Collimator based tracking with an add-on multileaf collimator: Moduleaf.

Radiotherapy is one of the most important methods used for the treatment of cancer. Irradiating a moving target is also one of the most challenging tasks to accomplish in modern radiotherapy. We have developed a tracking system by modifying an add-on collimator, the Siemens Moduleaf, for realtime applications in radiotherapy. As the add-on collimator works nearly completely independently of the linear accelerator (LinAc), no modifications to the latter were necessary. The adaptations to the Moduleaf were mainly software-based. In order to reduce the complexity of the system, outdated electronic parts were replaced with newer components where practical.Verification was performed by measuring the latency of the system as well as the impact on applied dose to a predefined target volume, moving in the leaf's travel direction. Latency measurements in the software were accomplished by comparing the target and current positions of the leaves. For dose measurements, a Gafchromic EBT2 film was placed beneath the target 4D phantom, in between solid water plates and moved alongside with it. Comparing the dose distribution on the film with a moving target between 'tracking disabled' towards 'tracking enabled' functions resulted in penumbra widths of 23 mm to 4 mm for 0.1 Hz sinusoidal movements with an amplitude of 32 mm, respectively. The maximum speed was therefore 20 mm s(-1). Latency was measured to be less than 50 ms for the signal runtimes. Based on the results, a tracking-capable add-on collimator seems to be a useful tool for reducing the margins for the treatment of small, slow-moving targets.

The role of computed tomography in the assessment of dental disease in 66 guinea pigs.

Sixty-six guinea pigs with dental disease were presented to the University of Veterinary Medicine, Vienna, Austria, from 2006 to 2010. Almost all patients had a history of eating difficulties (95 per cent) and underwent clinical and oral examination as well as CT of the head. Findings on extra- and intraoral examination were asymmetric elongation (n=28) and symmetric bridging (n=24) of cheek teeth, obliquely worn incisors (n=17), palpable lower jaw swellings (n=13), exophthalmos (n=10) and incisor macrodontia (n=6). Eighty per cent of guinea pigs with exophthalmos showed ipsilateral periapical disease of the maxillary cheek teeth on CT. Ninety-two per cent of patients with palpable lower jaw swellings showed corresponding dental pathologies on CT. Periapical disease of incisors (n=11) and cheek teeth (n=32) were the most common findings on CT. All abnormally large incisors were found on oral examination and CT, but macrodontia of cheek teeth could only be visualised by CT. Deviation of the lower jaw evaluated in awake animals by visual inspection appeared to correlate with cheek teeth abnormalities. Results emphasise the importance of diagnostic imaging, in particular CT, in guinea pigs with dental disease in order to localise lesions and underlying aetiologies.

A software program for the head impulse testing device (HITD).

The vestibulo-ocular reflex (VOR) uses head angular acceleration information transduced by the semicircular canals in the inner ear in order to drive eye movements that compensate for head rotations, and thus stabilize the visual scene on the retina. Peripheral and central vestibular pathologies may impair the function of the VOR, so that compensation becomes incomplete, making clear vision during head movement impossible. Powerful adaptive mechanisms quickly allow the central nervous system to use residual vestibular information or information provided through other senses to supplement the deficient VOR. Such recovery makes the clinical diagnosis difficult to classical testing techniques, yet the head impulse test allows to reveal vestibular deficits even in adapted patients. A compensatory saccade at the end of the head movement is the clinical sign of a vestibular deficit, and may be spotted by the experienced clinician. Here we describe the rationale and the software program driving a new computerized technique for reliably assessing vestibular function at different head angular accelerations, based on evaluating the ability of the patient in reading a character on the screen while the head is being rotated.

Traumatic diaphragmatic rupture in a cat with partial kidney displacement into the thorax.

A two-year-old, male, neutered, domestic shorthair cat was presented after suspected trauma. Diaphragmatic rupture with concomitant displacement of the right kidney into the thorax was diagnosed using ultrasound and intravenous urography. Avulsion of the renal pedicle and diaphragmatic rupture were confirmed and treated surgically with excellent outcome.

