HDR brachytherapy in vivo source position verification using a 2D diode array: A Monte Carlo study.

PURPOSE: This study aims to assess the accuracy of source position verification during high-dose rate (HDR) prostate brachytherapy using a novel, in-house developed two-dimensional (2D) diode array (the Magic Plate), embedded exactly below the patient within a carbon fiber couch. The effect of tissue inhomogeneities on source localization accuracy is examined. METHOD: Monte Carlo (MC) simulations of 12 source positions from a HDR prostate brachytherapy treatment were performed using the Geant4 toolkit. An Ir-192 Flexisource (Isodose Control, Veenendaal, the Netherlands) was simulated inside a voxelized patient geometry, and the dose deposited in each detector of the Magic Plate evaluated. The dose deposited in each detector was then used to localize the source position using a proprietary reconstruction algorithm. RESULTS: The accuracy of source position verification using the Magic Plate embedded in the patient couch was found to be affected by the tissue inhomogeneities within the patient, with an average difference of 2.1 ± 0.8 mm (k = 1) between the Magic Plate predicted and known source positions. Recalculation of the simulations with all voxels assigned a density of water improved this verification accuracy to within 1 mm. CONCLUSION: Source position verification using the Magic Plate during a HDR prostate brachytherapy treatment was examined using MC simulations. In a homogenous geometry (water), the Magic Plate was able to localize the source to within 1 mm, however, the verification accuracy was negatively affected by inhomogeneities; this can be corrected for by using density information obtained from CT, making the proposed tool attractive for use as a real-time in vivo quality assurance (QA) device in HDR brachytherapy for prostate cancer.

HDR brachytherapy afterloader quality assurance optimization using monolithic silicon strip detectors.

BACKGROUND: There currently exists no widespread high dose-rate (HDR) brachytherapy afterloader quality assurance (QA) tool for simultaneously assessing the afterloader's positional, temporal, transit velocity and air kerma strength accuracy. PURPOSE: The purpose of this study was to develop a precise and rigorous technique for performing daily QA of HDR brachytherapy afterloaders, incorporating QA of: dwell position accuracy, dwell time accuracy, transit velocity consistency and relative air kerma strength (AKS) of an Ir-192 source. METHOD: A Sharp ProGuide 240 mm catheter (Elekta Brachytherapy, Veenendaal, The Netherlands) was fixed 5 mm above a 256 channel epitaxial diode array 'dose magnifying glass' (DMG256) (Centre for Medical and Radiation Physics, University of Wollongong). Three dwell positions, each of 5.0 s dwell times, were spaced 13.0 mm apart along the array with the Flexitron HDR afterloader (Elekta Brachytherapy, Veenendaal, The Netherlands). The DMG256 was connected to a data acquisition system (DAQ) and a computer via USB2.0 link for live readout and post-processing. The outputted data files were analyzed using a Python script to provide positional and temporal localization of the Ir-192 source by tracking the centroid of the detected response. Measurements were repeated on a weekly basis, for a period of 5 weeks to determine the consistency of the measured parameters over an extended period. RESULTS: Using the DMG256 for relative AKS measurements resulted in measured values within 0.6%-3.0% of the expected activity over a 7-week period. The sub-millisecond temporal accuracy of the device allowed for measurements of the transit velocity with an average of (10.88 ± 1.01) cm/s for 13 mm steps. The dwell position localization for 1, 2, 3, 5, and 10 mm steps had an accuracy between 0.1 and 0.3 mm (3σ), with a fixed temporal accuracy of 10 ms. CONCLUSION: The DMG256 silicon strip detector allows for clinics to perform rigorous daily QA of HDR afterloader dwell position and dwell time accuracy with greater precision than the current standard methodology using closed circuit television and a stopwatch. Additionally, DMG256 unlocks the ability to perform measurements of transit velocity/time and relative AKS, which are not possible using current standard techniques.

Development of patient and catheter specific error thresholds for high dose rate prostate brachytherapy.

