Dosimetric Comparison Between Helical Tomotherapy and Volumetric Modulated Arc Therapy in Patients With Malignant Pleural Mesothelioma.

AIMS: To carry out a dosimetric comparison and constraints feasibility proof of adjuvant radiotherapy through helical tomotherapy or volumetric modulated arc therapy (VMAT) for malignant pleural mesothelioma patients after pleurectomy/decortication. MATERIALS AND METHODS: Retrospective calculations were carried out on previously acquired simulations. A whole-pleura volume with 50.4 Gy in 28 fractions was prescribed, simulating a no residual tumour situation. Calculations were carried out using an anisotropic analytical algorithm with a 2.0 mm grid. Beam-on time, planning target volume (PTV) coverage, homogeneity index and organ at risk exposure were compared. RESULTS: Sixteen patient plans were calculated per device. Constraints were met overall by both modalities. For helical tomotherapy and VMAT plans, median beam-on times were 13.8 (11.6-16.1) min and 6.4 (6.1-7.0) min; P = 0.006. The median left-sided radiotherapy PTV D98 were 48.1 (48.0-48.8) Gy and 47.6 (46.5-48.3) Gy; P = 0.023. No significant difference for right-sided radiotherapy was found. PTV D2 for left-sided radiotherapy was higher with VMAT (P = 0.014). For right-sided radiotherapy, helical tomotherapy showed higher doses (P = 0.039). No homogeneity index differences for left-sided radiotherapy (P = 1.00) and right-sided radiotherapy (P = 0.598) were seen. Significant organ at risk exposure differences were found on left-sided radiotherapy whole-lung V20, as well as D50 (both P = 0.008). Higher contralateral lung and ipsilateral kidney exposures were found with VMAT plans for both treatment sides. CONCLUSION: Adjuvant radiotherapy after pleurectomy/decortication in malignant pleural mesothelioma patients, with a VMAT- or helical tomotherapy-based platform, is dosimetrically feasible. Lung sparing was mostly improved with helical tomotherapy. Technique selection must be carried out according to availability and clinical criteria.

MRI during radiotherapy of glioblastoma : Does MRI allow for prognostic stratification?

AIM: To evaluate the role of magnetic resonance imaging (MRI) as a predictor for the clinical course in patients with glioblastoma. PATIENTS AND METHODS: In 64 patients with glioblastoma undergoing (chemo)radiotherapy MRI studies were obtained before radiation, after 30 gray (Gy), after 60 Gy and during follow-up. MRI findings were assigned to categories: definite progression, questionable progression, no change. Patients were followed clinically. RESULTS: At 30 Gy, 23 of 64 patients (36 %) demonstrated definite (dp; n = 15) or questionable (qp; n = 8) progression; in 41/64 (64 %) no change was found compared with preradiation MRI. After radiotherapy at 60 Gy, 26 of 64 (41 %) patients showed dp (n = 18) or qp (n = 8). In 2 cases with qp at the 30 Gy MRI, progress was unquestionable in the 60 Gy MRI study. In the 64 patients, 5 of the 60 Gy MRIs showed dp/qp after being classified as no change at the 30 Gy MRI, 2 of the 30 Gy MRIs showed qp, while the 60 Gy MRI showed tumour regression and 3 fulfilled the criteria for pseudoprogression during ongoing radiotherapy. The 30 Gy study allowed for prognostic stratification: dp/qp compared to stable patients showed median survival of 10.5 versus 20 months. CONCLUSION: MR follow-up after 30 Gy in patients undergoing (chemo)radiotherapy for glioblastoma allows prognostic appraisal. Pseudoprogression has to be taken into account, though rare in our setting. Based on these findings, early discussion of treatment modification is possible.

[Change of Taste during and after IM- /IG-Radiotherapy for Head and Neck Cancer Patients]. / Veränderungen des Schmeckvermögens durch IM-/IG-Strahlentherapie bei Kopf-Hals-Tumorpatienten.

