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Objective To provide an update on Australian persistent pain services (number, structure, funding, wait times, activity). Methods An updated national search was conducted. Of those identified, 74 persistent pain services provided detailed responses between July 2016 and February 2018 (64 adult, seven pediatric, two pelvic pain, and one cancer pain). A similar structure to the original Waiting in Pain (WIP) survey was used, and participants chose online or telephone completion. Results Pediatric pain services had more than doubled but remained limited. Adult services had also increased, with a concurrent decrease in median wait times and an increase in the number of new referrals seen each year. Despite this, some lengthy wait times (≥3 years) persisted. Wait times were longest at clinics using public or combined funding models and offering pain management group programs (PMGPs). Although clinical activity had increased, medical staffing had not, suggesting that clinics were operating differently. Privately funded clinics performed more procedures than publicly funded services. Use of PMGPs had increased, but program structure remained diverse. Conclusions Specialist pain services have expanded since the original WIP survey, facilitating treatment access for many. However, wait time range suggested that the most disadvantaged individuals still experienced the longest wait times, often far exceeding the recommended 6-month maximum wait. More needs to be done. Numerous developments (e.g., National Strategic Action Plan for Pain Management, health system changes as a result of the COVID-19 pandemic) will continue to influence the delivery of pain services in Australia, and repeated analysis of service structures and wait times will optimize our health system response to the management of this condition.

The goal of this work was to develop and test a cylindrical tissue-equivalent quality assurance (QA) phantom for micro computed tomography (microCT) image-guided small animal irradiators that overcomes deficiencies of existing phantoms due to its mouse-like dimensions and composition.The 8.6-cm-long and 2.4-cm-diameter phantom was three-dimensionally (3D) printed out of Somos NeXt plastic on a stereolithography (SLA) printer. The modular phantom consisted of four sections: (a) CT number evaluation section, (b) spatial resolution with slanted edge (for the assessment of longitudinal resolution) and targeting section, (c) spatial resolution with hole pattern (for the assessment of radial direction) section, and (d) uniformity and geometry section. A Python-based graphical user interface (GUI) was developed for automated analysis of microCT images and evaluated CT number consistency, longitudinal and radial modulation transfer function (MTF), image uniformity, noise, and geometric accuracy. The phantom was placed at the imaging isocenter and scanned with the small animal radiation research platform (SARRP) in the pancake geometry (long axis of the phantom perpendicular to the axis of rotation) with a variety of imaging protocols. Tube voltage was set to 60 and 70 kV, tube current was set to 0.5 and 1.2 mA, voxel size was set to 200 and 275 μm, imaging times of 1, 2, and 4 min were used, and frame rates of 6 and 12 frames per second (fps) were used. The phantom was also scanned in the standard (long axis of the phantom parallel to the axis of rotation) orientation. The quality of microCT images was analyzed and compared to recommendations presented in our previous work that was derived from a multi-institutional study. Additionally, a targeting accuracy test with a film placed in the phantom was performed. MicroCT imaging of the phantom was also simulated in a modified version of the EGSnrc/DOSXYZnrc code. Images of the resolution section with the hole pattern were acquired experimentally as well as simulated in both the pancake and the standard imaging geometries. The radial spatial resolution of the experimental and simulated images was evaluated and compared to experimental data.For the centered phantom images acquired in the pancake geometry, all imaging protocols passed the spatial resolution criterion in the radial direction (1.5 lp/mm @ 0.2 MTF), the geometric accuracy criterion (200 μm), and the noise criterion (55 HU). Only the imaging protocol with 200-μm voxel size passed the criterion for spatial resolution in the longitudinal direction (1.5 lp/mm @ 0.2 MTF). The 70-kV tube voltage dataset failed the bone CT number consistency test (55 HU). Due to cupping artifacts, none of the imaging protocols passed the uniformity test of55 HU. When the phantom was scanned in the standard imaging geometry, image uniformity and longitudinal MTF were satisfactory; however, the CT number consistency failed the recommended limit. A targeting accuracy of 282 and 251 μm along the x- and z-direction was observed. Monte Carlo simulations confirmed that the radial spatial resolution for images acquired in the pancake geometry was higher than the one acquired in the standard geometry.The new 3D-printed phantom presents a useful tool for microCT image analysis as it closely mimics a mouse. In order to image mouse-sized animals with acceptable image quality, the standard protocol with a 200-μm voxel size should be chosen and cupping artifacts need to be resolved.