BACKGROUND: In-vivo source tracking has been an active topic of research in the field of high-dose rate brachytherapy in recent years to verify accuracy in treatment delivery. Although detection systems for source tracking are being developed, the allowable threshold of treatment error is still unknown and is likely patient-specific due to anatomy and planning variation. PURPOSE: The purpose of this study was to determine patient and catheter-specific shift error thresholds for in-vivo source tracking during high-dose-rate prostate brachytherapy (HDRPBT). METHODS: A module was developed in the previously described graphical processor unit multi-criteria optimization (gMCO) algorithm. The module generates systematic catheter shift errors retrospectively into HDRPBT treatment plans, performed on 50 patients. The catheter shift model iterates through the number of catheters shifted in the plan (from 1 to all catheters), the direction of shift (superior, inferior, medial, lateral, cranial, and caudal), and the magnitude of catheter shift (1-6 mm). For each combination of these parameters, 200 error plans were generated, randomly selecting the catheters in the plan to shift. After shifts were applied, dose volume histogram (DVH) parameters were re-calculated. Catheter shift thresholds were then derived based on plans where DVH parameters were clinically unacceptable (prostate V100 < 95%, urethra D0.1cc > 118%, and rectum Dmax > 80%). Catheter thresholds were also Pearson correlated to catheter robustness values. RESULTS: Patient-specific thresholds varied between 1 to 6 mm for all organs, in all shift directions. Overall, patient-specific thresholds typically decrease with an increasing number of catheters shifted. Anterior and inferior directions were less sensitive than other directions. Pearson's correlation test showed a strong correlation between catheter robustness and catheter thresholds for the rectum and urethra, with correlation values of -0.81 and -0.74, respectively (p < 0.01), but no correlation was found for the prostate. CONCLUSIONS: It was possible to determine thresholds for each patient, with thresholds showing dependence on shift direction, and number of catheters shifted. Not every catheter combination is explorable, however, this study shows the feasibility to determine patient-specific thresholds for clinical application. The correlation of patient-specific thresholds with the equivalent robustness value indicated the need for robustness consideration during plan optimization and treatment planning.

Viability of focal dose escalation to prostate cancer intraprostatic lesions using HDR prostate brachytherapy.

PURPOSE: This study aimed to determine the viability of focal dose escalation to prostate cancer intraprostatic lesions (IPLs) from multiparametric magnetic resonance (mpMRI) and prostate-specific membrane antigen positron emission tomography (PSMA-PET) images using high-dose-rate (HDR) prostate brachytherapy (pBT). METHODS AND MATERIALS: Retrospective data from 20 patients treated with HDR pBT was utilized. The interobserver contouring variability of 5 observers was quantified using the dice similarity coefficient (DSC) and mean distance to agreement (MDA). Uncertainty in propagating IPL contours to trans-rectal ultrasound (TRUS) was quantified using a tissue equivalent prostate phantom. Feasibility of incorporating IPLs into HDR pBT planning was tested on retrospective patient data. RESULTS: The average observer DSC was 0.65 (PSMA-PET) and 0.52 (mpMRI). The uncertainty in propagating IPL contours was 0.6 mm (PSMA-PET), and 0.4 mm (mpMRI). Uncertainties could be accounted for by expanding IPL contours by 2 mm to create IPL PTVs. The mean D98% achieved using HDR pBT was 166% and 135% for the IPL and IPL PTV contours, respectively. CONCLUSIONS: Focal dose escalation to IPLs identified on either PSMA-PET or mpMRI is viable using TRUS-based HDR pBT. Utilizing HDR pBT allows dose escalation of up to 166% of the prescribed dose to the prostate.

Feasibility of online adaptive HDR prostate brachytherapy: A novel treatment concept.

PURPOSE: The purpose of this study was to determine the feasibility of online adaptive transrectal ultrasound (TRUS)-based high-dose-rate prostate brachytherapy (HDRPBT) through retrospective simulation of source positioning and catheter swap errors on patient treatment plans. METHOD: Source positioning errors (catheter shifts in 1 mm increments in the cranial/caudal, anterior/posterior, and medial/lateral directions up to ±6 mm) and catheter swap errors (between the most and least heavily weighted) were introduced retrospectively into DICOM treatment plans of 20 patients that previously received TRUS HDRPBT. Dose volume histogram (DVH) indices were monitored as errors were introduced sequentially into individual catheters, simulating potential errors throughout treatment. Whenever DVH indices were outside institution thresholds: prostate V100% <95%, urethra D0.1cc >118% and rectum Dmax >80%, the plan was adapted using remaining catheters (i.e., simulating previous catheters as previously delivered). The final DVH indices were recorded. RESULTS: Prostate coverage (V100% >95%) could be maintained for source position errors up to 6 mm through online plan adaptation. The source position error at which the urethra D0.1cc and rectum Dmax was able to return to clinically acceptable levels using online adaptation varied between 6 mm to 1 mm, depending on the direction of the source position error and patient anatomy. After introduction of catheter swap errors to patient plans, prostate V100% was recoverable using online adaptation to near original plan characteristics. Urethra D0.1cc and rectum Dmax showed less recoverability. CONCLUSION: Online adaptive HDRPBT maintains the prostate V100% to clinically acceptable values for majority of directional shifts. However, the current online adaptive method may not correct for source position errors near organs at risk.