OBJECTIVE: Taste dysfunction is a common side effect during irradiation of head and neck. Our aim was to determine the time-dependent course and a possible dependency of this side effect to the radiation-dose during irradiation with helical tomotherapy. PATIENTS AND METHODS: 31 patients with malignant tumours in the region of head and neck received an IG-/IM-radiotherapy (helical tomotherapy).The median total dose was 63 Gy (range 30-66 Gy). For all patients the subjective taste dysfunction was documented and correlated to the median (D50) tongue dose. RESULTS: A subjective taste dysfunction was registered by the patients themselves after 9 BT (days of radiotherapy) (median). This correlates to a mean dose (D50) of 15.3 Gy (back third of tongue (back ZD)), 11.3 Gy (middle ZD), 8.2 Gy (front ZD). A subjective ageusia occurred after 15 BT (median) (28.9 Gy (back ZD), 22.2 Gy (middle ZD), 17.7 Gy (front ZD)). A starting recovery was registered by 77% of the patients in the first 6-8 weeks after the end of radiotherapy. CONCLUSION: The time-dependent course of taste dysfunction during radiotherapy and the following recovery is predictable. A dependency of taste dysfunction to radiation-dose exists. Based on the collected data a targeted dose reduction to the tongue with a view to minimize the taste dysfunction is thinkable and aim of further studies.

Quality of patient positioning during cerebral tomotherapy irradiation using different mask systems.

BACKGROUND AND PURPOSE: Patient immobilization during brain tumor radiotherapy is achieved by employing different mask systems. Two innovative mask systems were developed to minimize the problems of claustrophobic patients. Our aim was to evaluate whether the quality of patient immobilization using the new mask systems was equivalent to the standard mask system currently in use. MATERIAL AND METHODS: Thirty-three patients with cerebral target volumes were irradiated using the Hi-Art II tomotherapy system between 2010 and 2012. Each group of 11 patients was fitted with one of the two new mask systems (Crystal® or Open Face® mask, Orfit) or the standard three-point mask (Raycast®-HP, Orfit) and a total of 557 radiotherapy fractions were evaluated. After positioning was checked by MV-CT, the necessary table adjustments were noted. Data were analyzed by comparing the groups, and safety margins were calculated for nonimage-guided irradiation. RESULTS: The mean values of the table adjustments were: (a) lateral (mm): - 0.22 (mask 1, standard deviation (σ): 2.15); 1.1 (mask 2, σ: 2.4); - 0.64 (mask 3, σ: 2.9); (b) longitudinal (mm): - 1 (mask 1, σ: 2.57); - 0.5 (mask 2, σ: 4.7); - 1.22 (mask 3, σ: 2.52); (c) vertical (mm): 0.62 (mask 1, σ: 0.63); 1.2 (mask 2, σ: 1.0); 0.57 (mask 3, σ: 0.28); (d) roll: 0.35° (mask 1, σ: 0.75); 0° (mask 2, σ: 0.8); 0.02° (mask 3, σ: 1.12). The outcomes suggest necessary safety margins of 5.49-7.38 mm (lateral), 5.4-6.56 mm (longitudinal), 0.82-3.9 mm (vertical), and 1.93-4.5° (roll). There were no significant differences between the groups. CONCLUSIONS: The new mask systems improve patient comfort while providing consistent patient positioning.

Magnetic resonance imaging analysis of anterior and posterior eye segment displacement during ocular gaze shifts.

PURPOSE: To determine the relationship between movements of the posterior and anterior eye segments during arbitrary gaze shifts and to obtain information for monitoring fixation during radiotherapy for ocular diseases. METHODS: We examined eye movements of ten emmetropic volunteers in a 1.5 T magnetic resonance system. Using a T2-weighted ultrafast turbo-spin echo sequence (UTSE), the eyes were examined within 21 seconds. Sagittal and transversal eye slices were obtained in five passages in five gaze directions (straight ahead, 15 degrees above, 15 degrees below, 15 degrees right and 15 degrees left of the primary position). Displacement of the posterior eye segment was analyzed in relation to the movement of the anterior segment in all directions. RESULTS: The relationship between the movements of the anterior and posterior eye segment was 1:0.8 (+/- 0.06 SD) during horizontal gaze shifts and 1:1.16 (+/- 0.11 SD) during vertical gaze shifts. CONCLUSIONS: Magnetic resonance imaging showed that the relationship between anterior and posterior eye segments was different during horizontal and vertical eye movements, indicating the presence of more than one center of rotation. Compared to the anterior eye segment, there was less displacement of the posterior eye segment during horizontal eye movements and more displacement during vertical eye movements.

