Advantage of proton-radiotherapy for pediatric patients and adolescents with Hodgkin's disease.

Radiotherapy is frequently used in the therapy of lymphoma. Since lymphoma, for example Hodgkin's disease, frequently affect rather young patients, the induction of secondary cancer or other long-term adverse effects after irradiation are important issues to deal with. Especially for mediastinal manifestations numerous organs and substructures at risk play a role. The heart, its coronary vessels and cardiac valves, the lungs, the thyroid and, for female patients, the breast tissue are only the most important organs at risk. In this study we investigated if proton-radiotherapy might reduce the dose delivered to the organs at risk and thus minimize the therapy-associated toxicity. METHODS: In this work we compared the dose delivered to the heart, its coronary vessels and valves, the lungs, the thyroid gland and the breast tissue by different volumetric photon plans and a proton plan, all calculated for a dose of 28.8 Gy (EURO-NET-PHL-C2). Target Volumes have been defined by F18-FDG PET-positive areas, following a modified involved node approach. Data from ten young female patients with mediastinal lymphoma have been evaluated. Three different modern volumetric IMRT (VMAT) photon plans have been benchmarked against each other and against proton-irradiation concepts. For plan-evaluation conformity- and homogeneity-indices have been calculated as suggested in ICRU 83. The target volume coverage as well as the dose to important organs at risk as the heart with its substructures, the lungs, the breast tissue, the thyroid and the spinal cord were calculated and compared. For statistical evaluation mean doses to organs at risk were evaluated by non- parametric Kruskal-Wallis calculations with pairwise comparisons. RESULTS: Proton-plans and three different volumetric photon-plans have been calculated. Proton irradiation results in significant lower doses delivered to organ at risk. The median doses and the mean doses could be decreased while PTV coverage is comparable. As well conformity as homogeneity are slightly better for proton plans. For several organs a risk reduction for secondary malignancies has been calculated using literature data as reference. According to the used data derived from literature especially the secondary breast cancer risk, the secondary lung cancer risk and the risk for ischemic cardiac insults can be reduced significantly by using protons for radiotherapy of mediastinal lymphomas. CONCLUSION: Irradiation with protons for mediastinal Hodgkin-lymphoma results in significant lower doses for almost all organs at risk and is suitable to reduce long term side effects for pediatric and adolescent patients.

Predicting the outcome of mid-urethral tape surgery for stress urinary incontinence using preoperative urodynamics - a systematic review.

Urodynamics are currently widely used in most of urogynecology services, mainly as a diagnostic tool routinely preoperatively or for complicated cases. The urodynamic parameters, mainly Valsalva leak point pressure (VLPP) and maximum urethral closure pressure (MUCP), are increasingly researched for the promising value in predicting the outcome of urinary incontinence surgery. Despite the increasing evidence, their predictive role for mid-urethral sling surgery outcome is still unclear. We systematically searched theliterature for articles published between January 1990 to January 2014, analysing the value of urodynamic variables in predicting the outcome of mid-urethral sling surgery. We calculated relative risks of failure of surgery for patients with low MUCP and VLPP compared with those with high values.Low preoperative MUCP was associated with higher risk of failure for both transobturator and retropubic techniques (RR1.83; 95% confidence interval (CI) 1.44-2.33 and RR 1.41;95% CI 1.17-1.69 respectively). Low preoperative VLPP was predictive as well for higher risk of failure for both transobturator and retropubic routes (RR 1.76; 95% CI 1.37-2.28 and RR 2.01; 95% CI 1.56-2.60 respectively). Concluding, preoperative MUCP and VLPP could be used as predictors for postoperative outcome after mid-urethral sling surgery for SUI.

Development and performance evaluation of a dynamic phantom for biological dosimetry of moving targets.

A dynamic phantom has been developed to allow for measurement of 3D cell survival distributions and the corresponding distributions of the RBE-weighted dose (RBED) in the presence of motion. The phantom consists of two 96-microwell plates holding Chinese hamster ovary cells inside a container filled with culture medium and is placed on a movable stage. Basic biological properties of the phantom were investigated without irradiation and after irradiation with a carbon ion beam, using both a stationary (reference) exposure and exposure during motion of the phantom perpendicular to the beam with beam tracking. There was no statistically significant difference between plating efficiency measured in the microwells with and without motion (0.75) and values reported in the literature. Mean differences between measured and calculated cell survival for these two irradiation modes were within +/-5% of the target dose of 6 Gy (RBE).

Nuclear fragmentation cross-sections of 400 A MeV 36Ar and 40Ar in collisions with light and heavy target nuclei.

We have measured fragmentation cross-sections of Ar projectile nuclei at beam energy of 400 A MeV using experimental set-ups with plastic nuclear track detectors and different targets. In this paper total charge changing cross-sections and elemental fragmentation cross-sections for the production of fragments with charges ZF > or = 7 in interactions with H, C, Al, Cu, Ag and Pb target nuclei are presented. The dependence of the cross-sections on the fragment charge number and target charge number are discussed. The experimental results are compared to predictions of semi empirical cross-section models.

Sensitivity to augmentin and cephalosporines of some bacterial strains isolated from hospitalized patients.

The study allowed the determination of the degree of antibacterial efficiency of three antimicrobial agents belonging to the betalactamine family namely cefuroxime (IInd generation), ceftazidime (IIIrd generation) and augmentin. Likewise the relationship bacterial species-antibiotic could be established. It was found that the pathogenic staphylococcus strains were very sensitive to cefuroxime (92.1%) and equally sensitive to ceftazidime and augmentin (61.0%). The enterococci were 100% sensitive to augmentin and 100% resistant to both cephalosporines. The enterobacteriaceae presented a higher percentage of sensitive strains to cephalosporines than to augmentin 89.6% of the E. coli strains were sensitive to ceftazidime, 77.9% to cefuroxime and 27.3% to augmentin. Klebsiella was sensitive in 68.2%, 45.14% and 13.6% of the cases to ceftazidime, cefuroxime and respectively augmentin. Proteus presented 64.7% strains sensitive to ceftazidime, 35.3% sensitive to cefuroxime and 29.3% sensitive to augmentin. All the enterobacter strains proved resistant to the three antibiotics studied.