involvement of mediastinal structures, curative resection is unlikely to be achieved in patients with locally advanced esophageal carcinoma (Stage III, T3-T4/N0-N1/M0). Most available data indicate that neoadjuvant radiochemotherapy leads in a significant number of patients to downstaging of the tumor, increases the rate of R0 resection, improves local tumor control, and prolongs the recurrence free interval. However, neoadjuvant radiochemotherapy resulted in a marked increase of morbidity and postoperative mortality without improvement of survival. At present, neoadjuvant therapy is still experimental and there is no consensus for an optimal treatment regimen. Its use outside of an investigational setting can not be recommended. Future research must focus on more effective and less toxic neoadjuvant modalities (e.g. new chemotherapy agents, hyperthermia).