Search

Radiotherapy is a common approach for the treatment of a wide variety of cancer types. Available data indicate that nanoparticles can enhance the effect of radiotherapy. We report the use of human mesenchymal stem cells to selectively deliver gold nanoparticles (GNPs) to MDA-MB-231 breast tumor xenografts in mice for the purpose of enhancing the effect of radiation therapy. Targeted delivery of GNPs to the tumor site, followed by irradiation of the tumor, enabled control of tumor growth. The results indicate that tumor-selective GNP delivery by human mesenchymal stem cells may represent a viable way to enhance the effectiveness of radiotherapy.

Current FDA-approved imaging modalities are inadequate for localizing prostate cancer biochemical recurrence (BCR).Men with rising PSA ≥0.2 ng/mL after prostatectomy or ≥2 ng/mL above nadir after radiotherapy were eligible. The primary endpoint was correct localization rate (CLR), defined as positive predictive value with an additional requirement of anatomic lesion colocalization betweenA total of 208 men with a median baseline PSA of 0.8 ng/mL (range: 0.2-98.4 ng/mL) underwentPerformance of

Twenty-five years ago, oligometastatic disease was proposed as an intermediary clinical state of cancer with unique implications for therapies that may impact cancer evolution and patient outcome. Identification of limited metastases that are potentially amenable to targeted therapies fundamentally depends on the sensitivity of diagnostic tools, including new-generation imaging methods. For men with biochemical recurrence after definitive therapy of the primary prostate cancer, PET/CT using either the FDA-approved radiolabeled amino acid analogue

Coronavirus disease 2019 (COVID-19), a highly contagious respiratory disease, has rapidly become a global pandemic. Chest X-ray imaging could serve an important role in early diagnosis of the disease. Deep learning methods have recently shown promise in disease detection tasks. The aim of this study was to develop a deep learning-based approach for detection of COVID-19 in chest X-ray images. Data were extracted from an opensource COVID-19 database developed by Cohen JP. The data consisted of X-ray images of patients with COVID-19, with other pneumonias or with no findings. The 205 images were randomly partitioned into training, validation and test datasets containing 143, 32, and 30 images, respectively, using a 70%/15%/15% split. The performance of several deep convolutional neural network (CNN)-based architectures, including VGG16, ResNet50, DenseNet121, and InceptionV3, were evaluated on the disease detection task. These networks were first pretrained on the ImageNet dataset consisting of natural images and then further fine-tuned on the task of detecting COVID-19 in chest X-ray images. The networks were then evaluated on the test set by assessing overall accuracy, area under receiver operating characteristic curve (AUROC), sensitivity and specificity. The performance of the networks trained from scratch without pretraining on ImageNet was also compared to the performance of the networks that were first pretrained on ImageNet and then fine-tuned on the detection task. DenseNet121 had the best performance on the test set with an overall accuracy of 90.0% (95% confidence interval (CI): 78.6%, 100%), an AUROC of 0.95, a sensitivity of 91.3% and a specificity of 85.7%. The pretrained DenseNet121 also significantly outperformed the DenseNet121 trained from scratch with a 30.0% improvement in overall accuracy. The proposed deep learning-based approach showed significant promise for detection of COVID-19 in chest X-ray images.

PET with small molecules targeting prostate-specific membrane antigen (PSMA) is being adopted as a clinical standard for prostate cancer imaging. In this study, we evaluated changes in uptake on PSMA-targeted PET in men starting abiraterone or enzalutamide. Methods: This prospective, single-arm, 2-center, exploratory clinical trial enrolled men with metastatic castration-resistant prostate cancer initiating abiraterone or enzalutamide. Each patient was imaged with (18)F-DCFPyL at baseline and within 2–4 mo after starting therapy. Patients were followed for up to 48 mo from enrollment. A central review evaluated baseline and follow-up PET scans, recording change in SUV(max) at all disease sites and classifying the pattern of change. Two parameters were derived: the δ-percent SUV(max) (DPSM) of all lesions and the δ-absolute SUV(max) (DASM) of all lesions. Kaplan–Meier curves were used to estimate time to therapy change (TTTC) and overall survival (OS). Results: Sixteen evaluable patients were accrued to the study. Median TTTC was 9.6 mo (95% CI, 6.9–14.2), and median OS was 28.6 mo (95% CI, 18.3–not available [NA]). Patients with a mixed-but-predominantly-increased pattern of radiotracer uptake had a shorter TTTC and OS. Men with a low DPSM had a median TTTC of 12.2 mo (95% CI, 11.3–NA) and a median OS of 37.2 mo (95% CI, 28.9–NA), whereas those with a high DPSM had a median TTTC of 6.5 mo (95% CI, 4.6–NA, P = 0.0001) and a median OS of 17.8 mo (95% CI, 13.9–NA, P = 0.02). Men with a low DASM had a median TTTC of 12.2 mo (95% CI, 11.3–NA) and a median OS of NA (95% CI, 37.2 mo–NA), whereas those with a high DASM had a median TTTC of 6.9 mo (95% CI, 6.1–NA, P = 0.003) and a median OS of 17.8 mo (95% CI, 13.9–NA, P = 0.002). Conclusion: Findings on PSMA-targeted PET 2–4 mo after initiation of abiraterone or enzalutamide are associated with TTTC and OS. Development of new lesions or increasing intensity of radiotracer uptake at sites of baseline disease are poor prognostic findings suggesting shorter TTTC and OS.

