A Systematic Review on the Diagnostic Value of Fibroblast Activation Protein Inhibitor PET/CT in Genitourinary Cancers.

In contemporary oncologic diagnostics, molecular imaging modalities are pivotal for precise local and metastatic staging. Recent studies identified fibroblast activation protein as a promising target for molecular imaging across various malignancies. Therefore, we aimed to systematically evaluate the current literature on the utility of fibroblast activation protein inhibitor (FAPI) PET/CT for staging patients with genitourinary malignancies. Methods: A systematic Embase and Medline search was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) process, on August 1, 2023. Relevant publications reporting on the diagnostic value of FAPI PET/CT in genitourinary malignancies were identified and included. Studies were critically reviewed using a modified version of a tool for quality appraisal of case reports. Study results were summarized using a narrative approach. Results: We included 22 retrospective studies with a cumulative total of 69 patients, focusing on prostate cancer, urothelial carcinoma of the bladder and of the upper urinary tract, renal cell carcinoma, and testicular cancer. FAPI PET/CT was able to visualize both local and metastatic disease, including challenging cases such as prostate-specific membrane antigen (PSMA)-negative prostate cancer. Compared with radiolabeled 18F-FDG and PSMA PET/CT, FAPI PET/CT showed heterogeneous performance. In selected cases, FAPI PET/CT demonstrated superior tumor visualization (i.e., better tumor-to-background ratios and visualization of small tumors or metastatic deposits visible in no other way) over 18F-FDG PET/CT in detecting local or metastatic disease, whereas comparisons with PSMA PET/CT showed both superior and inferior performances. Challenges in FAPI PET/CT arise from physiologic urinary excretion of most FAPI radiotracers, hindering primary-lesion visualization in the bladder and upper urinary tract, despite generally providing high tumor-to-background ratios. Conclusion: The current findings suggest that FAPI PET/CT may hold promise as a future tool to aid clinicians in detecting genitourinary malignancies. Given the substantial heterogeneity among the included studies and the limited number of patients, caution in interpreting these findings is warranted. Subsequent prospective and comparative investigations are anticipated to delve more deeply into this innovative imaging modality and elucidate its role in clinical practice.

PET/CT Limitations and Pitfalls in Urogenital Cancers.

Hybrid FDG PET/CT plays a vital role in oncologic imaging and has been widely adopted for the staging and restaging of a variety of malignancies. Its diagnostic value in urogenital malignancies is less well-known, not at least because of the variable FDG avidity of these tumor entities, the sites of these tumors, and technical challenges associated with sequential imaging of CT and PET. PET/CT interpretation thus can be especially challenging and is associated with many pitfalls, which can lead to both false-positive and false-negative diagnoses as well as incorrect assessment of metabolic change following therapy. Currently, FDG PET/CT is not the standard of care for the initial diagnosis or staging of early-stage or low-risk urogenital cancers; however, it can help evaluate distant metastatic disease, response to therapy, and disease recurrence in high-risk patients. Knowledge of imaging features of tumor metabolic avidity and pitfalls is essential for accurate interpretation.

Understanding the Lymphatics: An Updated Review of the N Category of the AJCC 8th Edition for Urogenital Cancers.

OBJECTIVE. Organ-specific nonregional and regional lymph nodes vary considerably among tumors. Nonregional lymph node involvement equals metastasis, which is critical to detect to ensure correct tumor staging, management, and prognosis. Knowledge of nodal nomenclature and anatomy is therefore essential in every cross-sectional imaging study. CONCLUSION. This article reviews the most important changes and highlights of the N category of the American Joint Committee on Cancer 8th edition of the TNM classification for urogenital cancers.