BACKGROUND: The goal of the current study was to investigate the tumor control probability (TCP) of advanced radiotherapy technologies for stage III non-small cell lung cancer (NSCLC) and to evaluate potential interplay effects between their applications. MATERIALS AND METHODS: Three-dimensional conformal radiotherapy (3D-CRT) with conventionally fractionated doses of 66 Gy served as reference for 13 patients with stage III NSCLC. Isotoxic dose escalation relative to the corresponding 3D-CRT plans was performed for three technologies and their combinations: intensity-modulated radiotherapy (IMRT), IMRT with a simultaneous integrated boost (IMRT-SIB) of 10% to the gross tumor volume (GTV), and adaptive re-planning twice during the treatment course (ART). All analyses were based on accumulated dose distributions using deformable image registration of CT images, which were acquired weekly during the treatment course. RESULTS: IMRT reduced the mean lung dose (MLD) by 5.6% ± 3.8% compared to 3D-CRT. ART resulted in lung sparing of 7.9% ± 4.8% and 9.2% ± 3.9% in 3D-CRT and IMRT planning, respectively. IMRT and ART escalated the irradiation dose by 6.6% ± 3.2% and 8.8% ± 6.3%, respectively, which was not statistically different. For the 7 patients with the largest GTVs, IMRT-SIB was superior to IMRT and ART with dose escalation of 11.9% ± 3.7%. The combination of ART, IMRT, and SIB achieved maximum dose escalation in all 13 patients by 17.1% ± 5.4% on average, which increased TCP from 19.9% ± 7.0 to 37.1% ± 10.1%. Adaptive re-planning was required to continuously conform the escalated and hypofractionated SIB doses to the shrinking tumor. CONCLUSION: Combining advanced radiotherapy technologies is considered as a safe and effective strategy to maximize local tumor control probability in stage III NSCLC.

To evaluate a novel respiratory motion compensation strategy combining gated beam delivery with the mean target position (MTP) concept for pulmonary stereotactic body radiotherapy (SBRT).Four motion compensation strategies were compared for 10 targets with motion amplitudes between 6mm and 31mm: the internal target volume concept (plan(ITV)); the MTP concept where safety margins were adapted based on 4D dose accumulation (plan(MTP)); gated beam delivery without margins for motion compensation (plan(gated)); a novel approach combining gating and the MTP concept (plan(gatedMTP)).For 5/10 targets with an average motion amplitude of 9mm, the differences in the mean lung dose (MLD) between plan(gated) and plan(MTP) were10%. For the other 5/10 targets with an average motion amplitude of 19mm, gating with duty cycles between 87.5% and 75% reduced the residual target motion to 12mm on average and 2mm safety margins were sufficient for dosimetric compensation of this residual motion in plan(gatedMTP). Despite significantly shorter duty cycles, plan(gated) reduced the MLD by10% compared to plan(gatedMTP). The MLD was increased by 18% in plan(MTP) compared to that of plan(gatedMTP).For pulmonary targets with motion amplitudes10-15mm, the combination of gating and the MTP concept allowed small safety margins with simultaneous long duty cycles.

Background and Purpose Computer controlled breath-hold effectively reduces organ motion for image-guided precision radiotherapy of lung tumors. However, the acquisition time of 3D cone-beam-CT (CBCT) exceeds maximum breath-hold times. We have developed an approach enabling online verification using CBCT image acquisition with ABC®-based breath-hold. Methods Patient CBCT images were acquired with ABC®-based repeat breath-hold. The clinical situation was also simulated with a Motion Phantom. Reconstruction of patient and phantom images with selection of free-breathing and breath-hold projections only was performed. Results CBCT-imaging in repeat breath-hold resulted in a precisely spherical appearance of a tumor-mimicking structure in the phantom. A faint "ghost" structure (free-breathing phases) can be clearly discriminated. Mean percentage of patient breath-hold time was 66%. Reconstruction based on free-breathing-only shows blurring of both tumor and diaphragm, reconstruction based on breath-hold projections only resulted in sharp contours of the same structures. From the phantom experiments, a maximal repositioning error of 1mm in each direction can be estimated. Discussion and Conclusion CBCT during repetitive breath hold provides reliable soft-tissue-based positioning. Fast 3D-imaging during one breath-hold is currently under development and has the potential to accelerate clinical linac-based volume imaging.

Introduction One method to overcome the problem of lung tumour movement in patients treated with radiotherapy is to restrict tumour motion with an active breathing control (ABC) device. This study evaluated the feasibility of using ABC in patients receiving radical radiotherapy for non-small cell lung cancer. Methods Eighteen patients, median (range) age of 66 (44–82) years, consented to the study. A training session was conducted to establish the patient’s breath hold level and breath hold time. Three planning scans were acquired using the ABC device. Reproducibility of breath hold was assessed by comparing lung volumes measured from the planning scans and the volume recorded by ABC. Patients were treated with a 3-field coplanar beam arrangement and treatment time (patient on and off the bed) and number of breath holds recorded. The tolerability of the device was assessed by weekly questionnaire. Quality assurance was performed on the two ABC devices used. Results 17/18 patients completed 32 fractions of radiotherapy using ABC. All patients tolerated a maximum breath hold time >15 s. The mean (SD) patient training time was 13.8 (4.8) min and no patient found the ABC very uncomfortable. Six to thirteen breath holds of 10–14 s were required per session. The mean treatment time was 15.8 min (5.8 min). The breath hold volumes were reproducible during treatment and also between the two ABC devices. Conclusion The use of ABC in patients receiving radical radiotherapy for NSCLC is feasible. It was not possible to predict a patient’s ability to hold breath. A minimum tolerated breath hold time of 15 s is recommended prior to commencing treatment.

