The aim was to evaluate stereotactic body radiation therapy (SBRT) treatment planning variability for early stage nonsmall cell lung cancer (NSCLC) with respect to the published guidelines of the Stereotactic Radiotherapy Working Group of the German Society for Radiation Oncology (DEGRO).

The starting question was a planning study to evaluate the possible benefit in lung sparing of IMRT (step and shoot) or IMAT compared to 3D conformal radiotherapy in oesophageal cancer.

The aim of our investigation was to evaluate the best suitable irradiation technique for anal cancer in clinal routine.

The Winston-Lutz test verifies the mechanical accuracy of the isocenter in stereotactic radiotherapy. A lead ball inside a small beam is exposed to film applying different combinations of the gantry angle and the table angle. The increasing replacement of films by digital images requires alternative imaging methods. The suitability of two different electronic portal imaging systems and of a system based on digital luminescence radiography was investigated.

The goal of JGRT is to provide the tools needed to manage both inter- and intrafraction motion to improve the accuracy of treatment delivery [4]. Like IMRT, IGRT, cranial, especially extracranial stereotactic radiotherapy is a process involving all steps in the treatment process including patient immobilization, CT simulation, treatment planning, plan verification, patient set up verification & correction, delivery, and QA.The contribution compares different patient positioning systems - Flat panel versus ExacTrac-Xray versus CT on rails system. Where two of them are used for gated radiotherapy. The topic deals with some specific quality assurance requirements for commissioning and QA of these medical imaging devices.

We introduce a differential equation system of order 3 describing the excitation of the muscle cell of heart. The model consider the driven oscillations of intracellular ionic-concentration in coupling with membrane potential under variation of a relaxation constant and the frequency of excitation. Solving varieties describing limited cycles, respectively driven oscillator are typically over an extensive range. That is not inconsistent with hitherto existing results of time series analysis (complexity analysis) on longtime-EKG-reception. Furthermore we discuss an possibly founded strange attractor of heart muscle cell excitation.

Purpose: To develop and evaluate a correction method for lateral electron disequilibrium and tissue inhomogeneities in lung tissues applicable to the BrainSCAN treatment planning system. Methods and Materials: Four noncoplanar 6-MV photon beams with different beam diameters were applied to the right lung of a thorax phantom. The measured/calculated dose value ratio was evaluated as a function of a parameter that describes the degree of the lateral electron disequilibrium based on the primary dose. Results: The dose ratio showed a clearcut linear dependency on the disequilibrium parameter. Applying the proposed correction method, only minor differences between the measured and calculated doses were found for lesions > 1cm. However, for lesions < 1cm surrounded by lung tissue the difference was <= 15%. Conclusion: The data have indicated a relevant magnitude of the correction factor only for lung lesions < 1cm. (c) 2006 Elsevier Inc.

The suitability of the storage phosphor plate system ACR 2000 RT (Eastman Kodak Corp., Rochester, MN, USA), that is destined for portal verification as well as for portal simulation imaging in radiotherapy, had to be proven by the comparison with a highly sensitive verification film.

Dedicated mask systems nowadays allow the use of stereotactic radiotherapy in fractionated regimes, therefore combining the advantages of high precision radiotherapy with the biological benefit of fractionation. Therefore the knowledge of institution specific isocenter accuracy is essential for decision-making about margins to be allowed to form the planning target volume.