ACR appropriateness criteria post-treatment surveillance of bladder cancer: 2021 update

Urothelial cancer is the second most common cancer, and cause of cancer death, related to the genitourinary tract. The goals of surveillance imaging after the treatment of urothelial cancer of the urinary bladder are to detect new or previously undetected urothelial tumors, to identify metastatic disease, and to evaluate for complications of therapy. For surveillance, patients can be stratified into one of three groups: 1) nonmuscle invasive bladder cancer with no symptoms or additional risk factors; 2) nonmuscle invasive bladder cancer with symptoms or additional risk factors; and 3) muscle invasive bladder cancer. This document is a review of the current literature for urothelial cancer and resulting recommendations for surveillance imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Emergency room imaging in patients with genitourinary cancers: analysis of the spectrum of CT findings and their relation to patient outcomes.

PURPOSE: To assess the spectrum of computed tomography (CT) findings in patients with genitourinary cancers visiting the emergency room (ER) and evaluate the relationship between CT findings and overall survival (OS). METHODS: Retrospective analysis of consecutive patients with genitourinary cancers undergoing CT during an ER visit at a tertiary cancer center during a 20-month period. CTs were considered positive if there were findings relevant to the presenting complaint(s). Demographic/clinical variables were recorded. OS was evaluated using Kaplan-Meier curves. Univariate and multivariate Cox proportional hazards regression (HR) was used to evaluate OS predictors. RESULTS: Two hundred twenty-seven patients (243 visits) were included. The most common primary tumors were prostate (121 [49.8%]), bladder/urothelial (78 [32.1%]), and renal (69 [28.4%]). Common presenting complaints were abdominal pain (67 [27.6%]), respiratory symptoms (49 [20.2%]), neurological signs (37 [15.2%]), and fever (34 [14.0%]). CT findings were positive in 172 patients (70.8%) and included new/increased metastases (21.4% [52/243]), fluid collections (7.4% [18/243]), urinary tract infection/inflammation (6.2% [15/243]), enteritis/colitis (5.3% [13/243]), and pneumonia (4.9% [12/243]). A positive ER CT was associated with patient admission (p = 0.01). At multivariate analysis, independently predictive factors of shorter survival were positive ER CT (HR = 2.09 [95% CI 1.16-3.76, p = 0.01), hospital admission (HR = 2.17 [95% CI 1.38-3.41], p < 0.01), and recent systemic treatment (HR = 2.10 [95% CI 1.32-3.35], p < 0.01). CONCLUSION: When CT was performed, it was able to identify a structural cause for the presenting complaint in the majority of patients with genitourinary cancers attending the ER. A positive ER CT was associated with hospital admission and poorer overall survival.

Thoracic Manifestations of Genitourinary Neoplasms and Treatment-related Complications.

Genitourinary (GU) malignancies are a diverse group of common and uncommon neoplasms that may be associated with significant mortality. Metastases from GU neoplasms are frequently encountered in the chest, and virtually all thoracic structures can be involved. Although the most common imaging manifestations include hematogenous dissemination manifesting with peripheral predominant bilateral pulmonary nodules and lymphatic metastases manifesting with mediastinal and hilar lymphadenopathy, some GU malignancies exhibit unique features. We review the general patterns, pathways, and thoracic imaging features of renal, adrenal, urothelial, prostatic, and testicular metastatic neoplasms, as well as provide a discussion of treatment-related complications that might manifest in the chest. Detailed reporting of these patterns will allow the imager to assist the referring clinicians and surgeons in accurate determination of the stage, prognosis, and treatment options available for the patient. Awareness of specific treatment-related complications further allows the imager to enhance patient safety through accurate and timely reporting of potentially life-threatening consequences of therapies.

A review of the principles of texture analysis and its role in imaging of genitourinary neoplasms.

Advances in the management of genitourinary neoplasms have resulted in a trend towards providing patients with personalized care. Texture analysis of medical images, is one of the tools that is being explored to provide information such as detection and characterization of tumors, determining their aggressiveness including grade and metastatic potential and for prediction of survival rates and risk of recurrence. In this article we review the basic principles of texture analysis and then detail its current role in imaging of individual neoplasms of the genitourinary system.

Diffusion-Weighted Genitourinary Imaging.

