Comparing Breast Conservation Surgery Seromas Contoured by Radiation Therapists versus those Contoured by a Radiation Oncologist in Radiation Therapy Planning for Early-Stage Breast Cancer

IntroductionIn the management of early-stage breast cancer using radiation therapy, computed tomography (CT) simulation is used to identify the breast conservation surgery (BCS) seroma as a proxy for the tumour bed. The delineation or contouring of the seroma is generally a task performed by a radiation oncologist (RO). With increasing patient numbers and other demands placed on ROs, the scope of practice for radiation therapists (RTs) is continually expanding, and the need for skills transfer from one profession to another has been investigated in recent years.This study aims to compare the BCS seroma volumes contoured by RTs with those contoured by ROs to add evidence in support of expanding the RTs' role in the treatment planning process in the management of early-stage breast cancer.MethodsA study was undertaken using the CT-simulation (CT-sim) data sets of patients with early-stage breast cancer treated in 2013. The CT-sim data sets had BCS seromas contoured by 1 of 5 ROs as part of routine clinical management. This study involved 4 RTs who each used the patient information to identify and contour breast seromas on 50 deidentified CT-sim data sets. Metrics used to compare RT versus RO contours included volume size, overlap between volumes, and geographical distance from the centre of volumes.ResultsThere were 50 CT-sim data sets with 1 RO contour and 4 RT contours analysed. The contour volumes of the 4 RTs and the ROs were assessed. Although there were 50 CT-sim data sets presented to each RT, analysis was carried out on 45, 43, 46, and 45 CT-sim data sets. There were no comparisons made where contours were not delineated. The contour volumes of the 4 RTs and the ROs were assessed with an interclass correlation coefficient, with a result of excellent reliability (0.975, 95% [0.963, 0.985]). The DICE similarity coefficient was used to compare the overlap of each RT contour with the RO contour; the results were favourable with mean (95% CI) DSCs 0.685, 0.640, 0.678, and 0.681, respectively. Comparing the RT and RO geographical centre of the seroma volumes, good to excellent reliability between the RTs and ROs was demonstrated (95% CI mean RO vs RT distances (mm): 3.75, 4.99, 7.71, and 3.39). There was no statistically significant difference between the distances (P = 0.65).ConclusionBCS seromas contoured by RTs compared well with those contoured by an RO. This research has provided further evidence to support RTs in assuming additional contouring responsibilities in radiation therapy planning for patients with early-stage breast cancer.     

Evaluating the Effectiveness of an Electronic Learning Tool for Volumetric Imaging Training—Perceptions of Radiation Therapy Professionals

PurposeDaily volumetric imaging through cone-beam computed tomography (CBCT) has greatly impacted the roles and responsibilities of radiation therapists (RTTs). A CBCT eLearning module was developed at our cancer centre to equip RTTs with critical thinking skills and clinical judgement required in a CBCT guidance environment. This study aims to evaluate the effectiveness of the electronic module and its impact on the learner's outcome from the perspectives of various radiation therapy professions and to assess the applicability of the eLearning module to RTTs, oncologists, and physicists.Methods and MaterialsThe module “Myths in Cone-Beam Computed Tomography Practice” was evaluated by participants from our in-house accelerated education program. A 21-item questionnaire was developed to assess the module effectiveness. Two cohorts of attendees from the in-house accelerated education program (19 oncologists, 14 physicists, 14 therapists) were asked to voluntarily complete the survey following review of the module. Data analyses were performed between groups to determine differences in their perceptions.ResultsTwenty-one participants (5 oncologists, 3 physicists, 13 therapists) responded to the survey yielding a response rate of 44.68%. Survey responses indicate learners found the format user friendly, clear, and easy to navigate. All participants agreed that the electronic format of this module is conducive to learning with 60% agreement that this module is more useful than live sessions; 94.74% agreed that the module increases confidence in practicing image-guided radiation therapy.ConclusionsThis module is a useful resource for all disciplines of radiation medicine. While the electronic format of this module may be useful worldwide in centres requiring training of their employees in volumetric image-guided radiation therapy, live interactive sessions should supplement this training.     

