Radiology

Global Outreach for U.S. Radiology Training Programs Abstract Purpose of Review Utilization of medical imaging is increasing in the developing world, creating new opportunities for U.S. radiology training programs to establish international electives for interested faculty and residents. Though the nature of each initiative will vary, the process of creating a global outreach elective involves core elements. Recent Findings Development of a sustainable and impactful global elective requires forethought and planning, including abiding by regulations from governing bodies and preparation for practicing in a culturally different and often resource-limited environment. Summary This article will provide a summary of requirements for creating and sustaining a global outreach elective and provide ideas and resources for overcoming common roadblocks.

Imaging in Lung Cancer Abstract Purpose of Review To describe the current role of imaging in the detection, staging, therapy planning and response assessment in lung cancer. Recent Findings Lung cancer screening using low-dose CT has been shown to reduce mortality in risk groups of active or former smokers and has, thus, been recommended by several societies and organisations worldwide. There remain, however, questions regarding optimum definition of risk factors and screening intervals. Staging criteria for lung cancer have been updated in the 8th edition of the TNM staging to better reflect prognosis. Preliminary research in radiomics in lung cancer has provided data that may add to identification of early lung cancer, prediction of prognosis and therapy response. Targeted systemic therapy has recently had a significant impact in advanced lung cancer both in terms of efficacy and toxicity, but radiologists need to be aware that response assessment criteria differ from those used for classic chemotherapy, and new side effects that may occur. Summary Modern imaging, particulary exploiting radiomics will improve early detection, classification, staging, therapy planning and ultimately, hopefully, prognosis in lung cancer.

PET Imaging of Hepatocellular Carcinoma Abstract Purpose of Review Positron emission tomography has not traditionally played a major role in the evaluation of hepatocellular carcinoma (HCC). Owing to high background liver uptake and molecular mechanisms within HCC lesions, uptake of 18F-fluorodeoxyglucose (FDG) is variable and prior studies have shown only modest overall detection of intrahepatic disease. Recent Findings Tracers such as 18F- and 11C-choline as well as 11C-acetate have been explored either in isolation or together with 18F-FDG have shown greater promise in detection of intrahepatic lesions, but yet are not in widespread clinical use. 68 Ga-Prostate specific membrane antigen is a tracer developed for use in prostate cancer but a pilot study and several case reports have indicated that there may be the potential for use in the evaluation of HCC. Summary Increased rates of lesion detection using 18F-FDG may be seen in poorly differentiated tumors and in the setting of metastatic disease or within recurrent tumor following loco-regional therapies and FDG uptake may indicate a greater risk of recurrence following transplantation. Further work will be required to elucidate the precise role of other non FDG tracers in the evaluation of patients at risk for or with HCC.

Humanitarian Teleradiology Abstract Purpose of Review To outline the current state of humanitarian teleradiology: scope of projects, technical and organization challenges, and to outline how recent technological developments will change the face of humanitarian teleradiology and global health. Recent Findings Technical and information technology improvements in recent years have enabled small- and large-scale teleradiology projects in many regions, some quite remote, of low- and middle-income countries (LMICs). These are aimed at alleviating the severe shortage of radiologists in LMICs. Teleradiology offers an opportunity for radiologists in high-income countries (HICs) to volunteer and contribute on an ongoing basis without the commitment of time and effort required by volunteers in other forms of global health. Recent and anticipated improvements in internet availability, as well as the emergence of artificial intelligence (AI), will continue to change the face of teleradiology and radiology in LMICs. Summary Humanitarian teleradiology provides valuable benefits to patient care in LMICs, and the combination of AI and widespread access to high-speed internet will revolutionize the field within the next decade.

Emerging Role of Fluciclovine and Other Next Generation PET Imaging Agents in Prostate Cancer Management Abstract Purpose of Review Prostate cancer recurrence after definitive therapy is not uncommon. Recurrent disease is first detected by the elevation of prostate specific antigen (PSA) and may often be radiographically occult. The use of molecular imaging for the localization and staging of recurrent prostate cancer is promising. 18F-Fluciclovine is a synthetic amino acid analog positron emission tomography (PET) tracer which has demonstrated great utility in the evaluation of patients with suspected recurrence disease. Other newer PET tracers such 68Ga/18F-PSMA-ligands are being investigated for prostate imaging with promising results. The purpose of this article is to review the emerging role of fluciclovine in clinical practice for patients with prostate cancer. Recent Findings Since the approval of fluciclovine by the Food and Drug Administration, the modality is widely used in the USA for patients with suspect disease recurrence. With the coming approval of newer generation of PET tracers, it is important to understand the unique mechanism of action and the diagnostic performance of fluciclovine PET/CT in prostate cancer imaging to allow better allocation of the radiotracers. Summary This review article provides a broad literature review of the current and the future potential role of fluciclovine PET/CT in prostate cancer imaging.