Prostate-specific membrane antigen (PSMA; also termed glutamate carboxypeptidase II (GCP II)) is abundantly expressed in prostate cancer. It has been shown recently that PSMA is expressed in neovasculature of differentiated thyroid cancer. In this study, we show that 18F-DCFPyl might detect neovasculature in advanced, metastatic differentiated thyroid cancer (DTC). We first stained the preserved lymph node samples of three patients with DTC who had undergone total thyroidectomy and neck dissection for cervical lymph node metastatic disease to identify PSMA expression, with the PSMA antibody (DAKO Monoclonal). Then, we performed 18F-DCFPyl imaging in two other advanced DTC patients with elevated serum thyroglobulin (Tg), indicative of residual disease. We compared the findings with contemporaneous FDG PET/CT scan, conventional Imaging (CT,MRI) and whole-body scan performed with I123/I131. All the three lymph node samples stained positive for PSMA expression in the neovasculature. In the first imaged patient, 18F-DCFPyl detected activity within the retropharyngeal CT contrast-enhancing lymph node. Compared to FDG PET/CT, the 18F-DCFPyl scan showed a greater SUV (3.1 vs 1.8). In the second imaged patient, 18F-DCFPyl showed intense uptake in the L3 vertebra (not seen on the post treatment 131I scan or the 18F-FDG PET/CT). MRI of the lumbar spine confirmed the presence of sclerotic-lytic lesion at the location, consistent with metastatic disease. Our exploratory study is proof of principle, that the prostate cancer imaging agent 18F-DCFPyl may prove useful for the localization of metastases, in patients with metastatic RAI-refractory DTC by detecting neoangiogenesis within the tumor.

35 Background: The OSPREY clinical trial was a phase 2/3 prospective study of prostate specific membrane antigen (PSMA) PET/CT using piflufolastat F 18. Piflufolastat F 18 (aka 18F-DCFPyL or PyL) is a novel PSMA-targeting radiopharmaceutical approved for imaging of PCa pts both at initial staging and for disease recurrence. Here we describe SUV results by biopsy status, baseline PSA levels, and Gleason score (GS). Methods: Piflufolastat F 18 -PET/CT was evaluated in men with NCCN high-risk PCa scheduled to undergo radical prostatectomy with pelvic lymphadenectomy (RP-PLND) (Cohort A) and men with radiologically suspected recurrent/metastatic PCa (Cohort B). A single IV dose of 9 mCi (333 MBq) of piflufolastat F 18 was administered followed by PET/CT acquisition 1-2 hours later. Piflufolastat F 18 uptake in various lesion locations as defined by maximum and peak SUV (SUVmax, SUVpeak) were determined by three blinded, independent central readers for each tissue (e.g., bone, lymph nodes (LN), soft tissue). To measure SUVs, the reader placed a volume of interest (VOI) on each identified lesion. SUVmax was defined as the maximum single-voxel SUV within the VOI. SUVpeak within the VOI was defined as the average SUV within a fixed-sized VOI (1 cm diameter sphere), representing the cluster with the highest average SUV. Results: 345 men underwent piflufolastat F 18-PET/CT. Cohort B (n = 93 evaluable) SUVmax and SUVpeak were significantly higher for biopsy positive (+) (one biopsy lesion/pt) when compared to biopsy negative (-) lesions from bone and LN. SUVpeak for biopsied bone and LN (Cohort B) appeared to increase with rising baseline PSA. In high-risk PCa pts, SUVpeak for prostate (Cohort A; n = 252 evaluable) increased with baseline PSA and were highest for GS 9-10 (Table). Conclusions: Piflufolastat F 18-PET/CT uptake was significantly higher in biopsy + lesions and increased with baseline PSA. Prostate SUVpeak was highest for GS 9-10. Clinical trial information: NCT02981368. [Table: see text]

Enterobacterales represent the largest group of bacterial pathogens in humans and are responsible for severe, deep-seated infections, often resulting in sepsis or death. They are also a prominent cause of multidrug-resistant (MDR) infections, and some species are recognized as biothreat pathogens. Tools for noninvasive, whole-body analysis that can localize a pathogen with specificity are needed, but no such technology currently exists. We previously demonstrated that positron emission tomography (PET) with 2-deoxy-2-[(18)F]fluoro-D-sorbitol ((18)F-FDS) can selectively detect Enterobacterales infections in murine models. Here, we demonstrate that uptake of (18)F-FDS by bacteria occurs via a metabolically conserved sorbitol-specific pathway with rapid in vitro (18)F-FDS uptake noted in clinical strains, including MDR isolates. Whole-body (18)F-FDS PET/computerized tomography (CT) in 26 prospectively enrolled patients with either microbiologically confirmed Enterobacterales infection or other pathologies demonstrated that (18)F-FDS PET/CT was safe, could rapidly detect and localize Enterobacterales infections due to drug-susceptible or MDR strains, and differentiated them from sterile inflammation or cancerous lesions. Repeat imaging in the same patients monitored antibiotic efficacy with decreases in PET signal correlating with clinical improvement. To facilitate the use of (18)F-FDS, we developed a self-contained, solid-phase cartridge to rapidly (