An Investigation of the Feasibility and Utility of a Low-dose Cone-beam Computed Tomography Scan Protocol for Head and Neck Cancer Patients

IntroductionRoutine use of cone-beam computed tomography (CBCT) scan protocols as part of the image guidance process (image-guided radiation therapy) has become an integral part of the practice of radiation therapists (RTs). Concerns regarding imaging dose as well as increased in-room time for patients led to reluctance among site group members to adopt CBCT for all radical head and neck cancer (HNC) patients at our institution. This investigation set out to assess the feasibility and utility of a revised CBCT scan protocol with the aim of supporting daily CBCT for HNC patients receiving radiation therapy.MethodsThe project was performed in three phases. Phase 1 involved the experimental adjustment of CBCT scan protocol parameters in clinical use for HNC patients at our institution. An Elekta Synergy linear accelerator with kilovoltage CBCT capability and a RANDO head phantom were used for scan acquisition procedures. Image registration using bony anatomy was performed on two image sets generated using the current clinical scan protocol (HNS20) and an experimental modified scan protocol (MHNS20). Image registration results were compared by two investigators. Measurements of scan doses using a metal–oxide–semiconductor field-effect transistor and a Unidose meter were performed. Catphan phantom images were acquired using HNS20 and MHNS20 protocols. In phase 2, ten volunteer RTs performed image registration and matching processes on two image sets performed using HNS20 and MHNS20 protocols. RTs were unaware of the scan protocols used for image acquisition. A threshold of 3 mm was set (the current maximum couch shift allowance in the clinical HNC IGRT protocol) to compare the image registration data from HNS20 and MHNS20. In phase 3, after research ethics board approval, 10 HNC patients consented to the study. Two pretreatment CBCT scans were performed: scan 1 was acquired using MHNS20 protocol, and scan 2 was acquired using the HNS20 protocol. A threshold of 2 mm was set to compare the differences in couch shift data resulting from the image registration of the two image sets. Comparison of HNS20 and MHNS20 based on image registration results was performed.ResultsIn phase 1, radiation doses measured by the investigators on the left optical lens using a metal–oxide–semiconductor field-effect transistor and a Unidose meter indicated that the MHNS20 protocol would result in a lower dose to the left optical lens. In phase 2, shifts of the treatment table to achieve the planned isocentre, which were recorded after the image matching process, were within 3 mm in 80% of the RT procedures. In the y-axis (superior/inferior direction), 100% of the procedures were within 3 mm. In the z-axis (anterior/posterior) and x-axis (lateral), 90% of the procedures were within 3 mm. Qualitative data from a questionnaire completed by RTs after the image matching indicated that 50% of the RTs had no preference between the images sets in terms of visibility of structures. Forty percent of RTs had no preference regarding speed of matching or preference for registration between the image sets. When a preference was indicated, the HNS20 scan protocol was chosen by the RTs. In phase 3, couch shift data recorded after each CBCT scan were compared. All results in all three planes for 10 patients included in the study were within the 2-mm threshold.ConclusionsThe feasibility and clinical utility of a potential lower-dose CBCT scan protocol has been investigated. The modified protocol (MHNS20) produced image data acceptable within current practice using bony anatomy for registration purposes. The MHNS20 protocol also delivered lower doses to the left optical lens and therefore potentially to other pertinent structures. The actual delivered doses to patients during IGRT procedures using the MHNS20 may be different than those measured during this investigation.     

Development and Implementation of an Electronic Learning Module for Volumetric Image-Guided Radiation Therapy

