The PerPAIN trial: a pilot randomized controlled trial of personalized treatment allocation for chronic musculoskeletal pain-a protocol

BACKGROUND

The therapy of chronic musculoskeletal pain (CMSP) is complex and the treatment results are often insufficient despite numerous therapeutic options. While individual patients respond very well to specific interventions, other patients show no improvement. Personalized treatment assignment offers a promising approach to improve response rates; however, there are no validated cross-disease allocation algorithms available for the treatment of chronic pain in validated personalized pain interventions. This trial aims to test the feasibility and safety of a personalized pain psychotherapy allocation with three different treatment modules and estimate initial signals of efficacy and utility of such an approach compared to non-personalized allocation.

METHODS

This is a randomized, controlled assessor-blinded pilot trial with a multifactorial parallel arm design. CMSP patients (n = 105) will be randomly assigned 1:1 to personalized or non-personalized treatment based on a cluster assignment of the West Haven-Yale Multidimensional Pain Inventory (MPI). In the personalized assignment condition, patients with high levels of distress receive an emotional distress-tailored intervention, patients with pain-related interference receive an exposure/extinction-tailored treatment intervention and patients who adapt relatively well to the pain receive a low-level smartphone-based activity diary intervention. In the control arm, patients receive one of the two non-matching interventions. Effect sizes will be calculated for change in core pain outcome domains (pain intensity, physical and emotional functioning, stress experience, participant ratings of improvement and satisfaction) after intervention and at follow-up. Feasibility and safety outcomes will assess rates of recruitment, retention, adherence and adverse events. Additional data on neurobiological and psychological characteristics of the patients are collected to improve treatment allocation in future studies.

CONCLUSION

Although the call for personalized treatment approaches is widely discussed, randomized controlled trials are lacking. As the personalization of treatment approaches is challenging, both allocation and intervention need to be dynamically coordinated. This study will test the feasibility and safety of a novel study design in order to provide a methodological framework for future multicentre RCTs for personalized pain psychotherapy.

TRIAL REGISTRATION

German Clinical Trials Register, DRKS00022792 ( https://www.drks.de ). Prospectively registered on 04/06/2021.

Live-Wires Using Path-Graphs

Objectives: This article discusses our new Path-Graph approach for the interactive Live-Wire segmentation method in 2D applied to pre-segmented data. Furthermore, we examine whether or not the Live-Lane extension provides advantages in combination with pre-segmentation.

Methods: We automatically over-segment the image data in a preprocessing step, using region growing with an automatic seed point generation. The Live-Wire algorithm is applied on this mosaic data by using the outlines of the homogeneous regions as the basis for graph building. We present a new definition of this underlying graph where the edges of the standard graphs are turning into vertices and the vertices of the new graph are defined by the edge connectivity in the standard graph. For better differentiation we name our new graph Path-Graph and the original defined graph Node-Graph.

Results: The quality evaluation is done by comparing our segmentation results with existing model data. We show that using the Path-Graph as basis for the Live-Wire algorithm instead of the Node-Graph allows for a finer segmentation. We achieve a reduction of incorrectly classified pixels by 20.66 per cent and a decrease of the mean boundary deviation by 11.61 per cent. Since savings on cost tree calculations are compensated by additional computation time required to compute the Live-Lanes, a performance loss of 2.41 per cent is measured.

Conclusions: Our redefinition of the underlying graph increases the quality of the Live-Wire segmentation. The Live-Lane extension in combination with pre-segmentation is not justified for our data.

Optimization of Single Voxel MR Spectroscopy Sequence Parameters and Data Analysis Methods for Thermometry in Deep Hyperthermia Treatments

OBJECTIVE

The difference in the resonance frequency of water and methylene moieties of lipids quantifies in magnetic resonance spectroscopy the absolute temperature using a predefined calibration curve. The purpose of this study was the investigation of peak evaluation methods and the magnetic resonance spectroscopy sequence (point-resolved spectroscopy) parameter optimization that enables thermometry during deep hyperthermia treatments.

MATERIALS AND METHODS

Different Lorentz peak-fitting methods and a peak finding method using singular value decomposition of a Hankel matrix were compared. Phantom measurements on organic substances (mayonnaise and pork) were performed inside the hyperthermia 1.5-T magnetic resonance imaging system for the parameter optimization study. Parameter settings such as voxel size, echo time, and flip angle were varied and investigated.

RESULTS

Usually all peak analyzing methods were applicable. Lorentz peak-fitting method in MATLAB proved to be the most stable regardless of the number of fitted peaks, yet the slowest method. The examinations yielded an optimal parameter combination of 8 cm³ voxel volume, 55 millisecond echo time, and a 90° excitation pulse flip angle.

