Toxizität und cytostatische Wirkung von PtCl2(NH3)2 nach i. v. und intratumoraler Injektion / Toxicity and Cytostatic Effect of PtCl2(NH3)2 after i. v. and i. t. Injection

oxizität und cytostatisch e W irkung von PtCl2(NH3)2 nach i. v. und intratumoraler Injektion Toxicity and Cytostatic Effect of PtCl2(NH3)2 after i. v. and i. t. Injection In tumor bearing mice intratumoral injection of PtCl2(NH3)2-solution increases the cytostatic effect while decreasing its toxicity in comparison to i. v. injection. In­ tratumoral injections of water-in-oil emulsions of the platin-compound are less cytostatic but have a consider­ ably lower toxicity.

[The central island tongue flap for the reconstruction of the anterior floor of the mouth]

BACKGROUND

There are several techniques described for the reconstruction of the anterior floor of mouth after tumour surgery. Here, we point out the advantages of the central island tongue flap for this indication.

PATIENTS AND METHODS

We report on 20 patients with medium sized defect in the anterior floor of mouth, which was reconstructed with the central island tongue flap. Besides this surgical technique, we discuss the results of oral rehabilitation after a follow-up period of at least 3 months.

RESULTS

There was now flap necrosis or loss, and the median time for flap formation was less than 45 min. In the follow-up we found successful oral rehabilitation in speech and swallowing.

Gemcitabine in the treatment of advanced head and neck cancer

AIMS

Several new chemotherapy agents show varying degrees of activity in head and neck cancer. One of them is gemcitabine, which is a new nucleoside analogue with an innovative cytostatic mode of action. Gemcitabine has demonstrated a broad spectrum anti-tumoural effect and a favourable toxicity profile. These attributes prompted us to introduce gemcitabine into the treatment of head-and-neck tumours.

MATERIALS AND METHODS

Ten heavily pre-treated patients with recurrent and incurable squamous-cell carcinoma of the head and neck (SCCHN) were treated with Gem. The initial cycle consisted of six administrations of the drug (1250 mg/m2 once weekly intravenously over 30 min) followed by a week without cytotoxic treatment. All following cycles were composed of two infusions once weekly (d1, 8), followed by a week of rest.

RESULTS

Toxic effects, length of survival and tumour response was assessable in eight patients owing to one suicide and loss of one patient for follow-up. One complete remission, two partial remissions and three 'no change' situations (stable disease) were observed, yielding a response rate of 37.5%. Median survival was 8 months (range 3-12). The incidence of haematological toxicity was low, with grade 3-4 neutropenia in less than 10%. Flu-like symptoms were reported by one-third of patients.

CONCLUSIONS

In this small phase-II study, gemcitabine demonstrated a high anti-tumoural activity in SCCHN, with a favourable toxicity profile. Gemcitabine seems to be a promising new drug without severe burden even for patients who are refractory to other cytostatic drugs. Within recent years, the activity and tolerability of gemcitabine was documented in several phase I and phase II trials, especially in combination with cisplatin, and paclitaxel resp, carboplatin/paclitaxel, cisplatin/ifosfamide, and 5-fluorouracil/paclitaxel. The results of these trials will be outlined in the discussion.

Interferon-induced remission of rapidly growing aggressive fibromatosis in the temporal fossa

Aggressive fibromatosis is the name for uncommon soft-tissue neoplasms arising within musculoaponeurotic tissue. They show benign histologic features but have an aggressive local behaviour and frequently recur after surgery or radiation. A 48-year-old black woman presented with recurrent aggressive fibromatosis after primary radiotherapy in the left temporal fossa involving the base of the skull. The patient received interferon alpha2a subcutaneously for 6 months. A slow but steady reduction of the tumour was observed, and pre-existing symptoms disappeared.

An intraosseous lipoma in the frontal bone—a case report

A rare case of a recurrent intraosseous lipoma affecting the frontoparietal skull is reported. The diagnostic difficulties, histopathologic features and surgical therapy are presented.

Technical Aspects and Results of Surgery for Craniosynostosis

BACKGROUND

The timing and extent of surgery continue to be a matter of discussion in current craniosynostosis management.

PATIENTS AND METHODS

We retrospectively reviewed the first 159 children seen from 1996 to 2000 of a total of 243 patients presenting with suspected craniosynostosis. We did not establish a surgical indication in 74 children (47%), either because their malformations were of different origin without associated craniosynostosis (11/7%) or they presented with only mild clinical manifestations of sutural synostosis (63/40%). In 85 cases (53%), we established a surgical indication. Parents did not follow our recommendation in two cases (1%). In 83 cases, we performed diagnosis-related remodeling at the age of 4-12 months. Demographic data, clinical follow-up findings, and regular photo documentation were analyzed.

