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Zhang J.,CHI St. Lukes Health | Arena C.,CHI St. Lukes Health | Pednekar A.,CHI St. Lukes Health | Pednekar A.,Philips | And 4 more authors.
Journal of Magnetic Resonance Imaging | Year: 2016

Purpose Magnetic resonance elastography (MRE) can estimate liver stiffness (LS) noninvasively. We prospectively assessed whether motion-encoding gradient (MEG) direction, slice position, or high-caloric food intake affects the repeatability of MRE measurements of LS. Materials and Methods Twenty healthy volunteers (8 women, 12 men; age, 48 ± 12 years) were imaged in a 3.0T scanner at four timepoints: twice after overnight fasting (B1, B2) and twice after consuming a 1050-calorie standardized meal (A1, A2; after 30 and 60 min, respectively). Each session comprised sequential MRE acquisitions in which MEG was applied in three orthogonal directions with three slices positioned over the liver for each. Between sessions, the participants were repositioned to assess test-retest reproducibility. Results The LS measurements before/after food intake were 3.36 ± 1.31 kPa/3.22 ± 1.03 kPa, 2.04 ± 0.33 kPa/2.27 ± 0.38 kPa, and 2.47 ± 0.50 kPa/2.64 ± 0.76 kPa for MEG superimposed along the anterior-posterior (AP), foot-head (FH), and right-left (RL) directions, respectively. Before and after food intake, LS estimates were lower and more reproducible (<10% coefficient of variation) when the MEG was in the FH direction, not the AP or RL direction. Liver stiffness estimates were significantly elevated after meal consumption when the MEG was in the FH direction (P < 0.05 for B1 vs. A1, B1 vs. A2, B2 vs. A1, and B2 vs. A2). Conclusion MRE estimates of LS were highly reproducible, particularly when MEG was applied in the FH direction, suggesting that this method could be used for long-term monitoring of antifibrotic therapy without repeated biopsies. High-caloric food intake resulted in slightly elevated LS on MRE. J. MAGN. RESON. IMAGING 2016;43:704-712. © 2015 Wiley Periodicals, Inc. Source

Chang J.Y.,University of Houston | Senan S.,VU University Amsterdam | Paul M.A.,VU University Amsterdam | Mehran R.J.,University of Houston | And 21 more authors.
The Lancet Oncology | Year: 2015

Background: The standard of care for operable, stage I, non-small-cell lung cancer (NSCLC) is lobectomy with mediastinal lymph node dissection or sampling. Stereotactic ablative radiotherapy (SABR) for inoperable stage I NSCLC has shown promising results, but two independent, randomised, phase 3 trials of SABR in patients with operable stage I NSCLC (STARS and ROSEL) closed early due to slow accrual. We aimed to assess overall survival for SABR versus surgery by pooling data from these trials. Methods: Eligible patients in the STARS and ROSEL studies were those with clinical T1-2a (<4 cm), N0M0, operable NSCLC. Patients were randomly assigned in a 1:1 ratio to SABR or lobectomy with mediastinal lymph node dissection or sampling. We did a pooled analysis in the intention-to-treat population using overall survival as the primary endpoint. Both trials are registered with ClinicalTrials.gov (STARS: NCT00840749; ROSEL: NCT00687986). Findings: 58 patients were enrolled and randomly assigned (31 to SABR and 27 to surgery). Median follow-up was 40·2 months (IQR 23·0-47·3) for the SABR group and 35·4 months (18·9-40·7) for the surgery group. Six patients in the surgery group died compared with one patient in the SABR group. Estimated overall survival at 3 years was 95% (95% CI 85-100) in the SABR group compared with 79% (64-97) in the surgery group (hazard ratio [HR] 0·14 [95% CI 0·017-1·190], log-rank p=0·037). Recurrence-free survival at 3 years was 86% (95% CI 74-100) in the SABR group and 80% (65-97) in the surgery group (HR 0·69 [95% CI 0·21-2·29], log-rank p=0·54). In the surgery group, one patient had regional nodal recurrence and two had distant metastases; in the SABR group, one patient had local recurrence, four had regional nodal recurrence, and one had distant metastases. Three (10%) patients in the SABR group had grade 3 treatment-related adverse events (three [10%] chest wall pain, two [6%] dyspnoea or cough, and one [3%] fatigue and rib fracture). No patients given SABR had grade 4 events or treatment-related death. In the surgery group, one (4%) patient died of surgical complications and 12 (44%) patients had grade 3-4 treatment-related adverse events. Grade 3 events occurring in more than one patient in the surgery group were dyspnoea (four [15%] patients), chest pain (four [15%] patients), and lung infections (two [7%]). Interpretation: SABR could be an option for treating operable stage I NSCLC. Because of the small patient sample size and short follow-up, additional randomised studies comparing SABR with surgery in operable patients are warranted. Funding: Accuray Inc, Netherlands Organisation for Health Research and Development, NCI Cancer Center Support, NCI Clinical and Translational Science Award. © 2015 Elsevier Ltd. Source

