Hazard testing to reduce risk in the development of automated planning tools.

PURPOSE: Hazard scenarios were created to assess and reduce the risk of planning errors in automated planning processes. This was accomplished through iterative testing and improvement of examined user interfaces. METHODS: Automated planning requires three user inputs: a computed tomography (CT), a prescription document, known as the service request, and contours. We investigated the ability of users to catch errors that were intentionally introduced into each of these three stages, according to an FMEA analysis. Five radiation therapists each reviewed 15 patient CTs, containing three errors: inappropriate field of view, incorrect superior border, and incorrect identification of isocenter. Four radiation oncology residents reviewed 10 service requests, containing two errors: incorrect prescription and treatment site. Four physicists reviewed 10 contour sets, containing two errors: missing contour slices and inaccurate target contour. Reviewers underwent video training prior to reviewing and providing feedback for various mock plans. RESULTS: Initially, 75% of hazard scenarios were detected in the service request approval. The visual display of prescription information was then updated to improve the detectability of errors based on user feedback. The change was then validated with five new radiation oncology residents who detected 100% of errors present. 83% of the hazard scenarios were detected in the CT approval portion of the workflow. For the contour approval portion of the workflow none of the errors were detected by physicists, indicating this step will not be used for quality assurance of contours. To mitigate the risk from errors that could occur at this step, radiation oncologists must perform a thorough review of contour quality prior to final plan approval. CONCLUSIONS: Hazard testing was used to pinpoint the weaknesses of an automated planning tool and as a result, subsequent improvements were made. This study identified that not all workflow steps should be used for quality assurance and demonstrated the importance of performing hazard testing to identify points of risk in automated planning tools.

Pathologic angiogenesis in the bone marrow of humanized sickle cell mice is reversed by blood transfusion.

Sickle cell disease (SCD) is a monogenic red blood cell (RBC) disorder with high morbidity and mortality. Here, we report, for the first time, the impact of SCD on the bone marrow (BM) vascular niche, which is critical for hematopoiesis. In SCD mice, we find a disorganized and structurally abnormal BM vascular network of increased numbers of highly tortuous arterioles occupying the majority of the BM cavity, as well as fragmented sinusoidal vessels filled with aggregates of erythroid and myeloid cells. By in vivo imaging, sickle and control RBCs have significantly slow intravascular flow speeds in sickle cell BM but not in control BM. In sickle cell BM, we find increased reactive oxygen species production in expanded erythroblast populations and elevated levels of HIF-1α. The SCD BM exudate exhibits increased levels of proangiogenic growth factors and soluble vascular cell adhesion molecule-1. Transplantation of SCD mouse BM cells into wild-type mice recapitulates the SCD vascular phenotype. Our data provide a model of SCD BM, in which slow RBC flow and vaso-occlusions further diminish local oxygen availability in the physiologic hypoxic BM cavity. These events trigger a milieu that is conducive to aberrant vessel growth. The distorted neovascular network is completely reversed by a 6-week blood transfusion regimen targeting hemoglobin S to <30%, highlighting the plasticity of the vascular niche. A better insight into the BM microenvironments in SCD might provide opportunities to optimize approaches toward efficient and long-term hematopoietic engraftment in the context of curative therapies.

Establishment of a qualified integrated care system after total knee arthroplasty as a role of regional rheumatoid and degenerative arthritis centers.

BACKGROUND: The geriatric population and advanced knee osteoarthritis are rapidly increasing in Korea, and the socioeconomic burden of total knee arthroplasty (TKA) is increasing. This study aimed to analyze the demographic, clinical and socioeconomic characteristics of patients who underwent TKA and to differentiate the factors affecting participation in inpatient-intensive rehabilitation programs after TKA in the Jeju regional rheumatoid and degenerative arthritis center established by the government. METHODS: This retrospective cohort study included 845 patients (735 females; 72.0 ± 5.8 years) diagnosed with primary osteoarthritis (OA) of the knee who underwent elective unilateral primary TKA between January 2013 and June 2016. Demographic, clinical, and socioeconomic characteristics, including age, body mass index, obesity, length of stay, OA severity, underlying disease, education level, occupation, and location of residence were reviewed. Patients were allocated to the TKA-only group (home discharge) and to the TKA + rehab group (participation in post-TKA rehabilitation). The variables were analyzed and compared before and after the establishment of the center and according to participation in intensive rehabilitation. RESULTS: Patients who underwent TKA were mostly female, in the 60 s, and had a high prevalence of comorbidities and obesity. After the rehabilitation center's establishment, the intensive post-TKA participation increased profoundly from 3% to 59.2%. Participants after the center establishment had lower mean BMI and a higher proportion of K-L grade 4 compared to those before the center establishment. The location of residence was the only factor differentiating the participation in the intensive rehabilitation. CONCLUSION: The regional rheumatoid and degenerative arthritis center was appropriate to satisfy the high unmet need for participating in the intensive rehabilitation after TKA and to execute the qualified integrated post-TKA care system. Policy support should ensure the early rehabilitation and a qualified integrated care system and prepare for the increased burden of revision. Future longitudinal studies should be conducted to assess the long-term effect of the integrated post-TKA rehabilitation program on functional outcomes and patient survivorship free from revision.

