ACR Appropriateness Criteria® Screening for Abdominal Aortic Aneurysm.

Abdominal aortic aneurysm (AAA) is a significant vascular disease found in 4% to 8% of the screening population. If ruptured, its mortality rate is between 75% and 90%, and it accounts for up to 5% of sudden deaths in the United States. Therefore, screening of AAA while asymptomatic has been a crucial portion of preventive health care worldwide. Ultrasound of the abdominal aorta is the primary imaging modality for screening of AAA recommended for asymptomatic adults regardless of their family history or smoking history. Alternatively, duplex ultrasound and CT abdomen and pelvis without contrast may be appropriate for screening. 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 process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Low PSA radiographic disease progression on C11-choline PET.

Background: For men with prostate cancer, radiographic progression may occur without a concordant rise in prostate-specific antigen (PSA). Our study aimed to assess the prevalence of radiographic progression using C-11 choline positron emission tomography (PET) imaging in patients achieving ultra-low PSA values and to evaluate clinical outcomes in this patient population. Methods: In a single institution study, we reviewed the prospectively maintained Mayo Clinic C-11 Choline PET metastatic prostate cancer registry to identify patients experiencing radiographic disease progression (rDP) on C-11 choline PET scan while the PSA value was less than 0.5 ng/mL. Disease progression was confirmed by tissue biopsy or response to subsequent therapy. Clinicopathologic variables were abstracted by trained research personnel. Overall survival was estimated using the Kaplan-Meier method. Intergroup differences were assessed using the log-rank test. A univariate and multivariate Cox regression model was performed to investigate variables associated with poor survival after rDP. Results: A total of 1323 patients within the registry experienced rDP between 2011 and 2021, including 220 (16.6%) men with rDP occurring at low PSA level. A median (interquartile range [IQR]) of 54.7 (19.7-106.9) months elapsed between the time of prostate cancer diagnosis and low PSA rDP, during which 173 patients (78%) developed castration-resistant prostate cancer (CRPC). Sites of low PSA rDP included local recurrence (n = 17, 8%), lymph node (n = 90, 41%), bone (n = 94, 43%) and visceral metastases (n = 19, 9%). Biopsy at the time of rDP demonstrated small-cell or neuroendocrine features in 21% of patients with available tissue. Over a median (IQR) follow-up of 49.4 (21.3-95.1) months from the time of low PSA rDP, 46% (n = 102) of patients died. Factors associated with poorer survival outcomes include advanced age at rDP, CRPC status, bone and visceral metastasis (p value <0.05). Visceral metastases were associated with decreased overall survival (p = 0.009 by log-rank) as compared with other sites of rDP. Conclusions: Men with prostate cancer commonly experience metastatic progression at very low or even undetectable PSA levels. Periodic imaging, even at low absolute PSA values, may result in more timely identification of disease progression.

ACR Appropriateness Criteria® Lower Extremity Chronic Venous Disease.

Lower extremity venous insufficiency is a chronic medical condition resulting from primary valvular incompetence or, less commonly, prior deep venous thrombosis or extrinsic venous obstruction. Lower extremity chronic venous disease has a high prevalence with a related socioeconomic burden. In the United States, over 11 million males and 22 million females 40 to 80 years of age have varicose veins, with over 2 million adults having advanced chronic venous disease. The high cost to the health care system is related to the recurrent nature of venous ulcerative disease, with total treatment costs estimated >$2.5 billion per year in the United States, with at least 20,556 individuals with newly diagnosed venous ulcers yearly. Various diagnostic and treatment strategies are in place for lower extremity chronic venous disease and are discussed in this document. 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.

Clinical practice in prostate PET imaging.