CONCLUSION

The Lorentz peak-fitting method in MATLAB was the most reliable peak analyzing method. Measurements in homogeneous and heterogeneous phantoms resulted in optimized parameters for the magnetic resonance spectroscopy sequence for thermometry.

Low-cost flexible thin-film detector for medical dosimetry applications

The purpose of this study is to characterize dosimetric properties of thin film photovoltaic sensors as a platform for development of prototype dose verification equipment in radiotherapy. Towards this goal, flexible thin‐film sensors of dose with embedded data acquisition electronics and wireless data transmission are prototyped and tested in kV and MV photon beams. Fundamental dosimetric properties are determined in view of a specific application to dose verification in multiple planes or curved surfaces inside a phantom. Uniqueness of the new thin‐film sensors consists in their mechanical properties, low‐power operation, and low‐cost. They are thinner and more flexible than dosimetric films. In principle, each thin‐film sensor can be fabricated in any size (mm² – cm² areas) and shape. Individual sensors can be put together in an array of sensors spreading over large areas and yet being light. Photovoltaic mode of charge collection (of electrons and holes) does not require external electric field applied to the sensor, and this implies simplicity of data acquisition electronics and low power operation. The prototype device use for testing consists of several thin film dose sensors, each of about 1.5 cm×5 cm area, connected to simple readout electronics. Sensitivity of the sensors is determined per unit area and compared to EPID sensitivity, as well as other standard photodiodes. Each sensor independently measures dose and is based on commercially available flexible thin‐film aSi photodiodes. Readout electronics consists of an ultra low‐power microcontroller, radio frequency transmitter, and a low‐noise amplification circuit implemented on a flexible printed circuit board. Detector output is digitized and transmitted wirelessly to an external host computer where it is integrated and processed. A megavoltage medical linear accelerator (Varian Tx) equipped with kilovoltage online imaging system and a Cobalt source are use to irradiate different thin‐film detector sensors in a Solid Water phantom under various irradiation conditions. Different factors are considered in characterization of the device attributes: energies (80 kVp, 130 kVp, 6 MV, 15 MV), dose rates (different ms × mA, 100–600 MU/min), total doses (0.1 cGy‐500 cGy), depths (0.5 cm–20 cm), irradiation angles with respect to the detector surface (0°‐180°), and IMRT tests (closed MLC, sweeping gap). The detector response to MV radiation is both linear with total dose (~1‐400 cGy) and independent of dose rate (100‐600 Mu/min). The sensitivity per unit area of thin‐film sensors is lower than for aSi flat‐panel detectors, but sufficient to acquire stable and accurate signals during irradiations. The proposed thin‐film photodiode system has properties which make it promising for clinical dosimetry. Due to the mechanical flexibility of each sensor and readout electronics, low‐cost, and wireless data acquisition, it could be considered for quality assurance (e.g., IMRT, mechanical linac QA), as well as real‐time dose monitoring in challenging setup configurations, including large area and 3D detection (multiple planes or curved surfaces).

PACS number: 87.56.Fc

High throughput film dosimetry in homogeneous and heterogeneous media for a small animal irradiator

PURPOSE

We have established a high-throughput Gafchromic film dosimetry protocol for narrow kilovoltage beams in homogeneous and heterogeneous media for small-animal radiotherapy applications. The kV beam characterization is based on extensive Gafchromic film dosimetry data acquired in homogeneous and heterogeneous media. An empirical model is used for parameterization of depth and off-axis dependence of measured data.

METHODS

We have modified previously published methods of film dosimetry to suit the specific tasks of the study. Unlike film protocols used in previous studies, our protocol employs simultaneous multi-channel scanning and analysis of up to nine Gafchromic films per scan. A scanner and background correction were implemented to improve accuracy of the measurements. Measurements were taken in homogeneous and inhomogeneous phantoms at 220 kVp and a field size of 5 × 5 mm(2). The results were compared against Monte Carlo simulations.

RESULTS

Dose differences caused by variations in background signal were effectively removed by the corrections applied. Measurements in homogeneous phantoms were used to empirically characterize beam data in homogeneous and heterogeneous media. Film measurements in inhomogeneous phantoms and their empirical parameterization differed by about 2%-3%. The model differed from MC by about 1% (water, lung) to 7% (bone). Good agreement was found for measured and modelled off-axis ratios.