BackgroundImage-guided radiation therapy (IGRT) through daily cone-beam computed tomography (CBCT) has significantly impacted the role of the radiation therapist at our institution; continuing education is crucial to ensure safe practice of technology in the clinical environment. The purpose of this work was to develop and implement an electronic learning (eLearning) module as a yearly refresher for CBCT-practicing radiation therapists.MethodsTo provide an innovative interface to engage the learner's interest, a module themed “Myths in Cone Beam Computed Tomography Practice” was developed by content experts at our institution. The eLearning tool focused on the technical aspects and fundamental theory of CBCT acquisition, with an aim to refresh the user's knowledge and confidence in image fusion and assessment. Ten myths were identified in the module and evidence-based content was referenced within each myth to support theory. Evaluation of the learner was performed through a multiple choice quiz at the end of the module. The tool and 12 multiple choice questions were reviewed and validated by subject matter and non–subject matter experts in CBCT–IGRT before departmental implementation.ResultsThe CBCT eLearning module has been clinically implemented and used over the last 3 years by radiation therapists in our department. Completion of the tool is an annual mandatory requirement for CBCT-practicing therapists; over 100 participants completed the module per year. The median time for module completion decreased over the 3-year interval, from 42 minutes 25 seconds during the first year of implementation to 20 minutes and 48 seconds in the third year.ConclusionsAn electronic online training tool for CBCT refresher training has been developed and implemented at our institution, with an aim to equip staff with the critical thinking skills and clinical judgment required to operate in a CBCT–IGRT environment. The module's format ensures delivery of consistent information as a component of yearly continuing education for radiation therapists.     

Role Development for Radiation Therapists: An Examination of the Computed Tomographic Simulation Procedure for Patients Receiving Radiation Therapy for Breast Cancer

PurposeThis study investigated the role of radiation therapists (RTs) in the computed tomographic (CT) simulation procedure for patients receiving radiation therapy for breast cancer at a large comprehensive cancer clinic. RTs had developed a “hybrid role” whereby they practiced autonomously during a “therapist-led CT simulation.” As well as CT scanning, RTs assessed the images, performed isocentre and field placement, and contoured the organs at risk in preparation for dosimetrists to optimize the dose distribution. A comparison between the confidence of the radiation oncologists (ROs) in delegating tasks to RTs for this procedure was compared with the RTs' confidence (self-assessed) in performing the task. Changes to the patient's plan after the CT procedure were recorded to examine the level of autonomy that was achieved as well as to identify areas for the development of RT skill, knowledge, and judgment.MethodsA prospective mixed method two phase study was performed. In phase 1, seven key areas of critical tasks performed by RTs in the CT simulation procedure were identified and documented by the study population. Changes made to these critical tasks after CT simulation was complete were categorized. Responsibility for the changes (RT or RO), the presence of the RO at the CT simulation, and other issues were documented. In phase 2, surveys were distributed to ROs and RTs to rank their confidence levels of RTs performing the identified critical tasks during the CT simulation.ResultsFor phase 1, 330 CT simulation cases for breast cancer over a 4-month period were documented. Eighty-four percent of cases remained unchanged and were approved by the RO; the majority of changes were initiated by a second more experienced RT. The majority of changes were related to cardiac coverage for left-sided patients (4.8%) and scar coverage (3.3%). ROs were present for 42% of the cases. For phase 2, 9 RO surveys (75% response) and 21 RT surveys (81% response) were returned. The majority of ROs and RTs agreed that they had confidence in RTs' abilities to perform the identified critical tasks. Factors that influenced RTs' confidence were complexity of the patient; self-confidence; and experience of the RT, RO practice preferences, and RT training availability and consistency.ConclusionsRTs have achieved a level of autonomy in their practice illustrated in the CT simulation process for breast cancer patients. This may be expanded with continued training and education. Formal mentoring relationships in CT simulation may aid in knowledge development. Enhanced communication between ROs and RTs will improve the process. This will enable RTs to provide a more efficient process and better patient care through improvements to continuity, flow, and quality.     