This review article aims to provide an overview on of diffusion-weighted MR imaging (DW-MR imaging) in the urogenital tract. Compared with conventional cross-sectional imaging methods, the additional value of DW-MR imaging in the detection and further characterization of benign and malignant lesions of the kidneys, bladder, prostate, and pelvic lymph nodes is discussed as well as the role of DW-MR imaging in the evaluation of treatment response.

Advances in medical imaging for the diagnosis and management of common genitourinary cancers.

Medical imaging of the 3 most common genitourinary (GU) cancers-prostate adenocarcinoma, renal cell carcinoma, and urothelial carcinoma of the bladder-has evolved significantly during the last decades. The most commonly used imaging modalities for the diagnosis, staging, and follow-up of GU cancers are computed tomography, magnetic resonance imaging (MRI), and positron emission tomography (PET). Multiplanar multidetector computed tomography and multiparametric MRI with diffusion-weighted imaging are the main imaging modalities for renal cell carcinoma and urothelial carcinoma, and although multiparametric MRI is rapidly becoming the main imaging tool in the evaluation of prostate adenocarcinoma, biopsy is still required for diagnosis. Functional and molecular imaging using 18-fluorodeoxyglucose-PET and sodium fluoride-PET are essential for the diagnosis, and especially follow-up, of metastatic GU tumors. This review provides an overview of the latest advances in the imaging of these 3 major GU cancers.

Applications of PET/MR Imaging in Urogynecologic and Genitourinary Cancers.

Positron emission tomograph (PET)-magnetic resonance (MR) is a new modality combining PET and MR. In gynecologic cancers it can be used for staging of cervical and endometrial cancer, planning of radiation therapy in cervical cancer, assessing response to chemotherapy in ovarian cancer, and detection of recurrence in most gynecologic cancers. It is being explored for prostate cancer and other genitourinary cancers, but is still in experimental stages.

ENABLE (Exportable Notation and Bookmark List Engine): an Interface to Manage Tumor Measurement Data from PACS to Cancer Databases.

Oncologists evaluate therapeutic response in cancer trials based on tumor quantification following selected "target" lesions over time. At our cancer center, a majority of oncologists use Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 quantifying tumor progression based on lesion measurements on imaging. Currently, our oncologists handwrite tumor measurements, followed by multiple manual data transfers; however, our Picture Archiving Communication System (PACS) (Carestream Health, Rochester, NY) has the ability to export tumor measurements, making it possible to manage tumor metadata digitally. We developed an interface, "Exportable Notation and Bookmark List Engine" (ENABLE), which produces prepopulated RECIST v1.1 worksheets and compiles cohort data and data models from PACS measurement data, thus eliminating handwriting and manual data transcription. We compared RECIST v1.1 data from eight patients (16 computed tomography exams) enrolled in an IRB-approved therapeutic trial with ENABLE outputs: 10 data fields with a total of 194 data points. All data in ENABLE's output matched with the existing data. Seven staff were taught how to use the interface with a 5-min explanatory instructional video. All were able to use ENABLE successfully without additional guidance. We additionally assessed 42 metastatic genitourinary cancer patients with available RECIST data within PACS to produce a best response waterfall plot. ENABLE manages tumor measurements and associated metadata exported from PACS, producing forms and data models compatible with cancer databases, obviating handwriting and the manual re-entry of data. Automation should reduce transcription errors and improve efficiency and the auditing process.

Neuroendocrine neoplasms of the genitourinary tract in adults: cross-sectional imaging spectrum.

Neuroendocrine (NE) neoplasms of the genitourinary (GU) tract in adults are rare tumors with distinct histopathology and variable biological behavior and imaging findings. They may be primary or metastatic in origin. The spectrum of primary GU tract NE neoplasms includes carcinoid, small cell carcinoma, large cell NE carcinoma, and paraganglioma. The tumors commonly show positivity to specific immunohistochemical markers and characteristic dense-core granules at the ultra-structural level. Although imaging findings are nonspecific and accurate differentiation from the more common malignancies of the individual organs is not possible, cross-sectional imaging modalities play an important role in the diagnosis, staging, and surveillance of these tumors. Somatostatin receptor scintigraphy (octreotide scan) may be useful in the detection and treatment of metastatic disease in select patients. Knowledge of the various NE tumors of the adult GU tract and familiarity with their pathological and imaging findings permit optimal patient management.