Positron emission tomography (PET) imaging in prostate cancer has advanced significantly in the past decade with prostate cancer targeted radiopharmaceuticals now playing a growing role in diagnosis, staging, and treatment. This narrative review focuses on the most commonly used PET radiopharmaceuticals in the USA: prostate-specific membrane antigen (PSMA), fluciclovine, and choline. 18F-fluorodeoxyglucose (FDG) is used in many other malignancies, but rarely in prostate cancer. Previous literature is discussed regarding each radiopharmaceutical's utility in the settings of screening/diagnosis, initial staging, biochemical recurrence, advanced disease, and evaluation prior to targeted radiopharmaceutical therapy and radiation therapy. PET imaging has demonstrated utility over traditional imaging in various scenarios; however, there are few head-to-head studies comparing PET radiopharmaceuticals. PSMA radiopharmaceuticals are the newest tracers developed and have unique properties and uses, especially at low prostate-specific antigen (PSA) levels. However, each PET radiopharmaceutical has different properties which can affect image interpretation. Choline and fluciclovine have minimal urinary activity, whereas PSMA agents can have high urinary activity which may affect locoregional disease evaluation. Of the three radiopharmaceuticals, only PSMA is approved for both diagnostic and therapeutic indications with 177Lu-PSMA. A variety of diagnostic PET radiotracers for prostate cancer allows for increased flexibility, especially in the setting of supply chain and medication shortages. For the time being, keeping a diverse group of PET radiopharmaceuticals for prostate cancer is justifiable.

Early PSA decline after starting second-generation hormone therapy in the post-docetaxel setting predicts cancer-specific survival in metastatic castrate-resistant prostate cancer.

BACKGROUND: The objective of this study was to evaluate the prognostic value of early PSA decline following initiation of second-generation hormone therapy (2nd HT), namely abiraterone acetate or enzalutamide, in patients with taxane-refractory metastatic castrate-resistant prostate cancer (mCRPC) and evaluate utility of this metric in informing intensified surveillance/imaging protocols. METHODS: We retrospectively identified 75 mCRPC patients treated with 2nd HT following docetaxel failure (defined as PSA rise and radiographic progression). Patients were categorized patients into two cohorts based on the first PSA within 3 months after initiation of therapy: PSA reduction ≥50% (Group A) and PSA reduction <50% (Group B). The primary endpoint was cancer-specific mortality (CSM). The secondary endpoint was radiographic disease progression (rDP) on 2nd HT. In univariate and multivariate analyses, we investigated factors associated with rPD and CSM. RESULTS: We included 75 patients (52 in Group A, 23 in Group B) in the analytic cohort. Baseline clinico-demographic characteristics, including median age, primary Gleason score risk group, median pre-treatment PSA, disease burden, site of metastases, and pre-treatment ECOG score were not statistically different between the two groups. Median follow up time was 30 months and the median time to radiographic disease progression was 28.1 and 12.5 months (p = 0.002) in cohorts A and B, respectively. On univariate and multivariate analyses, both PSA reduction ≥50% and volume of metastatic disease were significantly associated with a decreased risk of radiographic disease progression (HR 0.41, 95% CI 0.21-0.80, p = 0.0113) as well as a decreased risk of cancer-specific mortality (HR 0.29, 95% CI 0.09-0.87, p = 0.0325). CONCLUSION: PSA reduction ≥50% within 3 months of starting 2nd HT was associated with significantly improved radiographic disease progression-free survival and 3-year cancer-specific mortality. This suggests using PSA 50%-decline metric in surveillance patients with on 2nd HT and identifies patients who require further evaluation with imaging.

A Review of Theranostics: Perspectives on Emerging Approaches and Clinical Advancements.