Screening of diabetic patients for microalbuminuria in primary care--The PROSIT-Project. Proteinuria Screening and Intervention.

The PROSIT (Proteinuria Screening and Intervention) Project started in 1993 in order to obtain data on the prevalence of micro- and macroalbuminuria in diabetic patients treated in primary care, to establish an easy screening programme for microalbuminuria, in which also diabetic patients can participate in self-responsibility, and to implement a specific intervention programme for incipient nephropathy. In 58 representative doctor's offices 647 diabetic patients were included, who performed at home self-tests for microalbuminuria on three days within one week using the early morning urine and a newly developed qualitative immunologic test-strip for microalbuminuria. After storage they returned the same urine samples to their doctors' offices for semiquantitative retesting with the immunologic test-strip Micral-Test II. In case of positive results the proteinuria dipstick Combur-9-Test was applied in order to exclude other causes of positive microalbuminuria (e.g. urinary tract infection). Data of 569 patients (6% Type 1, 88% Type 2 and 6% secondary diabetes) could be analysed. Both qualitative self-testing for microalbuminuria at home and semiquantitative retesting in doctors' offices were found to be feasible. Based on semiquantitative retesting the prevalences of microalbuminuria (macroalbuminuria) were 19.6% (0%) in Type 1 diabetes, 17.2% (10.8%) in Type 2 diabetes and 11.7% (7.8%) in secondary diabetes. Type 2 diabetic patients showed a clear correlation between albuminuria and diabetes duration, HbA1c, serum creatinine, triglycerides as well as micro- and macrovascular complications. 227 patients with micro- or macroalbuminuria were included into the ongoing PROSIT intervention programme.

Focusing Optics for High-Energy X-ray Diffraction.

Novel focusing optical devices have been developed for synchrotron radiation in the energy range 40-100 keV. Firstly, a narrow-band-pass focusing energy-tuneable fixed-exit monochromator was constructed by combining meridionally bent Laue and Bragg crystals. Dispersion compensation was applied to retain the high momentum resolution despite the beam divergence caused by the focusing. Next, microfocusing was achieved by a bent multilayer arranged behind the crystal monochromator and alternatively by a bent Laue crystal. A 1.2 micro m-high line focus was obtained at 90 keV. The properties of the different set-ups are described and potential applications are discussed. First experiments were performed, investigating with high spatial resolution the residual strain gradients in layered polycrystalline materials. The results underline that focused high-energy synchrotron radiation can provide unique information on the mesoscopic scale to the materials scientist, complementary to existing techniques based on conventional X-ray sources, neutron scattering or electron microscopy.

Applications of high-energy synchrotron radiation for structural studies of polycrystalline materials.

The large penetration power of high-energy X-rays (>60 keV) raises interesting prospects for new types of structural characterizations of polycrystalline materials. It becomes possible in a non-destructive manner to perform local studies, within the bulk of the material, of the fundamental materials physics properties: grain orientations, strain, dislocation densities etc. In favourable cases these properties may be mapped in three dimensions with a spatial resolution that matches the dimensions of the individual grains. Imbedded volumes and interfaces become accessible. Moreover, the high energies allow better in-situ studies of samples in complicated environments (industrial process optimization). General techniques for research in this energy range have been developed using broad-band angle-dispersive methods, on-line two-dimensional detectors and conical slits. Characterizations have been made at the level of the individual grains and grain boundaries as well as on ensembles of grains. The spatial resolution is presently of the order of 10-100 micom. Four examples of applications are presented along with an outlook.

[Double-barrelled replacement-plasty of the anterior cruciate ligament with fascia lata strips]. / Die doppelläufige Ersatzplastik des vorderen Kreuzbandes mit dem Fascia-lata-Streifen.

An intra-articular reconstruction of the anterior cruciate ligament (ACL) in chronic and acute ruptures is described, which we call doubling-back ACL substitution. The McIntosh graft is used to fix it, starting from the posterior origin of the ACL and passing to the anterior region of its insertion and through the anteromedial tibial head, returning over the top with isometric conditions. Since April 1987, this procedure has been applied in 60 patients this way, 48 of whom we saw again between April and June 1990. There are only 2 unstable joints; 46 patients have stable knees. Most of them are engaging in sport again.