18F-FDG PET/CT delayed images with forced diuresis for revaluating abdominopelvic malignancies.

PURPOSE: The aim of this retrospective study was to evaluate the role of delayed images after forced diuresis coupled with oral hydration in abdominopelvic 18F-FDG PET/CT. MATERIALS AND METHODS: Forty-six patients consisting of 17 urological diseases, 9 gynecological tumors, 18 colorectal malignancies, and 2 cancers of unknown primary site were retrospectively analyzed. All patients who presented with indeterminate or equivocal abdominopelvic foci on standard 18F-FDG PET/CT underwent a delayed abdominopelvic imaging after administration of 20 mg furosemide intravenously and extra water intake of 500 mL. PET/CT images before and after furosemide were compared with each other and their findings correlated with pathology or clinical follow-up (>6 months). RESULTS: On initial PET/CT, the glucose metabolism characters of lesions were disguised by radioactive urine, or some undetermined 18F-FDG accumulating foci near the urinary tract appeared. While postdiuretic PET/CT demonstrated an excellent urinary tracer washout, and hypermetabolic lesions could be clearly detected and precisely localized in all cases. On the other hand, the suspected active foci caused by potential stagnation of excreted 18F-FDG in urinary tract were eliminated. The sensitivity, specificity, and accuracy were 94.4% (34/36), 8/10, 91.3% (42/46), respectively. Furthermore, the additional lesions with surrounding invasion or locoregional metastasis were discovered in 8 of 46 (17.4%) patients only by the delayed images, including 2 gynecological and 6 rectal malignancies. CONCLUSION: Detection of abdominopelvic malignancies can be improved using delayed 18F-FDG PET/CT images after a diuretic and oral hydration.

[Extraosseous abnormalities and artifacts in skeletal scintigraphy].

OBJECTIVE: to specify frequency, patterns and diagnostic significance of extraosseous soft tissue findings in 99mTc-pyrophosphate skeletal scintigraphy. MATERIAL AND METHODS: Results of skeletal scintigraphy from 1060 patients (447 men, 613 women) were analyzed. Scanning in "whole body" mode started in 3-4 hours after 740 MBq of radiotracer activity intravenous administration, and performed in anterior and posterior projections in continuous table motion mode at rate of 6-8 cm per minute. Single photon emission computed tomography/computed tomography (SPECT/CT) was additionally performed when necessary. RESULTS: Extraosseous scintigraphic findings were discovered in 161 (15.2%) patients, they can be divided into three categories: nephrourological (7.7%), soft tissue (5.4%) and artifacts (2.1%). First category included anatomical and functional changes in the urinary system (kidney location anomalies and nonobstructive uropathies). SPECT/CT was performed to differentiate calycostasis in the projection of the upper group of calyces and focal changes of the ribs. Soft tissue extrarenal findings included diffuse or focal RP hyperfixation within breasts (29 patients), thyroid glands (15), myocardium (5), scrotum (4) and abdominal cavity (4). Symmetrical increased RP accumulation in breast or thyroid lobes was accepted as normal. Pathologic soft tissue findings in 11 patients were verified by history or instrumental data: breast cancer (2), testicular cancer (1), nodular goiter (2), uterine fibroids (2), primary cancer with liver metastases (1), association of "hot kidney" phenomenon with chemotherapy (2), and "superscan" phenomenon with myelofibrosis (1). Causes of radiotracer artifacts in the liver and spleen (14) were of radiopharmaceutical factors, in axillary lymph node (7)--partially infiltrative radiopharmaceuticals administration, in the colon (1)--previous myocardial perfusion scintigraphy. CONCLUSION: Analysis and interpretation of abnormal extraosseous findings in skeletal scintigraphy is an essential component of additional diagnostic information, that can influence subsequent diagnostic and therapeutic tactics.