RESULTS

After a mean follow-up of 3 years and 8 months, the results were satisfactory in 68 cases (82%). Of 15 cases (18%) with only limited improvement, two children were submitted to a second intervention. Another two children had to be reoperated on immediately for insufficient hemostasis. In the largest subgroup of children (47) with sagittal synostosis, there was no difference in outcome between surgery performed before and after 6 months of age.

DISCUSSION

Surgical indication and assessment of results are based on subjective criteria which limit the comparison with the literature. Our results correspond to those of similar published series. Most of the unfavorable results could be attributed either to inadequate adaptation of the surgical technique to the individual form of the malformation or to a significant secondary loss of correction in multi-sutural synostosis.

CONCLUSIONS

The overall results of surgery within the first year of life were satisfactory in 82%. Standard procedures need to be adapted carefully to the individual form of craniosynostosis to avoid unfavorable results. We therefore propose a new surgical technique based on a statistically averaged modular system of skull models to replace freehand remodeling.

[Esthetic rehabilitation of rhinophyma]

BACKGROUND

Rhinophyma is an uncommon progressively disfiguring process of the nose which occurs most often in middle-aged white men. The supposed association with increased alcohol abuse often leads to psychological problems for the person concerned.

PATIENTS AND METHODS

We describe ten cases of patients with slowly progressive tumorous deformation of the nose. They were treated with a stepwise surgical approach consisting of tangential excision for debulking, sculpting with scissors, and finally contouring by dermabrasion.

RESULTS

An esthetically pleasing result was achieved in all cases, making social reintegration for the patients possible. In the follow-up of at least 12 months no recurrence was seen and no scars occurred.

Automatic patient registration in computer assisted maxillofacial surgery

In this paper, a new approach for patient registration in computer assisted maxillofacial surgery is presented. The method uses a unique structure of markers embedded in a reference frame for the automatic detection of the coordinate system of the medical imaging data during the surgical intervention. With the new method, the inaccurate and time consuming process of manually identifying markers in the data volume and manually teaching them to a navigation system can be replaced. The method and algorithms for the automatic marker detection are described in this paper. Experiments with 45 data sets of patients proove the robustness, usability and safety of the new method. The method has been integrated into the navigation system RoboDent for dental implant surgery.

Recombinant human erythropoietin in the treatment of head and neck tumour anaemia

At the time of first diagnosis, patients with squamous cell carcinoma in the head and neck are often in the advanced stage of their disease, therefore surgery is not a viable option for treatment. These patients also present frequently a high grade of anaemia as a result of either the malignant process itself or of the following therapy. The incidence of anaemia and the need for transfusion depends on several factors, such as the type and intensity of radiotherapy and radiochemotherapy. Multimode therapeutic concepts such as radio-chemotherapy are being applied with increasing frequency, resulting in an ever increasing need for transfusion with great effects on the patient's quality of life. Even more important to tumour patients is the role of the haemaglobin (Hb) value as a prognostic factor for survival and/or local tumour control. A large number of studies show that recombinant human erythropoietin (r-HuEPO) is effective in the treatment of tumour-induced anaemia and prevention and correction of chemotherapy and radiotherapy-induced anaemia. The simultaneous application of r-HuEPO with chemotherapy can prevent patients with head and neck tumours from developing anaemia or can reduce the extent of the anaemia and the need for transfusion. Comparable effects were observed both in patients undergoing platinum-based and non-platinum-based chemotherapy. The direct correlation between anaemia, tumour hypoxia and poor response to radio and/or chemotherapy has been clinically proven. Recombinant human erythropoietin administration improves the therapeutic outcome and the patients' prognosis.

Intraoperative computed tomography with the mobile CT Tomoscan M during surgical treatment of orbital fractures

Up to now it has only been possible to monitor the alignment of orbital floor fractures postoperatively with a computed tomography (CT) examination with coronal sectioning. If this showed an incorrect positioning, renewed surgery and anaesthetics were often required. The purpose of this study was the implementation and definition of the spectrum of indications for intraoperative CT examinations while keeping patient radiation exposure to a minimum. Thirty-two orbital fracture cases were examined pre- and intraoperatively using the mobile computer tomograph Tomoscan M in coronal sectioning. In this patient collective, 12 cases showed an isolated orbital floor fracture and twenty cases an orbital floor fracture associated with a zygomatic fracture. The technical prerequisite for these examinations was the construction of a suitable radiolucent operating table which permitted coronal sections to be made with the CT-Gantry tilted. The authors aimed to reduce radiation exposure by optimizing the technical setting parameters and closely defining the scan region for the operator. In three of 32 cases there were no surgical indications following clinical and preoperative CT examination. In three of the 20 cases with associated zygomatic fracture a closed reduction with a reduction hook was carried out, and no revision was necessary after the intraoperative CT examination. In 26 cases an open reduction was carried out. Of these open reduced fractures, four had to be revised after intraoperative CT monitoring; one of the isolated orbital floor fractures and three of those associated with a zygomatic fracture. Intraoperative CT monitoring of orbital floor fractures is considered a useful surgical aid. Its advantages are immediate monitoring of the surgical reduction, the presence of the surgeon during scanning enabling him to determine directly the relevant sections to scan, and the resulting radiation exposure.