To prospectively evaluate the distribution of PSMA-targeted PET-avid lesions in prostate cancer (PCa) patients with biochemical recurrence in a Chinese cohort. The relationships between PSA levels, disease-free time after prostatectomy, and 68Ga-PSMA-11 PET/computed tomography (CT) findings were investigated. Inclusion criteria included histopathologically proven prostate adenocarcinoma, two consecutive PSA levels > 0.20 ng/mL, and negative CT of the abdomen and pelvis or magnetic resonance imaging of the pelvis and whole-body bone scan. Exclusion criteria were non-prostate malignancy within 3 years and persistent PSA after radical prostatectomy. Patients with findings of recurrent disease on re-staging conventional imaging were excluded, as were patients previously treated with systemic therapy and/or salvage therapy. 51 patients were enrolled in this study. 34/51 (66.7%) patients had at least one site of 68Ga-PSMA-11 uptake consistent with PCa. 23.5% of patients had recurrence in the prostate bed, 27.4% had pelvic lymph nodes, 15.7% had extrapelvic lymph node metastases, and 17.6% had bone metastases. For patients with lymph node involvement/metastasis, bone metastasis, and patients with both, their median serum PSA levels were 1.83 ng/mL, 4.03 ng/mL, and 2.54 ng/mL, respectively. They were diagnosed with recurrence with a median of 2.06 years, 1.15 years, and 2.54 years after radical prostatectomy, respectively. In this study of Chinese men with biochemical recurrence, added value for the detection of lesions compatible with sites of PCa was found with 68Ga-PSMA-11 PET/CT over conventional imaging. The observed patterns of disease spread may have implications for understanding the biology of early prostate cancer metastasis.

Recent years have witnessed a rapidly expanding use of artificial intelligence and machine learning in medical imaging. Generative adversarial networks (GANs) are techniques to synthesize images based on artificial neural networks and deep learning. In addition to the flexibility and versatility inherent in deep learning on which the GANs are based, the potential problem-solving ability of the GANs has attracted attention and is being vigorously studied in the medical and molecular imaging fields. Here this narrative review provides a comprehensive overview for GANs and discuss their usefulness in medical and molecular imaging on the following topics: (I) data augmentation to increase training data for AI-based computer-aided diagnosis as a solution for the data-hungry nature of such training sets; (II) modality conversion to complement the shortcomings of a single modality that reflects certain physical measurement principles, such as from magnetic resonance (MR) to computed tomography (CT) images or vice versa; (III) de-noising to realize less injection and/or radiation dose for nuclear medicine and CT; (IV) image reconstruction for shortening MR acquisition time while maintaining high image quality; (V) super-resolution to produce a high-resolution image from low-resolution one; (VI) domain adaptation which utilizes knowledge such as supervised labels and annotations from a source domain to the target domain with no or insufficient knowledge; and (VII) image generation with disease severity and radiogenomics. GANs are promising tools for medical and molecular imaging. The progress of model architectures and their applications should continue to be noteworthy.

The purpose of this study was to investigate the feasibility and diagnostic efficacy of (68)Ga-prostate-specific membrane antigen (PSMA) PET/CT combined with PET/ultrasound-guided biopsy in the diagnosis of prostate cancer (PCa). Methods: In total, 31 patients with a previously negative prostate biopsy but persistent elevated serum prostate-specific antigen (PSA) were imaged with a (68)Ga-PSMA PET/CT ligand before undergoing repeat prostate biopsy. On the basis of the proposed Prostate Cancer Molecular Imaging Standardized Evaluation criteria, (68)Ga-PSMA PET/CT results were interpreted as negative (molecular-imaging-for-PSMA expression score [miPSMA-ES] of 0–1) or positive (miPSMA-ES of 2–3). All patients underwent standard template systematic biopsy with up to 4 additional PET/ultrasound-guided biopsy cores. The sensitivity, specificity, positive and negative predictive values, and accuracy of (68)Ga-PSMA PET/CT were determined. In addition, the correlation between the miPSMA-ES and the detection rate of PCa was also analyzed. Univariate logistic regression models were established using (68)Ga-PSMA PET/CT semiquantitative analysis parameters to predict the outcome of repeat prostate biopsy. Results: The median age of patients was 65 y (range, 53–81 y), and the median PSA level was 18.0 ng/mL (range, 5.48–49.77 ng/mL). PCa was detected in 15 of 31 patients (48.4%), and 12 of 31 patients (38.7%) had clinically significant PCa (csPCa). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of (68)Ga-PSMA PET/CT in the diagnosis of csPCa were 100.0%, 68.4%, 66.7%, 100.0%, and 80.6%, respectively. The detection rate of PCa increased with the increase in miPSMA-ES. The detection rates of csPCa in the miPSMA-ES 0–1, 2, and 3 groups were 0%, 54.5%, and 85.7%, respectively. Semiquantitative analysis of (68)Ga-PSMA PET/CT images showed that predictive models based on the SUV(max) of prostate lesion, tumor–to–normal-prostate background SUV(max), and tumor–to–normal-liver background SUV(max) could effectively predict csPCa; area under the curves were 0.930, 0.877, and 0.956, respectively. Conclusion: This study preliminarily confirmed that (68)Ga-PSMA PET/CT imaging, combined with PET/ultrasound-guided prostate biopsy, can effectively detect csPCa. Prebiopsy (68)Ga-PSMA PET/CT had predictive value for csPCa in the studied patient population.

Three-dimensional (3D) visualizations of volumetric data from computed tomography (CT) acquisitions can be important adjuncts to interpretation of two-dimensional (2D) reconstructions. Recently, the 3D technique known as cinematic rendering (CR) was introduced, allowing photorealistic images to be created from standard CT acquisitions. CR methodology is under increasing investigation for use in the display of regions of complex anatomy and as a tool for education and preoperative planning. In this article, we will illustrate the potential utility of CR for evaluating the urinary bladder and associated pathology. The urinary bladder is susceptible to a multitude of neoplastic and inflammatory conditions and their sequelae. The intrinsic properties of CR may prove useful for the display of subtle mucosal/luminal irregularities, the simultaneous display of soft tissue detail with high-resolution maps of associated tumor neovasculature, and the improved display of spatial relationships to aid pre-procedural planning. Further refinement of presets for CR image creation and prospective evaluation of urinary bladder CR in real-world settings will be important for widespread clinical adoption.