Therapeutic Radiographers at the Helm: Moving Towards Radiographer-Led MR-Guided Radiotherapy

IntroductionMagnetic resonance–guided adaptive radiotherapy (MRgART) has the potential to improve treatment processes and outcomes for a variety of tumour sites; however, it requires significant clinical resources. Magnetic resonance linear accelerator (MR-linac) treatments require a daily multidisciplinary presence for delivery. To facilitate sustainable MRgART models, agreed protocols facilitating therapeutic radiographer (RTT)-led delivery must be developed to establish a service similar to conventional image-guided radiotherapy (IGRT). This work provides a clinical perspective on the implementation of a protocol-driven ‘clinician-lite’ MRgART workflow at one institution.MethodsTo identify knowledge, skills, and competence required at each step in the MRgART workflow, an interdisciplinary informal survey and needs assessment were undertaken to identify additional or enhanced skills required for MRgART, over and above those required for conventional cone-beam computed tomography–based IGRT. The MRgART pathway was critically evaluated by relevant professionals to encourage multidisciplinary input and discussion, allowing an iterative development of the RTT-led workflow. Starting with the simplest online adaptation strategy, consisting of a virtual couch shift and online replanning, clear guidelines were established for the delivery of radical prostate radiotherapy with a reduction in staff numbers present.ResultsThe MRgART-specific skills identified included MRI safety and screening, MR image acquisition, MRI-based anatomy, multimodality image interpretation and registration, and treatment plan evaluation. These skills were developed in RTTs via tutorials, workshops, focussed self-directed reading, teaching of colleagues, and end-to-end workflow testing. After initial treatments and discussions, roles and responsibilities of the three professional groups (clinicians, RTTs, and physicists) have evolved to achieve a ‘clinician-lite’ workflow for simple radical prostate treatments.DiscussionThrough applying a definitive framework and establishing agreed threshold and action levels for action within anticipated treatment scenarios similar to those in cone-beam computed tomography–based IGRT, we have implemented a ‘clinician-lite’ workflow for simple adaptive treatments on the MR-linac. The responsibility for online plan evaluation and approval now rests with physicists and RTTs to streamline MRgART. Early evaluation of the framework after treatment of 10 patients has required minimal online clinician input (1.5% of 200 fractions delivered).ConclusionA ‘clinician-lite’ prostate treatment workflow has been successfully introduced on the MR-linac at our institution and will serve as a model for other tumour sites, using more complex adaptive strategies. Early indications are that this framework has the potential to improve patient throughput and efficiency. Further identification and validation of roles and responsibilities such as online contouring, and more interactive online planning, will facilitate RTTs to fully lead in the online workflow as adaptive radiotherapy becomes ever more complex.     

宫颈癌患者锥形束CT影像剂量计算的算法修正

目的 利用修正算法对宫颈癌患者锥形束CT（CBCT）影像进行修正,探讨CBCT影像剂量计算的准确性。方法 采用CIRS-062电子密度模体分别在Brilliance CT Big Bore 4D-CT模拟定位机及Truebeam加速器机载CBCT上执行CT扫描,获得计划CT（pCT）和CBCT的CT值-相对电子密度曲线。采用直方图匹配算法对CBCT影像的CT值进行修正,得到修正后的CBCT（mCBCT）。将25例宫颈癌患者的调强放疗计划分别移植到模体和患者的pCT、CBCT和mCBCT上进行剂量计算,比较其绝对剂量和剂量分布的差异。结果 模体等中心处,CBCT计算的绝对剂量与pCT计算的绝对剂量偏差为0.87%±0.24%,mCBCT与pCT的偏差为0.05%±0.03%,差异有统计学意义（t=3.625,P<0.05）。患者治疗等中心处,CBCT计算的绝对剂量与pCT计算的绝对剂量偏差为1.05%±0.32%,mCBCT与pCT的偏差为0.18%±0.09%,差异有统计学意义（t=3.023,P<0.05）。靶区剂量分布的剂量体积图显示,mCBCT的剂量分布和pCT的剂量分布相似,而CBCT的剂量分布和pCT的剂量分布差异较明显。结论 CBCT影像经算法修正后,可用于宫颈癌放疗中的剂量计算,并能提高剂量计算的准确性。     

Examining the Effectiveness of Action Plans Derived from the Root Cause Analysis of Incidents Occurring in a Radiation Therapy Department