Dosimetric analysis of MR-LINAC treatment plans for salvage spine SBRT re-irradiation.

PURPOSE: We investigated the feasibility of thoracic spine stereotactic body radiotherapy (SBRT) using the Elekta Unity magnetic resonance-guided linear accelerator (MRL) in patients who received prior radiotherapy. We hypothesized that Monaco treatment plans can improve the gross tumor volume minimum dose (GTVmin) with spinal cord preservation and maintain consistent plan quality during daily adaptation. METHODS: Pinnacle clinical plans for 10 patients who underwent thoracic spine SBRT (after prior radiotherapy) were regenerated in the Monaco treatment planning system for the Elekta Unity MRL using 9 and 13 intensity-modulated radiotherapy (IMRT) beams. Monaco adapt-to-position (ATP) and adapt-to-shape (ATS) workflow plans were generated using magnetic resonance imaging with a simulated daily positional setup deviation, and these adaptive plans were compared with Monaco reference plans. Plan quality measures included target coverage, Paddick conformity index, gradient index, homogeneity index, spinal cord D0.01cc , esophagus D0.01cc , lung V10, and skin D0.01cc . RESULTS: GTVmin values from the Monaco 9-beam and 13-beam plans were significantly higher than those from Pinnacle plans (p < 0.01) with similar spinal cord dose. Spinal cord D0.01cc , esophagus D0.01cc , and lung V10 did not statistically differ among the three plans. The electron-return effect did not induce remarkable dose effects around the lungs or skin. While in the ATP workflow, a large increase in GTVmin was observed at the cost of a 10%-50% increase in spinal cord D0.01cc , in the ATS workflow, the spinal cord dose increase was maintained within 3% of the reference plan. CONCLUSION: These findings show that MRL plans for thoracic spine SBRT are safe and feasible, allowing tumor dose escalation with spinal cord preservation and consistent daily plan adaptation using the ATS workflow. Careful plan review of hot spots and lung dose is necessary for safe MRL-based treatment.

Development and validation of a checklist for use with automatically generated radiotherapy plans.

PURPOSE: To develop a checklist that improves the rate of error detection during the plan review of automatically generated radiotherapy plans. METHODS: A custom checklist was developed using guidance from American Association of Physicists in Medicine task groups 275 and 315 and the results of a failure modes and effects analysis of the Radiation Planning Assistant (RPA), an automated contouring and treatment planning tool. The preliminary checklist contained 90 review items for each automatically generated plan. In the first study, eight physicists were recruited from our institution who were familiar with the RPA. Each physicist reviewed 10 artificial intelligence-generated resident treatment plans from the RPA for safety and plan quality, five of which contained errors. Physicists performed plan checks, recorded errors, and rated each plan's clinical acceptability. Following a 2-week break, physicists reviewed 10 additional plans with a similar distribution of errors using our customized checklist. Participants then provided feedback on the usability of the checklist and it was modified accordingly. In a second study, this process was repeated with 14 senior medical physics residents who were randomly assigned to checklist or no checklist for their reviews. Each reviewed 10 plans, five of which contained errors, and completed the corresponding survey. RESULTS: In the first study, the checklist significantly improved the rate of error detection from 3.4 ± 1.1 to 4.4 ± 0.74 errors per participant without and with the checklist, respectively (p = 0.02). Error detection increased by 20% when the custom checklist was utilized. In the second study, 2.9 ± 0.84 and 3.5 ± 0.84 errors per participant were detected without and with the revised checklist, respectively (p = 0.08). Despite the lack of statistical significance for this cohort, error detection increased by 18% when the checklist was utilized. CONCLUSION: Our results indicate that the use of a customized checklist when reviewing automated treatment plans will result in improved patient safety.