Imaging of Extranodal Genitourinary Lymphoma.

The genitourinary (GU) system is commonly affected by disseminated lymphoma. Rarely, lymphoma can originate from and remain localized to one of the GU organs and thus presents as primary extranodal disease. Up to 40% of lymphomas present as extranodal disease, with only 3% having the GU system as the primary site of involvement. This article describes and correlates the radiologic and pathologic features of extranodal lymphomatous disease affecting the GU system with specific focus on the kidneys, adrenal glands, testicles, and ovaries. Lymphoma of the uterine body and cervix, external female genitalia, urinary bladder, and prostate gland is briefly discussed.

Ultrasound-Guided Transvaginal Core Biopsy of Pelvic Masses: Feasibility, Safety, and Short-Term Follow-Up.

OBJECTIVE: The purpose of this study was to evaluate the diagnostic accuracy and safety of ultrasound (US)-guided transvaginal core biopsy of pelvic masses. MATERIALS AND METHODS: Fifty-five pelvic masses in 55 consecutive women who underwent US-guided transvaginal core biopsy were enrolled in our study. All lesions were detected on CT or MRI before biopsy. The procedure was performed with local anesthesia using a transvaginal US probe equipped with a guide and an 18-gauge needle with an automatic biopsy gun. We evaluated the diagnostic accuracy and complication rate of the procedure. RESULTS: All acquired specimens were adequate for the histopathologic analysis. The overall diagnostic accuracy of US-guided transvaginal core biopsy was 93% (51/55). Of the 55 lesions, 46 (84%) were confirmed to be either benign or malignant tumors, and five (9%) were diagnosed as active or chronic inflammatory lesions. Four lesions (7%) were not histopathologically diagnosed after biopsy: two were confirmed as fibrothecoma and leiomyosarcoma after surgery, and the remaining two were clinically determined to be recurrent cancer. In terms of minor complications, vaginal bleeding occurred in 10 patients (18%), and gross hematuria occurred in two patients (4%). These complications resolved spontaneously in all patients without further workup or treatment. CONCLUSION: US-guided transvaginal core biopsy seems to be safe and reliable procedure for the histopathologic diagnosis of pelvic masses.

Malignancy and mesenteric panniculitis.

AIM: Mesenteric panniculitis (MP) is a chronic inflammatory process of the small bowel mesentery that has been reported in conjunction with malignancy. The objectives of the present study were to identify the frequency and type of cancers that may coexist with MP and whether these can be seen on the initial diagnostic computerised tomography (CT). METHOD: A prospective database was kept of patients diagnosed with MP in the Canterbury region of New Zealand between 1 January 2003 and 31 December 2014. CT scans were independently reviewed. Clinical records were reviewed and family doctors were contacted for additional information. RESULTS: There were 302 patients with possible MP identified and 259 in whom it was confirmed on review. Seventy-eight patients had a diagnosis of malignancy, with 54 having a current cancer (59 total cancers), 33 a past cancer and nine both. Of the 59 current cancers the most common primary sites were colorectum (19), lymph nodes (17), kidney (six) and prostate (four). Fifty-four were at sites included on an abdominal CT scan. At all sites [except prostate (0/4)] there were high rates of detection on CT with 44/54 cancers visible including 20/23 gastrointestinal tract, 14/17 lymphomas and 9/9 non-prostate urogenital tract malignancies. Six people were subsequently diagnosed with cancer after the index CT. CONCLUSION: When MP occurs in association with malignancy, the commonest primary sites are large bowel, the lymph nodes and the urogenital tract. In those with MP on imaging, any cancer except prostate can usually be seen on the index CT. Further extensive investigation in asymptomatic patients is therefore likely to be of low yield.