PurposeIn 2011, the Canadian Partnership for Quality Radiotherapy developed guidelines for quality improvement. In the same year, a large academic cancer centre initiated a program of root cause analysis (RCA) and incident learning for major incidents. RCAs were performed on seven incidents; more than 40 action items were developed with the intent to prevent these incidents from recurring. The aim of this study was to determine the efficacy of implementation of the six action items, evaluate radiation therapists' (RTTs') awareness of these new action items, and determine whether communication among staff members was satisfactory.Methods and MaterialsThe study consisted of two components. Part one examined four action items using a questionnaire distributed to all RTTs at the cancer centre. Part two examined two action items by auditing the radiation treatment software, MOSAIQ.ResultsStaff communication and RTTs' awareness of the action items ranged from 71% to 98%. For the first four action items, although most RTTs were aware of them, only 40%–70% of RTTs always or often used these action items and considered them effective. The fifth action item, implementation of the new breast tolerance setting, had 51% more overrides after implementation. Further investigation indicated only 40% of the tangent breast setups had new tolerance settings applied.ConclusionsCommunication plays an important role in the dissemination and application of interventions identified from an RCA. A standardized route of communication is required to ensure that all RTTs fully understand an action item. A follow-up program and continuous monitoring of the action items are key to an effective RCA program.     

The Feasibility of Telephone Follow-up Led by a Radiation Therapist: Experience in a Multidisciplinary Bone Metastases Clinic

Telephone follow-up may be a useful tool for outcome assessment in the palliative population, eliminating the need for repeated travel compared with conventional clinical follow-up. The aim of this study was to determine the feasibility of telephone follow-up performed by a radiation therapist (RTT) for patients treated in a multidisciplinary palliative radiotherapy (RT) bone metastases clinic. After training by a nurse practitioner (NP) and radiation oncologist (RO), the RTT performed telephone follow-up for the Rapid Access Palliative Radiotherapy Program Bone Metastases Clinic at the Cross Cancer Institute. Follow-up calls were made to patients at 1 and 4 weeks after completion of palliative RT. Symptoms were evaluated with the Edmonton Symptom Assessment Scale (ESAS). Patient feedback, RTT comfort level with each call and the number of times the RTT needed input from the NP or RO regarding patient management was recorded. Feasibility of telephone follow-up was determined by the percentage of patients who were successfully contacted at the 1- and 4-week periods, the number of patients completing assessments, the number of times that RO or NP input was required, patient feedback, RTT comfort level, and NP and RO feedback. Between February 2 and July 20, 2009, 30 of 53 patients (57%) were contacted at the 1-week follow-up, and 26 (49%) were contacted at the 4-week follow-up. Overall, 72% of patients completed the telephone assessment at 1 or 4 weeks. The RTT required input from the RO or NP for four patients. Patient, NP and RO feedback was positive, and RTT comfort level was high. RTT-led telephone follow-up is a feasible approach for follow-up among patients who have received palliative RT. Future directions include implementation of RTT-led follow-up as part of routine care in the RAPRP and development of RTT capacity in other clinical RT settings.     

A Feasibility Study on the Identification of Postlumpectomy Seromas by a Radiation Therapist Compared with That by Radiation Oncologists in Radiation Therapy Planning for Early Stage Breast Cancer

IntroductionComputed tomography (CT) simulation is currently used to identify the tumour bed in patients with early stage breast cancer requiring whole-breast and boost radiation therapy. Postlumpectomy breast seromas as visible on CT data have been identified as a proxy for the tumour bed. This study aims to quantify the incidence of postsurgical tumour bed seromas identified at CT simulation and report how well a radiation therapist (RT) is able to identify these seromas compared with those contoured by radiation oncologists (ROs).Methods and MaterialsA study was undertaken on electronic patient records and the CT-simulation datasets of early stage breast cancer patients treated in 2013 at the Calvary Mater Newcastle to identify the presence of seromas. Patient and tumour characteristics were reviewed. Data analysed included seroma volumes, as contoured by the ROs, as part of the standard voluming procedure. One RT rated seroma visibility based on the level of difficulty when viewing the seroma.ResultsOut of 108 CT datasets, an RT was able to identify the presence of a seroma in 102 cases vs. 104 as contoured by ROs. The number of observed agreements was 106 (98.15% of the observations), and the number of agreements expected by chance was 98.4 (91.15% of the observations). The Kappa statistics equalled 0.791 (SE of kappa = 0.143). The strength of agreement is considered to be “substantial.”ConclusionRTs play an integral role in contouring during the planning process, and there is scope to expand this role. This research introduced the first step by confirming that a radiation therapist is able to identify seromas on CT-simulation data when compared those contoured by an RO.     