Brain stereotactic radiosurgery using MR-guided online adaptive planning for daily setup variation: An end-to-end test.

Online magnetic resonance (MR)-guided radiotherapy is expected to benefit brain stereotactic radiosurgery (SRS) due to superior soft tissue contrast and capability of daily adaptive planning. The purpose of this study was to investigate daily adaptive plan quality with setup variations and to perform an end-to-end test for brain SRS with multiple metastases treated with a 1.5-Tesla MR-Linac (MRL). The RTsafe PseudoPatient Prime brain phantom was used with a delineation insert that includes two predefined structures mimicking gadolinium contrast-enhanced brain lesions. Daily adaptive plans were generated using six preset and six random setup variations. Two adaptive plans per daily MR image were generated using the adapt-to-position (ATP) and adapt-to-shape (ATS) workflows. An adaptive patient plan was generated on a diagnostic MR image with simulated translational and rotational daily setup variation and was compared with the reference plan. All adaptive plans were compared with the reference plan using the target coverage, Paddick conformity index, gradient index (GI), Brain V12 or V20, optimization time and total monitor units. Target doses were measured as an end-to-end test with two ionization chambers inserted into the phantom. With preset translational variations, V12 from the ATS plan was 17% lower than that of the ATP plan. With a larger daily setup variation, GI and V12 of the ATS plan were 10% and 16% lower than those of the ATP plan, respectively. Compared to the ATP plans, the plan quality index of the ATS plans was more consistent with the reference plan, and within 5% in both phantom and patient plans. The differences between the measured and planned target doses were within 1% for both treatment workflows. Treating brain SRS using an MRL is feasible and could achieve satisfactory dosimetric goals. Setup uncertainties could be accounted for using online plan adaptation. The ATS workflow achieved better dosimetric results than the ATP workflow at the cost of longer optimization time.

Comparison of setup accuracy and efficiency between the Klarity system and BodyFIX system for spine stereotactic body radiation therapy.

BACKGROUND: Spine stereotactic body radiation therapy (SBRT) uses highly conformal dose distributions and sharp dose gradients to cover targets in proximity to the spinal cord or cauda equina, which requires precise patient positioning and immobilization to deliver safe treatments. AIMS: Given some limitations with the BodyFIX system in our practice, we sought to evaluate the accuracy and efficiency of the Klarity SBRT patient immobilization system in comparison to the BodyFIX system. METHODS: Twenty-three patients with 26 metastatic spinal lesions (78 fractions) were enrolled in this prospective observational study with one of two systems - BodyFIX (n = 11) or Klarity (n = 12). All patients were initially set up to external marks and positioned to match bony anatomy on ExacTrac images. Table corrections given by ExacTrac during setup and intrafractional monitoring and deviations from pre- and posttreatment CBCT images were analyzed. RESULTS: For initial setup accuracy, the Klarity system showed larger differences between initial skin mark alignment and the first bony alignment on ExacTrac than BodyFIX, especially in the vertical (mean [SD] of 5.7 mm [4.1 mm] for Klarity vs. 1.9 mm [1.7 mm] for BodyFIX, p-value < 0.01) and lateral (5.4 mm [5.1 mm] for Klarity vs. 3.2 mm [3.2 mm] for BodyFIX, p-value 0.02) directions. For set-up stability, no significant differences (all p-values > 0.05) were observed in the maximum magnitude of positional deviations between the two systems. For setup efficiency, Klarity system achieved desired bony alignment with similar number of setup images and similar setup time (14.4 min vs. 15.8 min, p-value = 0.41). For geometric uncertainty, systematic and random errors were found to be slightly less with Klarity than with BodyFIX based on an analytical calculation. CONCLUSION: With image-guided correction of initial alignment by external marks, the Klarity system can provide accurate and efficient patient immobilization. It can be a promising alternative to the BodyFIX system for spine SBRT while providing potential workflow benefits depending on one's practice environment.

Group singing improves quality of life for people with Parkinson's: an international study.