Endovascular management of a bleeding mandibular arteriovenous malformation by transfemoral venous embolization with NBCA

A 13-year-old boy presented with an arteriovenous malformation (AVM) involving the left mandible that bled after intraoral biopsy. The AVM was treated on an emergency basis by primary intravenous delivery of n-butyl cyanoacrylate after transfemoral catheterization, resulting in complete anatomic and clinical cure.

Engaging staff nurses in evidence-based research to identify nursing practice problems and solutions

This article illustrates how one academic health science center in a large metropolitan area sought to improve the quality of patient care by soliciting the input of their nursing staff in devising an action plan for change. The research model incorporated both survey and focus group methods used by nursing leaders in administration and practice to identify and prioritize nursing research and clinical needs in their organization. The goal was to establish consensus among clinicians and researchers about significant issues in the institution requiring in-depth attention. A second objective was to design a survey instrument that is easy to complete and could be distributed, collected, and analyzed easily, thereby providing empirical data to the clinicians in a timely manner and in a simple format. This expedited process enabled specific action plans to be developed around the identified problems. Moreover, the process promoted interest in advancing nursing research and evidence-based practice among the clinicians and administrators.

[Robotics]

Content of this paper is the current state of the art of robots in surgery and the ongoing work on the field of surgical robotics at the Clinic for Maxillofacial Surgery at the Charité. Robots in surgery allows the surgeon to transform the accuracy of the imaging systems directly during the intervention and to plan an intervention beforehand. In this paper firstly the state of the art is described. Subsequently the scientific work at the clinic is described in detail. The paper closes with a outlook for future applications of robotics systems in maxillofacial surgery.

Reconstruction of the contracted ocular socket with free full-thickness mucosa graft

Patients who have undergone enucleation of the eye can be treated with glass eye prostheses, provided retention is adequate. Inadequate retention due to contraction of the conjunctival mucosa is a common problem which frequently affects the lower fornix first. This can be corrected using a free full-thickness buccal mucosa graft. Indications, operative procedures and postoperative results are presented.

Immunohistochemical assessment of the tumour-associated epitopes CD44v6 and E48 in tumour-free lymph nodes from patients with squamous cell carcinoma in the head-neck region

We examined immunohistochemically 370 tumour-free lymph nodes from 41 patients with a head and neck squamous cell carcinoma (HNSCC) to clarify whether the tumour-associated epitopes CD44v6 and E48 are suitable for adjuvant postoperative immunotherapy. All the positively immunostained cells found were single cells. CD44v6+ cells were found in 55% of the lymph nodes, with their numbers increasing in pN>0-patients (62%). Only pN>0-patients had abundant to massive CD44v6+ cells. A comparison with mononuclear cells in lymphatic tissue from control patients suggested a similarity with activated T-cells. In the 41 cancer patients there were significantly fewer lymph nodes with E48+ cells (11%), but the number of E48+ cells increased in pN> 1-patients (29%) with predominantly abundant E48+ cells. We conclude from the comparison with the epithelial marker EMA that the E48+ single cells are epithelial in origin. Only a specific E48 peptide sequence appears suitable for adjuvant immunotherapy in patients with head-neck tumours.

[Bilateral rehabilitation with an implant-anchored orbital prosthesis]

From the aesthetic point of view, a patient can be completely rehabilitated after the loss of an eye with the insertion of an artificial eye made of glass. If the delicate structures of the eyelids have been severely damaged, however, or if the eye socket does not provide adequate retention for an eye prosthesis, rehabilitation becomes more difficult, and sometimes cannot be achieved with a cosmetically satisfactory result. In such cases, a facial prosthesis offers an alternative solution. Stable retention can be ensured with craniofacial implants. Single-sided rehabilitation by this method is quite common, but bilateral treatment is a rarity. We report on the prosthetic rehabilitation of a patient after exenteration on both sides due to retinoblastomas.

[3D-computed tomography for spatial arrangement of the cranial bones of the human fetus]

Aim of the study was to assess the value of in vitro three-dimensional computed tomography (3D-CT) as a new method for the depiction of the fetal skull. 3D-CT images of a fetal head of 24 weeks gestational age were generated with the implemented software on the basis of contiguous CT slices of 1 mm thickness. 3D-CT gave real three-dimensional information about morphology and spatial arrangement of the cranial bones. Using cutting and rotating procedures fast evaluation of all imaged ossified structures in arbitrary views without disturbing superpositions was possible, thus allowing easy identification and accurate description of the cranial bones and making isolated examinations of particular macroscopic sections of the specimens unnecessary. Advantages of 3D-CT over other evaluation techniques for the fetal cranium and its limitations are discussed. In conclusion, 3D-CT promises to be an effective tool for the investigation of fetal cranial development.

