Investigation of the Kinematic Upper-Limb Movement Assessment (KUMA): A Pilot Study.

Purpose: Upper limb movement disorders are common after stroke and can severely impact activities of daily living. Available clinical measures of these disorders are subjective and may lack the sensitivity needed to track a patient's progress and to compare different therapies. Kinematic analyses can provide clinicians with more objective measures for evaluating the effects of rehabilitation. We present a novel method to assess the quality of upper limb movement: the Kinematic Upper-limb Movement Assessment (KUMA). This assessment uses motion capture to provide three kinematic measures of upper limb movement: active range of motion, speed, and compensatory trunk movement. The researchers sought to evaluate the ability of the KUMA to distinguish motion in the affected versus unaffected limb. Method: We used the KUMA with three participants with stroke to assess three single-joint movements in: wrist flexion and extension, elbow flexion and extension, and shoulder flexion/extension and abduction/adduction. Participants also completed the Modified Ashworth Scale and the Chedoke-McMaster Stroke Assessment, two clinical measures of functional ability. Results: The KUMA distinguished between affected and unaffected upper limb motion. Conclusions: The KUMA provides clinicians with supplementary objective information for motion characterization that is not available through clinical measures alone. The KUMA can complement existing clinical measures such as the MAS and CMSA and can be helpful for monitoring patient progress.

Objectif : les troubles des mouvements de membres supérieurs sont courants après un accident vasculaire cérébral et peuvent nuire fortement aux activités de la vie quotidienne. Les mesures cliniques disponibles pour ces troubles sont subjectives et ne possèdent peut-être pas la sensibilité nécessaire pour suivre le progrès d'un patient et comparer les diverses thérapies. Les analyses de cinématique peuvent fournir aux cliniciens des mesures plus objectives pour évaluer les effets de la réadaptation. Les auteurs présentent une nouvelle méthode pour évaluer la qualité des mouvements des membres supérieurs : l'évaluation cinématique des mouvements des membres supérieurs (KUMA, pour Kinematic Upper-limb Movement Assessment ). Cette évaluation fait appel à la capture des mouvements pour fournir trois mesures cinématiques des mouvements des membres supérieurs : l'amplitude de mouvements actifs, la vitesse et le mouvement compensatoire du tronc. Les chercheurs ont cherché à évaluer la capacité de la KUMA à distinguer le mouvement du membre touché par rapport au membre non touché. Méthodologie : les chercheurs ont utilisé la KUMA auprès de trois participants ayant subi un accident vasculaire cérébral pour évaluer trois mouvements monoarticulaires : flexion et extension du poignet, flexion et extension du coude, et flexion et extension, abduction et adduction de l'épaule. Les participants ont également utilisé l'échelle modifiée d'Ashworth (MAS) et l'évaluation Chedoke-McMaster de l'accident vasculaire cérébral (AVC), deux mesures cliniques de la capacité fonctionnelle. Résultats : la KUMA distinguait le mouvement du membre supérieur atteint de celui qui ne l'était pas. Conclusions : La KUMA fournit aux cliniciens de l'information objective supplémentaires pour caractériser les mouvements d'une manière qui n'est pas disponible par les seules mesures cliniques. La KUMA peut compléter les mesures cliniques en place comme l'échelle modifiée d'Ashworth et l'évaluation Chedoke-McMaster de l'AVC et peut être utile pour surveiller le progrès des patients.

Dosimetric evaluation of MRI-to-ultrasound automated image registration algorithms for prostate brachytherapy.

PURPOSE: Identifying dominant intraprostatic lesions (DILs) on transrectal ultrasound (TRUS) images during prostate high-dose-rate brachytherapy treatment planning remains a significant challenge. Multiparametric MRI (mpMRI) is the tool of choice for DIL identification; however, the geometry of the prostate on mpMRI and on the TRUS may differ significantly, requiring image registration. This study assesses the dosimetric impact attributed to differences in DIL contours generated using commonly available MRI to TRUS automated registration: rigid, semi-rigid, and deformable image registration, respectively. METHODS AND MATERIALS: Ten patients, each with mpMRI and TRUS data sets, were included in this study. Five radiation oncologists with expertise in TRUS-based high-dose-rate brachytherapy were asked cognitively to transfer the DIL from the mpMRI images of each patient to the TRUS image. The contours were analyzed for concordance using simultaneous truth and performance level estimation (STAPLE) algorithm. The impact of DIL contour differences due to registration variability was evaluated by comparing the STAPLE-DIL dosimetry from the reference (STAPLE) plan with that from the evaluation plans (manual and automated registration) for each patient. The dosimetric impact of the automatic registration approach was also validated using a margin expansion that normalizes the volume of the autoregistered DILs to the volumes of the STAPLE-DILs. Dose metrics including D90, Dmean, V150, and V200 to the prostate and DIL were reported. For urethra and rectum, D10 and V80 were reported. RESULTS: Significant differences in DIL coverage between reference and evaluation plans were found regardless of the algorithm methodology. No statistical difference was reported in STAPLE-DIL dosimetry when manual registration was used. A margin of 1.5 ± 0.8 mm, 1.1 ± 0.8 mm, and 2.5 ± 1.6 mm was required to be added for rigid, semi-rigid, and deformable registration, respectively, to mitigate the difference in STAPLE-DIL coverage between the evaluation and reference plans. CONCLUSION: The dosimetric impact of integrating an MRI-delineated DIL into a TRUS-based brachytherapy workflow has been validated in this study. The results show that rigid, semi-rigid, and deformable registration algorithms lead to a significant undercoverage of the DIL D90 and Dmean. A margin of at least 1.5 ± 0.8 mm, 1.1 ± 0.8 mm, and 2.5 ± 1.6 mm is required to be added to the rigid, semi-rigid, and deformable DIL registration to be suitable for DIL-boosting during prostate brachytherapy.