CONCLUSIONS

EBT2 films are a valuable tool for characterization of narrow kV beams, though care must be taken to eliminate disturbances caused by varying background signals. The usefulness of the empirical beam model in interpretation and parameterization of film data was demonstrated.

SU-E-T-163: Thin-Film Organic Photocell (OPV) Properties in MV and KV Beams for Dosimetry Applications

PURPOSE

To characterize dosimetric properties of low-cost thin film organic-based photovoltaic (OPV) cells to kV and MV x-ray beams for their usage as large area dosimeter for QA and patient safety monitoring device.

METHODS

A series of thin film OPV cells of various areas and thicknesses were irradiated with MV beams to evaluate the stability and reproducibility of their response, linearity and sensitivity to absorbed dose. The OPV response to x-rays of various linac energies were also characterized. Furthermore the practical (clinical) sensitivity of the cells was determined using IMRT sweeping gap test generated with various gap sizes. To evaluate their potential usage in the development of low cost kV imaging device, the OPV cells were irradiated with kV beam (60-120 kVp) from a fluoroscopy unit. Photocell response to the absorbed dose was characterized as a function of the organic thin film thickness and size, beam energy and exposure for kV beams as well. In addition, photocell response was determined with and without thin plastic scintillator.

RESULTS

Response of the OPV cells to the absorbed dose from kV and MV beams are stable and reproducible. The photocell response was linearly proportional to the size and about slightly decreasing with the thickness of the organic thin film, which agrees with the general performance of the photocells in visible light. The photocell response increases as a linear function of absorbed dose and x-ray energy. The sweeping gap tests performed showed that OPV cells have sufficient practical sensitivity to measured MV x-ray delivery with gap size as small as 1 mm.

CONCLUSIONS

With proper calibration, the OPV cells could be used for online radiation dose measurement for quality assurance and patient safety purposes. Their response to kV beam show promising potential in development of low cost kV radiation detection devices.

Live-wires using path-graphs

OBJECTIVES

This article discusses our new Path-Graph approach for the interactive Live-Wire segmentation method in 2D applied to pre-segmented data. Furthermore, we examine whether or not the Live-Lane extension provides advantages in combination with pre-segmentation.

METHODS

We automatically over-segment the image data in a preprocessing step, using region growing with an automatic seed point generation. The Live-Wire algorithm is applied on this mosaic data by using the outlines of the homogeneous regions as the basis for graph building. We present a new definition of this underlying graph where the edges of the standard graphs are turning into vertices and the vertices of the new graph are defined by the edge connectivity in the standard graph. For better differentiation we name our new graph Path-Graph and the original defined graph Node-Graph.

RESULTS

The quality evaluation is done by comparing our segmentation results with existing model data. We show that using the Path-Graph as basis for the Live-Wire algorithm instead of the Node-Graph allows for a finer segmentation. We achieve a reduction of incorrectly classified pixels by 20.66 per cent and a decrease of the mean boundary deviation by 11.61 per cent. Since savings on cost tree calculations are compensated by additional computation time required to compute the Live-Lanes, a performance loss of 2.41 per cent is measured.

CONCLUSIONS

Our redefinition of the underlying graph increases the quality of the Live-Wire segmentation. The Live-Lane extension in combination with pre-segmentation is not justified for our data.

Operation planning of correction osteotomies in 3D

This paper discusses an operation planning system for correction osteotomies. It is based on 3D data obtained from CT/MR of the bone and it allows to perform a 3D planning. The physician can individually determine anatomical landmarks for measuring geometric parameters of the bone like length, angle and torsion angle. In a virtual scene he or she can set a single cut or can remove/insert a wedge, dissecting the bones. The bone parts can be rearranged in 3D space. Optimization routines allow that the physician only defines the position of the cut, the orientation of the cut plane, the rearrangement of the bone and the optimization for the maximal overlap of the cortical bone can be processed automatically. The system is currently in use at the Trauma department at the University of Ulm. A case study shows the results by applying this system.

[Cathi-training on virtual patients for catheter interventions]

In this paper we present a trainings system for catheter interventions, especially PCTAs also called ballon dilatation. Despite the large number of such interventions the education of the cardiologist is still based on learning on the patient. This means risk to the patient and additional cost. To overcome these problems we developed the CathI system (Catheter Instruction System), a realistic computerbased training system. It provides the physician with the same equipment found in a catheter laboratory, e.g. original control instruments for the flouroscopy system, syringes, catheters, and guide wires. CathI only replaces patient and C-arm by a virtual patient and a virtual x-ray system.