The Impact of Correcting for Translational and Rotational Errors Using the HexaPOD in Head and Neck Stereotactic Body Radiation Therapy Patients

BackgroundThe HexaPOD has been developed to correct for errors in six degrees of freedom (6DOF), which enables it with the potential to improve setup accuracy. This is critical in hypofractionated head and neck (H&N) stereotactic body radiation therapy (SBRT) plans, which have highly conformal dose distributions and close proximity of critical normal structures.PurposeThe purpose of the study was to investigate whether using the HexaPOD to correct for error in 6DOF will increase setup accuracy for H&N SBRT patients.Methods and MaterialsFor each of the 20 SBRT H&N patients in this study, two sets of global computed tomography scans and cone beam computed tomography matches were performed for the first and last fraction of each patient's treatment. One of the global matches included corrections for rotations and the other did not. Next, sub-regions of interest, based on bony landmarks, were identified for each patient and local registrations were performed to match these sub-regions of interest to determine local sub-region errors in the global registration. The differences in local error, with and without rotations, were examined to determine whether the residual local setup errors were significantly different.ResultsT-test results demonstrate a statistically significant difference in local error when correcting for rotations vs. not, in all 6DOF. When examining the actual magnitude of residual error reduction using three-dimensional vectors of the average translational differences, an average reduction of 0.9 mm is observed when 6DOF corrections are applied.ConclusionsResidual setup errors in each of the 6DOF were statistically significant; however, the magnitude depicts a very small reduction in residual error <1 mm. Clinically, this makes a very small difference because the planning target volume (PTV) presumably covers an expansion of 3–5 mm.     

Investigating opinions of,and perceptions to,advanced practice radiation therapist roles

IntroductionThe demand for cancer services is growing due to increased incidence and the number of people who survive their initial diagnosis but require ongoing therapy. One method of increasing capacity in radiation oncology is to delegate tasks from one professional group to another. In the last ten years there has been increasing interest in advanced practice radiation therapist (APRT) roles. The majority of the Australian literature relates to metropolitan radiation oncology centres with a paucity of information from regional or rural settings. This study sought to explore the knowledge of, and attitudes to APRT roles of members of three professional groups in public radiation oncology centres in Tasmania.MethodData was collected through a self-reported online survey from radiation oncologists (RO), radiation oncology medical physicists (ROMP) and radiation therapists (RT) working in Tasmanian public radiation oncology services regarding their knowledge and understanding of APRT roles, acceptance and support for the roles and where APRTs could contribute to improving patient care. The survey incorporated a combination of five point Likert scale, Yes/No/Don't know and Yes/No/Not Applicable choices. The survey was reviewed by a professional panel of RT, RO and ROMP from mainland Australian radiation oncology centres.ResultsAt the time of survey invitation, there were 52 RTs, 7 ROs, and 7 ROMPs working in the identified departments. The survey had an overall response rate of 48.5%with profession specific response rates of 48.1% (RT), 42.9% (RO) and 57.1% (ROMP). General agreement was found amongst survey respondents with regards to understanding of APRT roles having themes of clinical expertise, leadership, communication, collaboration and teaching. Where participants were offered a list of tasks to choose those appropriate to APRT roles, the highest agreement was with “Contour organs at risk per protocol”, “Image review – soft tissue online decision making/adaptive RT” and “Principal investigator in clinical research. The notion of establishing ARPT roles was well supported, as strong agreement was found with the statements related to improvement in job satisfaction, opportunities, recruitment and retention for RTs, and that APRTs could be used to relieve workload of other professionals.ConclusionThis exploratory study found that the respondents were generally in favour of APRT roles, but that they were not clear about the tasks to be performed by APRTs. It was identified that patients, ROs, ROMPs, RTs and the department would benefit from the implementation of APRT roles. Sseveral areas of practice were identified by respondents which they perceived would improve the quality of patient care     