Micro-column affinity test and gel test: comparative study of two techniques for red cell antibody screening.

BACKGROUND AND OBJECTIVES: We describe the results of a comparative evaluation of a gel test (ID Micro Typing) and a micro-column affinity test (MCAT, Cellbind Screen) for red cell antibody screening and identification under routine conditions. MATERIALS AND METHODS: 3,000 serum samples of patients from the Mannheim University Hospital were tested in parallel by means of the gel test and the MCAT, using the low-ionic-strength-saline indirect antiglobulin test and the protein G affinity technique, respectively. Test cells used were the same in all tests. In addition, we performed titration studies with all detected antibodies as well as with 59 frozen sera containing antibodies of known specificity. RESULTS: A total of 154 antibodies (5.1%) were detected, 149 by gel test and 147 by MCAT. The overall sensitivity and specificity of the gel test was 96.8 and 96.5% and of the MCAT 95.5 and 97.2%. No significant differences between the gel test and MCAT were found when the titer scores of all 213 (fresh and frozen) antibodies were used to check the results. The mean scores for the gel test and the MCAT were 26.8 and 28.5, respectively. For anti-Fy(a) and anti-Kell, a significantly higher titration score could be obtained in the MCAT, whereas anti-Lu(a) showed a significantly higher score with the gel test. CONCLUSION: For the screening of unexpected red blood cell antibodies, the MCAT is as sensitive as the gel indirect antiglobulin test. The sensitivity and specificity of the two systems are more or less the same although it seems that IgM antibodies are better detected by the gel test.

[Increased thrombin time in a patient with multiple myeloma]. / Verlängerte Thrombinzeit bei einem Patienten mit multiplem Myelom.

We describe a 56-year-old patient with multiple myeloma and very high paraprotein concentration (IgG kappa). Coagulation studies showed unclottable thrombin and reptilase times caused by impaired fibrin polymerization presumably due to the paraproteinemia. There was no obvious bleeding tendency. The differential diagnosis of thrombin time prolongation includes inhibition of the added thrombin by exogenous heparin, hirudin or seldom by endogenous heparin-like anticoagulants or by acquired (bovine) thrombin antibodies, qualitative fibrinogen disorders (congenital and acquired dysfibrinogenemia), quantitative fibrinogen disorders (severe hypo- and afibrinogenemia) and delayed fibrin polymerization due to fibrin/fibrinogen degradation products, paraproteins and antibodies against fibrin(ogen). In multiple myeloma, thrombin time prolongation may seldom be due to endogenous heparin-like anticoagulants or antibodies to thrombin and more frequently to impaired fibrin polymerization by paraproteins. Simultaneous reptilase time prolongation as present in this case hints to this latter possibility.

[Decreased Quick percentage, acquired factor X deficiency, hemarthrosis and ecchymosis: amyloidosis]. / Verminderter Quickprozentwert, akquirierter Faktor X-Mangel, Gelenksblutung und Hautblutungen: Amyloidose.

A 68-year-old woman suffered from spontaneous hemarthrosis of the right elbow joint in april 1994. Cutaneous ekchymoses had been noted since summer 1993. Prothrombin time was prolonged (Quick percentage 40-50%) and was not corrected by prolonged administration of vitamin K. Coagulation studies showed isolated factor X (FX) deficiency without circulating FX inhibitor. This suggested the diagnosis of systemic amyloidosis which was retrospectively confirmed in small bowel biopsy specimens obtained one year before. Bilateral femoral head necrosis and femoral neck fracture due to amyloidosis, necessitated orthopedic surgery. The patient died four weeks postoperatively after several episodes of bleeding complications. Isolated FX deficiency may be hereditary but should--in the clinical context--also evoke the diagnosis of systemic amyloidosis. The possible bleeding tendency associated with amyloidosis is not attributable to acquired FX deficiency alone, but may also be caused by amyloid deposition in the microvasculature leading to acquired vascular hemorrhagic diathesis.