Theranostics is the combination of two approaches-diagnostics and therapeutics-applied for decades in cancer imaging using radiopharmaceuticals or paired radiopharmaceuticals to image and selectively treat various cancers. The clinical use of theranostics has increased in recent years, with U.S. Food and Drug Administration (FDA) approval of lutetium 177 (177Lu) tetraazacyclododecane tetraacetic acid octreotate (DOTATATE) and 177Lu-prostate-specific membrane antigen vector-based radionuclide therapies. The field of theranostics has imminent potential for emerging clinical applications. This article reviews critical areas of active clinical advancement in theranostics, including forthcoming clinical trials advancing FDA-approved and emerging radiopharmaceuticals, approaches to dosimetry calculations, imaging of different radionuclide therapies, expanded indications for currently used theranostic agents to treat a broader array of cancers, and emerging ideas in the field. Keywords: Molecular Imaging, Molecular Imaging-Cancer, Molecular Imaging-Clinical Translation, Molecular Imaging-Target Development, PET/CT, SPECT/CT, Radionuclide Therapy, Dosimetry, Oncology, Radiobiology © RSNA, 2023.

Metastasis-directed Therapy Without Androgen Deprivation Therapy in Solitary Oligorecurrent Prostate Cancer.

PURPOSE: As controversy remains regarding the role of metastasis-directed therapy in patients with oligometastatic prostate cancer, we sought to characterize outcomes of metastasis-directed therapy without concomitant androgen deprivation therapy in the specific subset of patients with a solitary metastatic lesion on C-11 choline positron emission tomography imaging whose primary tumor has already been treated. MATERIALS AND METHODS: We identified 124 consecutive prostate cancer patients from 2008 to 2018 with a solitary oligorecurrent metastatic lesion on positron emission tomography imaging who were treated with metastasis-directed therapy without androgen deprivation therapy from the Mayo Clinic C-11 choline registry. Metastasis-directed therapy consisted of either stereotactic body radiation therapy or surgical excision. RESULTS: Of these 124 patients, 67 were treated with surgery (median follow-up 54 months) and 57 patients were treated with stereotactic body radiation therapy (median follow-up 53 months). Of patients treated with surgery, 80.5% had >50% decline in prostate specific antigen at first follow-up, and the 3-year radiographic progression-free survival was 29%. Median time to initiation of systemic therapy in this cohort was 18.5 months (interquartile range 8.4-44.7 months). Meanwhile, for patients treated with stereotactic body radiation therapy, 40.3% had >50% decline in prostate specific antigen at first follow-up, and the 3-year radiographic progression-free survival was 17%. Similarly, median time to initiation of systemic therapy was 17.8 months (interquartile range 7.1-42.3 months). CONCLUSIONS: This study represents the first reported series of metastasis-directed therapy without androgen deprivation therapy in patients with solitary oligorecurrent metastatic prostate cancer. These results suggest that metastasis-directed therapy without androgen deprivation therapy can delay initiation of systemic therapy and highlight the need for further prospective study for select patients with solitary metastatic recurrences of prostate cancer.

ACR Appropriateness Criteria® Plexopathy: 2021 Update.

Plexopathy may be caused by diverse pathologies, including trauma, nerve entrapment, neoplasm, inflammation, infection, autoimmune disease, hereditary disease, and idiopathic etiologies. For patients presenting with brachial or lumbosacral plexopathy, dedicated plexus MRI is the most appropriate initial imaging modality for all clinical scenarios and can identify processes both intrinsic and extrinsic to the nerves. Other imaging tests may be appropriate for initial imaging depending on the clinical scenario. This document addresses initial imaging strategies for brachial and lumbosacral plexopathy in the following clinical situations: nontraumatic plexopathy with no known malignancy, traumatic plexopathy (not perinatal), and plexopathy occurring in the context of a known malignancy or posttreatment syndrome. 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.

ACR Appropriateness Criteria® Nontraumatic Aortic Disease.

Nontraumatic aortic disease can be caused by a wide variety of disorders including congenital, inflammatory, infectious, metabolic, neoplastic, and degenerative processes. Imaging examinations such as radiography, ultrasound, echocardiography, catheter-based angiography, CT, MRI, and nuclear medicine examinations are essential for diagnosis, treatment planning, and assessment of therapeutic response. Depending upon the clinical scenario, each of these modalities has strengths and weaknesses. Whenever possible, the selection of a diagnostic imaging examination should be based upon the best available evidence. 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. The purpose of this document is to assist physicians select the most appropriate diagnostic imaging examination for nontraumatic aortic diseases.