[Computer assisted surgery, 2001 development and prospects. Results of a congress at Reisensburg Castle, 23-24 November 2000]]

The progress in computer assisted surgery (CAS) is influenced by new technologies in imaging as well as by the input of the users. At present, CAS procedures are established in dorsal spine instrumentation, prosthetics and long bone surgery. Present status and future of CAS was a topic of an expert meeting at the Reisensburg castle. Imaging will speed up in the future using multi-detector techniques. C-arm navigation will gain more information using the 3D technology intraoperatively. CT based navigation procedures are standard in spine and will be established in pelvic surgery. CAS in robotics at the moment means the use of robot-assistance. A new concept is the modality-based navigated surgery, which can be used at various skeletal locations. Visualization of patient data will improve using 3D semi-transparencies with real time update. In the future it will be mandatory to find algorithms to fuse the different possibilities and techniques. A new concept of surgical training is necessary to teach CAS procedures. Therefore discussion must go on to improve these systems.

[Computer-assisted surgery: developments and prospects in 2001. Results of a workshop at Schloss Reisenburg, 23-24 November 2000]

The progress in computer assisted surgery (CAS) is influenced by new technologies in imaging as well as by the input of the users. At present, CAS procedures are established in dorsal spine instrumentation, prosthetics and long bone surgery. Present status and future of CAS was a topic of an expert meeting at the Reisensburg castle. Imaging will speed up in the future using multi-detector techniques. C-arm navigation will gain more information using the 3D technology intraoperatively. CT based navigation procedures are standard in spine and will be established in pelvic surgery. CAS in robotics at the moment means the use of robot-assistance. A new concept is the modality-based navigated surgery, which can be used at various skeletal locations. Visualization of patient data will improve using 3D semi-transparencies with real time update. In the future it will be mandatory to find algorithms to fuse the different possibilities and techniques. A new concept of surgical training is necessary to teach CAS procedures. Therefore discussion must go on to improve these systems.

Computer assisted treatment of pelvis fractures

The presented approach is the realization of a minimal invasive treatment of pelvis fractures using the computer aided surgery (CAS). Main problem of tracking of major bone fragments after reposition is solved by implementing of 3D ultrasound to obtain intraoperative bone surfaces. Preoperative and intraoperative data sets are matched. Major fragments are tracked. The real time navigation is possible.

Computer simulation of osteotomy correction

This paper describes a novel approach to correct osteotomy deformities of long bones using virtual reality and image processing techniques on personal computers. The discussed method allows to simulate osteotomy corrections by implementing a single cut and a rearrangement of the dissected bone parts. It allows the surgeon to directly control the pre-operative situation and the post-operative result of the simulation by comparing bone-length, angles, and torsion of the bone. In addition, he or she obtains the coordinates and angles of the planned cut relative to anatomical landmarks.

Real-time direct volume rendering in functional magnetic resonance imaging

Direct volume rendering is a visualization method that allows display of all information hidden in three-dimensional data sets of, for example, computed tomography or magnetic resonance imaging (MRI). In contrast to commonly used surface rendering methods, these algorithms need no preprocessing but suffer from a high computational complexity. A real-time rendering system, VIRIM (Vitec: Visualization Technology GmbH, Mannheim, Germany), cuts down rendering times of minutes on normal workstations to an interactive rate of 1 second or less. The immediate visual feedback allows interactive steering of the visualization process to achieve insight into the internal three-dimensional structure of objects. Additional information is obtained by using an interactive gray-value segmentation tool that both allows segmentation of the data set according to bone, tissue, and liquor and display of multifunctional data sets (e.g., functional MRI [fMRI] data sets). Thus, real-time direct volume rendering allows segmentation and volume data processing of functional and anatomical MR data sets simultaneously. As this method can be integrated in the clinical routine, it is of great importance for real-time motion artifact detection and the interpretation of fMRI data acquired during cognitive experiments with normal subjects and psychiatric patients. Because of the free programmability of VIRIM, more complex matching procedures are currently being investigated for future implementation.

Cardiovascular responses to norepinephrine and arginine vasopressin infusion in chronically catheterized fetal lambs

Fetal cardiovascular responses to infused norepinephrine (NE) and arginine vasopressin (AVP) were compared in bilaterally vagotomized and chronically catheterized (control) fetal lambs. In the control fetuses, NE infusion was characterized during the first five minutes by a decreased fetal heart rate (FHR) and increased mean arterial blood pressure (MABP) and by a preejection period (PEP) followed by a gradual return to the original values. NE infusion in vagotomized fetuses was followed by tachycardia, decreased PEP without the initial prolongation and an MABP response similar to that in the controls. AVP in control fetuses caused a persistent decrease in the FHR and increase in MABP and PEP. Vagotomy affected only the FHR response: the decrease was persistent but smaller. AVP produced persistent fetal cardiovascular responses regardless of vagotomy; however, the biphasic response FHR pattern, suggestive of NE tachyphylaxis, was eliminated by vagotomy.