HDR prostate brachytherapy plan robustness and its effect on in-vivo source tracking error thresholds: A multi-institutional study.

PURPOSE: The purpose of this study was to examine the effect of departmental planning techniques on appropriate in-vivo source tracking error thresholds for high dose rate (HDR) prostate brachytherapy (BT) treatments, and to determine if a single in-vivo source tracking error threshold would be appropriate for the same patient anatomy. METHODS: The prostate, rectum, and urethra were contoured on a single patient transrectal ultrasound (TRUS) dataset. Anonymized DICOM files were disseminated to 16 departments who created an HDR prostate BT treatment plan on the dataset with a prescription dose of 15 Gy in a single fraction. Departments were asked to follow their own local treatment planning guidelines. Source positioning errors were then simulated in the 16 treatment plans and the effect on dose-volume histogram (DVH) indices calculated. Change in DVH indices were used to determine appropriate in-vivo source tracking error thresholds. Plans were considered to require intervention if the following DVH conditions occurred: prostate V100% < 90%, urethra D0.1cc > 118%, and rectumtt Dmax > 80%. RESULTS: There was wide variation in appropriate in-vivo source tracking error thresholds among the 16 participating departments, ranging from 1 to 6 mm. Appropriate in-vivo source tracking error thresholds were also found to depend on the direction of the source positioning error and the endpoint. A robustness parameter was derived, and found to correlate with the sensitivity of plans to source positioning errors. CONCLUSIONS: A single HDR prostate BT in-vivo source tracking error threshold cannot be applied across multiple departments, even for the same patient anatomy. The burden on in-vivo source tracking devices may be eased through improving HDR prostate BT plan robustness during the plan optimisation phase.

Examination of the utility of the promoting action on research implementation in health services framework for implementation of evidence based practice in residential aged care settings.

AIM: This study examined the relevance and fit of the PARiHS framework (Promoting Action on Research Implementation in Health Services) as an explanatory model for practice change in residential aged care. BACKGROUND: Translation of research knowledge into routine practice is a complex matter in health and social care environments. Examination of the environment may identify factors likely to support and hinder practice change, inform strategy development, predict and explain successful uptake of new ways of working. Frameworks to enable this have been described but none has been tested in residential aged care. METHODS: This paper reports preliminary qualitative analyses from the Encouraging Best Practice in Residential Aged Care Nutrition and Hydration project conducted in New South Wales in 2007-2009. We examined congruence with the PARiHS framework of factors staff described as influential for practice change during 29 digitally recorded and transcribed staff interviews and meetings at three facilities. FINDINGS: Unique features of the setting were flagged, with facilities simultaneously filling the roles of residents' home, staff's workplace and businesses. Participants discussed many of the same characteristics identified by the PARiHS framework, but in addition temporal dimensions of practice change were flagged. CONCLUSION: Overall factors described by staff as important for practice change in aged care settings showed good fit with those of the PARiHS framework. This framework can be recommended for use in this setting. Widespread adoption will enable cross-project and international synthesis of findings, a major step towards building a cumulative science of knowledge translation and practice change.

Comparison of TG43 and Hounsfield Unit-based TG186 brachytherapy dose metrics in Oncentra Brachy for 100 patients receiving interstitial partial breast irradiation.

PURPOSE: The aim of the study was to conduct a retrospective analysis of 100 patients who received interstitial accelerated partial breast irradiation at a single institution, comparing the standard American Association of Physicists in Medicine Task Group (TG) 43 dose calculation algorithm to the model-based dose calculation algorithms (MBDCAs) available in the Oncentra Brachy treatment planning system. METHODS AND MATERIALS: Dose-volume histogram parameters were compared between the different dose calculation algorithms for the planning target volume and organs at risk. and a statistical analysis was performed. The resulting changes in isodose distribution were assessed, with the worst-case data presented. RESULTS: The TG43 algorithm calculated higher doses to all structures compared with the MBDCAs. The largest discrepancy was observed for the skin, with maximum doses on average 2.0% lower with the MBDCA. The newly released Hounsfield Unit-based algorithm further decreased the skin dose compared with TG43 by <0.5%. CONCLUSIONS: This study demonstrates that the differences between TG43 and MBDCA as implemented in Oncentra Brachy for accelerated partial breast irradiation are clinically insignificant in the treatment area and nearby organs at risk. Justification for investing in MBDCAs for this treatment site is limited when considering the additional calculation time, introduced uncertainties, and cost.