ACR Appropriateness Criteria® Radiologic Management of Portal Hypertension.

Cirrhosis is a heterogeneous disease that cannot be studied as a single entity and is classified in two main prognostic stages: compensated and decompensated cirrhosis. Portal hypertension, characterized by a pathological increase of the portal pressure and by the formation of portal-systemic collaterals that bypass the liver, is the initial and main consequence of cirrhosis and is responsible for the majority of its complications. A myriad of treatment options exists for appropriately managing the most common complications of portal hypertension, including acute variceal bleeding and refractory ascites. 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.

ACR Appropriateness Criteria® Head Trauma: 2021 Update.

Head trauma (ie, head injury) is a significant public health concern and is a leading cause of morbidity and mortality in children and young adults. Neuroimaging plays an important role in the management of head and brain injury, which can be separated into acute (0-7 days), subacute (<3 months), then chronic (>3 months) phases. Over 75% of acute head trauma is classified as mild, of which over 75% have a normal Glasgow Coma Scale score of 15, therefore clinical practice guidelines universally recommend selective CT scanning in this patient population, which is often based on clinical decision rules. While CT is considered the first-line imaging modality for suspected intracranial injury, MRI is useful when there are persistent neurologic deficits that remain unexplained after CT, especially in the subacute or chronic phase. Regardless of time frame, head trauma with suspected vascular injury or suspected cerebrospinal fluid leak should also be evaluated with CT angiography or thin-section CT imaging of the skull base, respectively. 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.

ACR Appropriateness Criteria® Myelopathy: 2021 Update.

Myelopathy is a clinical diagnosis with localization of the neurological findings to the spinal cord, rather than the brain or the peripheral nervous system, and then to a particular segment of the spinal cord. Myelopathy can be the result of primary intrinsic disorders of the spinal cord or from secondary conditions, which result in extrinsic compression of the spinal cord. While the causes of myelopathy may be multiple, the acuity of presentation and symptom onset frame a practical approach to the differential diagnosis. Imaging plays a crucial role in the evaluation of myelopathy with MRI the preferred modality. 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.

Radium-223 in the Third-Line Setting in Metastatic Castration-Resistant Prostate Cancer: Impact of Concomitant Use of Enzalutamide on Overall Survival (OS) and Predictors of Improved OS.

INTRODUCTION: Radium-223 (Ra-223) has been recommended for bone-dominant metastatic castration-resistant prostate cancer (mCRPC). Second-generation hormone therapy in combination with Ra-223 in mCRPC has been utilized, yet its benefit has not been well elucidated. We investigated the potential survival benefit of concomitant enzalutamide with Ra-223 in the third-line setting and predictors of improved overall survival (OS). PATIENTS AND METHODS: We retrospectively identified 51 patients with bone-dominant mCRPC that were treated with Ra-223 in the postchemotherapy and post-hormone therapy setting, either alone (group A; n = 32) or with concomitant enzalutamide (group B; n = 19). The primary endpoint was to study the OS difference between groups A and B. The secondary endpoint was to identify predictors of improved OS with Ra-223 in the third-line setting. RESULTS: Mean age was 70.9 years, median baseline prostatic-specific antigen (PSA) was 23.1 ng/mL, alkaline phosphatase was 91 IU/L, and hemoglobin was 12.5 g/dL. There was no difference in median OS between groups A and B, at 20.4 versus 17.5 months, respectively (P = .5186). In univariate and multivariate analyses, only pre-Ra-223 PSA < 30 ng/mL and Eastern Cooperative Oncology Group performance status < 2 were associated with improved OS. CONCLUSION: In our study cohort, concomitant use of enzalutamide with Ra-223 in the mCRPC setting was not associated with improved OS. Only pretreatment PSA < 30 ng/mL and pretreatment Eastern Cooperative Oncology Group performance status < 2 were associated with improved OS. Further prospective studies are warranted.