BACKGROUND: Prostate cancer recurrence is found in up to 40% of men with prior definitive (total prostatectomy or whole-prostate radiation) treatment. Prostate-specific membrane antigen PET agents such as 2-(3-{1-carboxy-5-[(6-[18F]fluoro-pyridine 3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid ((18)F-DCFPyL) may improve detection of recurrence compared with multiparametric MRI; however, histopathologic validation is lacking. PURPOSE: To determine the sensitivity, specificity, and positive predictive value (PPV) of (18)F-DCFPyL PET/CT based on histologic analysis and to compare with pelvic multiparametric MRI in men with biochemically recurrent prostate cancer. MATERIALS AND METHODS: Men were prospectively recruited after prostatectomy and/or radiation therapy with rising prostate-specific antigen level (median, 2.27 ng/mL; range, 0.2–27.45 ng/mL) and a negative result at conventional imaging (bone scan and/or CT). Participants underwent (18)F-DCFPyL PET/CT imaging and 3.0-T pelvic multiparametric MRI. Statistical analysis included Wald and modified χ(2) tests. RESULTS: A total of 323 lesions were visualized in 77 men by using (18)F-DCFPyL or multiparametric MRI, with imaging detection concordance of 25% (82 of 323) when including all lesions in the MRI field of view and 53% (52 of 99) when only assessing prostate bed lesions. (18)F-DCFPyL depicted more pelvic lymph nodes than did MRI (128 vs 23 nodes). Histologic validation was obtained in 80 locations with sensitivity, specificity, and PPV of 69% (25 of 36; 95% confidence interval [CI]: 51%, 88%), 91% (40 of 44; 95% CI: 74%, 98%), and 86% (25 of 29; 95% CI: 73%, 97%) for (18)F-DCFPyL and 69% (24 of 35; 95% CI: 50%, 86%), 74% (31 of 42; 95% CI: 42%, 89%), and 69% (24 of 35; 95% CI: 50%, 88%) for multiparametric MRI (P = .95, P = .14, and P = .07, respectively). In the prostate bed, sensitivity, specificity, and PPV were 57% (13 of 23; 95% CI: 32%, 81%), 86% (18 of 21; 95% CI: 73%, 100%), and 81% (13 of 16; 95% CI: 59%, 100%) for (18)F-DCFPyL and 83% (19 of 23; 95% CI: 59%, 100%), 52% (11 of 21; 95% CI: 29%, 74%), and 66% (19 of 29; 95% CI: 44%, 86%) for multiparametric MRI (P = .19, P = .02, and P = .17, respectively). The addition of (18)F-DCFPyL to multiparametric MRI improved PPV by 38% overall (P = .02) and by 30% (P = .09) in the prostate bed. CONCLUSION: Findings with 2-(3-{1-carboxy-5-[(6-[18F]fluoro-pyridine 3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid ((18)F-DCFPyL) were histologically validated and demonstrated high specificity and positive predictive value. In the pelvis, (18)F-DCFPyL depicted more lymph nodes and improved positive predictive value and specificity when added to multiparametric MRI. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Zukotynski and Rowe in this issue.

Clinician-scientists are commonly characterized as health care professionals who are proficient in both research and clinical practice. Their dual expertise positions them to play a vital role in translating research outcomes to clinical practice. However, economic changes in the past few decades are threatening their very survival. The purposes of this article are to review some of the economic forces that pose the greatest risks to clinician-scientists in the modern era and to glean lessons from the business world in overcoming these challenges. Health care consolidation and decreasing reimbursements are putting increasing financial pressure on academic institutions, leaving them more inclined to cut back on departmental research support. Innovative companies commit a certain percentage of their revenue to research and discovery. Academic institutions should similarly view their research budget as research and discovery that will sustain the future growth of radiology. They should quantify and define expectations for academic productivity, focus on return on investment, and bolster the infrastructure to foster commercial partnerships that can provide additional revenue to support the research mission. Success in academics does not occur by accident. It requires more than individual talent and hard work. It also requires institutional leaders who are committed to developing future academic leaders and supporting innovation.

Prostate-specific membrane antigen (PSMA; also termed glutamate carboxypeptidase II (GCP II)) is abundantly expressed in prostate cancer. It has been shown recently that PSMA is expressed in neovasculature of differentiated thyroid cancer. In this study, we show that (18)F-DCFPyl might detect neovasculature in advanced, metastatic differentiated thyroid cancer (DTC). We first stained the preserved lymph node samples of three patients with DTC who had undergone total thyroidectomy and neck dissection for cervical lymph node metastatic disease to identify PSMA expression, with the PSMA antibody (DAKO Monoclonal). Then, we performed (18)F-DCFPyl imaging in two other advanced DTC patients with elevated serum thyroglobulin (Tg), indicative of residual disease. We compared the findings with contemporaneous FDG PET/CT scan, conventional Imaging (CT,MRI) and whole-body scan performed with I(123)/I(131). All the three lymph node samples stained positive for PSMA expression in the neovasculature. In the first imaged patient, (18)F-DCFPyl detected activity within the retropharyngeal CT contrast-enhancing lymph node. Compared to FDG PET/CT, the (18)F-DCFPyl scan showed a greater SUV (3.1 vs 1.8). In the second imaged patient, (18)F-DCFPyl showed intense uptake in the L3 vertebra (not seen on the post treatment (131)I scan or the (18)F-FDG PET/CT). MRI of the lumbar spine confirmed the presence of sclerotic-lytic lesion at the location, consistent with metastatic disease. Our exploratory study is proof of principle, that the prostate cancer imaging agent (18)F-DCFPyl may prove useful for the localization of metastases, in patients with metastatic RAI-refractory DTC by detecting neoangiogenesis within the tumor.

