Purpose: This is a retrospective study in which we define multiple metrics for similarity and then inquire on the relationship between similarity and currently used dosimetric quantities describing preimplant and postimplant plans.
Methods And Materials: We analyzed a unique cohort of 94 consecutively performed prostate seed implant patients, associated with excellent dosimetric and clinical outcomes. For each patient, an ultrasound (US) preimplant and two CT postimplant (Day 0 and Day 30) studies were available. Measures for similarity were created and computed using feature vectors based on two classes of moments: first, invariant to rotation and translation, and the second polar-radius moments invariant to rotation, translation, and scaling. Both similarity measures were calibrated using controlled perturbations (random and systematic) of seed positions and contours in different size implants, thus producing meaningful numerical threshold values used in the clinical analysis.
Results: An important finding is that similarity, for both seed distributions and contours, improves significantly when scaling invariance is added to translation and rotation. No correlation between seed and contours similarity was found. In the setting of preplanned prostate seed implants using preloaded needles, based on our data, similarity between preimplant and postimplant plans does not correlate with either minimum dose to 90% of the volume of the prostate or analogous similarity metrics for prostate contours.
Conclusions: We have developed novel tools and metrics, which will allow practitioners to better understand the relationship between preimplant and postimplant plans. Geometrical similarity between a preplan and an actual implant, although useful, does not seem to be necessary to achieve minimum dose to 90% of the volume of the prostate-good dosimetric implants.
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http://dx.doi.org/10.1016/j.brachy.2014.06.002 | DOI Listing |
Rev Cardiovasc Med
January 2025
Department of Cardiovascular Medicine, Wonkwang University Medical School, 54536 Iksan, Republic of Korea.
Background: Right ventricular (RV) pacing exacerbates heart failure and increases cardiac mortality in patients with reduced ejection fraction (EF). However, its impact on left ventricular dysfunction in patients with preserved EF remains inconclusive. This study investigates the relationship between RV pacing, global longitudinal strain (GLS), and EF in patients with preserved EF.
View Article and Find Full Text PDFESC Heart Fail
January 2025
Division of Cardiology, Department of Medicine, Hospital of the University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
Aims: Right ventricular (RV) failure (RVF) after left ventricular assist device (LVAD) implant is an important cause of morbidity and mortality. Modern, data-driven approaches for defining and predicting RVF have been under-utilized.
Methods: Two hundred thirty-two patients were identified with a mean age of 55 years; 40 (17%) were women, 132 were (59%) Caucasian and 74 (32%) were Black.
Circ Cardiovasc Interv
January 2025
Department of Pediatrics, Pediatric Cardiology (J.K.Y., L.W., A.C.T., H.C., A.W.R., L.F.P., S.R.C., A.M.D., D.B.M.), Stanford University, Palo Alto, CA.
Background: Varying rates of nonsustained ventricular tachycardia (NSVT) have been reported early after transcatheter pulmonary valve replacement (TPVR) with the Harmony valve, but data regarding rhythm outcomes beyond hospital discharge are limited. This study aims to characterize ventricular arrhythmias after Harmony TPVR from implant through mid-term follow-up.
Methods: Ventricular arrhythmia data from postimplant telemetry and follow-up extended rhythm monitoring (ERM) were analyzed after Harmony TPVR.
J Nutr Health Aging
December 2024
Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China. Electronic address:
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