A randomized trial of routine prenatal ultrasound

Nine hundred fifteen of 2171 pregnant patients had no indication for ultrasound at their first prenatal visit and were randomly assigned to receive either a single routine screening ultrasound or usual prenatal care. The estimated date of confinement was altered in 24.9% of routine-ultrasound patients and in 11.6% of usual-care patients through ultrasound examinations obtained for a subsequent clinical indication. Of these, 8.3% of routine-ultrasound and 5.2% of usual-care patients had gestational age errors of 2 weeks or more. There were no differences between the groups in inductions for post-dates pregnancy (7.0 versus 7.5%; P = .87), total inductions (22.6 versus 24.9%; P = .61), or adverse perinatal outcomes (6.7 versus 8.3%; P = .63). Both sets of twins were detected in the screened group. In the usual-care group, five of seven pairs of twins (71%) were diagnosed by 24 weeks' gestation. There was no benefit found from routine ultrasound as performed in this study.

Effects of norepinephrine on lung fluid flow rate in the chronically catheterized fetal lamb

The influence of norepinephrine on lung fluid flow rate was studied in seven chronically catheterized fetal lambs. Lung fluid was collected through a catheter inserted into the fetal trachea. In six experiments, continuous saline solution infusion for 1 hour followed by equivolumnar norepinephrine (3.0 micrograms/min) for 1 hour via the fetal jugular vein was carried out. In three additional experiments (two fetuses), a 3.0 mg intravenous bolus of propranolol was administered before norepinephrine infusion. Saline solution infusion did not influence the lung fluid flow rate or fetal biophysical and biochemical parameters. Norepinephrine increased fetal blood pressure by 22% and decreased lung fluid flow by 45% from control values. Lung fluid flow rate recovered within 2 hours after the end of the norepinephrine infusion. Pretreatment with propranolol did not alter the results. In addition to previous reports that demonstrated beta-sympathomimetic agonist-enhanced reabsorption of lung fluid from fetal alveolar epithelial cells, our present results suggest that a reduction in fetal lung fluid secretion may be implemented as well through stimulation of alpha-sympathomimetic receptor sites in the pulmonary vasculature.

Experimentally produced sinusoidal fetal heart rate pattern in the chronically instrumented fetal lamb

A sinusoidal fetal heart rate and elevated fetal arginine vasopressin levels were found in two bled fetal lambs. Arginine vasopressin was continuously infused intravenously in chronically instrumented fetal lambs at rates ranging between 1.0 and 90 mlU/kg/min. No sinusoidal heart rate occurred in 21 experiments on six control animals with intact vagal nerves. Atropine at doses less than 0.4 mg had no effect (six experiments on three animals). Higher doses of atropine (greater than 1.2 mg) resulted in sinusoidal heart rate (24 experiments on six animals). Twenty-three infusions were performed in five bilaterally vagotomized fetuses, and the sinusoidal heart rate was successfully induced in 17 experiments. The arginine vasopressin infusion rate was less than 1.5 mlU/kg/min on the six occasions in which the sinusoidal heart rate did not appear. All sinusoidal heart rate patterns were associated with fluctuation of fetal arterial pressure at the same frequency. There was a linear correlation between the amplitude of sinusoidal heart rate and magnitude of arterial blood pressure fluctuation. The amplitude of sinusoidal heart rate increased with the concentration of arginine vasopressin infused. Modification of sinusoidal heart rate pattern was attempted with use of sympathetic agonists and antagonists. The possible etiology and mechanisms of sinusoidal heart rate pattern are discussed.

Some epidemiologic studies of HBSAg in Greece

In an epidemiologic study in 17 villages from different areas of Greece, 2898 persons were examined in order to find possible relations between HBSAg prevalence, altitude and endemic goitre morbidity. A lower prevalence with a significant difference was found in areas with a high altitude as compared with those with a low one, in endemic goitre than non-endemic areas, and in low altitude endemic than in low altitude non-endemic areas. Goitrous subjects had a lower HBSAg prevalence than non-goitrous subjects, but the difference was of borderline significance. The results can probably be explained by the presence of an environmental factor associated with altitude acting together with a host factor predisposing to endemic goitre and favouring the immunity to HBV infection.