Magnetic Resonance Imaging of Tumor Associated Macrophages: Clinical Translation.
Clinical cancer research : an official journal of the American Association for Cancer Research
Tumor associated macrophages (TAM) in malignant tumors have been linked to tumor aggressiveness and represent a new target for cancer immunotherapy. As new TAM-targeted immunotherapies are entering clinical trials, it is important to detect and quantify TAM with non-invasive imaging techniques. The purpose of this study was to determine if ferumoxytol-enhanced MRI can detect TAM in lymphomas and bone sarcomas of pediatric patients and young adults.In a first-in-patient, IRB-approved prospective clinical trial, 25 pediatric and young adult patients with lymphoma or bone sarcoma underwent ferumoxytol-enhanced MRI. To confirm ferumoxytol enhancement, five pilot patients (2 lymphoma, 3 bone sarcoma) underwent pre- and post-contrast MRI. Subsequently, 20 patients (10 lymphoma, 10 bone sarcoma) underwent ferumoxytol-enhanced MRI 24-48 hours after intravenous injection, followed by tumor biopsy/resection and macrophage staining. To determine if ferumoxytol-MRI can differentiate tumors with different TAM content, we compared T2* relaxation times of lymphomas and bone sarcomas. Tumor T2* values of 20 patients were correlated with CD68+ and CD163+ TAM quantities on histopathology.Significant ferumoxytol tumor enhancement was noted on post-contrast scans compared to pre-contrast scans (P = 0.036). Bone sarcomas and lymphomas demonstrated significantly different MRI enhancement and TAM density (P < 0.05). Within each tumor group, T2* signal enhancement on MR images correlated significantly with the density of CD68+ and CD163+ TAM (P < 0.05).Ferumoxytol-enhanced MRI is immediately clinically applicable and could be used to stratify patients with TAM-rich tumors to immune-targeted therapies and to monitor tumor response to these therapies.
View details for PubMedID 29764855
Whole-body PET/MRI of Pediatric Patients: The Details That Matter.
Journal of visualized experiments : JoVE
Integrated PET/MRI is a hybrid imaging technique enabling clinicians to acquire diagnostic images for tumor assessment and treatment monitoring with both high soft tissue contrast and added metabolic information. Integrated PET/MRI has shown to be valuable in the clinical setting and has many promising future applications. The protocol presented here will provide step-by-step instructions for the acquisition of whole-body 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) PET/MRI data in children with cancer. It also provides instructions on how to combine a whole-body staging scan with a local tumor scan for evaluation of the primary tumor. The focus of this protocol is to be both comprehensive and time-efficient, which are two ubiquitous needs for clinical applications. This protocol was originally developed for children above 6 years, or old enough to comply with breath-hold instructions, but can also be applied to patients under general anesthesia. Similarly, this protocol can be modified to fit institutional preferences in terms of choice of MRI pulse sequences for both the whole-body scan and local tumor assessment.
View details for PubMedID 29286486
Calyceal diverticulum: a benign imitator of serious pathology.
BMJ case reports
A 72-year-old man with lung cancer underwent positron emission tomography CT (PET-CT) as a part of cancer staging. As an incidental finding, the PET-CT revealed a renal mass with metabolic and morphological characteristics of a malignant tumour. A diagnostic CT scan revealed a Bosniak III renal cyst, and malignancy could not be excluded. For correct Bosniak classification, a multiphasic contrast-enhanced CT was performed and the renal mass was finally diagnosed as a calyceal diverticulum. This case report summarises how calyceal diverticula may mimic serious pathology, leading to diagnostic difficulties.
View details for DOI 10.1136/bcr-2013-202301
View details for PubMedID 24872479
View details for PubMedCentralID PMC4039884