BackgroundThe rapid adoption of image-guidance in prostate intensity-modulated radiotherapy (IMRT) results in longer treatment times, which may result in larger intrafraction motion, thereby negating the advantage of image-guidance. This study aims to qualify and quantify the contribution of image-guidance to the temporal dependence of intrafraction motion during prostate IMRT.MethodsOne-hundred and forty-three patients who underwent conventional IMRT (n=67) or intensity-modulated arc therapy (IMAT/RapidArc, n=76) for localized prostate cancer were evaluated. Intrafraction motion assessment was based on continuous RL (lateral), SI (longitudinal), and AP (vertical) positional detection of electromagnetic transponders at 10 Hz. Daily motion amplitudes were reported as session mean, median, and root-mean-square (RMS) displacements. Temporal effect was evaluated by categorizing treatment sessions into 4 different classes: IMRTc (transponder only localization), IMRTcc (transponder + CBCT localization), IMATc (transponder only localization), or IMATcc (transponder + CBCT localization).ResultsMean/median session times were 4.15/3.99 min (IMATc), 12.74/12.19 min (IMATcc), 5.99/5.77 min (IMRTc), and 12.98/12.39 min (IMRTcc), with significant pair-wise difference (p<0.0001) between all category combinations except for IMRTcc vs. IMATcc (p>0.05). Median intrafraction motion difference between CBCT and non-CBCT categories strongly correlated with time for RMS (t-value=17.29; p<0.0001), SI (t-value=−4.25; p<0.0001), and AP (t-value=2.76; p<0.0066), with a weak correlation for RL (t-value=1.67; p=0.0971). Treatment time reduction with non-CBCT treatment categories showed reductions in the observed intrafraction motion: systematic error (Σ)<0.6 mm and random error (σ)<1.2 mm compared with ≤0.8 mm and <1.6 mm, respectively, for CBCT-involved treatment categories.ConclusionsFor treatment durations >4-6 minutes, and without any intrafraction motion mitigation protocol in place, patient repositioning is recommended, with at least the acquisition of the lateral component of an orthogonal image pair in the absence of volumetric imaging.
Adaptive morphing with and without segment weight optimization can be used to compensate for the independent motion of the prostate and lymph nodes when combined with daily imaging or other methods to track the prostate motion. This method allows the delivery of the correct dose to both the prostate and lymph nodes with only small changes to the dose delivered to the target volumes.
Objective: To determine whether handheld widefield optical coherence tomography (OCT) can be used to document retinopathy of prematurity (ROP) stage while using scleral depression to improve peripheral views. Design: Prospective observational study. Participants: Consecutive neonates admitted to the neonatal intensive care unit (NICU) in a single academic medical center who also met criteria for ROP screening and consented for research imaging. Methods: Scleral depression was combined with widefield OCT using an investigational 400-kHz, 55-degree field of view handheld OCT during ROP screening from October 28, 2020 to March 03, 2021. Main Outcome Measures: Acquisition of en face and B-scan imaging of the peripheral retina to objectively assess early vitreoretinal pathology, including the demarcation between vascularized and anterior avascular retina, the presence of early ridge formation, and small neovascular tufts. Results: Various stages of ROP were detected using a rapid acquisition OCT system. In one neonate, serial OCT imaging over a five-week period demonstrated accumulation of neovascular tufts with progression to stage 3 ROP with extraretinal fibrovascular proliferation along the ridge. Videography of this technique is included in this report for instructional purposes. Conclusions: Serial examinations using widefield OCT and scleral depression may improve detection and documentation of ROP disease progression. Earlier detection of ROP-related proliferation may prevent vitreoretinal traction, retinal detachment, and blindness.
To describe Get Fruved year 03 components and outcomes. Description: Get Fruved is a health promotion intervention utilizing Community Based Participatory Research to develop and test a social marketing and environmental change intervention to prevent unwanted weight gain among older adolescents. The intervention was developed, refined, and pilot/feasibility tested at four intervention colleges with four other colleges as control. One high school (HS) served as a site for initial development and feasibility testing of the program and data collection tools. Evaluation: In 2015-2016 (college wave I), 578 nonfirst year students and 1,148 first year college students (FYCS) completed physical assessments and online surveys and 4,595 FYCS completed online-only surveys. In fall 2016, wave II online survey assessments were completed with 2,491 new FYCS and 237 HS students. Weight was the primary outcome, but since the intervention focused only on obesity-prevention, healthrelated behaviors, numerous health-related behaviors were assessed. Conclusions and Implications: Two-year post assessments with college wave I, and one-year post assessments with college wave II will be completed in May 2017. As of year 03, twelve new instruments/methods have been developed/validated, three college courses created, seventy-five presentations conducted, and a college toolkit (providing a systematic approach to promoting health for obesity prevention) has been developed for national testing and dissemination. In year 04, intervention refinement and feasibility testing will occur on eight additional HS campuses. In years 04 and 05 the toolkit will be tested for effectiveness using a Randomized Control Trial design on new college and HS campuses.
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