直线加速器机载锥形束CT图像散射的修正方法

目的 对直线加速器机载锥形束CT(CBCT)散射修正方法进行研究.方法 在CBCT射线源前放置一个"指交叉"形的阻挡光栅,对Catphan 504模体进行扫描,分别获得CBCT图像和扇形束CT图像.利用基于阈值的图像分割算法跟踪机架旋转过程中阻挡光栅在CBCT图像中的位置,提取散射样本后利用插值法估计散射信号分布,采用改进的半扇扫描重建算法重建散射修正后的图像.结果 散射修正后的Catphan 504模体图像与扇形束CT重建的图像接近.与散射修正前比较,散射修正后CT值误差从100.86 HU下降到15.74 HU,散射修正后低对比度分辨力平均提高1.37倍.结论 基于阈值的图像分割算法准确跟踪阻挡光栅的位置,在铅片区域可采集散射信号,其余区域可通过改进的半扇扫描算法完成单次扫描的图像重建.     

Automated Delineation of the Normal Urinary Bladder on Planning CT and Cone Beam CT

PurposeTo quantify the volumetric effect of delineation variability when using manual versus semiautomated tools to contour the normal bladder on planning computed tomography (CT) and cone beam CT.MethodsFollowing research ethics board approval, 10 prostate cancer patients were selected. For each patient, one pretreatment cone beam CT (CBCT) was randomly selected from the first treatment week and registered to the planning CT (planCT). Model-based auto adaptation was used to delineate the outer bladder (OB) surface for the planCT. That contour was then propagated and manually adapted onto the CBCT. A second observer delineated OB for the planCT and CBCT using typical manual methods. These delineation procedures were repeated four times on each image set, with observers blinded to the previous contours. Metrics of volumetric, geometric, and overlap concordance were used to compare the manual and automated OB contours.ResultsThe mean pairwise difference between the manual and model-based planCT volumes was 4 cm³ (2%), and the model-based contours exhibited approximately half the observer variation of the manual ones (3 cm³, 2%). The mean of pairwise differences between the manual and propagated CBCT volumes was 13 cm³ (8%), but the propagated contours exhibited approximately half the observer related volume variation (11 cm³, 6%). Small CBCT bladder volumes displayed larger observer variation with manual methods (r², −0.640). Variability between the automated contours was significantly smaller than for the corresponding manual observations (P = .004 and .002, respectively). Metrics of three-dimensional overlap concordance indicated excellent agreement within and between the delineation methods. Automated CBCT contours were significantly smoother than the manual ones (surface sphericity index, 1.29 vs. 1.35; P = .03).ConclusionsVolumetric, geometric, and overlap metrics all indicated that planCT and CBCT automated OB contours fell within the range of manually delineated contours. The CBCT propagated contours were significantly smoother and associated with smaller intraobserver variability, compared with manual contours. Importantly, the findings from this research suggest that contour propagation may be more robust than manual delineation, especially in the presence of poor image quality.     

Occupational burnout among radiation therapy technologists in Italy before and during COVID-19 pandemic

IntroductionRadiation therapy technologists (RTTs) are exposed to high stress levels which may lead to burnout, which could be further increased by the current pandemic. The aim of our study was to assess burnout and stress among Italian RTTs before and during the pandemic.MethodsThe Italian Association of Radiation Therapy and Medical Physics Technologists (AITRO) and the Italian Federation of Scientific Radiographers Societies (FASTeR) proposed a national online survey, including the Maslach Burnout Inventory assessing emotional exhaustion (EE), depersonalisation (DP), and personal accomplishment (PA) to RTTs before and during the pandemic. Multivariate regression analyses and χ² tests were used for data analysis.ResultsWe obtained 367 answers, 246 before and 121 during the pandemic. RTTs before and during the pandemic showed high EE and DP, intermediate PA. Median EE was 37 (interquartile range [IQR] 31–46] before and 37 (IQR 30–43) during the pandemic, median DP was 16 (IQR 13–21) and 15 (IQR 12–20), respectively. PA was 31 (IQR 28–34) and 32 (IQR 28–34), respectively. Through multivariate analysis, being female and having children led to higher EE scores before and during the pandemic (p≤0.026). Only the presence of workplace stress management courses was related to lower DP before and being female was related to higher DP during the pandemic (p<0.001). Being female, having children, and working with paediatric patients were related to lower PA before and during the pandemic (p≤0.015).ConclusionOur study highlighted high burnout levels for RTTs regardless of the pandemic. Future interventions aimed at preventing burnout should be implemented in their work environment, independently of the impact of exceptional events.     

