Magnetic Resonance Imaging In Planning Research Articles

Practice Patterns for the Treatment of Uveal Melanoma with Iodine-125 Plaque Brachytherapy: Ocular Oncology Study Consortium Report 5

Background: Treatment planning for I-125 plaque therapy for uveal melanoma has advanced significantly since the Collaborative Ocular Melanoma Study trial, with more widely available image-guided planning and improved dosimetry. Objective: We evaluated real-world practice patterns for I-125 plaque brachytherapy in the United States by studying practice patterns at centers that comprise the Ocular Oncology Study Consortium (OOSC). Methods: The OOSC database and responses to a treatment practice survey were evaluated. The database contains treatment information from 9 institutions. Patients included in the database were treated between 2010 and 2014. The survey was conducted in 2018 and current treatment planning methods and prescriptions were queried. Results: Examination of the OOSC database revealed that average doses to critical structures were highly consistent, with the exception of one institution. Survey responses indicated that most centers followed published guidelines regarding dose and prescription point. Dose rate ranged from 51 to 118 cGy/h. As of 2018, most institutions use pre-loaded plaques and fundus photographs and/or computed tomography or magnetic resonance imaging in planning. Conclusions: While there were differences in dosimetric practices, overall agreement in plaque brachytherapy practices was high among OOSC institutions. Clinical margins and planning systems were similar among institutions, while prescription dose, dose rates, and dosimetry varied.

Changes in Brain Metastasis During Radiosurgical Planning

To determine whether there are any changes in brain metastases or resection cavity volumes between planning magnetic resonance imaging (MRI) and radiosurgery (RS) treatment and whether these led to a change in management or alteration in the RS plan. Patients undergoing RS for brain metastasis or tumor resection cavities had a standardized planning MRI (MRI-1) performed and a repeat verification MRI (MRI-2) 24hours before RS. Any change in management, including replanning based on MRI-2, was recorded. Thirty-four patients with a total of 59 lesions (44 metastases and 15 tumor resection cavities) were assessed with a median time between MRI-1 and MRI-2 of 7days. Seventeen patients (50%) required a change in management based on the changes seen on MRI-2. For patients with 7days or less between scans, 41% (9 of 22) required a change in management; among patients with 8days or more between scans, 78% (7 of 9) required a change in management. Per lesion, 32 out of 59 lesions required replanning, including 7 of 15 (47%) cavities and 25 of 44 (57%) metastases, with the most common reason (23 lesions) being an increase in gross target volume (tumor) or clinical target volume (tumor cavity). Measurable changes occur in brain metastasis over a short amount of time, with a change in management required in 41% of patients with 7days between MRI-1 and MRI-2 and in 78% of patients when there is a delay longer than 7days. We therefore recommend that the time between planning MRI and RS treatment be as short as possible.

Magnetic resonance imaging planning in children with complex congenital heart disease - A new approach.

ObjectivesTo compare a standard sequential 2D Planning Method (2D-PM) with a 3D offline Planning Method (3D-PM) based on 3D contrast-enhanced magnetic resonance angiography (CE-MRA) in children with congenital heart disease (CHD).DesignIn 14 children with complex CHD (mean: 2.6 years, range: 3 months to 7.6 years), axial and coronal cuts were obtained with single slice spin echo sequences to get the final double oblique longitudinal cut of the targeted anatomical structure (2D-PM, n = 31). On a separate workstation, similar maximal intensity projection (MIP) images were generated offline from a 3D CE-MRA. MIP images were localizers for repeated targeted imaging using the previous spin echo sequence (3D-PM). Finally, image coverage, spatial orientation and acquisition time were compared for 2D-PM and 3D-PM.Main outcome measures2D-PM and 3D-PM images were similar: both perfectly covered the selected anatomic regions and no spatial differences were found (p>0.05). The mean time for creation of the final imaging plane was 241 ± 31 s (2D-PM) compared to 71 ± 18 s (3D-PM) (p<0.05).Conclusions3D-PM shows similar results compared to 2D-PM, but allows faster and offline planning thereby reducing the scan time significantly. As newly developed high-resolution 3D datasets can also be used further improvement of this technology is expected.

English

MRI is an accurate, noninvasive imaging modality for evaluation of knee injuries, and determines the patient management, saving them from unnecessary arthroscopy. Our study focuses on the fundamental biomechanical forces underlying the most common injuries and correlate MRI findings with specific traumatic mechanisms. We conducted a retrospective study on 138 patients having prior history of knee trauma. The studies evaluated cruciate ligament tears, collateral ligament injuries, chondromalacia patella, bone marrow contusions, joint INTRODUCTION : Since the initial application in 1984, Magnetic resonance (MR) imaging of the knee has undergone significant advances for evaluation of the menisci, ligaments, bone marrow contusions. MR examination, a noninvasive modality, is now routinely used to assess a wide spectrum of internal knee derangements and articular disorders and has virtually replaced conventional arthrography in the evaluation of the menisci and the cruciate ligaments. Biomechanical forces play a very vital role in ascertaining the type of knee injuries. In addition to diagnostic benefits and in the selection of surgical candidates with preoperative planning MR imaging has proved valuable. Further, improved patient-doctor communication and reduction in the cost of MR knee studies has contributed to their greater acceptance by the orthopaedic community. MRI has become the imaging modality of choice for the evaluation of the painful knee following injury. It can detect soft tissue abnormalities (meniscal, cruciate, collateral ligament tears) and microtrabecular fractures that cannot be detected by plain film.