Evaluation of the urinary bladder using three-dimensional CT cinematic rendering.

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.

Multidisciplinary total eradication therapy (TET) in men with newly diagnosed oligometastatic prostate cancer.

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.

Cinematic rendering of focal liver masses.

Cinematic rendering (CR) is a recently described three-dimensional (3D) rendering technique that generates photorealistic images based on a new lighting model. This review illustrates the potential application of CR in the evaluation of focal liver masses. CR shows promise in improving the visualization of enhancement pattern and internal architecture, local tumor extension, and global disease burden, which may be helpful in focal liver mass characterization and pretreatment planning.

3D CT cinematic rendering of the spleen: Potential role in problem solving.

Cinematic rendering (CR) is a new 3D visualization methodology for volumetric diagnostic imaging including computed tomography (CT) datasets composed of isotropic voxels. CR produces photorealistic images with enhanced detail relative to other 3D visualization methods and realistic shadowing. In this review, we provide a number of examples of splenic pathology visualized with CR including conditions affecting the splenic vasculature, neoplasms, and accessory spleens. These examples are compared to 2D CT and traditional 3D CT techniques and the potential advantages of CR are highlighted. CR displays textural changes in the splenic parenchyma to particular advantage, and a portion of this review will be devoted to examples of how textural features can help distinguish intrapancreatic accessory spleens from neuroendocrine tumors.

PET imaging of prostate-specific membrane antigen in prostate cancer: current state of the art and future challenges.

BACKGROUND: Prostate-specific membrane antigen (PSMA) is a cell surface enzyme that is highly expressed in prostate cancer (PCa) and is currently being extensively explored as a promising target for molecular imaging in a variety of clinical contexts. Novel antibody and small-molecule PSMA radiotracers labeled with a variety of radionuclides for positron emission tomography (PET) imaging applications have been developed and explored in recent studies. METHODS: A great deal of progress has been made in defining the clinical utility of this class of PET agents through predominantly small and retrospective clinical studies. The most compelling data to date has been in the setting of biochemically recurrent PCa, where PSMA-targeted radiotracers have been found to be superior to conventional imaging and other molecular imaging agents for the detection of locally recurrent and metastatic PCa. RESULTS: Early data, however, suggest that initial lymph node staging before definitive therapy in high-risk primary PCa patients may be limited, although intraoperative guidance may still hold promise. Other examples of potential promising applications for PSMA PET imaging include non-invasive characterization of primary PCa, staging and treatment planning for PSMA-targeted radiotherapeutics, and guidance of focal therapy for oligometastatic disease. CONCLUSIONS: However, all of these indications and applications for PCa PSMA PET imaging are still lacking and require large, prospective, systematic clinical trials for validation. Such validation trials are needed and hopefully will be forthcoming as the fields of molecular imaging, urology, radiation oncology and medical oncology continue to define and refine the utility of PSMA-targeted PET imaging to improve the management of PCa patients.

Prostate-specific membrane antigen as a target for cancer imaging and therapy.

The prostate-specific membrane antigen (PSMA) is a molecular target whose use has resulted in some of the most productive work toward imaging and treating prostate cancer over the past two decades. A wide variety of imaging agents extending from intact antibodies to low-molecular-weight compounds permeate the literature. In parallel there is a rapidly expanding pool of antibody-drug conjugates, radiopharmaceutical therapeutics, small-molecule drug conjugates, theranostics and nanomedicines targeting PSMA. Such productivity is motivated by the abundant expression of PSMA on the surface of prostate cancer cells and within the neovasculature of other solid tumors, with limited expression in most normal tissues. Animating the field is a variety of small-molecule scaffolds upon which the radionuclides, drugs, MR-detectable species and nanoparticles can be placed with relative ease. Among those, the urea-based agents have been most extensively leveraged, with expanding clinical use for detection and more recently for radiopharmaceutical therapy of prostate cancer, with surprisingly little toxicity. PSMA imaging of other cancers is also appearing in the clinical literature, and may overtake FDG for certain indications. Targeting PSMA may provide a viable alternative or first-line approach to managing prostate and other cancers.

Free radicals in the stratosphere: a new observational technique.

A new approach to in situ observations of trace reactive species in the stratosphere is described. A balloon-borne system, floating 40 kilometers above the earth's surface, successfully lowered and then retracted a cluster of instruments a distance of 12 kilometers on a filament of Kevlar. This instrument cluster is capable of detecting gas-phase free radicals at the part-per-trillion level. The suspended instrument array has excellent stability and has been used to measure atomic oxygen concentrations in the stratosphere.