How We Do It: A Multidisciplinary Approach to 177Lu DOTATATE Peptide Receptor Radionuclide Therapy.

Lutetium 177 (177Lu) DOTA-0-Tyr3-Octreotate (DOTATATE) peptide receptor radionuclide therapy (PRRT) is an effective treatment for advanced gastroenteropancreatic neuroendocrine tumors. This review presents a clinical practice workflow that has been successful since 177Lu DOTATATE PRRT was approved by the U.S. Food and Drug Administration. The workflow relies heavily on the input of a multidisciplinary team and involves a nuclear medicine consultation service, tumor board, and specific preparations in advance of therapy and day-of-therapy procedures. A systematic checklist designed to ensure appropriate selection of treatment candidates and identification of any concerns to address to safely administer PRRT is provided. All patients were evaluated with gallium 68 DOTATATE PET/CT, and in cases of high-grade tumors, they were also evaluated with fluorine 18 fluorodeoxyglucose PET/CT, with imaging findings reviewed as part of the systematic checklist before PRRT. Adverse effects are discussed and imaging follow-up regimens are reviewed, including alternative diagnostic contrast materials. Approaches to multiple challenging patient scenarios are illustrated through case examples. Finally, alternative theranostic radionuclides and treatment strategies are discussed.

ACR Appropriateness Criteria® Seizures and Epilepsy.

Seizures and epilepsy are a set of conditions that can be challenging to diagnose, treat, and manage. This document summarizes recommendations for imaging in different clinical scenarios for a patient presenting with seizures and epilepsy. MRI of the brain is usually appropriate for each clinical scenario described with the exception of known seizures and unchanged semiology (Variant 3). In this scenario, it is unclear if any imaging would provide a benefit to patients. In the emergent situation, a noncontrast CT of the head is also usually appropriate as it can diagnose or exclude emergent findings quickly and is an alternative to MRI of the brain in these clinical scenarios. 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.

ACR Appropriateness Criteria® Thoracic Outlet Syndrome.

Thoracic outlet syndrome (TOS) is the clinical entity that occurs with compression of the brachial plexus, subclavian artery, and/or subclavian vein at the superior thoracic outlet. Compression of each of these structures results in characteristic symptoms divided into three variants: neurogenic TOS, venous TOS, and arterial TOS, each arising from the specific structure that is compressed. The constellation of symptoms in each patient may vary, and patients may have more than one symptom simultaneously. Understanding the various anatomic spaces, causes of narrowing, and resulting neurovascular changes is important in choosing and interpreting radiological imaging performed to help diagnose TOS and plan for intervention. This publication has separated imaging appropriateness based on neurogenic, venous, or arterial symptoms, acknowledging that some patients may present with combined symptoms that may require more than one study to fully resolve. Additionally, in the postoperative setting, new symptoms may arise altering the need for specific imaging as compared to preoperative evaluation. 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.

ACR Appropriateness Criteria® Clinically Suspected Vascular Malformation of the Extremities.

Vascular malformations of the extremities represent a wide spectrum of lesions, broadly divided into high-flow and low-flow categories. High-flow lesions include arteriovenous malformations and arteriovenous fistulas, while the more common low-flow lesions consist of venous and lymphatic malformations. The clinical presentation of vascular malformations is variable and can include extremity pain, discoloration, focal mass, or diffuse extremity enlargement. A vascular murmur can also be present and is more typical of high-flow lesions. While vascular malformations can often be diagnosed or strongly suspected by clinical features alone, imaging is often used to confirm the diagnosis, determine lesion characteristics and extent, and/or plan for treatment. Among the imaging options available, those usually appropriate for initial imaging of suspected vascular malformation are MR angiography without and with intravenous contrast, MRI without and with intravenous contrast, CT angiography with intravenous contrast, or US duplex Doppler. 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.