Diagnostic Performance of 18F-DCFPyL-PET/CT in Men with Biochemically Recurrent Prostate Cancer: Results from the CONDOR Phase III, Multicenter Study.

PURPOSE: Current FDA-approved imaging modalities are inadequate for localizing prostate cancer biochemical recurrence (BCR). 18F-DCFPyL is a highly selective, small-molecule prostate-specific membrane antigen-targeted PET radiotracer. CONDOR was a prospective study designed to determine the performance of 18F-DCFPyL-PET/CT in patients with BCR and uninformative standard imaging. EXPERIMENTAL DESIGN: 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 between 18F-DCFPyL-PET/CT and a composite standard of truth (SOT). The SOT consisted of, in descending priority (i) histopathology, (ii) subsequent correlative imaging findings, or (iii) post-radiation PSA response. The trial was considered a success if the lower bound of the 95% confidence interval (CI) for CLR exceeded 20% for two of three 18F-DCFPyL-PET/CT readers. Secondary endpoints included change in intended management and safety. RESULTS: A total of 208 men with a median baseline PSA of 0.8 ng/mL (range: 0.2-98.4 ng/mL) underwent 18F-DCFPyL-PET/CT. The CLR was 84.8%-87.0% (lower bound of 95% CI: 77.8-80.4). A total of 63.9% of evaluable patients had a change in intended management after 18F-DCFPyL-PET/CT. The disease detection rate was 59% to 66% (at least one lesion detected per patient by 18F-DCFPyL-PET/CT by central readers). CONCLUSIONS: Performance of 18F-DCFPyL-PET/CT achieved the study's primary endpoint, demonstrating disease localization in the setting of negative standard imaging and providing clinically meaningful and actionable information. These data further support the utility of 18F-DCFPyL-PET/CT to localize disease in men with recurrent prostate cancer.See related commentary by True and Chen, p. 3512.

A Phase 2/3 Prospective Multicenter Study of the Diagnostic Accuracy of Prostate Specific Membrane Antigen PET/CT with 18F-DCFPyL in Prostate Cancer Patients (OSPREY).

PURPOSE: Prostate specific membrane antigen-targeted positron emission tomography/computerized tomography has the potential to improve the detection and localization of prostate cancer. OSPREY was a prospective trial designed to determine the diagnostic performance of 18F-DCFPyL-positron emission tomography/computerized tomography for detecting sites of metastatic prostate cancer. MATERIALS AND METHODS: Two patient populations underwent 18F-DCFPyL-positron emission tomography/computerized tomography. Cohort A enrolled men with high-risk prostate cancer undergoing radical prostatectomy with pelvic lymphadenectomy. Cohort B enrolled patients with suspected recurrent/metastatic prostate cancer on conventional imaging. Three blinded central readers evaluated the 18F-DCFPyL-positron emission tomography/computerized tomography. Diagnostic performance of 18F-DCFPyL-positron emission tomography/computerized tomography was based on imaging results compared to histopathology. In cohort A, detection of pelvic nodal disease (with specificity and sensitivity as co-primary end points) and of extrapelvic metastases were evaluated. In cohort B, sensitivity and positive predictive value for prostate cancer within biopsied lesions were evaluated. RESULTS: A total of 385 patients were enrolled. In cohort A (252 evaluable patients), 18F-DCFPyL-positron emission tomography/computerized tomography had median specificity of 97.9% (95% CI: 94.5%-99.4%) and median sensitivity of 40.3% (28.1%-52.5%, not meeting prespecified end point) among 3 readers for pelvic nodal involvement; median positive predictive value and negative predictive value were 86.7% (69.7%-95.3%) and 83.2% (78.2%-88.1%), respectively. In cohort B (93 evaluable patients, median prostate specific antigen 11.3 ng/ml), median sensitivity and positive predictive value for extraprostatic lesions were 95.8% (87.8%-99.0%) and 81.9% (73.7%-90.2%), respectively. CONCLUSIONS: The primary end point for specificity was met while the primary end point for sensitivity was not. The high positive predictive value observed in both cohorts indicates that 18F-DCFPyL-positive lesions are likely to represent disease, supporting the potential utility of 18F-DCFPyL-positron emission tomography/computerized tomography to stage men with high-risk prostate cancer for nodal or distant metastases, and reliably detect sites of disease in men with suspected metastatic prostate cancer.

Reorganising the emergency department to manage the COVID-19 outbreak.

BACKGROUND: The COVID-19 disease outbreak that first surfaced in Wuhan, China, in December 2019, has taken the world by storm and ravaged almost every country in the world. Emergency departments (ED) in hospitals are on the frontlines, serving an essential function in identifying these patients, isolating them early whilst providing urgent medical care. This outbreak has reinforced the role of Emergency Medicine in public health. This paper documents the challenges faced and measures taken by a tertiary hospital's ED in Singapore, in response to the outbreak. MAIN BODY: The ED detected the first case of COVID-19 in Singapore on 22 January 2020 in a Chinese tourist and also the first case of locally transmitted COVID-19 on 3 February 2020. The patient journeys through the patient reception area in the ED and undergoes fever screening before being shunted to isolation areas within the ED. Management and disposition of suspect COVID-19 patients are guided by a close-knit collaboration between ED and department of infectious diseases. With increasing number of patients, back-up plans for expansion of space and staff augmentation have been enacted. Staff safety is also of utmost importance, with provision and guidelines for personal protective equipment and team segregation to ensure no cross-contamination across staff. These have been made possible with an early setup of an operational command and control structure within the ED, managing manpower, logistics, operations, communication and information management and liaison with other clinical departments. CONCLUSION: With the large numbers of undifferentiated patients managed by the ED to date, more than 820 patients with COVID-19 have been identified in the hospital. Not a single member of the staff of the SGH Emergency Department has come down with the illness. The various measures undertaken by the department have helped to ensure good staff morale and strict adherence to safety procedures. We share the lessons learnt so that others who manage EDs around the world can benefit from our experience.