Objectives: Group singing has been reported to enhance quality of life (QoL) and mental health in older people. This paper explored whether there are differences in the effects of group singing intervention on people with Parkinson's (PwPs) in Australia, UK and South Korea.Methods: The study included PwPs (N = 95; mean age = 70.26; male 45%) who participated in a standardised 6-month weekly group singing programme. Parkinson's health-related QoL measure (PDQ39) and mental health assessment (DASS) were administered at baseline and follow-up. ANOVAs were performed with significance set as p < .05.Results: ANOVAs revealed main effects of Time on the Stigma and Social Support subscales of PDQ39; both showed a small but significant improvement over time. However, the social support reduction was moderated by country; social support was improved only in South Korean participants. The reduction in stigma was greater than previously reported minimal clinically important differences, as was the social support reduction in South Korean participants. In terms of mental health, ANOVAs revealed that the scores of Anxiety and Stress domains of DASS significantly decreased from pre-test to post-test with small effect sizes.Conclusion: This first international singing study with PwPs demonstrated that group singing can reduce stigma, anxiety and stress and enhance social support in older adults living with Parkinson's. The findings are encouraging and warrant further research using more robust designs.

Clinical implementation of automated treatment planning for whole-brain radiotherapy.

The purpose of the study was to develop and clinically deploy an automated, deep learning-based approach to treatment planning for whole-brain radiotherapy (WBRT). We collected CT images and radiotherapy treatment plans to automate a beam aperture definition from 520 patients who received WBRT. These patients were split into training (n = 312), cross-validation (n = 104), and test (n = 104) sets which were used to train and evaluate a deep learning model. The DeepLabV3+ architecture was trained to automatically define the beam apertures on lateral-opposed fields using digitally reconstructed radiographs (DRRs). For the beam aperture evaluation, 1st quantitative analysis was completed using a test set before clinical deployment and 2nd quantitative analysis was conducted 90 days after clinical deployment. The mean surface distance and the Hausdorff distances were compared in the anterior-inferior edge between the clinically used and the predicted fields. Clinically used plans and deep-learning generated plans were evaluated by various dose-volume histogram metrics of brain, cribriform plate, and lens. The 1st quantitative analysis showed that the average mean surface distance and Hausdorff distance were 7.1 mm (±3.8 mm) and 11.2 mm (±5.2 mm), respectively, in the anterior-inferior edge of the field. The retrospective dosimetric comparison showed that brain dose coverage (D99%, D95%, D1%) of the automatically generated plans was 29.7, 30.3, and 32.5 Gy, respectively, and the average dose of both lenses was up to 19.0% lower when compared to the clinically used plans. Following the clinical deployment, the 2nd quantitative analysis showed that the average mean surface distance and Hausdorff distance between the predicted and clinically used fields were 2.6 mm (±3.2 mm) and 4.5 mm (±5.6 mm), respectively. In conclusion, the automated patient-specific treatment planning solution for WBRT was implemented in our clinic. The predicted fields appeared consistent with clinically used fields and the predicted plans were dosimetrically comparable.

Significance of Cycle Ergometer as a Measure of Peak Aerobic Capacity in the Disabled.

BACKGROUND: To compare different physiological responses between treadmill and cycle ergometer in stroke patients in regard to community ambulation, and to determine strong predictors of equipment-dependent VO2peak and its related factors among physical fitness parameters and finally to establish the significance of cycle ergometer as a measure of VO2peak in the disabled according to gait function. METHODS: Sixty-three stroke survivors were enrolled in this study and were grouped according to the gait speed (32 non-community ambulators <0.8 m/s:31 community ambulators ≥0.8 m/s). All participants performed exercise stress test (EST) with treadmill and cycle ergometer and rehabilitation function tests. RESULTS: Community ambulators achieved higher VO2peak by treadmill, but non-community ambulators showed similar VO2peak between treadmill and cycle ergometer due to gait problems. The gait speed and endurance were strong predictors of difference of peak aerobic capacity between treadmill and cycle ergometer (multiple regression analysis, adjusted R2=0.458). CONCLUSION: Cycle ergometer might be more appropriate for non-community ambulatory stroke patients to assess the peak aerobic capacity. Gait speed and gait distance could affect equipment-dependent cardiopulmonary performance significantly in the disabled. Therefore, the careful consideration of comprehensive and objective physical function including gait endurance, and speed and prescription of appropriate exercise intensity and equipment depending on the severity should be needed to improve the cardiopulmonary fitness and physical function adequately in stroke rehabilitation.