Zhang J.,CHI St. Lukes Health | Zhang J.,University of Houston | Fischer J.,CHI St. Lukes Health | Warner L.,Philips | And 3 more authors.
Journal of Magnetic Resonance Imaging | Year: 2015

Purpose: To estimate the local thermal conductivity of uterine fibroid in vivo at a high temperature range (60-80°C) typically encountered in magnetic resonance imaging-guided high-intensity focused ultrasound (MRgHIFU) surgery. The thermal conductivity of uterine fibroids in vivo is unknown and knowledge about tissue thermal conductivity may aid in effective delivery of thermal energy for ablation. Materials and Methods: All subjects (nine women) provided written informed consent to participate in this Institutional Review Board-approved study. A total of 10 fibroids were treated using MRgHIFU surgery with real-time temperature monitoring during both heating and cooling periods. The local thermal conductivity was determined by analyzing the spatiotemporal spread of temperature during the cooling period. Results: The thermal conductivity of MRgHIFU-treated uterine fibroids was 0.47 ± 0.07 W·m-1·K-1 (range: 0.25∼0.67 W·m-1·K-1) which is slightly lower than the reported value for skeletal muscle at temperatures of <40°C (0.52 to 0.62 W·m-1·K-1). Conclusion: It is possible to estimate the thermal conductivity of uterine fibroids in vivo from the spatiotemporal spread of temperature around the HIFU focus during the cooling period. © 2014 Wiley Periodicals, Inc. Source

Giardina T.D.,Baylor College of Medicine | Giardina T.D.,University of Houston | Callen J.,Macquarie University | Georgiou A.,Macquarie University | And 6 more authors.
Patient Education and Counseling | Year: 2015

To determine physician perspectives about direct notification of normal and abnormal test results. Methods: We conducted a cross-sectional survey at five clinical sites in the US and Australia. The US-based study was conducted via web-based survey of primary care physicians and specialists between July and October 2012. An identical paper-based survey was self-administered between June and September 2012 with specialists in Australia. Results: Of 1417 physicians invited, 315 (22.2%) completed the survey. Two-thirds (65.3%) believed that patients should be directly notified of normal results, but only 21.3% were comfortable with direct notification of clinically significant abnormal results. Physicians were more likely to endorse direct notification of abnormal results if they believed it would reduce the number of patients lost to follow-up (OR. =. 4.98, 95%CI. =. 2.21-1.21) or if they had personally missed an abnormal test result (OR. =. 2.95, 95%CI. =. 1.44-6.02). Conversely, physicians were less likely to endorse if they believed that direct notification interfered with the practice of medicine (OR. =. 0.39, 95%CI. =. 0.20-0.74). Conclusion: Physicians we surveyed generally favor direct notification of normal results but appear to have substantial concerns about direct notification of abnormal results. Practice implications: Widespread use of direct notification should be accompanied by strategies to help patients manage test result abnormalities they receive. © 2015. Source

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