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133 results on '"Wilkens, J.J."'

5. The dosimetric impact of stabilizing spinal implants in radiotherapy treatment planning with protons and photons: standard titanium alloy vs. radiolucent carbon‐fiber‐reinforced PEEK systems

Author

Müller, B.S., Ryang, Y.M., Oechsner, M., Düsberg, M., Meyer, B., Combs, S.E., and Wilkens, J.J.

Subjects
Titanium, Photons, treatment planning, Polymers, Radiotherapy Planning, Computer-Assisted, IMPT, Carbon-fibre-reinforced Peek, Impt, Spinal Instrumentation, Radiolucent Spinal Implants, Radiation Therapy, Treatment Planning, spinal instrumentation, Radiotherapy Dosage, Ketones, equipment and supplies, radiation therapy, Polyethylene Glycols, carbon‐fibre‐reinforced PEEK, Benzophenones, Carbon Fiber, Alloys, Proton Therapy, Humans, Radiation Oncology Physics, Radiotherapy, Intensity-Modulated, radiolucent spinal implants, Protons, Retrospective Studies
Abstract

Background Throughout the last years, carbon-fibre-reinforced PEEK (CFP) pedicle screw systems were introduced to replace standard titanium alloy (Ti) implants for spinal instrumentation, promising improved radiotherapy (RT) treatment planning accuracy. We compared the dosimetric impact of both implants for intensity modulated proton (IMPT) and volumetric arc photon therapy (VMAT), with the focus on uncertainties in Hounsfield unit assignment of titanium alloy.Methods Retrospective planning was performed on CT data of five patients with Ti and five with CFP implants. Carbon-fibre-reinforced PEEK systems comprised radiolucent pedicle screws with thin titanium-coated regions and titanium tulips. For each patient, one IMPT and one VMAT plan were generated with a nominal relative stopping power (SP) (IMPT) and electron density (rho) (VMAT) and recalculated onto the identical CT with increased and decreased SP or rho by +/- 6% for the titanium components.Results Recalculated VMAT dose distributions hardly deviated from the nominal plans for both screw types. IMPT plans resulted in more heterogeneous target coverage, measured by the standard deviation sigma inside the target, which increased on average by 7.6 +/- 2.3% (Ti) vs 3.4 +/- 1.2% (CFP). Larger SPs lead to lower target minimum doses, lower SPs to higher dose maxima, with a more pronounced effect for Ti screws.Conclusions While VMAT plans showed no relevant difference in dosimetric quality between both screw types, IMPT plans demonstrated the benefit of CFP screws through a smaller dosimetric impact of CT-value uncertainties compared to Ti. Reducing metal components in implants will therefore improve dose calculation accuracy and lower the risk for tumor underdosage.

Published
2020

9. Patient individual phase gating for stereotactic radiation therapy of early stage non-small cell lung cancer (NSCLC)

Author

Kraus, K.M., Oechsner, M., Wilkens, J.J., Kessel, K.A., Münch, S., and Combs, S.E.

Subjects
Aged, 80 and over, Lung Neoplasms, Radiotherapy, Science, Radiotherapy Planning, Computer-Assisted, Respiration, Dose-Response Relationship, Radiation, Radiotherapy Dosage, Middle Aged, Radiosurgery, Article, Tumor Burden, Applied physics, Motion, Carcinoma, Non-Small-Cell Lung, Medicine, Humans, Four-Dimensional Computed Tomography, Lung cancer, Aged
Abstract

Stereotactic body radiotherapy (SBRT) applies high doses and requires advanced techniques to spare surrounding tissue in the presence of organ motion. In this work patient individual phase gating is investigated. We studied peripheral and central primary lung tumors. The internal target volume (ITV) was defined including different numbers of phases picked from a 4D Computed tomography (CT) defining the gating window (gw). Planning target volume (PTV) reductions depending on the gw were analyzed. A treatment plan was calculated on a reference phase CT (rCT) and the dose for each breathing phase was calculated and accumulated on the rCT. We compared the dosimetric results with the dose calculated when all breathing phases were included for ITV definition. GWs including 1 to 10 breathing phases were analyzed. We found PTV reductions up to 38.4%. The mean reduction of the lung volume receiving 20 Gy due to gating was found to be 25.7% for peripheral tumors and 16.7% for central tumors. Gating considerably reduced esophageal doses. However, we found that simple reduction of the gw does not necessarily influence the dose in a clinically relevant range. Thus, we suggest a patient individual definition of the breathing phases included within the gw.