Effect of Cognitive Reserve on Risk of Cognitive Impairment and Recovery After Stroke: The KOSCO Study.

Background and Purpose- The theory of cognitive reserve (CR) was introduced to account for individual differences in the clinical manifestation of neuropathology. This study investigated whether CR has a modulating effect on cognitive impairment and recovery after stroke. Methods- This study is an interim analysis of the Korean Stroke Cohort for Functioning and Rehabilitation. A total of 7459 patients with first-ever stroke were included for analysis. Education, occupation, and composite CR scores derived from those 2 variables were used as CR proxies. Scores from the Korean version of the Mini-Mental State Examination analyzed for 30 months after stroke onset were analyzed. Results- Lower CR increased the risk of cognitive impairment after stroke. The odds ratio was 1.89 (95% CI, 1.64-2.19) in patients with secondary education and 2.42 (95% CI, 2.03-2.90) in patients with primary education compared with patients with higher education. The odds ratio was 1.48 (95% CI, 1.23-1.98) in patients with a skilled manual occupation and 2.01 (95% CI, 1.42-2.83) in patients with a nonskilled manual occupation compared with patients with a managerial or professional occupation. In the multilevel model analysis, the Korean version of the Mini-Mental State Examination total score increased during the first 3 months (1.93 points per month) and then plateaued (0.02 point per month). The slopes were moderated by the level of education, occupation, and composite CR score: the higher the level of education, occupation, or CR score, the faster the recovery. In the older adult group, the Korean version of the Mini-Mental State Examination scores showed a long-term decline that was moderated by education level. Conclusions- Education and occupation can buffer an individual against cognitive impairment caused by stroke and promote rapid cognitive recovery early after stroke. In addition, higher education minimizes long-term cognitive decline after stroke, especially in older patients. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT03402451.

3D-printed headrest for frameless Gamma Knife radiosurgery: Design and validation.

PURPOSE: Frameless Gamma Knife stereotactic radiosurgery (SRS) uses a moldable headrest with a thermoplastic mask for patient immobilization. An efficacious headrest is time consuming and difficult to fabricate due to the expertise required to mold the headrest within machine geometrical limitations. The purpose of this study was to design and validate a three-dimensional (3D)-printed headrest for frameless Gamma Knife SRS that can overcome these difficulties. MATERIALS AND METHODS: A headrest 3D model designed to fit within the frameless adapter was 3D printed. Dosimetric properties of the 3D-printed headrest and a standard-of-care moldable headrest were compared by delivering a Gamma Knife treatment to an anthropomorphic head phantom fitted with an ionization chamber and radiochromic film. Ionization measurements were compared to assess headrest attenuation and a gamma index was calculated to compare the film dose distributions. A volunteer study was conducted to assess the immobilization efficacy of the 3D-printed headrest compared to the moldable headrest. Five volunteers had their head motion tracked by a surface tracking system while immobilized in each headrest for 20 min. The recorded motion data were used to calculate the average volunteer movement and a paired t-test was performed. RESULTS: The ionization chamber readings were within 0.55% for the 3D-printed and moldable headrests, and the calculated gamma index showed 98.6% of points within dose difference of 2% and 2 mm distance to agreement for the film measurement. These results demonstrate that the headrests were dosimetrically equivalent within the experimental uncertainties. Average motion (±standard deviation) of the volunteers while immobilized was 1.41 ± 0.43 mm and 1.36 ± 0.51 mm for the 3D-printed and moldable headrests, respectively. The average observed volunteer motion between headrests was not statistically different, based on a P-value of 0.466. CONCLUSIONS: We designed and validated a 3D-printed headrest for immobilizing patients undergoing frameless Gamma Knife SRS.

Validation of PTV margin for Gamma Knife Icon frameless treatment using a PseudoPatient® Prime anthropomorphic phantom.