联合ExactTrac X-Ray与Cone Beam CT在NSCLC-SBRT中的应用分析

目的探讨应用ExactTrac x-Ray(ETX)与Cone Beam CT(CBCT)分析非小细胞肺癌立体定向放疗(NSCLC-SBRT)中分次间及分次内的误差差异。方法随机选取22例行SBRT的NSCLC患者,所有患者治疗前行CBCT扫描,图像配准范围为肺部肿块并兼顾胸腔轮廓与脊柱等骨性标记,获得移位误差后进行修正并开始治疗。在治疗开始及结束分别选择0°与1800进行2次ETX拍片验证(ETX-0,etx-180),从而获得分次内移位误差,图像配准范围为胸腔轮廓及脊柱等骨性标志。CBCT获得图像与定位CT图像配准得到左右(X)、上下(Y)、前后(Z)方向的平移误差和绕前后(R)方向的旋转误差,ETX拍摄获得双斜位片,与计划DRR配准后得到平移误差和旋转误差,记录两种验证方式的移位误差值,对CBCT及ETX验证进行组间配对t检验。结果分次间CBCT扫描在X、Y、Z、R方向的平均移位误差分别为(0.38±0.26)cm,(0.49±0.37)cm,(0.32±0.19)cm,(0.85±0.60)cm。分次内在X与Y方向,ETX_180较ETX_0平均移位误差分别增加21.7%与19.2%,且差异有统计学意义(P<0.05),在Z与R方向,ETX验证间差异无统计学意义(P>0.05)。结论NSCLC-SBRT分次间行CBCT图像引导能明显减少摆位误差,分次内行ETX拍片验证能有效监测单个治疗过程中的移位误差,提高治疗精度。     

基于条状挡板的kV级锥形束CT散射校正

目的 校正锥形束CT投影中的散射信号,以提高图像质量。 方法 使用条状挡板测量Varian机载kV级锥形束CT投影图像中的散射信号,并将其从再次扫描的投影中扣除,以获得原始射线的投影图像。使用空域自适应的BayesShrink小波对投影图像进行去噪处理,并导入Varian On Board Imager工作站进行重建;比较处理前后的图像质量。 结果 校正后图像的低对比度分辨力提高,噪声降低,CT值的准确性和均匀性得到改善。 结论 条状挡板能准确获取投影图像中的散射信号;扣除散射信号后使用小波阈值法去噪,可有效提高图像质量。     

Acupuncture for treatment of insomnia: An overview of systematic reviews

PurposeTo evaluate the reliability of the methodological quality and outcome measures of systematic review (SR) /meta-analysis (MA) of acupuncture for insomnia.MethodsWe conducted a comprehensive literature search for SRs with MAs in seven international and Chinese databases. Two reviewers independently extracted data and assessed the methodological quality of the reviews according to the Assessing the Methodological Quality of Systematic Reviews 2 (AMSTAR-2), the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to rate the quality of evidence.ResultsThirty-four reviews were included. The AMSTAR-2 score showed that most of the included studies were of low methodological quality and included only two high-quality literatures. The lowest score were the item 10 (all the studies didn't report on the sources of funding for the studies included in the review), item 7(32 studies didn't provide a list of excluded studies and justify the exclusions) and item 3 (27 studies didn't explain their selection of the study designs for inclusion in the review).ConclusionMost of the reviews included suggested that the acupuncture group was more effective than the control group in the treatment of insomnia, but the methodological quality of most of the studies and the quality of evidence were low.