[Health in the USSR in the era of Perestroika]. / La santé en URSS à l'heure de la Perestroïka.

For years, the Health Service of the USSR was considered a model and a guide. Countries in the Third World were invited to follow its various elements in organizing their own national health systems. But, since August 1987, everybody has known that the Health Service of the USSR is in a very bad situation. Official reports, journals of the Party and declarations of the health authorities all emphasized the catastrophic state of the health care organization in USSR: rising mortality rates, alcohol and drug abuse, extensive pollution, hospitals without hygiene or equipment, lack of professionalism and extended corruption among medical doctors and other health workers, patients' dissatisfaction etc... Of special concern are the cardiovascular and maternal mortality rates which are now much higher than in other countries. In the wake of perestroïka, a plan of reform was initiated by the Party and the Government, and was announced in 1988 by Health Minister E.N. Tchazov. The basic principle of the Health Service in the USSR remains prevention. Nevertheless, a great number of new measures will be implemented. Health information and care will be brought to the people by health workers. Mass screening for the most frequent diseases will be performed. Computers will be used on a large scale for managing high risk groups. Health centers will be strengthened. But the most revolutionary element of the reform will be the extension of the "paying sector", with increased number of facilities having financial autonomy. These facilities provide care and require some payment from the patients. They existed previously, but in the future they will be increased and strengthened. This means that the patients will have to pay more money but the services will be likely improved. The future will show whether the plan will succeed or fail.

[Experiences with the use of cerium nitrate silver sulfadiazine in the local treatment of thermal injuries in childhood]. / Erfahrungen mit der Anwendung von Cerium-Nitrat-Silbersulfadiazin bei der Lokalbehandlung thermischer Verletzungen im Kindesalter.

Ointment containing cerium nitrate and silver sulphadiazine (Flammacerium) was applied to 47 children with second-degree to third-degree thermal injuries, with something between five and 60 per cent of the body surface being affected, as had been reported in a one-year prospective study. This ointment proved to be superior to several alternative approaches with regard to local properties, antimicrobial effectiveness, and applicability to several degree of burns. The process of treatment can be optimised due to unproblematic applicability in open and closed variants under both hospitalised and outpatient conditions. This assessment has been underlined by good to very good therapeutic results.

Damage of erythrocytes by activated oxygen generated in hypoxic rat liver.

The implication of activated oxygen in the interaction between hypoxic rat liver and circulating erythrocytes was investigated. Reduced species of oxygen generated in hypoxic liver owing to accelerated purine nucleotide degradation via xanthine oxidase initiate alterations of plasma membrane and glutathione system of erythrocytes. Osmotic fragility, hemolysis rate and erythrocytic GSSG:GSH ratio may be considered as appropriate indicators of oxidative load in liver and other tissues. Addition of erythrocytes to the perfusion medium attenuates the GSSG efflux of hypoxic liver from 2.7 +/- 0.5 nmol x g w.w.-1 x min-1 to 1.4 +/- 0.2 nmol x g w.w.-1 x min-1 Thus, circulating erythrocytes protect the liver against oxidative attack.

Alteration of erythrocytes by reduced species of oxygen generated in hypoxic rat liver during perfusion.

Activated species of oxygen produced in the hypoxic rat liver leave the cells and attack the membrane of circulating erythrocytes. Therefore the metabolic and structural changes of red blood cells may be appropriate indicators of an oxidative loading in tissues. The circulating erythrocytes exert a profound protective, "radical scavenger effect" on the liver tissue.

[The storage capability of pre-filled disposable plastic syringes]. / Untersuchungen zur Lagerfähigkeit vorgefüllter Plasteinwegspritzen.

The storage stability of a pre-filled plastic disposable syringe (piston type) of polypropylene as to solvents and ambient oxygen has been studied. To assess the permeability and impermeability of the sealing component parts, the syringes had been stored in a long-time test under different types of seal and different temperatures. Based on the results, the polypropylene plastic disposable syringes were on principal suited to be used in solvents as glycol, ethanol or water, the protection against ambient oxygen is, however, an insufficient one.