Towards real time in-vivo rectal dosimetry during trans-rectal ultrasound based high dose rate prostate brachytherapy using MOSkin dosimeters.

PURPOSE: To compare the dose measured by MOSkin dosimeters coupled to a trans-rectal ultrasound (TRUS) probe to the dose predicted by the brachytherapy treatment planning system (BTPS) during high dose rate (HDR) prostate brachytherapy (pBT), and to examine the feasibility of performing real-time catheter-by-catheter analysis of in-vivo rectal dosimetry during TRUS based HDR pBT. METHOD: Four MOSkin dosimeters were coupled to a TRUS probe during 20 TRUS-based HDR pBT treatment fractions. The measured MOSkin doses were retrospectively compared to those predicted by the BTPS for the total treatment fraction, as well as on a per catheter basis. RESULTS: The average relative percentage difference between MOSkin measured and BTPS predicted doses for a total treatment fraction was 0.3% ± 11.6% (k = 1), with a maximum of 23.2% and a minimum of -29.0%. The average relative percentage difference per catheter was +2.5% ± 16.9% (k = 1). The majority (64%) of per catheter MOSkin measured doses agreed with the treatment planning system within the calculated uncertainty budget of 12.3%. CONCLUSION: The results of the study agreed well with previously published data, despite differences in clinical workflows. To improve the redundancy to potential dosimeter errors, a minimum of 4 MOSkin dosimeters should be used when performing real-time in-vivo rectal dosimetry for HDR pBT, and error thresholds should be based off the total combined uncertainty estimate of measurement. 'Real time' error thresholds can be more confidently applied in the future through enhanced integration between IVD systems with both the imaging device and the BTPS/afterloader.

Derivation of in vivo source tracking error thresholds for TRUS-based HDR prostate brachytherapy through simulation of source positioning errors.

PURPOSE: The purpose of this study was to simulate treatment planning source positioning errors in transrectal ultrasound-based real-time high-dose-rate prostate brachytherapy treatments and determine appropriate in vivo source tracking error thresholds. METHODS AND MATERIALS: Treatment planning source positioning errors were simulated for 20 patient plans in the brachytherapy treatment planning system by manually adjusting the dwell position coordinates within selected catheters without plan reoptimization. The change in dose-volume histogram (DVH) indices was calculated as a function of the source positioning error. The magnitude of the change in the DVH indices was then used to derive appropriate in vivo source tracking error thresholds. RESULTS: Source positioning error thresholds to prevent potentially significant changes in prostate (target) DVH metrics ranged from 2 to 5 mm, dependent on the direction of the source positioning error, as well as the relative weight of the dwell position within the plan, and its position relative to the patient anatomy. Source positioning error thresholds to prevent potentially clinically significant changes in organ at risk DVH metrics were found to be complex and patient-dependent. CONCLUSIONS: In vivo source tracking error thresholds for transrectal ultrasound-based real-time high-dose-rate prostate brachytherapy were investigated via the simulation of treatment planning source positioning errors. These error thresholds were found to be dependent not only on the direction of the error, but also on the endpoint. There is still the potential for larger changes in DVH indices to occur for catheter shifts smaller than the proposed threshold levels in this study.

A Monte Carlo study on the feasibility of real-time in vivo source tracking during ultrasound based HDR prostate brachytherapy treatments.

PURPOSE: This study aims to assess the accuracy of in-vivo source tracking during real-time trans-rectal ultrasound (TRUS) based high dose rate (HDR) prostate brachytherapy (pBT) through Monte Carlo simulations of multiple HDR pBT treatments with a two-dimensional (2D) diode array, the Magic Plate 900 (MP900), embedded below the patient in a carbon-fibre couch. METHOD: Monte Carlo simulations of source positions representing three separate real-time TRUS based HDR pBT treatments were performed using the Geant4 toolkit. For each source position, an Ir-192 source was simulated inside a voxelized patient geometry. Dose deposited from each source position to the MP900 diodes was used to perform source tracking, and the MP900 calculated position compared to known source positions from the treatment plan. Thresholding techniques were implemented to improve source tracking accuracy with the TRUS probe present. RESULTS: The average three-dimensional source position reconstruction discrepancy was 11.9 ±â€¯2.4 mm and 1.5 ±â€¯0.3 mm with and without the TRUS probe, respectively. Thresholding techniques improved the source position reconstruction discrepancy in the presence of the TRUS probe to 1.8 ±â€¯0.4 mm. CONCLUSION: Inclusion of the TRUS probe inside the patient negatively affects source tracking accuracy when using the MP900 diode array for HDR pBT verification. Modification of the source tracking algorithm using thresholding techniques improves source tracking in the presence of the TRUS probe, achieving similar accuracy as when the TRUS probe is not present. This study demonstrates that accurate in-vivo source tracking during real-time TRUS based HDR pBT is feasible using the Magic Plate system.