[Isolated lung transplantation--evaluation of patients and initial results]. / Die isolierte Lungentransplantation--Evaluation von Patienten und erste Resultate.

Between November 1992 and May 1994 we performed 10 single and 5 double lung transplants in patients with end-stage lung diseases due to lymphangioleiomyomatosis (4), cystic fibrosis (3), pulmonary hypertension (3), pulmonary fibrosis (3) and chronic obstructive lung disease (2). In the 13 patients (87%) surviving for median 245 (19-567) days, FEV1 improved from median 640 ml to 1410 ml and the 12-minute walk distance from median 315 to 1100 meters. 10 patients (77%) enjoy a good or even excellent quality of life. 2 patients died 11 and 62 days postoperatively, due to multi-organ failure and invasive pulmonary aspergillosis respectively. The main postoperative problems are fungal and cytomegalovirus infections and chronic rejection in the form of bronchiolitis obliterans. In Switzerland as elsewhere, lung transplantation has become an established modality for the management of end-stage diseases of the lung and pulmonary circulation.

[Hemoptysis]. / Hämoptoe.

We report on a patient with hemoptysis and discuss the differential diagnosis and the relevant diagnostic steps. The importance of the patient's history and of the clinical findings, as well as the value of the radiological and endoscopic workup, are emphasized.

[Alcoholic pellagra encephalopathy: an underestimated treatable entity]. / Die alkoholische Pellagra-Enzephalopathie: Eine unterschätzte, behandelbare Entität.

Alcoholic pellagra-encephalopathy is an underestimated entity, which is characterized by alteration in the level and content of consciousness, marked oppositional hypertonus and myoclonus. This entity should be included in the differential diagnosis of encephalopathy in ethanol abusers. The spontaneous course is potentially lethal. Therapy consists of substitution of nicotinic acid in the form of nicotinamide. It is emphasized that any chronic ethanol abuser with neurological symptoms should receive substitution of all B-group vitamins including nicotinamide.

Amphotericin B refractory aspergillosis after itraconazole: evidence for significant antagonism.

Failure of amphotericin B to halt aspergillosis in a patient previously treated with itraconazole raised the question of whether amphotericin B lost its activity as a result of antagonism between the two antifungal drugs. Azoles exhaust the target of amphotericin B on the fungal cell membrane. Accordingly amphotericin B in vitro lost its activity against six isolates of Aspergillus fumigatus after exposure to subfungicidal concentrations of itraconazole. Prior treatment of mice with itraconazole abolished the protective effect of amphotericin B, even when itraconazole was stopped before starting amphotericin B therapy. These observations raise concern about sequential therapy of aspergillosis with itraconazole followed by amphotericin B.

[Surgical stabilization of femoral fracture following implantation of straight shaft prostheses]. / Die operative Stabilisierung der Oberschenkelfraktur nach Geradschaftprothesen-Implantation.

Fractures of the shaft of the femur at the level of a hip endoprosthesis may cause serious problems in regard to operative stabilization as well as to bony union. The therapeutic procedure and the clinical course are described in two patients. The technical procedure is demonstrated on a plastic femur model. The advantages of cementless implantation of the femoral shaft are discussed in view of this complication.

[Experiences with the inferior rectus abdominis flap]. / Erfahrungen mit dem unteren Rectus abdominis-Lappen.

Cadaveric anatomical preparations of the deep inferior epigastric artery showed the origin, the course, and the size of the artery to be consistent with few variations. Flaps which have been dissected on this vascular system can be used as island flaps or free flaps. The indications, application, and technical details, especially with regards to closure of the abdominal wall, are discussed in nine cases. The good results achieved by the use of this flap, particularly in long and narrow defects, serve as a recommendation for this type of management.