Somatostatin Receptor Positron Emission Tomography: Beyond Gastroenteropancreatic Neuroendocrine Tumors Abstract Purpose of Review Similar to various gastroenteropancreatic (GEP) neuroendocrine tumors (NETs), somatostatin receptors (SSTRs) are overexpressed in a wide array of malignant and benign conditions. Using somatostatin positron emission tomography (PET) analogs ([68Ga]DOTA-peptides) this overexpression of SSTRs can be exploited for clinical management in terms of diagnosis, therapy, and for peptide receptor radionuclide therapy (PRRT). Recent Findings Recent reports suggest that [68Ga]DOTA-peptide PET tracers have an emerging role in the management of wide array of non-GEP-NETs due to overexpression of SSTRs. The potential role of SSTR-PET imaging in the management of medullary thyroid cancer, paraganglioma, Merkel cell carcinoma, phosphaturic mesenchymal tumors, and inflammation will be discussed. The emerging role of theranostic and personalized medicine with PRRT using peptides labeled with yttrium-90 (90Y) or lutetium-177 (177Lu) beta emitters will also be discussed. Summary SSTR-PET imaging with [68Ga]DOTA-peptides has utility in malignant and benign conditions other than GEP-NETs. Combining SSTR-PET with other anatomic and functional imaging modalities has demonstrated superior diagnostic accuracy. The presence of SSTRs in these conditions opens up new possibilities in the management of these conditions in terms of imaging and therapeutics.

Technology-Mediated Education in Global Radiology: Opportunities and Challenges Abstract Purpose of review This review explores opportunities and challenges in utilizing technology-mediated educational strategies for radiology education in parts of the world where attending radiologist support is limited. In efforts to increase the number of radiologists globally, radiology residencies have been established in regions where radiologists are scarce, several of which have partnerships with programs in other parts of the world. Technology-mediated educational strategies could leverage these partnerships to provide critical infrastructure to these recently established residencies. Recent findings The efficacies of strategies such as teleradiology and teleconferencing in global radiology have been evaluated, as have the effectiveness of technology-mediated educational tools in radiology. The topic of technology-mediated instruction for the newly established radiology residencies in other parts of the world has not yet been described or assessed, however. Summary Technology-mediated education has potential in the expanding realm of global radiology resident education, but there are some important constraints in the execution of these programs.

Amino Acid PET Imaging of Glioma Abstract Purpose of Review Gliomas are among the most lethal malignancies in the world with dismal outcomes for high-grade tumors. These lesions are difficult to completely characterize with conventional magnetic resonance imaging and amino acid positron emission tomography is a rapidly progressing area of research with widespread clinical use. Recent Findings Amino acid positron emission tomography allows for more accurate glioma characterization compared to traditional imaging techniques including grading of disease, delineation of tumor spread, identification of recurrent disease, and prognosis. While the summarized radiotracers share some diagnostic properties, each also has its own weaknesses and strengths. Summary This article summarizes recent developments and clinical applications of the most widely used amino acid radiotracers. While none of these agents are FDA approved in the United States, they are considered standard of care in Europe and other parts of the world with > 10,000 studies being performed in some centers (Langen et al. in J Neurooncol 120(3):665–666, 2014).

Molecular Imaging of Renal Malignancy: A Review Abstract Purpose of Review Renal cell carcinoma (RCC) is a common malignancy that is often detected incidentally in patients undergoing cross-sectional imaging of the abdomen for workup of pain or other symptoms. Due to overlap in imaging findings of RCC and benign tumors, biopsy may be necessary to confirm the diagnosis. Biopsies are occasionally non-diagnostic, however, and in small lesions or patients with comorbidities may not be technically feasible. Molecular imaging techniques can characterize tumors as being more likely malignant or benign and obviate the need for invasive testing, as well as providing accurate whole-body staging in patients with known RCC. Recent Findings PET/CT with 18F-FDG and other radionuclides can identify primary renal masses with higher malignant potential and also allows for sensitive detection of metastatic RCC. SPECT/CT imaging with 99mTc-sestamibi can provide useful information to support the diagnosis of benign oncocytic neoplasms over more aggressive RCC subtypes. Investigational molecular imaging techniques such as immunoPET and hyperpolarized 13C MRI have also shown promise in renal mass characterization. Summary This review article aims to outline the various molecular imaging modalities available in the evaluation of primary renal tumors and in whole-body staging of metastatic RCC.

Thyroid Sonography: Nuclear Medicine Point of View Abstract Purpose of Review The American Cancer Society estimated that cancer of the thyroid causes 53,990 new cases and about 2060 deaths in 2018. The chance of being diagnosed with thyroid cancer has risen and this increment seems to be the result of increased use of ultrasound, CT and MR imaging examinations for reasons unrelated to the thyroid. Up to 50% of adults in central Europe have one or multiple thyroid nodules. However, the prevalence of latent carcinoma in an unselected autopsy study was 8.6%. The main diagnostic task is to differentiate between benign and malignant lesions, preferably based upon on ultrasound parameters or scoring systems like TI-RADS. Recent Findings Although there are no pathognomonic features for malignant thyroid nodules at ultrasonography or any other imaging modality, sonography of the thyroid gland has beyond doubt become the imaging method of choice for the last three decades, combined with FNA in suspicious cases. Summary Several technological improvements like ultrasound elastography, and a proliferating literature of different scoring systems allow the conclusion that ultrasound is an important gatekeeper for further diagnostic steps but not capable, so far, to identify autonomy or malignancy with a sufficiently high accuracy.