To evaluate the outcomes of total eradication therapy (TET), designed to eradicate all sites of visible cancer and micrometastases, in men with newly diagnosed oligometastatic prostate cancer (OMPCa). Men with ≤ 5 sites of metastases were enrolled in a prospective registry study, underwent neoadjuvant chemohormonal therapy, followed by radical prostatectomy, adjuvant radiation (RT) to prostate bed/pelvis, stereotactic body radiation therapy (SBRT) to oligometastases, and adjuvant hormonal therapy (HT). When possible, the prostate-specific membrane antigen targeted 18F-DCFPyL PET/CT (18F-DCFPyL) scan was obtained, and abiraterone was added to neoadjuvant HT. Twelve men, median 55 years, ECOG 0, median PSA 14.7 ng/dL, clinical stages M0—1/12 (8%), M1a—3/12 (25%) and M1b—8/12 (67%), were treated. 18F-DCFPyL scan was utilized in 58% of cases. Therapies included prostatectomy 12/12 (100%), neoadjuvant [docetaxel 11/12 (92%), LHRH agonist 12/12 (100%), abiraterone + prednisone 6/12 (50%)], adjuvant radiation [RT 2/12 (17%), RT + SBRT 4/12 (33%), SBRT 6/12 (50%)], and LHRH agonist 12/12 (100%)]. 2/5 (40%) initial patients developed neutropenic fever (NF), while 0/6 (0%) subsequent patients given modified docetaxel dosing developed NF. Otherwise, TET resulted in no additive toxicities. Median follow-up was 48.8 months. Overall survival was 12/12 (100%). 1-, 2-, and 3-year undetectable PSA’s were 12/12 (100%), 10/12 (83%) and 8/12 (67%), respectively. Median time to biochemical recurrence was not reached. The outcomes suggest TET in men with newly diagnosed OMPCa is safe, does not appear to cause additive toxicities, and may result in an extended interval of undetectable PSA.

The purpose of this study was to prospectively evaluate the distribution of PSMA-targeted, PET-avid lesions in prostate cancer (PCa) patients with biochemical recurrence in a Chinese cohort. The relationships between PSA levels, disease-free time after prostatectomy, and

Growing evidence suggests that 2-deoxy-2-[18F]fluoro-D-glucose (18FDG)–positron emission tomography/computed tomography (PET/CT) is a useful imaging technique for the evaluation of fever of unknown origin (FUO). This imaging technique allows for accurate localization of foci of hypermetabolism based on 18FDG uptake in glycolytically active cells that may represent inflammation, infection, or neoplasia. The presence of abnormal uptake can help direct further investigation that may yield a final diagnosis. A lack of abnormal uptake can be reasonably reassuring that these conditions are not present, thereby avoiding unnecessary additional testing. Insurers have not routinely covered outpatient 18FDG-PET/CT for the indication of FUO in the United States. However, data published since 2007 suggest early use in FUO diagnostic evaluations improves diagnostic efficiency and reduces costs. Clinicians and insurers should consider 18FDG-PET/CT as a useful tool when preliminary studies are unrevealing.

This review covers the state-of-the-art imaging in therapy assessment and surveillance of lung cancer with focus on the utility of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (

Introduction:Improved diagnostics are needed to better inform the treatment of men with biochemically recurrent (BCR) prostate cancer (PCa). 18F-DCFPyL is a novel PET agent that selectively binds w...

INTRODUCTION AND OBJECTIVE:Current imaging modalities are suboptimal for the initial staging of men at risk of harboring occult metastatic prostate cancer (PCa) because of the low positive and nega...

PURPOSE: To investigate the utility of prostate-specific membrane antigen (PSMA)-targeted [(18)F]DCFPyL positron emission tomography (PET)/X-ray computed tomography (CT) imaging for the detection of sites of disease in patients with metastatic non-clear cell renal cell carcinoma (RCC). PROCEDURES: Eight patients with metastatic non-clear cell RCC underwent imaging with PSMA-targeted [(18)F]DCFPyL PET/CT. Imaged RCC histologic subtypes included papillary RCC (n = 3), chromophobe RCC (n = 2), unclassified RCC (n = 2), and Xp11 translocation RCC (n = 1). Using comparison to conventional CT and/or magnetic resonance imaging as reference, two radiologists with expertise in nuclear medicine identified putative sites of disease on [(18)F]DCFPyL PET/CT and classified each lesion as having no radiotracer uptake, equivocal uptake, or definitive uptake. RESUTS: In total, 73 metastatic sites and 3 primary tumors compatible with sites of non-clear cell RCC were identified on conventional imaging. Metastatic sites of disease included lymph nodes (n = 40), venous thrombi (n = 3), pulmonary nodules (n = 10), bone lesions (n = 15), brain lesions (n = 3), and retroperitoneal masses (n = 2). Only 10 of the 73 lesions (13.7 %) were classified as having definitive radiotracer uptake (median SUV(max) = 3.25, range = 1.2–9.5), 14 lesions (19.2 %) had equivocal uptake (median SUV(max) = 2.85, range = 0.5–6.5), and 49 lesions (67.1 %) had no definitive uptake above background (median SUV(max) = 1.7, range = 0.2–3.0). The three primary renal tumors demonstrated lower radiotracer avidity relative to surrounding normal renal parenchyma. CONCLUSIONS: A small proportion of sites of non-clear cell RCC showed uptake of the PSMA-targeted radiotracer [(18)F]DCFPyL. Unlike for clear cell RCC, the results of this study indicate that PSMA-based PET is not appropriate for imaging other RCC subtypes.