The Gamma Knife Icon allows the treatment of brain tumors mask-based single-fraction or fractionated treatment schemes. In clinic, uniform axial expansion of 1 mm around the gross tumor volume (GTV) and a 1.5 mm expansion in the superior and inferior directions are used to generate the planning target volume (PTV). The purpose of the study was to validate this margin scheme with two clinical scenarios: (a) the patient's head remaining right below the high-definition motion management (HDMM) threshold, and (b) frequent treatment interruptions followed by plan adaptation induced by large pitch head motion. A remote-controlled head assembly was used to control the motion of a PseudoPatient® Prime head phantom; for dosimetric evaluations, an ionization chamber, EBT3 films, and polymer gels were used. These measurements were compared with those from the Gamma Knife plan. For the absolute dose measurements using an ionization chamber, the percentage differences for both targets were less than 3.0% for all scenarios, which was within the expected tolerance. For the film measurements, the two-dimensional (2D) gamma index with a 2%/2 mm criterion showed the passing rates of ≥87% in all scenarios except the scenario 1. The results of Gel measurements showed that GTV (D100 ) was covered by the prescription dose and PTV (D95 ) was well above the planned dose by up to 5.6% and the largest geometric PTV offset was 0.8 mm for all scenarios. In conclusion, the current margin scheme with HDMM setting is adequate for a typical patient's intrafractional motion.

Comorbidities in Patients With End-Stage Knee OA: Prevalence and Effect on Physical Function.

OBJECTIVE: To investigate the prevalence of comorbidities and their effect on physical function, quality of life (QOL), and pain, in patients with end-stage knee osteoarthritis (OA). DESIGN: A cross-sectional study. SETTING: A rehabilitation facility at university hospital. PARTICIPANTS: Patients (N=577; 503 women and 74 men) diagnosed with end-stage knee OA between October 2013 and June 2018. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Comorbidities were as follows: osteoporosis, presarcopenia, degenerative spine disease, diabetes, and hypertension. All patients completed the following performance-based physical function tests: stair-climbing test (SCT), 6-minute walk test (6MWT), timed Up and Go (TUG) test, and gait analysis. Self-reported physical function and pain were measured using Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and a visual analog scale (VAS), respectively, and self-reported QOL was measured using EuroQoL 5 dimensions (EQ-5D) questionnaire. RESULTS: Univariate analyses revealed that patients with osteoporosis had significantly higher scores in SCT ascent, SCT descent, TUG, WOMAC pain tests, and lower scores in 6MWT, gait speed, and cadence tests than those without osteoporosis. Patients with presarcopenia recorded higher scores in SCT ascent, TUG, EQ-5D, and lower scores in 6MWT and gait speed tests than those without presarcopenia. Patients with degenerative spine disease showed higher scores in WOMAC pain and lower scores in gait speeds than those without degenerative spine disease. Patients with diabetes showed higher scores in SCT ascent than those without diabetes, and patients with hypertension showed lower scores in 6MWT than those without hypertension. After adjusting age, sex, and body mass index, SCT descent retained significant association with osteoporosis, SCT ascent showed independent association with presarcopenia and diabetes, and WOMAC pain revealed significant association with degenerative spine disease. CONCLUSION: The results confirm associations between comorbidities, performance-based and self-reported physical functions, and QOL in patients with end-stage knee OA.

Factors associated with improvement or decline in cognitive function after an ischemic stroke in Korea: the Korean stroke cohort for functioning and rehabilitation (KOSCO) study.

BACKGROUND: We conducted a prospective cohort study to investigate prevalence of poststroke cognitive impairment at 3 and 12 months after stroke onset and identify clinical and demographic factors associated with improvement or decline in cognitive function between 3 months and 12 months. METHODS: We analyzed the cognitive assessments of total patients and patients older than 65 years separately. All patients with an ischemic stroke were divided into normal cognitive group (NCG) and impaired cognition group (ICG) by using a cutoff score on the Korean Mini-Mental State Examination (K-MMSE). Patients were additionally classified into 3 subgroups according to the changes in their K-MMSE scores between 3 and 12 months: Stable group with K-MMSE scores changes ranging from -2 to +2 points (-2 ≤ △MMSE ≤ +2); converter group with increase more than 3 points (3 ≤ △MMSE); and reverter group with decrease more than 3 points (-3 ≤ △MMSE). We also analyzed factors affecting cognitive change from 3 months to 12 months among the 3 groups including baseline medical record, stroke and treatment characteristics, and various functional assessments after 3 months. RESULTS: This study included 2,625 patients with the first time ischemic stroke. Among these patients, 1,735 (66.1%) were classified as NCG, while 890 patients (33.9%) were belonged to the ICG at 3 month. Within the NCG, 1,460 patients (82.4%) were stable group, 93 patients (5.4%) were converter group, and 212 patients (12.2%) were reverter group at 12 months onset. Within the ICG group, 472 patients (53.0%) were stable group, 321 patients (36.1%) were converter group, and 97 patients (10.9%) were reverter group. When different factors were investigated, the three subgroups in NCG and ICG showed significant different factors affecting cognitive function from 3 to 12 month. CONCLUSIONS: The prevalence of cognitive impairment showed difference between 3,12 months. To analyze the cognitive change from 3 month to 12 month, the proportion stable group was dominant in NCG and converter group was higher in ICG. By investigating the influencing factors from each group, we were able to identify the predictors including the age factor.