Camouflage in head and neck region--a non-invasive option for skin lesions

The technique of camouflage, a non-invasive procedure to correct flaws in the texture and colour of the facial skin, is presented. The acceptance and use of camouflaging by 52 patients with different diagnoses are presented. The advantages of camouflaging are discussed in comparison to medical tattooing.

Custom-made cast titanium implants produced with CAD/CAM for the reconstruction of cranium defects

Titanium implants for the reconstruction of bony skull defects, using data from three-dimensional spiral computer tomography, have been described by other authors. Instead of milling the implants from a titanium block, an advanced method of rapid prototyping for a fine casting process is presented. Casting vs milling offers several advantages. It is possible to form very thinly tapered structures and to obtain more complex geometrical structures with smaller diameters. Many geometrical forms, which cannot be milled for technical reasons, can be produced using this technique.

Simultaneous analysis of 4- and 5-series lipoxygenase and cytochrome P450 products from different biological sources by reversed-phase high-performance liquid chromatographic technique

Quantification of lipoxygenase and cytochrome P450 products of both arachidonic acid (AA) and eicosapentaenoic acid (EPA) is of broad interest due to the multiple biological activities of these compounds. We developed a method combining (i) solid-phase extraction, (ii) isocratic reversed-phase high-performance liquid chromatographic separation, and (iii) online photodiode array detection with spectrum analysis for identification and measurement of all main 4- and 5-series eicosanoids (leukotrienes, hydroxyeicosatetraenoic acids/hydroxyeicosapentaenoic acids, epoxyeicosatrienoic acids) within one run. With these procedures, standard mixtures of AA- and EPA-derived lipid mediators were recovered from different biological liquids, like lung perfusate, human bronchoalveolar lavage fluid, and cell supernatant with linear characteristics for each compound. Recoveries of the different lipid mediators exceeded 80% showing excellent reproducibility. Application of the method to isolated, perfused, and ventilated human lungs challenged with the calcium ionophore A23187 and to human neutrophils stimulated in the presence of arachidonic acid and eicosapentaenoic acid with N-formyl-methionyl-leucyl-phenylalanine demonstrated the generation of a large array of lipoxygenase and cytochrome P450 products. Thus, convenient quantification of 4- and 5-series eicosanoids in fluids of biological interest is achieved by a technique comprising solid-phase extraction, isocratic reversed-phase high-performance liquid chromatography, and photodiode array-based online spectrum analysis of eluting compounds.

[The assessment of skin tumors with magnetic resonance with high resolution and a paramagnetic contrast medium]

INTRODUCTION

The technologic improvement of surface coils in MRI has allowed better visualization of the skin and thus permitted the clinical use of this technique in dermatology. MRI allows to assess the depth and extent of skin tumors and to detect any malignant transformation. The MR differentiation between benign and malignant skin lesions relies on morphological criteria which however do not have an absolute diagnostic value. We investigated the role of paramagnetic contrast agents in the differentiation between benign and malignant skin lesions.

MATERIAL AND METHODS

Forty-one patients, 33 with benign and 8 with malignant skin tumors, were submitted to MRI. All the examinations were performed with a 1.5 T superconductive unit, with a 2.5 cm surface coil. Axial T1- and T2-weighted SE images were acquired with 2 mm slice thickness. Paramagnetic contrast material was administered to all patients. The signal intensity of the skin lesions was calculated before and after paramagnetic contrast agent administration positioning a region of interest. A percentage ratio of contrast enhancement was calculated to quantify contrast agent uptake and the relative values were compared between benign and malignant lesions. A qualitative analysis was also performed rating the contrast enhancement of each lesion as high, intermediate, or absent.

RESULTS

The quantitative analysis showed a statistically significant difference (p < .5) between the contrast enhancement values of benign and malignant lesions. In particular, malignancies had values ranging 117.3 (+/- 28.7) to 125 (+/- 32.4), while benign lesions had -20.6 to 99.8 (+/- 21.1). Conversely, no difference in contrast enhancement was found at qualitative analysis.

CONCLUSIONS

MRI is a promising tool for characterizing skin tumors. Our preliminary results should be confirmed on larger series of patients with the use of high temporal resolution imaging sequences.

Assessment of vascularity in reactive lymph nodes by means of D-galactose contrast-enhanced Doppler sonography

RATIONALE AND OBJECTIVES

A prospective study in signal-enhanced Doppler sonography of lymph nodes that were assumed pretherapeutically to be benign was performed to investigate characteristic sonomorphologic features and vascularity of reactively enlarged lymph nodes.