Conventional vs machine learning-based treatment planning in prostate brachytherapy: Results of a Phase I randomized controlled trial.

PURPOSE: The purpose of this study was to evaluate the noninferiority of Day 30 dosimetry between a machine learning-based treatment planning system for prostate low-dose-rate (LDR) brachytherapy and the conventional, manual planning technique. As a secondary objective, the impact of planning technique on clinical workflow efficiency was also evaluated. MATERIALS AND METHODS: 41 consecutive patients who underwent I-125 LDR monotherapy for low- and intermediate-risk prostate cancer were accrued into this single-institution study between 2017 and 2018. Patients were 1:1 randomized to receive treatment planning using a machine learning-based prostate implant planning algorithm (PIPA system) or conventional, manual technique. Treatment plan modifications by the radiation oncologist were evaluated by computing the Dice coefficient of the prostate V150% isodose volume between either the PIPA-or conventional-and final approved plans. Additional evaluations between groups evaluated the total planning time and dosimetric outcomes at preimplant and Day 30. RESULTS: 21 and 20 patients were treated using the PIPA and conventional techniques, respectively. No significant differences were observed in preimplant or Day 30 prostate D90%, V100%, rectum V100, or rectum D1cc between PIPA and conventional techniques. Although the PIPA group had a larger proportion of patients with plans requiring no modifications (Dice = 1.00), there was no significant difference between the magnitude of modifications between each arm. There was a large significant advantage in mean planning time for the PIPA arm (2.38 ± 0.96 min) compared with the conventional (43.13 ± 58.70 min) technique (p >> 0.05). CONCLUSIONS: A machine learning-based planning workflow for prostate LDR brachytherapy has the potential to offer significant time savings and operational efficiencies, while producing noninferior postoperative dosimetry to that of expert, conventional treatment planners.

Results of a phase I, non-randomized study evaluating a Magnetic Occult Lesion Localization Instrument (MOLLI) for excision of non-palpable breast lesions.

PURPOSE: Magnetic Occult Lesion Localization Instrument (MOLLI) is a wireless, non-radioactive alternative for non-palpable breast lesion localization. The primary objective of this first-in-human study was to evaluate the clinical feasibility of using MOLLI for intraoperative localization of non-palpable breast lesions. METHODS: Twenty women with non-palpable breast lesions at a single institution received a lumpectomy using the MOLLI guidance system. Patients were co-localized with magnetic and radioactive markers up to 7 days before excision by a dedicated breast radiologist under sonographic guidance. Both markers were localized intraoperatively using dedicated hand-held probes. The primary outcome was successful excision of the magnetic marker, confirmed radiographically and pathologically. Demographic data, margin positivity, and re-excision rates were collected. Surgical oncologists, radiologists, and pathology staff were surveyed for user satisfaction. RESULTS: Post-radiological analysis: Post-implant mammograms verified that 17/20 markers were placed directly in the lesion center. Radiologists reported that all marker implantations procedures were "easy" or "very easy" following a single training session. Post-surgical analysis: All MOLLI markers were successfully removed with the specimen during surgical excision. In all cases, surgeons ranked the MOLLI guidance system as "very easy" for lesion localization. Pathologic analysis: All patients had negative margins. All anatomic pathology staff ranked the MOLLI system as "very easy" to localize markers. CONCLUSIONS: The MOLLI guidance system is a reliable and accurate method for intraoperative localization of non-palpable breast lesions. Further evaluation of the MOLLI system in studies against current standards of care is required to demonstrate system cost-effectiveness and improved patient-reported outcomes.

Changes in ADC and T2-weighted MRI-derived radiomic features in patients treated with focal salvage HDR prostate brachytherapy for local recurrence after previous external-beam radiotherapy.