A technique is presented to allow a breathing pattern to be obtained from any multi-slice CT, cone-beam or other series of sequential chest x-ray image sets. The technique requires no extra signals to be recorded and does not need specific external or internal oscillating structures to be visible in the field of view. The breathing pattern is instead acquired from analysing the variation in pixel values between projection images. For cone-beam image sets, slowly varying changes, due to an angular attenuation dependence, must be corrected before the breathing trace analysis can begin. All the results of the new technique were checked visually and were in good agreement. If the studied image set could be analysed using the existing 'Amsterdam shroud' technique, then the results it provided were also used for comparison. In cases that allowed comparison by both techniques, the results were in agreement. The new technique was also shown to provide a usable signal when applied to cardiac motion.

A simple method of simulating possible coded aperture phase contrast X-ray imaging apparatus is presented. The method is based on ray tracing, with the rays treated ballistically within a voxelized sample and with the phase-shift-induced angular deviations and absorptions applied at a plane in the middle of the sample. For the particular case of a coded aperture phase contrast configuration suitable for small animal pre-clinical imaging we present results obtained using a high resolution voxel array representation of a mathematically-defined ‘digital’ mouse. At the end of the article a link to the software is supplied.

Objectives: The aim of this article was to test a simple approach of using pixel density values from fluoroscopy images to enable gated radiotherapy. Methods: Anterior and lateral (LAT) from images were acquired from 18 patients referred for radical radiotherapy for non-small cell lung cancer for a period of 30–45 s. The amplitude of movement and the number of breathing cycles were determined in the right–left (RL) and superoinferior (SI) directions on the anterior images and the anteroposterior (AP) and SI directions on the lateral images. The breathing pattern was created by analysing the variation in a summation of pixel values within a defined area. The greatest and lowest 30% of pixel values were set as the duty cycle to represent inhale and exhale amplitude-based gating. Results: A median of eight breathing cycles was captured for each patient with a duration of 2.2–11.8 s per cycle. The mean (range) motion was 4.7mm (2.4–5.8 mm), 7.2mm (2.3–17.6 mm), 6.2mm (1.9–13.8 mm) and 4.8mm (2.4–11.3mm) in the RL, SI (AP), SI (LAT) and AP directions, respectively. A total of 10/14 anterior videos and 7/11 LAT videos had correlations between motion and breathing of .0.6. Margins of 5.5 mm, 6.8mm and 6.6mm in the RL, SI and AP directions, respectively, were determined to gate in exhale. The benefit of gating was greater when motion was .5 mm. Conclusion: The simple approach of using pixel density values from fluoroscopy images to distinguish inhale from exhale and enable gating was successfully applied in all patients. This technique may potentially provide an accurate surrogate for tumour position.

Scatter in a detector and its housing can result in image degradation. Typically, such scatter leads to a low-spatial frequency ‘glare’ superimposed on the primary signal. We infer the glare-spread function (GSF) of an amorphous-silicon flat-panel detector via an edge-spread technique. We demonstrate that this spread (referred to as ‘scatter-glare’ herein) causes a low-spatial frequency drop in the associated modulation-transfer function. This results in a compression of the range of reconstructed CT (computed tomography) numbers and is an impediment to accurate CT-number calibration. We show that it can also lead to visual artefacts. This explains previously unresolved CT-number discrepancies in an earlier work (Poludniowski et al 2009 Phys. Med. Biol. 54 3847). We demonstrate that after deconvolving the GSF from the projection images, in conjunction with a correction for phantom-scatter, the CT-number discrepancies disappear. We show results for an in-house-built phantom with inserts of tissue-equivalent materials and for a patient scan. We conclude that where scatter-glare has not been accounted for, the calibration of cone-beam CT numbers to material density will be compromised. The scatter-glare measurement method we propose is simple and requires no special equipment. The deconvolution process is also straightforward and relatively quick (60 ms per projection on a desktop PC).

A new technique is presented for obtaining breathing traces from any sequential planar X-ray image-set, such as that acquired during a cone-beam CT scan (CBCT). The technique is based on extracting a signal from the fast variations in summations of pixels values. The method has been tested against existing methods using patient data and verified using a breathing phantom. The advantage of this technique over existing methods is that it can be completed for any field of view.