METHODS

Thirty-four patients with enlarged superficial lymph nodes of the neck were examined first by B-scan sonography then by Doppler sonography before and after administration of an ultrasound signal-enhancing agent. In B-scan sonography, lymph nodes were classified into three groups according to their sonomorphologic features: (1) homogeneous parenchyma, (2) a centrally located echogenoic line, and (3) a echogenoic "hilus reflex." In conventional and contrast-enhanced Doppler sonography, peak flow rate, pulsatility index, and resistive index were assessed. Sonomorphologic criteria were compared with histologic findings.

RESULTS

Reactively enlarged lymph nodes showed characteristic sonomorphologic patterns correlating to their histologic features. Echogenicity of the hilus corresponded to fibrosis (centrally located echogenoic line in 13 nodes; 38.2%) or fatty involution of the hili (echogenoic hilus reflex in 15 nodes; 44.1%). Administration of the galactose-based ultrasound contrast enhancer facilitated the assessment of hilar vessels, which projected to the echogenoic hili, respectively, actually additionally visualized a hilar vascularity in 10 of the 34 lymph nodes compared with conventional Doppler. Measured Doppler indices gave not a significant clue for identifying reactive lymph nodes or for differential diagnosis.

CONCLUSIONS

Qualitative sonomorphologic assessment of characteristic sonomorphologic features of reactive lymph nodes may serve as a valuable tool for examining reactively enlarged lymph nodes. Administration of an ultrasound echo enhancer allows the assessment of a characteristic nodal vascularity in reactive lymph nodes and were superior to conventional B-mode and conventional Doppler sonography.

Morphology of the development of the sagittal suture of mice

Syndesmotic sutures of the skull are formed by dense connective tissue and called "open"; they are "closed" by formation of a synostosis between adjacent bones. Open sutures are considered as areas of growth and as hinges. The importance of open sutures during the period of skull growth is reflected by pathological situations in which premature closure of the sutures occurs. As alterations of the FGF receptor have been reported in genetical disorders accompanied by premature suture closure (Bellus et al. 1996), the role of fibroblasts and connective tissue in the development of the sagittal suture of mice has been investigated by light and electron microscopy. Morphological changes of the sagittal suture at the following stages are reported: at embryonic day 18, days 1, 5, 9, 14, 20, 26, 28 after birth and in adult mice. Two skulls per stage were investigated. Early osteogenesis appeared in a thin plate, followed by a second plate underneath the first one. Both were separated by blood vessels. In general, vascularization preceded desmoid mineralization; the space around blood vessels was occupied by non-bone-forming cells leaving cavities for the presumptive bone marrow. Mineralization of the collagen-rich osteoid at the mineralizing rim of the bone plates was accompanied by apoptoses and cell disintegration. Newly formed bone was immediately covered by osteoblasts forming a sheet of bone-lining cells. At day 9, the double-layered bone plates of both sides reached the median area of the skull but were separated by non-mineralizing, collagen-rich connective tissue. From day 14 onwards, the bone plates thickened. Bone apposition, recognizable by the formation of collagen-rich osteoid and proceeding from day 14 pp onwards, occurred mainly at the outer and inner surfaces of the calvariae, but neither at bone marrow surfaces nor at the medial edges of the parietal bones. These opposite bone faces showed fewer osteoblasts and bone-lining cells, but an increased number of fibroblasts. Tendon-like collagen bundles connected both bone plates of the open suture of day 26 pp as well as in the adult mice, whereby synostotically closed areas alternated. Formation of an open, syndesmotic suture can, therefore, be described as a transition of bone-forming tissue into a bone-tendon junction. The results indicate the importance of the replacement of osteoblasts by fibroblasts at the sutural front of the bone plates in order to prevent a premature suture closure.

A method for the bony and dental reconstruction of the maxilla in dentate patients

Reconstruction was carried out on eleven patients using a vascularized full thickness calvarial bone flap following partial maxillectomy. The donor site was covered with a split calvarial bone graft. Intraorally a mucosal transposition flap was used to cover the graft. Six months later implants were inserted and were allowed to heal for three months before dental rehabilitation began. No serious complications were encountered.

Evaluation of metastases and reactive lymph nodes in Doppler sonography using an ultrasound contrast enhancer

RATIONALE AND OBJECTIVES

The authors conducted a prospective study in D-galactose signal-enhanced Doppler sonography of lymph nodes to investigate new aspects in differentiating malignant from reactive lymph nodes of patients with suspected malignancy of the neck.

METHODS

Twenty-one patients with suspected squamous epithelial cell carcinoma metastases of the neck were examined by Doppler sonography before and after administration of an ultrasound signal-enhancing agent, consisting of D-galactose microbubbles. Qualitative sonomorphology, peak flow rates, and pulsatility and resistive indices were assessed.