Melanoma currently lacks a reliable blood-based biomarker of disease activity, although circulating tumor DNA (ctDNA) may fill this role. We investigated the clinical utility (i.e., impact on clinical outcomes and interpretation of radiographic data) of measuring ctDNA in patients with metastatic or high-risk resected melanoma. Patients were prospectively accrued into ≥ 1 of three cohorts, as follows. Cohort A: patients with radiographically measurable metastatic melanoma who underwent comparison of ctDNA measured by a BEAMing digital PCR assay to tissue mutational status and total tumor burden; when appropriate, determinations about initiation of targeted therapy were based on ctDNA data. Cohorts B and C: patients with BRAF- or NRAS-mutant melanoma who had either undergone surgical resection of high-risk disease (cohort B) or were receiving or had received medical therapy for advanced disease (cohort C). Patients were followed longitudinally with serial ctDNA measurements with contemporaneous radiographic imaging to ascertain times to detection of disease activity and progressive disease, respectively. The sensitivity and specificity of the ctDNA assay were 86.8% and 100%, respectively. Higher tumor burden and visceral metastases were found to be associated with detectable ctDNA. In two patients in cohort A, ctDNA test results revealed a targetable mutation where tumor testing had not; both patients experienced a partial response to targeted therapy. In four of 30 patients with advanced melanoma, ctDNA assessments indicated evidence of melanoma activity that predicted radiographic evidence of disease progression by 8, 14, 25, and 38 weeks, respectively. CtDNA was detectable in three of these four patients coincident with radiographic evaluations that alone were interpreted as showing no evidence of neoplastic disease. Our findings provide evidence for the clinical utility of integrating ctDNA data in managing patients with melanoma in a real-world setting.

Imaging is often used to evaluate men with biochemical recurrence (BCR) of prostate cancer after definitive primary treatment (radical prostatectomy [RP] or radiotherapy [RT]). The goal of imaging is to identify the source of elevated or rising serum prostate-specific antigen (PSA) levels because

Both prostate-specific membrane antigen (PSMA)- and somatostatin receptor (SSTR)-targeted positron emission tomography (PET)-based imaging agents for prostate carcinoma and neuroendocrine tumors, respectively, are seeing rapidly expanding use. In addition to diagnostic applications, both classes of radiotracers can be used to triage patients for theranostic endoradiotherapy. While interpreting PSMA- or SSTR-targeted PET/computed tomography (CT) scans, the reader has to be aware of certain pitfalls. Adding to the complexity of the interpretation of those imaging agents, both normal biodistribution, and also false-positive and -negative findings differ between PSMA- and SSTR-targeted PET radiotracers. Herein summarized under the umbrella term molecular imaging reporting and data systems (MI-RADS), two novel RADS classifications for PSMA- and SSTR-targeted PET imaging are described (PSMA- and SSTR-RADS). Notably, PSMA- and SSTR-RADS are structured in a reciprocal fashion, i.e., if the reader is familiar with one system, the other system can readily be applied, as well. In the present review, we will discuss the most common pitfalls on PSMA- and SSTR-targeted PET/CT, briefly introduce PSMA- and SSTR-RADS, and define a potential future role of the umbrella framework MI-RADS compared to other classification systems.

Incidentally detected small renal masses (SRMs) may be one of several benign or malignant tumor histologies, and are heterogeneous in oncologic potential. Renal mass biopsy can be used to determine the histology of SRMs. However, this invasive approach has significant limitations. Technetium-99m sestamibi single photon emission computed tomography/computed tomography (To evaluate the clinical and economic value ofWe developed a decision analysis model to estimate the costs and health outcomes of competing management strategies for a healthy 65-yr-old patient with an asymptomatic SRM.Empiric surgery (reference); real-world clinical practice (RWCP) consisting of empiric surgery, thermal ablation, and active surveillance (alternative reference); renal mass biopsy (option 1);We assessed lifetime health utilities, measured in quality-adjusted life years (QALYs), and direct medical costs from a health payer perspective. We calculated the incremental cost-effectiveness ratio (ICER) for options 1-3 versus the reference and alternative reference arms, with a willingness-to-pay threshold of $50 000/QALY. Univariate, multivariate, and probabilistic sensitivity analyses were performed.Option 3 had a very low risk of untreated malignant tumors (0.2%, vs 2.1% for option 1, 4.2% for option 2, and 0% for empiric surgery) and the highest probability of leaving benign tumors untreated (84.4%, vs 53.9% for option 1, 51.7% for option 2, and 0% for empiric surgery). Option 3 dominated empiric surgery and options 1 and 2 (ie, lower costs and higher QALYs). Compared with RWCP, options 1-3 were all cost effective; option 3 had the lowest ICER of $18 821/QALY. These findings were robust to alternative input values. Study limitations included data uncertainties and a limited number of centers from whichOur research suggests that by using a noninvasive imaging test, known as technetium-99m sestamibi single photon emission computed tomography/computed tomography, to diagnose small renal masses, urologists may avoid unnecessary surgery for benign tumors and minimize the risk of leaving a malignant tumor untreated. Moreover, the use of this strategy to diagnose small renal masses is cost effective for the health care system.