Can Lowering the Guidance Force of Robot-Assisted Gait Training Induce a Sufficient Metabolic Demand in Subacute Dependent Ambulatory Patients With Stroke?

OBJECTIVE: To assess the effects of guidance force (GF) and gait speed (GS) on cardiorespiratory responses and energy cost in subacute dependent ambulatory patients with stroke. DESIGN: Cross-sectional study. SETTING: University rehabilitation hospital. PARTICIPANTS: Patients with subacute stroke (N=10; mean age, 64.50±19.20y) who were dependent ambulators (functional ambulation category ≤2). INTERVENTIONS: Patients participated in cardiorespiratory tests during robot-assisted gait training. Subjects walked at a fixed percentage (50%) of body weight support and various percentages of GF (100%, 80%, and 60%) and GS (1.4 and 1.8km/h). The therapist encouraged patients to maximize their locomotor ability. MAIN OUTCOME MEASURES: During the cardiorespiratory tests, oxygen consumption (V˙o2), heart rate, and respiratory exchange ratio were measured continuously to assess cardiometabolic demands. RESULTS: There were no significant differences in cardiometabolic demands according to GS (1.4 vs 1.8km/h). There were no significant differences in cardiometabolic demands according to GF at a GS of 1.4km/h. However, lowering GF decreased V˙o2 when comparing GFs of 100% (6.89±2.38mL/kg/min), 80% (6.46±1.73mL/kg/min), and 60% (5.77±1.71mL/kg/min) at a GS of 1.8km/h (P=.03). CONCLUSIONS: Lowering the GF of robot-assisted gait training at a higher GS cannot induce a sufficient cardiometabolic demand for subacute dependent ambulatory patients with stroke. This implies that it is important to take the patient's functional ability into consideration when choosing training protocols.

Dosimetric and radiobiological comparison for quality assurance of IMRT and VMAT plans.

INTRODUCTION: The gamma analysis used for quality assurance of a complex radiotherapy plan examines the dosimetric equivalence between planned and measured dose distributions within some tolerance. This study explores whether the dosimetric difference is correlated with any radiobiological difference between delivered and planned dose. METHODS: VMAT or IMRT plans optimized for 14 cancer patients were calculated and delivered to a QA device. Measured dose was compared against planned dose using 2-D gamma analysis. Dose volume histograms (for various patient structures) obtained by interpolating measured data were compared against the planned ones using a 3-D gamma analysis. Dose volume histograms were used in the Poisson model to calculate tumor control probability for the treatment targets and in the Sigmoid dose-response model to calculate normal tissue complication probability for the organs at risk. RESULTS: Differences in measured and planned dosimetric data for the patient plans passing at ≥94.9% rate at 3%/3 mm criteria are not statistically significant. Average ± standard deviation tumor control probabilities based on measured and planned data are 65.8±4.0% and 67.8±4.1% for head and neck, and 71.9±2.7% and 73.3±3.1% for lung plans, respectively. The differences in tumor control probabilities obtained from measured and planned dose are statistically insignificant. However, the differences in normal tissue complication probabilities for larynx, lungs-GTV, heart, and cord are statistically significant for the patient plans meeting ≥94.9% passing criterion at 3%/3 mm. CONCLUSION: A ≥90% gamma passing criterion at 3%/3 mm cannot assure the radiobiological equivalence between planned and delivered dose. These results agree with the published literature demonstrating the inadequacy of the criterion for dosimetric QA and suggest for a tighter tolerance.