RESULTS

Compared with conventional Doppler, enhanced Doppler sonography gave detailed additional information about vascularization of metastases or reactive lymph nodes. Signal-enhanced Doppler of metastases showed a relatively characteristic pattern of vascularity, therefore facilitating differential diagnoses and allowing better discrimination from surrounding tissue, demonstrated by the infiltration of neighboring vessels in the neck. Concerning reactive lymph nodes, vascularization could be stated and measured in many cases only after signal enhancement. Evaluating peak velocities and pulsatility and resistive indices could not differentiate significantly malignant from reactive lymph nodes.

CONCLUSIONS

Administration of a D-galactose-based signal-enhancer helps to differentiate malignant from reactive lymph nodes of the neck. It is superior to conventional Doppler by improving evaluation of the vascularity and could be of use for staging procedures.

Computed tomographic study of bone availability for facial prosthesis-bearing endosteal implants

In a computed tomographic study, 56 patients with facial defects were examined to assess the availability of bone for extraoral Brånemark implants (3 or 4 mm long, 3.75 mm diameter) to bear facial prostheses. Bone depths were determined in the auriculotemporal (2-8 mm), infraorbital (0-10 mm), lateroorbital (8-14 mm), supraorbital (1-14 mm) and medioorbital (1-6 mm) areas as well as at the base of the nasal skeleton (1-5 mm). The low values for the supraorbital and infraorbital areas were determined at the points closest to the frontal- and maxillary sinuses, respectively. Implantation in these areas would be permissible only under certain conditions. The very thin osseous structures of the nasal region also present problems for implants. In the auriculotemporal region, the bone width is always sufficient, but at the orbital margin it can vary from 3 to 8 mm. The three-year success rates for implant survival were found to be 100% and 85.8% respectively for auricular and orbital defects. No serious skin complications were seen. Six patients (10.7%) required secondary corrective surgery in a total of 13 implant areas.

[A phase-I/II study on the local hyperthermia of cervical N2/N3 lymph node metastases]

BACKGROUND

Patients with advanced lymph node metastases from head and neck tumors at stage N2/N3 (i.e. UICC IV) present a difficult therapeutic problem. Despite combined radio-chemotherapy and hyperfractionated and/or accelerated fractionation regimens, local control of these tumors remains unsatisfactory. For this reason, the value of local radio wave/microwave hyperthermia was examined for this patient group in a phase I/II study.

3D-computed tomography: a new method for the evaluation of fetal cranial morphology

This study is the first presentation of three-dimensional computed tomography (3D-CT) for the in vitro evaluation of the prenatal human cranium. The study was based on CT examinations from 26 aborted normal fetuses between 10 and 25 weeks gestational age. Incremental coronal and transverse CT slices of 1 mm thickness and a threshold segmentation algorithm were used to generate 3D-CT reconstructions (surface-shaded display, SSD) of the cranial bones similar to their anatomical appearance. The threshold of the segmentation algorithm was selected after comparison of the 3D-CT images generated with varying thresholds and graphically reconstructed histological serial sections of particular sutures in five specimens. The variation of the segmentation threshold resulted in alterations of the bone sizes and suture widths. However, 3D-CT images allowed sensitive identification of the cranial ossification centers and accurate evaluation of the bone topography. Cutting and rotating procedures made it possible to evaluate all imaged bones in arbitrary views without disturbing superpositions, thus making isolated examinations of particular macroscopic sections of the specimens unnecessary. In conclusion, 3D-CT of the fetal cranium promises to be of considerable help in the evaluation of prenatal cranial development.

Structure-based alignment and comparative molecular field analysis of acetylcholinesterase inhibitors

The method of comparative molecular field analysis (CoMFA) was used to develop quantitative structure-activity relationships for physostigmine, 9-amino-1,2,3,4-tetrahydroacridine (THA), edrophonium (EDR), and other structurally diverse inhibitors of acetylcholinesterase (AChE). The availability of the crystal structures of enzyme/inhibitor complexes (EDR/AChE, THA/AChE, and decamethonium (DCM)/AChE) (Harel, M.; et al. Quaternary ligand binding to aromatic residues in the active-site gorge of acetylcholinesterase. Proc. Natl. Acad. Sci. U.S.A. 1993, 90, 9031-9035) provided information regarding not only the active conformation of the inhibitors but also the relative mutual orientation of the inhibitors in the active site of the enzyme. Crystallographic conformations of EDR and THA were used as templates onto which additional inhibitors were superimposed. The application of cross-validated R2 guided region selection method, recently developed in this laboratory (Cho, S.J.; Tropsha, A. Cross-Validated R2 Guided Region Selection for Comparative Molecular Field Analysis (CoMFA): A Simple Method to Achieve Consistent Results. J. Med. Chem. 1995, 38, 1060-1066), to 60 AChE inhibitors led to a highly predictive CoMFA model with the q2 of 0.734.

