Differentiated resistance training of the paravertebral muscles in patients with unstable spinal bone metastasis under concomitant radiotherapy: study protocol for a randomized pilot trial

Background: Metastatic bone disease is a common and severe complication in patients with advanced cancer. Radiotherapy (RT) has long been established as an effective local treatment for metastatic bone disorder. This study assesses the effects of RT combined with muscle-training exercises in patients with unstable bone metastases of the spinal column from solid tumors. The primary goal of this study is to evaluate the feasibility of muscle-training exercises concomitant to RT. Secondly, quality of life, fatigue, overall and bone survival, and local control will be assessed. Methods/Design: This study is a single-center, prospective, randomized, controlled, explorative intervention study with a parallel-group design to determine multidimensional effects of a course of exercises concomitant to RT on patients who have unstable metastases of the vertebral column, first under therapeutic instruction and subsequently performed by the patients themselves independently for strengthening the paravertebral muscles. On the days of radiation treatment the patients will be given four different types of exercises to ensure even isometric muscle training of all the spinal muscles. In the control group progressive muscle relaxation will be carried out parallel to RT. The patients will be randomized into two groups: differentiated muscle training or progressive muscle relaxation with 30 patients in each group. Discussion: Despite the clinical experience that RT is an effective treatment for bone metastases, there is insufficient evidence for a positive effect of the combination with muscle-training exercises in patients with unstable bone metastases. Our previous DISPO-1 trial showed that adding muscle-training exercises to RT is feasible, whereas this was not proven in patients with an unstable spinal column. Although associated with several methodological and practical challenges, this randomized controlled trial is needed. Trial registration: ClinicalTrials.gov, identifier: NCT02847754. Registered on 27 July 2016

Establishing stereotactic body radiotherapy with flattening filter free techniques in the treatment of pulmonary lesions - initial experiences from a single institution

Background: Stereotactic body radiotherapy (SBRT) using flattening filter free (FFF)-techniques has been increasingly applied during the last years. However, clinical studies investigating this emerging technique are still rare. Hence, we analyzed toxicity and clinical outcome of pulmonary SBRT with FFF-techniques and performed dosimetric comparison to conventional techniques using flattening filters (FF). Materials and methods: Between 05/2014 and 06/2015, 56 consecutive patients with 61 pulmonary lesions were treated with SBRT in FFF-mode. Central lesions received 8 × 7.5 Gy delivered to the conformally enclosing 80%-isodose, while peripheral lesions were treated with 3 × 15 Gy, prescribed to the 65%-isodose. Early and late toxicity (after 6 months) as well as initial clinical outcomes were evaluated. Furthermore, [deleted] plan quality and efficiency were evaluated by analyzing conformity, beam- on and total treatment delivery times in comparison to plans with FF-dose application. Results: Median follow-up time was 9.3 months (range 1.5–18.0 months). Early toxicity was low with only 5 patients (8.9 %) reporting CTCAE 2° or higher side-effects. Only one patient (1.8 %) was diagnosed with radiation-induced pneumonitis CTCAE 3°, while 2 (3.6 %) patients suffered from pneumonitis CTCAE 2°. After 6 months, no toxicity greater than CTCAE 2° was reported. 1-year local progression-free survival, distant progression-free survival and overall survival were 92.8 %, 78.0 %, and 94.4 %, respectively. While plan quality was similar for FFF- and FF-plans in respect to conformity (p = 0.275), median beam-on time as well as total treatment time were significantly reduced for SBRT in FFF-mode compared to FF-mode (p ≤ 0.001, p ≤ 0.001). Conclusions: Patient treatment with SBRT using FFF-techniques is safe and provides promising clinical results with only modest toxicity at significantly increased dose delivery speed

Tuning of the ‘Constant in gain Lead in phase’ Element for Mass-like Systems

The development of the high-tech industry has pushed the requirements of motion applications to extremes regarding precision, speed and robustness. A clear example is given by the wafer and reticle stages that require rigorous demands like robust nanometer precision and high-speed motion profiles to ensure product quality and production efficiency. Industrial workhorse Proportional Integral Derivative (PID) has been widely used for its simple implementation and good performance. However, PID is insufficient to meet the ever-increasing demands in the high-tech industry due to its inherent constraints of linear controllers such as the waterbed effect. To overcome these fundamental limitations, researchers have turned to nonlinear controllers. Nevertheless, most of the nonlinear controllers are difficult to design and implement and thus are not widely accepted in the industry. Reset control is anonlinear controller that is easy to implement and design since it maintains compatibility with the PID loop shaping technique using a pseudo-linear analysis tool named describing function method. However, the reset control as a nonlinear controller also introduces high order harmonics to the system that can negatively affect system performance by causing unwanted dynamics. Hence, describing function analysis as a linear approximation approach that only considers first harmonics is not accurate enough. Recently, a theory to analyze high order harmonics of nonlinear system in frequency domain termed higher order sinusoidal describing function has been developed, which enables the possibility to perform more precise analysis on reset systems. The majority of research on reset control has focused on the phase lag reduction but a novel reset element proposed in literature termed ”Constant in gain, Lead in phase” (CgLp) is used to provide broadband phase compensation and has been shown to improve system performance. However, there is no systematic designing and tuning approach in literature such that the full advantage of CgLp elements is extracted. This work focuses on the tuning of the CgLp elements in order to obtain optimal performance. High order harmonics are also considered in the tuning analysis since they are critical to system performance due to the effect of unwanted dynamics. When a group of CgLp elements are designed to provide pre-determined phase compensation at the crossover frequency, it is seen that the optimal tracking precision performance is always obtained with the case that has the highest frequency of third order harmonic peak and has almost the smallest magnitude of high order harmonics at low frequencies. Moreover,the second order CgLp controllers are observed to outperform the first order CgLp controller regarding tracking precision. On the other hand, configurations that have the lowest magnitude of third order harmonic at high frequency are found to have the best noise attenuation performance.Mechanical Engineering | Mechatronic System Design (MSD

Additional file 1: of Differentiated resistance training of the paravertebral muscles in patients with unstable spinal bone metastasis under concomitant radiotherapy: study protocol for a randomized pilot trial

SPIRIT 2013 Checklist: recommended items to address in a clinical trial protocol and related documents. (DOC 121 kb