Published
2020

23. PO-1035: Detection of radiation induced lung fibrosis using x-ray dark-field imaging in a murine model

Author

Gora, T., primary, Burkhardt, R., additional, Umkehrer, S., additional, Herzen, J., additional, Schilling, D., additional, Feuchtinger, A., additional, Walch, A.K., additional, Schmid, T.E., additional, Multhoff, G., additional, Noël, P.B., additional, Rummeny, E.J., additional, Pfeiffer, F., additional, Combs, S.E., additional, and Wilkens, J.J., additional

Published
2018
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28. Master of Science (MSc) program in radiation biology: An interdepartmental course bridging the gap between radiation-related preclinical and clinical disciplines to prepare next-generation medical scientists

Author

Combs, S.E., Kessel, C., Wilkens, J.J., Multhoff, G., Schmid, T.E., Vaupel, P., Trott, K.R., Berberat, P., and Atkinson, M.J.

Subjects
Clinical Radiation Sciences, Education, Immunology, Medical Informatics, Molecular Biology, Physics, Radiation Protection, Teaching
Abstract

Radiation biology is a highly interdisciplinary field at the interface of biology, physics, and medicine. It is characterized by rapid advances in biological and technical knowledge. The potential for using these advances to optimize medical care, radiation protection, and related fields can be exploited only with complementary activities to support the education of young academics. A small number of academic institutions have committed resources into radiation-related courses and curricula; however, few offer a comprehensive interdepartmental research and training program. At the Technical University of Munich (TUM), a full Master of Science (MSc) course in radiation biology has been established. This article describes the TUM MSc radiation biology program, discusses the scope of the field, the teaching goals, and the interdisciplinary curriculum. Detailed information on the full MSc program can be found continuously updated at www.radonc.med.tum.de/masterradiationbiology.

Published
2017

32. Paving the road for modern particle therapy - what can we learn from the experience gained with fast neutron therapy in Munich?

Author

Specht, H.M., Neff, T., Reuschel, W., Wagner, F.M., Kampfer, S., Wilkens, J.J., Petry, W., and Combs, S.E.

Subjects
technology, industry, and agriculture, Rbe, Adenoidcystic Carcinoma, Fast Neutron Therapy, Fast Neutrons, High-let Radiation, Reactor Neutrons
Abstract

While neutron therapy was a highly topical subject in the 70s and 80s, today there are only a few remaining facilities offering fast neutron therapy (FNT). Nevertheless, up to today more than 30,000 patients were treated with neutron therapy. For some indications like salivary gland tumors and malignant melanoma, there is clinical evidence that the addition of FNT leads to superior local control compared to photon treatment alone. FNT was available in Munich from 1985 until 2000 at the Reactor Neutron Therapy (RENT) facility. Patient treatment continued at the new research reactor FRM II in 2007 under improved treatment conditions, and today it can still be offered to selected patients as an individual treatment option. As there is a growing interest in high-linear energy transfer (LET) therapy with new hadron therapy centers emerging around the globe, the clinical data generated by neutron therapy might help to develop biologically driven treatment planning algorithms. Also FNT might experience its resurgence as a combinational partner of modern immunotherapies.

Published
2015

39. OC-0251: Development of the first pulse powered radiotherapy gantry system for a novel compact laser driven ion beam therapy

Author

Masood, U., primary, Baumann, M., additional, Bussmann, M., additional, Cowan, T.E., additional, Enghardt, W., additional, Herrmannsdoerfer, T., additional, Hofmann, K.M., additional, Karsch, L., additional, Kroll, F., additional, Schramm, U., additional, Schürer, M., additional, Wilkens, J.J., additional, and Pawelke, J., additional

Published
2015
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41. Corrigendum to “Instrumentation for diagnostics and control of laser-accelerated proton (ion) beams” [Phys Med 30 (2014) 255–270]

Author

Bolton, P.R., primary, Borghesi, M., additional, Brenner, C., additional, Carroll, D.C., additional, De Martinis, C., additional, Fiorini, F., additional, Flacco, A., additional, Floquet, V., additional, Fuchs, J., additional, Gallegos, P., additional, Giove, D., additional, Green, J.S., additional, Green, S., additional, Jones, B., additional, Kirby, D., additional, McKenna, P., additional, Neely, D., additional, Nuesslin, F., additional, Prasad, R., additional, Reinhardt, S., additional, Roth, M., additional, Schramm, U., additional, Scott, G.G., additional, Ter-Avetisyan, S., additional, Tolley, M., additional, Turchetti, G., additional, and Wilkens, J.J., additional

Published
2015
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