Arterial Stiffness in Subacute Stroke: Changing Pattern and Relationship with Functional Recovery.

BACKGROUND: To examine changing patterns in arterial stiffness and functional outcome in patients with subacute stroke, and to determine which parameter shows a strong correlation with the reversal of arterial stiffness, during a 3-month period of comprehensive rehabilitation therapy. METHODS: This descriptive, observational cohort study enrolled 60 patients (43 male and 17 female; average age, 62.7 years), and all received conventional rehabilitation therapy, during a 3-month period. Brachial-ankle pulse wave velocity (baPWV) was measured as an index of arterial stiffness. Functional assessments included the 6-minute walk test (6MWT), Fugl-Meyer Assessment of hemiparetic upper and lower limbs, the functional ambulatory category, the Berg balance scale, the Korean Mini-Mental Status Examination, and the Korean-Modified Barthel Index. All measurements were conducted at baseline and 1 and 3 months after stroke onset. RESULTS: Rehabilitation therapy resulted in a statistically significant improvement in baPWV since 3 months post stroke. Another functional outcome measure showed statistically significant improvements since 1 month after rehabilitation. Multivariable linear regression analysis revealed that a change in baPWV was significantly correlated with changes in the 6MWT. CONCLUSIONS: Three months of comprehensive rehabilitation therapy led to statistically significant improvements in arterial stiffness and functional outcomes during the subacute phase of stroke. Thus, the comprehensive rehabilitation focused on improving gait endurance would be warranted in subacute stroke patients.

Chronic Kidney Disease and Functional Outcomes 6 Months after Ischemic Stroke: A Prospective Multicenter Study.

BACKGROUND: The aim of this study was to investigate whether chronic kidney disease (CKD) predicts the outcome of the Functional Independence Measure (FIM) and the Korean version of the modified Barthel Index (K-MBI) 6 months after stroke with adjustment for age, gender, education, smoking, drinking, obesity, hypertension, diabetes mellitus, dyslipidemia, the FIM or K-MBI at discharge and the National Institutes of Health Stroke Scale (NIHSS) score 7 days post stroke. METHODS: This study is an interim report of the Korean Stroke Cohort for Functioning and Rehabilitation. The sample included 2,037 ischemic stroke patients aged 18 years or older. The FIM and K-MBI scores were assessed at discharge and at 6 months after the onset of stroke. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. CKD was defined as an eGFR <60 ml/min/1.73 m2. RESULTS: Overall, the mean age was 65.5 (±12.4) years. The proportion of men was 62.6%. The proportion of CKD cases was 12.7%. The means of the 6-month FIM and K-MBI were 109.8 (±27.9) and 87.0 (±26.4), respectively. In multiple linear regressions, the 6-month FIM after stroke was significantly associated with CKD (-2.85, p < 0.05), age (-0.29, p < 0.01), the FIM at discharge (0.46, p < 0.01) and the 7-day NIHSS score (-1.71, p < 0.01). Additionally, the post-stroke 6-month K-MBI was significantly associated with CKD (-2.88, p < 0.01), age (-0.27, p < 0.01), the K-MBI at discharge (0.46, p < 0.01) and the 7-day NIHSS score (-1.55, p < 0.01). CONCLUSIONS: This nationwide hospital-based cohort study showed that CKD might predict poor 6-month FIM and K-MBI scores in ischemic stroke patients.

Case report of meningiomatosis with aspiration of a dental bridge improved by comprehensive rehabilitation therapy.

[Purpose] The aim of this study was to ascertain the effect of comprehensive rehabilitation therapy on a quadriplegic patient with meningiomatosis and severe dysphagia. [Subject and Methods] Meningiomatosis is defined as multiple meningiomas involved in several intracranial regions, which occurs more frequently in elderly patients. The prognosis of meningiomatosis is mostly reported as benign, but the prognosis for some malignant cases can be poor. Furthermore, dysphagia in elderly patients with brain lesions may lead to foreign body aspiration, which can be fatal. The removable type of dental prosthesis is a common cause of aspiration, but aspiration is rare with the fixed type. [Results] This report presents a rare case of bronchial aspiration involving a fixed dental prosthesis in an elderly meningiomatosis patient that was improved following comprehensive rehabilitation therapy. [Conclusion] Thorough evaluation and individualized assessment of rehabilitation goals is recommended for the care of severe comorbid elderly patients.