A risk-based approach to development of ultrasound-based high-dose-rate prostate brachytherapy quality management.

PURPOSE: The purpose of this study was to apply a risk-based approach to the development of a quality management (QM) program for ultrasound-based high-dose-rate (HDR) prostate brachytherapy (pBT) treatment planning and delivery. METHODS AND MATERIALS: A QM program was developed by a multidisciplinary team, using both an in-house risk-and-benefit balance impact template (RABBIT) tool and a failure modes and effect analysis (FMEA). FMEA scores were determined by three physicists, one radiation therapist and two radiation oncologists who were familiar with the protocol. The QM program produced by both risk-based techniques was then compared and consolidated. RESULTS: The RABBIT tool identified 26 potential risks during the treatment planning and delivery process. During the FMEA, a total of 35 potential failure modes were identified from the seven major processes in ultrasound-based HDR pBT. For the 35 potential failure modes, risk priority number scores ranged from 14 to 267. The highest ranked failure mode was identified to be mislabeling/connection of the transfer tubes/catheters. From the risks analyses, a comprehensive QM program was developed. CONCLUSION: Both the RABBIT tool and process mapping and FMEA were shown to be valuable tools in developing a QM program for ultrasound-based HDR pBT treatments. A considerable number of the potential failure modes identified in both tools were related to human or procedural errors, highlighting the importance of checklists and protocols in delivering a safe and effective ultrasound-based HDR pBT treatment.

Semiconductor real-time quality assurance dosimetry in brachytherapy.

With the increase in complexity of brachytherapy treatments, there has been a demand for the development of sophisticated devices for delivery verification. The Centre for Medical Radiation Physics (CMRP), University of Wollongong, has demonstrated the applicability of semiconductor devices to provide cost-effective real-time quality assurance for a wide range of brachytherapy treatment modalities. Semiconductor devices have shown great promise to the future of pretreatment and in vivo quality assurance in a wide range of brachytherapy treatments, from high-dose-rate (HDR) prostate procedures to eye plaque treatments. The aim of this article is to give an insight into several semiconductor-based dosimetry instruments developed by the CMRP. Applications of these instruments are provided for breast and rectal wall in vivo dosimetry in HDR brachytherapy, urethral in vivo dosimetry in prostate low-dose-rate (LDR) brachytherapy, quality assurance of HDR brachytherapy afterloaders, HDR pretreatment plan verification, and real-time verification of LDR and HDR source dwell positions.

Dose accumulation of multiple high dose rate prostate brachytherapy treatments in two commercially available image registration systems.

PURPOSE: The purpose of this study was to assess whether deformable image registration (DIR) is required for dose accumulation of multiple high dose rate prostate brachytherapy (HDRPBT) plans treated with the same catheter pattern on two different CT datasets. METHOD: DIR was applied to 20 HDRPBT patients' planning CT images who received two treatment fractions on sequential days, on two different CT datasets, with the same implant. Quality of DIR in Velocity and MIM image registration systems was assessed by calculating the Dice Similarity Coefficient (DSC) and mean distance to agreement (MDA) for the prostate, urethra and rectum contours. Accumulated doses from each system were then calculated using the same DIR technique and dose volume histogram (DVH) parameters compared to manual addition with no DIR. RESULTS: The average DSC was found to be 0.83 (Velocity) and 0.84 (MIM), 0.80 (Velocity) and 0.80 (MIM), 0.80 (Velocity) and 0.81 (MIM), for the prostate, rectum and urethra contours, respectively. The average difference in calculated DVH parameters between the two systems using dose accumulation was less than 1%, and there was no statistically significant difference found between deformably accumulated doses in the two systems versus manual DVH addition with no DIR. CONCLUSION: Contour propagation using DIR in velocity and MIM was shown to be at least equivalent to inter-observer contouring variability on CT. The results also indicate that dose accumulation through manual addition of DVH parameters may be sufficient for HDRPBT treatments treated with the same catheter pattern on two different CT datasets.