Inflammation of the pancreas can present with a wide range of imaging findings from mild enlargement of the gland and surrounding infiltrative fat stranding through extensive glandular necrosis. Complications of pancreatitis are varied and include infected fluid collections, pseudocysts, and vascular findings such as pseudoaneurysms and thromboses. Cross-sectional imaging with computed tomography (CT) is one of the mainstays of evaluating patients with pancreatitis. New methods that allow novel visualization volumetric CT data may improve diagnostic yield for the detection of findings that provide prognostic information in pancreatitis patients or can drive new avenues of research such as machine learning. Cinematic rendering (CR) is a photorealistic visualization method for volumetric imaging data that are being investigated for a variety of potential applications including the life-like display of complex anatomy and visual characterization of mass lesions. In this review, we describe the CR appearance of different types of pancreatitis and complications of pancreatitis. We also note possible future directions for research into the utility of CR for pancreatitis.

Synthetic marijuana is a dangerous substance due to its potency, ever-changing composition, and unpredictable side effects. Recently, brodifacoum-contaminated synthetic marijuana has led to multiple deaths and morbidity throughout the USA from severe coagulopathy associated with use of this strain of the drug (brodifacoum is a rodenticide and potent Vitamin K antagonist/anticoagulant). We describe the clinical and radiologic findings in two patients who were diagnosed with, and treated for, ingestion of this new strain of synthetic marijuana. The radiologic manifestations were most notable for hemorrhagic pyelitis/ureteritis. Both patients required hospitalization with Vitamin K supplementation. The radiologic and clinical pictures in these patients are important for radiologists to recognize in order to help guide appropriate patient management.

Adrenalectomy is the standard of care for management of many adrenal tumor types and, in the United States alone, approximately 6000 adrenal surgeries are performed annually. Two general approaches to adrenalectomy have been described; (1) the open approach, in which a diseased adrenal is removed through a large (10-20 cm) abdominal wall incision, and (2) the minimally invasive approach, in which laparoscopy is used to excise the gland through incisions generally no longer than 1-2 cm. Given these disparate technique options, clear preoperative characterization of those specific disease features that inform selection of adrenalectomy approach is critically important to the surgeon. Because most of these features are directly assessed via preoperative abdominal imaging, in particular computed tomography (CT) scanning, a clear mutual understanding among surgeons and radiologists of those adrenal tumor features impacting operative approach selection is vital for planning adrenal surgery. In this context, we review the preoperative CT imaging features that specifically inform adrenalectomy approach selection, provide illustrative examples from our institution's imaging and surgical archives, and provide a stepwise guide to both the open and laparoscopic adrenalectomy approaches.

Erdheim-Chester disease (ECD) is an extremely rare and aggressive non-Langerhans histiocytic disorder. ECD typically presents with bone pain in middle-aged adults, although some patients present with multisystem disease involving the skeleton, central nervous system, cardiovascular system, lungs, and other disease sites. The etiology of ECD is currently unknown, but it is thought to be a reactive or neoplastic disorder. Recently, mutation of the BRAF gene has been found in >50% of ECD cases, and this gene has become a therapeutic target for patients with ECD. Vemurafenib, a BRAF inhibitor, has been approved by the FDA for treatment of ECD. This report presents an elderly male patient with an aggressive phenotype of ECD and highlights the utility of multimodality imaging in monitoring the clinical course and disease response to treatment with vemurafenib.

Background Synchronous squamous cell carcinoma of the head and neck (HNSCC) and non-Hodgkin’s lymphoma is a rare clinical scenario. It is unknown whether the R-CHOP chemotherapy for lymphoma would also be active against HNSCC. Herein, we present such a case and a review of the literature. Case presentation A 64 year-old female presented with painless jaundice. CT demonstrated a retroperitoneal mass and pathology showed follicular lymphoma. A base-of-tongue HPV+ squamous cell carcinoma was found incidentally on staging CT. R-CHOP chemotherapy was initiated. After 3 cycles of R-CHOP the lymphoma had a complete metabolic response and, unexpectedly, the HNSCC also demonstrated excellent response. The patient received another 3 cycles followed by radiation to the HNSCC and to date is in remission for both cancers. Conclusions This case highlights the exquisite sensitivity of HPV-related HNSCC, which should be taken into consideration in treatment prioritization of a concurrent diagnosis of a second cancer.

3D visualization methods for volumetric CT data have played an important role in diagnostic imaging of the small bowel, a structure which intrinsically crosses numerous slices in any 2D imaging plane. Recently, a new approach to 3D CT image creation has become available-cinematic rendering (CR). CR differs from other 3D methods in making use of a global lighting model that produces high surface detail and realistic shadowing effects that lead to 3D visualizations with photorealistic quality. Although the utility of these images for improving diagnostic accuracy has not yet been established, our group's early experience in regions of complex anatomy and pathology has been encouraging. In this pictorial review, we review the established role of 3D CT in many of the most common small bowel pathologies, provide examples of those pathologies visualized with CR, and suggest future directions for researchers to pursue.

Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein that is highly overexpressed on prostate cancer epithelial cells and for which there is a growing body of literature examining the role of small-molecule and antibody radiotracers targeted against this protein for prostate cancer detection and therapy. Despite its name, PSMA is also expressed, to varying degrees, in the neovasculature of a wide variety of nonprostate cancers; indeed, the pathology literature is replete with promising immunohistochemistry findings. Several groups have begun to correlate those pathology-level results with in vivo imaging and therapy in nonprostate cancers using the same PSMA-targeted agents that have been so successful in prostate cancer. The potential to leverage radiotracers targeted to PSMA beyond prostate cancer is a promising approach for many cancers, and PSMA-targeted agents may be able to supplement or fill gaps left by other agents. However, to date, most of the reported findings with PSMA-targeted radiotracers in nonprostate malignancies have been in case reports and small case series, and the field must adopt a more thorough approach to the design and execution of larger prospective trials to realize the potential of these promising agents outside prostate cancer.