PURPOSE: To explore the changes in T2-weighted (T2w) and apparent diffusion coefficient (ADC) magnetic resonance imaging -derived radiomic features of the gross tumor volume (GTV) from focal salvage high-dose-rate prostate brachytherapy (HDRB) and to correlate with clinical parameters. MATERIALS AND METHODS: Eligible patients included those with biopsy-confirmed local recurrence that correlated with MRI (T2w, ADC). Patients received 27 Gy in 2 fractions separated by 1 week to a quadrant consisting of the GTV. The MRI was repeated 1 year after HDRB. GTVs, planning target volumes, and normal prostate tissue control volumes were identified on the pre- and post-HDRB MRIs. Radiomic features from each GTV were extracted, and principle component analysis identified features with the highest variance. RESULTS: Pre- and post-HDRB MRIs were obtained from 14 trial patients. Principle component analysis showed that 18 and 17 features contributed to 93% and 86% of the variance observed in the T2w and ADC data, respectively. Sixteen T2w features and 1 ADC GTV feature were different from the control volumes in the pre-HDRB images (p < 0.05). Ten T2w and 7 ADC GTV post-HDRB features were different from those of pre-HDRB (p < 0.05). CONCLUSIONS: Exploratory analysis reveals several radiomic features in the T2w and ADC image GTVs that distinguish the GTV from healthy prostate tissue and change significantly after salvage HDRB.

Evaluation of a Ferromagnetic Marker Technology for Intraoperative Localization of Nonpalpable Breast Lesions.

OBJECTIVE: The purpose of this study was to evaluate the magnetic occult lesion localization instrument (MOLLI) system that involves implantation of a small, ferromagnetic marker to guide surgical excision of nonpalpable breast lesions. Characterization of the system was undertaken as part of what is, to our knowledge, the first study to assess the MOLLI system. MATERIALS AND METHODS: The MOLLI system consists of a handheld probe that can detect the position and distance of an implanted magnetic marker. The system presents the surgeon with an accurate assessment of lesion location and depth measurement for precise 3D localization. The marker is implanted under ultrasound or mammographic guidance at any time before the surgical procedure and requires no special precautions. Experimental analysis focused on characterization of the following aspects of the MOLLI system: visualization of the marker under imaging, 3D detection of the magnetic marker, spatial resolution of the probe to detect markers placed in close proximity, and the effect of signal interference on system performance. RESULTS: The MOLLI system can reliably detect mean (± SD) marker depths up to 53 ± 8.56 mm from the probe. Bracketing large lesions or localizing multiple lesions can be accomplished by placing markers as close as 10 mm apart, at depths of up to 42 mm. The biologically inert MOLLI marker is readily visible under ultrasound and mammographic guidance, and it is differentiable from radiologic clips. The effect of surgical instruments on MOLLI functioning is minimal and does not impact system accuracy or reliability. CONCLUSION: The MOLLI system offers an accurate and efficient alternative lesion localization method for nonpalpable breast lesions.

Clinical evaluation of an MRI-to-ultrasound deformable image registration algorithm for prostate brachytherapy.

PURPOSE: Identifying dominant intraprostatic lesions (DILs) on transrectal ultrasound (TRUS) images during prostate high-dose-rate brachytherapy (HDR-BT) treatment planning is challenging. Multiparametric MRI (mpMRI) is the tool of choice for DIL identification; however, the geometry of the prostate on mpMRI and on the TRUS may differ significantly, requiring image registration. This study evaluates the efficacy of an in-house software for MRI-to-TRUS DIL registration (MR2US) and compares its results to rigid and B-Spline deformable registration. METHODS AND MATERIALS: Ten patients with intermediate-risk prostate cancer, each with mpMRI and TRUS data sets, were included in this study. Five radiation oncologists (ROs) with expertise in TRUS-based HDR-BT were asked to cognitively contour the DIL onto the TRUS image using mpMRI as reference. The contours were analyzed for concordance using simultaneous truth and performance level estimation algorithm. Similarity indices, DIL volumes, and distance between centroid positions were measured to compare the consensus contours against the contours from ROs and the automated algorithms; registration time between all contouring methods was recorded. RESULTS: MR2US registration had the highest dice coefficients among all patients with a mean of 0.80 ± 0.13 in comparison to rigid (0.65 ± 0.20) and B-Spline (0.51 ± 0.30). The distance between centroid positions between simultaneous truth and performance level estimation contour and MR2US, rigid, and B-Spline contours were 5 ± 2, 7 ± 5, and 18 ± 11 mm, respectively. The average registration time was significantly shorter for MR2US (11 ± 2 s) and rigid algorithm (7 ± 1 s) compared to ROs (227 ± 27 s) and B-Spline (199 ± 38 s). CONCLUSIONS: The efficacy of integrating an MRI-delineated DIL into a TRUS-based BT workflow has been validated in this study. The MR2US software is fast and accurate enough to be used for DIL identification in prostate HDR-BT.