Hemiablative Focal Low Dose Rate Brachytherapy: A Phase II Trial Protocol.

BACKGROUND: The objective of focal brachytherapy (BT) is to provide effective prostate cancer control for low-risk disease but with reduced genitourinary, gastrointestinal and sexual side effects in a cost-effective way. OBJECTIVE: The aim of this study is to describe a phase II study examining technical and dosimetric feasibility and toxicity, quality of life changes, and local control with post-treatment biopsy outcomes in men with early stage low volume prostate cancer treated with focal iodine-125 seed BT. METHODS: The study design is a prospective, multicenter trial with a planned sample size of 20 patients including men with a minimum age of 60 years, a life expectancy estimated to be greater than 10 years, with low or low-tier intermediate risk prostate cancer, unilateral disease on the biopsy, and a Gleason score of ≤3+4 and <25% cores involved. The investigations specific for the study are multi-parametric magnetic resonance imaging (Mp-MRI) baseline, at 20 and 36 months to rule out high grade disease and a transperineal mapping biopsy (baseline and at 36 months) for more accurate patient selection. The hemigland region will receive 144 Gy. Standard normal tissue constraints will be considered as for a whole gland (WG) implant. Dosimetric parameters will be evaluated at day 30 after the implant. Toxicity and quality of life will be evaluated with international validated questionnaires focusing on urinary, rectal, sexual domain, and general health-related quality of life. The patients will complete this assessment at baseline and then approximately every 6 months after the implant up to 10 years. RESULTS: To date, one patient is involved in the trial. He underwent the pre-implant investigations which found bilateral disease. Therefore, a standard seed implant was performed. If the results from this trial provide evidence that the treatment is safe, feasible, and improves toxicity, funding will be sought to conduct a large, multicenter, randomized controlled trial (RCT). CONCLUSIONS: This protocol is designed to show feasibility in delivering hemigland focal therapy with seed BT. It may answer crucial questions and obtain data which will enable downstream decisions on focal low dose rate (LDR) prostate BT. CLINICALTRIAL: Clinicaltrial.gov NCT02643511; https://www.clinicaltrials.gov/ct2/show/NCT02643511 (Archived by Webcite at http://www.webcitation.org/6ghLCzIhY).

Salem witchcraft and lessons for contemporary forensic psychiatry.

In 1692 and 1693, in Salem, Massachusetts, more than 150 colonists were accused of witchcraft, resulting in 19 being hanged and one man being crushed to death. Contributions to these events included: historical, religious and cultural belief systems; social and community concerns; economic, gender, and political factors; and local family grievances. Child witnessing, certainty of physician diagnosis, use of special evidence in the absence of scholarly and legal scrutiny, and tautological reasoning were important factors, as well. For forensic psychiatry, the events at Salem in 1692 still hold contemporary implications. These events of three centuries ago call to mind more recent daycare sexual abuse scandals.

Ergonomic interventions for office workers with musculoskeletal disorders: a systematic review.

INTRODUCTION: Ergonomic interventions designed for office and computer work have become widely available and heavily marketed but there is little evidence to support their use with workers who already have a musculoskeletal disorder (MSD). The purpose of any ergonomic intervention can be to improve worker comfort, safety and/or productivity. The ergonomic research in secondary prevention typically focuses outcomes on improved worker comfort but less if any emphasis has been put on productivity and safety. The purpose of this study was to determine the level and quality of evidence supporting ergonomic interventions to improve the comfort, safety and/or productivity of office workers with symptoms of MSDs. METHOD: A search of the ergonomic intervention literature based on MSDs of four body areas (low back, upper limb, eye and neck) was employed. The studies underwent two levels of analysis for inclusion in a best-evidence synthesis approach, which included a priori evaluation of specific interventions relative to outcomes of comfort, safety and/or productivity. RESULTS: Twenty-seven out of 202 articles were synthesized based on relevance, quality and significant results. Only 8 articles were determined high quality and no strong levels of evidence were identified. Levels of evidence for specific ergonomic interventions ranged from insufficient to moderate. Generally outcomes were focused mostly on improved comfort of workers. CONCLUSIONS: There is still limited quality research that addresses ergonomic interventions designed for secondary prevention. Further high quality studies are needed to support evidence-based ergonomic interventions in practice. For all stakeholders to fully evaluate the usefulness of the ergonomic intervention studies need to attend to outcomes not only of worker comfort but also to productivity and safety.