Purpose of review To explore the role of molecular imaging in the characterization of renal masses. Recent findings Incidentally detected renal masses exhibit variable malignant potential related to their underlying histology. Patients presenting with a renal mass should undergo individual risk stratification including characterization of their tumor histology. At the present time, anatomical imaging techniques are unable to reliably distinguish between the various renal tumor subtypes. Although renal mass biopsy is helpful in this regard, there are limitations of this procedure. Molecular imaging offers a noninvasive means of determining the histology of renal tumors. Imaging tests that have shown particular promise for this application include I-girentuximab PET/CT for diagnosing clear cell renal cell carcinoma and Tc-sestamibi SPECT/CT for diagnosing renal oncocytomas and hybrid oncocytic/chromophobe tumors. Summary Molecular imaging offers a noninvasive means of determining the histology of renal tumors thereby aiding in the risk stratification of patients presenting with a renal mass. Future work aims to develop a molecular imaging test that employs dual radiotracers allowing for the more precise characterization of renal tumors in a convenient single radiologic study.

Kawasaki's disease (KD) is a vasculitis that predominantly affects children and can lead to the development of coronary artery aneurysms. These aneurysms can subsequently thrombose and occlude, which may lead to chest pain and other signs and symptoms of acute coronary syndrome in young patients. Coronary CT angiography, including 3D visualization techniques, is a common modality used in the follow-up of KD patients. In this series of three patients, we present the typical coronary artery imaging findings that can appear in these patients, with an emphasis on the use of the novel 3D technique of cinematic rendering (CR). CR utilizes a different lighting model than other 3D methods and is able to produce highly-detailed, photorealistic images. The potential advantages of CR images in understanding the complex mediastinal vascular anatomy and the relationships of coronary artery aneurysms to other anatomic structures are emphasized.

Acute aortic injuries are not common in the setting of severe blunt trauma, but lead to significant morbidity and mortality. High-quality MDCT with 2D MPRs and 3D rendering are essential to identify aortic trauma and distinguish anatomic variants and other forms of aortic pathology from an acute injury. Misinterpretation of mimics of acute aortic injury can lead to unnecessary arteriography and thoracic surgery. Since most traumatic injuries occur in the distal arch, radiologists must be cognizant of the range of appearances of variants related to the ductus diverticulum. Cinematic rendering (CR) is a new 3D post-processing tool that provides even greater anatomic detail than traditional volume rendering. In this case series, CR is used to impart to radiologists a better understanding of various anatomic configurations that can be seen with a ductus diverticulum.

Purpose: We prospectively evaluated the diagnostic performance of prostate specific membrane antigen targeted 18F-DCFPyL positron emission tomography/computerized tomography in the preoperative staging of men at high risk for harboring metastatic prostate cancer despite a negative conventional staging evaluation.Materials and Methods: Men with clinically localized high or very high risk prostate cancer were imaged with 18F-DCFPyL positron emission tomography/computerized tomography before undergoing radical prostatectomy with standardized pelvic lymph node dissection. The scans were interpreted by 2 blinded nuclear medicine readers and assessed for interreader variability as well as diagnostic accuracy for pelvic lymph node staging. Surgical pathology served as the reference standard to which 18F-DCFPyL scan findings were compared.Results: A total of 25 men contributed analyzable data to this study. Seven of these patients (28%) were found to have 1 or more positive lymph nodes on surgical pathology. Site...

Altered function of the alpha7 nicotinic acetylcholine receptor (α7-nAChR) is implicated in several neuropsychiatric diseases. Nevertheless, studies of the human cerebral α7-nAChR even in healthy aging are limited in number and to postmortem tissue. Methods The distribution of the cerebral α7-nAChR was estimated in nine brain regions in 25 healthy volunteers (ages 21–86 years; median 57 years, interquartile range 52 years) using [18F]ASEM with positron emission tomography (PET) imaging. Regional total distribution volume (VT) measurements were calculated using the Logan method from each subject's 90 min dynamic PET data and their metabolite-corrected plasma input function. Spearman's rank or Pearson's correlation analysis was used depending on the normality of the data. Correlation between age and regional 1) volume relative to intracranial volume (volume ratio) and 2) [18F]ASEM VT was tested. Correlation between regional volume ratio and [18F]ASEM VT was also evaluated. Finally, the relationship between [18F]ASEM VT and neuropsychological measures was investigated in a subpopulation of 15 elderly healthy participants (those 50 years of age and older). Bonferroni correction for multiple comparisons was applied to statistical analyses. Results A negative correlation between tissue volume ratio and age was observed in six of the nine brain regions including striatum and five cortical (temporal, occipital, cingulate, frontal, or parietal) regions. A positive correlation between [18F]ASEM VT and age was observed in all nine brain regions of interest (ROIs). There was no correlation between [18F]ASEM VT and volume ratio in any ROI after controlling for age. Regional [18F]ASEM VT and neuropsychological performance on each of eight representative subtests were not correlated among the well-performing subpopulation of elderly healthy participants. Conclusions Our results suggest an increase in cerebral α7-nAChR distribution over the course of healthy aging that should be tested in future longitudinal studies. The preservation of the α7-nAChR in the aging human brain supports the development of therapeutic agents that target this receptor for use in the elderly. Further study of the relationship between α7-nAChR availability and cognitive impairment over aging is needed.