Liquid Biopsy for Cancer: Review and Implications for the Radiologist.

Imaging and image-guided procedures play an imperative role in the screening, diagnosis, and surveillance of cancer. Although emerging imaging techniques now enable more precise molecular characterization of tumors, multigenetic tumor profiling for targeted therapeutic selection remains limited to direct tissue acquisition. Even in the context of targeted therapy, tumors adapt to acquire resistance. This necessitates serial monitoring, traditionally through tissue acquisition, to identify the molecular mechanism of resistance and to guide second-line therapy. An alternative to tissue acquisition is the collection of circulating tumor markers such as cell-free nucleic acids and circulating tumor cells in the peripheral blood. This noninvasive diagnostic approach is referred to as the liquid biopsy. The liquid biopsy is currently used clinically for therapeutic guidance when tissue acquisition is impossible or when the specimen is inadequate. It is also being studied in the context of screening, diagnosis, and surveillance. As cancer treatment continues to move toward a focus on precision medicine, this developing technology may alter and/or augment the role of imaging in the management of cancer. This review aims to outline the use of liquid biopsy in cancer and its potential impact on diagnostic imaging and image-guided procedures.

MR Neurographic Evaluation of Facial and Neck Pain: Normal and Abnormal Craniospinal Nerves below the Skull Base.

Cranial nerve disease outside the skull base is a common cause of facial and/or neck pain, which causes significant disability for patients and frustration for clinicians. Neuropathy in this region can be traumatic, idiopathic, or iatrogenic secondary to dental and surgical procedures. MR neurography is a modification of conventional MRI techniques dedicated to evaluation of peripheral nerves and is being increasingly used for imaging of peripheral neuropathies at various sites in the body. MR neurography facilitates assessment of different causes of craniofacial pain and cranial nerves and allows elegant depiction of a multitude of regional neuropathies. This article discusses the anatomy, pathologic conditions, and imaging findings of the commonly implicated but difficult to image infratentorial nerves, such as the peripheral trigeminal nerve and its branches, facial nerve, glossopharyngeal nerve, vagus nerve, hypoglossal nerve, and greater and lesser occipital nerves. ©RSNA, 2018.

Capacity Prioritization Initiative Reduced the Wait Time for Port Placement and Facilitated Increased Volume of Port Placements at a Large County Health System.

DESCRIPTION OF THE PROBLEM: Wait time from request to placement of ports in interventional radiology had increased from 14 to 27 days over a 4-month period. The goal of this project was to reduce the wait time by 15% within 4 months while accommodating additional volume. INSTITUIONAL APPROACH TO ADDRESS PROBLEM: Capacity analysis revealed 2 bottlenecks: (1) inadequate provider capacity for preprocedural visits in interventional radiology clinic and (2) inadequate number of spots for port placement in the angiography schedule. The intervention consisted of: (1) 2 reserved slots in the attending physician's morning clinic schedule and (2) 3 daily guaranteed spots for port placement in the angiography suite. Both changes were integrated into the electronic medical record scheduling system. DESCRIPTION OF OUTCOMES: After the intervention, per biweekly period, the number of port requests increased by 17% (Preintervention: 16.6 ± 3.1, Postintervention: 20.1 ± 4.1, P = 0.03), the number of completed clinic visits increased by 19% (Preintervention: 16.7 ± 5.1, Postintervention: 20.5 ± 3.6, P = 0.05), and the number of port placements increased by 19% (Preintervention: 16.9 ± 3.9, Postintervention: 21.0 ± 3.5, P = 0.02). The average wait time from request to placement decreased by 22% (Preintervention: 22.2 ± 4.4 days, Postintervention: 18.3 ± 3.4 days, P = 0.03), driven by a 49% decrease in wait time between request and clinic visit (Preintervention: 11.0 ± 2.3 days, Postintervention: 7.4 ± 1.0 days, P = 0.03). CONCLUSIONS: Prioritization of clinic and angiography suite capacity, integrated into the electronic scheduling system, significantly reduced the wait time for port placement, even with significant increases in the volume of port requests.

Blockade of VEGFR2 and not VEGFR1 can limit diet-induced fat tissue expansion: role of local versus bone marrow-derived endothelial cells.

BACKGROUND: We investigated if new vessel formation in fat involves the contribution of local tissue-derived endothelial cells (i.e., angiogenesis) or bone marrow-derived cells (BMDCs, i.e. vasculogenesis) and if antiangiogenic treatment by blockade of vascular endothelial growth factor (VEGF) receptors can prevent diet-induced obesity (DIO). METHODOLOGY/PRINCIPAL FINDINGS: We performed restorative bone marrow transplantation into wild-type mice using transgenic mice expressing green fluorescent protein (GFP) constitutively (driven by beta-actin promoter) or selectively in endothelial cells (under Tie2 promoter activation) as donors. The presence of donor BMDCs in recipient mice was investigated in fat tissue vessels after DIO using in vivo and ex vivo fluorescence microscopy. We investigated the roles of VEGF receptors 1 and 2 (VEGFR1/VEGFR2) by inducing DIO in mice and treating them with blocking monoclonal antibodies. We found only marginal (less than 1%) incorporation of BMDCs in fat vessels during DIO. When angiogenesis was inhibited by blocking VEGFR2 in mice with DIO, treated mice had significantly lower body weights than control animals. In contrast, blocking VEGFR1 had no discernable effect on the weight gain during DIO. CONCLUSIONS/SIGNIFICANCE: Formation of new vessels in fat tissues during DIO is largely due to angiogenesis rather than de novo vasculogenesis. Antiangiogenic treatment by blockade of VEGFR2 but not VEGFR1 may limit adipose tissue expansion.