[Contrast medium behavior of epithelial skin tumors and tumor-like changes in high resolution magnetic resonance tomography]

To evaluate the use of Gd-DTPA in imaging epithelial skin tumors and tumor-like lesions, 29 benign, 8 malignant and 4 semimalignant skin tumors were prospectively examined by high-resolution MRI at 1.5 Tesla using a 2.5-cm surface coil. For tumor assessment, transverse plain and contrast-enhanced scans (0.1 mmol Gd-DTPA/kg body mass) were performed (TR 500 ms, TE 25 ms, 3 acquisitions, 256 x 256 matrix, FOV 2.5 cm). Contrast enhancement was quantitively determined as the percent enhancement of signal intensity. Histologic findings were correlated using the Mann-Whitney-test (p < 0.05). Quality of contrast enhancement was independently assessed by three investigators, who mostly described inhomogeneous enhancement, regardless of histologic findings. Malignant tumors could not be differentiated from benign lesions by contrast enhancement. MRI using Gd-DTPA does not provide differentiation of skin tumor types.

Failure of gadopentetate dimeglumine-enhanced, high-resolution magnetic resonance imaging to differentiate among melanin-containing skin tumors

RATIONALE AND OBJECTIVES

We evaluated the diagnostic potential of gadopentetate dimeglumine-enhanced, high-resolution magnetic resonance (MR) imaging to differentiate benign from malignant melanin-containing skin tumors.

METHODS

Forty-five patients were prospectively examined using high-resolution MR imaging at 1.5 T using a 2.5-cm surface coil. For tumor assessment, T1-weighted and T2-weighted transverse spin-echo sequences were acquired. After intravenous administration of gadopentetate dimeglumine (0.1 mmol/kg), the T1-weighted transverse sequence was repeated. Contrast enhancement was quantitatively determined as the percentage increase of signal intensity. Histologic findings were correlated using the Wilcoxon signed-ranks test. The quality of contrast enhancement was assessed by three independent investigators who were unaware of the patients' history and histologic data. The signal-to-noise ratio (SNR) was calculated in the T2-weighted sequence. Significance was tested using the Wilcoxon signed-ranks test.

RESULTS

In all tumors, contrast enhancement was visually discernible. Half of the cases were enhanced inhomogeneously. The percentage of contrast enhancement did not correlate with histologic findings. Malignant melanomas could not be differentiated from benign melanocytic nevi with the use of gadopentetate dimeglumine. Determination of the SNR in T2-weighted sequences revealed no significant difference for histologic subgroups or tumor type.

CONCLUSION

Gadopentetate dimeglumine-enhanced MR imaging does not differentiate malignant melanomas from benign melanocytic nevi. Determination of the SNR in the T2-weighted sequences revealed no significant difference for histologic subgroups.

Local hyperthermia of N2/N3 cervical lymph node metastases: correlationof technical/thermal parameters and response

PURPOSE

Patients with advanced head and neck carcinomas, primarily nonresectable as well as recurrent cases, were treated in multimodality regimens with radiotherapy, chemotherapy, and local hyperthermia. Commercially available microwave and radiowave applicators were used in 50 patients with N2/N3 cervical lymph node metastases during more than 250 heat treatments. To assess technical suitability, the achieved power densities and thermal parameters were tested for correlation with anatomical and geometrical factors. To assess effectiveness, the response was compared with derived parameters of the achieved temperature distributions.

METHODS AND MATERIALS

The temperature measurement points (in thermometry catheters) documented by computerized tomography are labeled according to tissue depth, shielding by osseous structures, and location in relation to the external applicators. Relative and absolute specific absorption rates (SAR) and cooling coefficients are extracted from the temperature-time curves. Time-averaged temperature-position curves are evaluated to obtain index temperatures (T90, T50, T20), minimum/maximum tumor temperatures, cumulative minutes T90 > or = 43 degrees C, and 43 degrees C-equivalent min T90. Radiation dose, treatment time, and chemotherapy regiment are also considered. A response parameter is defined using the pre- and posttherapeutic tumor volumes. A multivariate variance analysis is performed for the dependent variables power density, thermal parameters, and response.

RESULTS

A significant correlation exists between power density and absorption, presence of a fat layer, and applicator illumination. The maximum depth is 5 cm, where SAR of >= 10 mW/g are registered. Achieved temperatures at individual measurement points are dependent on the SAR, and to a lesser extent, the perfusion-dependent cooling coefficients, but the index temperature T90 is only significantly related to intratumorally achieved SAR. The thermal gradient (T20-T50) and temperature peak (T20) are significantly influenced by the tumor volume. The response is directly related to the index temperature T90, equivalent minute T90 43 degrees C, and cumulative minutes T90 > or = 40.5 degrees C, and inversely related to the tumor volume.

CONCLUSIONS

Local hyperthermia using microwave and radiowave applicators in the head and neck region is a tolerable and clinically practical supplementary therapy used as part of multimodal regimens, and has already been proven to be effective. However, the analyses also demonstrated the limits of currently available technology, and confirm the need for continued methodical research.

Role of high-resolution magnetic resonance imaging for differentiating melanin-containing skin tumors

RATIONALE AND OBJECTIVES

The aim of the study was to evaluate the use of high resolution magnetic resonance imaging (MRI) for differentiation of melanin-containing skin tumors.

METHODS

Twenty-seven melanocytic nevi and 18 malignant melanomas were examined by high resolution MRI. Signal intensities and signal-to-noise (SNR) and contrast-to-noise ratios (CNR) of the tumors were determined in enhanced (T1, T2, water-suppression, and fat-suppression sequences) and contrast-enhanced images (T1 and fat-suppression sequences). The differences were tested for significance by a Wilcoxon test.

RESULTS

Malignant melanomas differed from melanocytic nevi in that they displayed a higher SNR in T2-weight and unenhanced and contrast-enhanced fat-suppression scan. Malignant melanomas exhibited a higher CNR than did benign lesions in unenhanced and contrast-enhanced fat-suppression sequences with dermis as reference tissue (P < 0.05) and in enhanced fat-suppression sequences with subcutis as reference tissue (P < 0.05).

CONCLUSIONS

The usefulness of SNR and CNR analysis on MRI for the differentiation of malignant skin tumors from benign skin tumors of the melanin-containing system is limited. Clinical and histologic examinations are, further, the important step in evaluation of melanin-containing skin tumors.

Immunocytologic detection of isolated tumor cells in bone marrow of patients with squamous cell carcinomas of the head and neck region

The well-documented specificity of anticytokeratin monoclonal antibodies for detection of epithelial micrometastatic cancer cells in bone marrow as a prognostic indicator inspired us to apply this approach to patients with squamous cell carcinomas (SSC) of the head and neck region. The sensitivity of the broad-spectrum anticytokeratin monoclonal antibody (mAb) A45-B/B3 used for tumor cell detection was demonstrated by immunostaining of cryostat sections from the respective primary tumors. Analysis of 31 patients with SSC revealed A45-B/B3-positive cells in 10 cases (32.3%) at frequencies of 1-207 per 1 x 10(6) mononuclear cells. Most specimens displayed isolated tumor cells, while cell clusters were found in only two cases (6.5%). The present data suggest that hematogenous dissemination of cancer cells is more frequent than expected from clinicopathologic staging of patients with SSC of the head and neck region.

Human immunodeficiency virus-associated squamous cell carcinomas of the head and neck presenting as oral and primary intraosseous squamous cell carcinomas

Six cases of squamous cell carcinoma arising in the head and neck of patients infected with the human immunodeficiency virus are described. This article reports the first two cases of primary intraosseous squamous cell carcinoma associated with infection with human immunodeficiency virus. Clinical presentation, results of imaging studies, histologic characteristics, therapies applied, and the clinical follow-up are described in detail for each of the six cases. These data are evaluated through a review of the current literature.

Venous graft as temporary arteriovenous shunt in free tissue transfer

A new method of interpositional venous graft in microvascular tissue transfer is described. The interpositional vein is transferred to the vessels of the recipient site primarily, forming an arteriovenous shunt. Later, when the microanastomosis to the flap is created, the shunt is divided into an arterial branch and a venous branch. This method reduces the ischemic time of the free flap and allows the use of interpositional grafts of optimal length.

Radioimmunoscintigraphy of squamous cell carcinoma in the head and neck region

Radioimmunoscintigraphy (RIS) with a monoclonal antibody (SQ 174, Biomira, Inc, Canada) is introduced as a new diagnostic method for detection of squamous cell carcinoma in the head and neck region. RIS could detect eight of the 10 primary tumors. One patient had histopathologically proven nodal disease. This lymph node was seen in RIS. No false positive results were seen in RIS, whereas sonography, computed tomography, and magnetic resonance imaging showed several false positive results.

Microsurgical and prosthetic reconstruction of patient with recurrent ameloblastoma extending into the skull base

A patient with recurrent ameloblastoma extending into the skull base is presented. An interdisciplinary treatment strategy is described, which included proper diagnosis by computed tomography (CT) and magnetic resonance imaging (MRI) scans and radical resection of the tumor in cooperation with the neurosurgeon, followed by reconstruction with microsurgical methods, and prosthetic rehabilitation based on an implant-supported epithesis.