Efficacy and Safety of High-Specific-Activity 131I-MIBG Therapy in Patients with Advanced Pheochromocytoma or Paraganglioma.

Patients with metastatic or unresectable (advanced) pheochromocytoma and paraganglioma (PPGL) have poor prognoses and few treatment options. This multicenter, phase 2 trial evaluated the efficacy and safety of high-specific-activity 131I-meta-iodobenzylguanidine (HSA 131I-MIBG) in patients with advanced PPGL. Methods: In this open-label, single-arm study, 81 PPGL patients were screened for enrollment, and 74 received a treatment-planning dose of HSA 131I-MIBG. Of these patients, 68 received at least 1 therapeutic dose (∼18.5 GBq) of HSA 131I-MIBG intravenously. The primary endpoint was the proportion of patients with at least a 50% reduction in baseline antihypertensive medication use lasting at least 6 mo. Secondary endpoints included objective tumor response as assessed by Response Evaluation Criteria in Solid Tumors version 1.0, biochemical tumor marker response, overall survival, and safety. Results: Of the 68 patients who received at least 1 therapeutic dose of HSA 131I-MIBG, 17 (25%; 95% confidence interval, 16%-37%) had a durable reduction in baseline antihypertensive medication use. Among 64 patients with evaluable disease, 59 (92%) had a partial response or stable disease as the best objective response within 12 mo. Decreases in elevated (≥1.5 times the upper limit of normal at baseline) serum chromogranin levels were observed, with confirmed complete and partial responses 12 mo after treatment in 19 of 28 patients (68%). The median overall survival was 36.7 mo (95% confidence interval, 29.9-49.1 mo). The most common treatment-emergent adverse events were nausea, myelosuppression, and fatigue. No patients had drug-related acute hypertensive events during or after the administration of HSA 131I-MIBG. Conclusion: HSA 131I-MIBG offers multiple benefits, including sustained blood pressure control and tumor response in PPGL patients.

Phase 1 Study of High-Specific-Activity I-131 MIBG for Metastatic and/or Recurrent Pheochromocytoma or Paraganglioma.

Context: No therapies are approved for the treatment of metastatic and/or recurrent pheochromocytoma or paraganglioma (PPGL) in the United States. Objective: To determine the maximum tolerated dose (MTD) of high-specific-activity I-131 meta-iodobenzylguanidine (MIBG) for the treatment of metastatic and/or recurrent PPGL. Design: Phase 1, dose-escalating study to determine the MTD via a standard 3 + 3 design, escalating by 37 MBq/kg starting at 222 MBq/kg. Setting: Three centers. Patients: Twenty-one patients were eligible, received study drug, and were evaluable for MTD, response, and toxicity. Intervention: Open-label use of high-specific-activity I-131 MIBG therapy. Main Outcome Measures: Dose-limiting toxicities, adverse events, radiation absorbed dose estimates, radiographic tumor response, biochemical response, and survival. Results: The MTD was determined to be 296 MBq/kg on the basis of two observed dose-limiting toxicities at the next dose level. The highest mean radiation absorbed dose estimates were in the thyroid and lower large intestinal wall (each 1.2 mGy/MBq). Response was evaluated by total administered activity: four patients (19%), all of whom received >18.5 GBq of study drug, had radiographic tumor responses of partial response by Response Evaluation Criteria in Solid Tumors. Best biochemical responses (complete or partial response) for serum chromogranin A and total metanephrines were observed in 80% and 64% of patients, respectively. Overall survival was 85.7% at 1 year and 61.9% at 2 years after treatment. The majority (84%) of adverse events were considered mild or moderate in severity. Conclusions: These findings support further development of high-specific-activity I-131 MIBG for the treatment of metastatic and/or recurrent PPGL at an MTD of 296 MBq/kg.

Potential roles of vaptans in heart failure: experience from clinical trials and considerations for optimizing therapy in target patients.

Hyponatremia is a known complication in patients with heart failure (HF). HF patients with severe congestion, hyponatremia, and renal insufficiency are difficult to manage and may have worse outcomes. A main cause of hyponatremia is inappropriately elevated level of plasma arginine vasopressin (AVP), which causes water retention at the collecting duct. AVP antagonists have thus been developed to increase aquaresis and serum sodium levels in patients with euvolemic and hypervolemic hyponatremia. Although tolvaptan, an AVP-2 receptor antagonist, did not show outcomes benefit in patients with decompensated HF, prospective studies are ongoing to evaluate its optimal role in targeted HF patients.

Review of Tolvaptan's Pharmacokinetic and Pharmacodynamic Properties and Drug Interactions.

Tolvaptan is an arginine vasopressin (AVP) antagonist that acts to increase excretion of free water (aquaresis) in patients without introducing electrolyte abnormalities or worsening renal function. It works via blockade of vasopressin-2 receptors at the renal collecting duct. Since the approval of tolvaptan for the treatment of hypervolemic and euvolemic hyponatremia in 2009, new studies have been reported to better characterize its pharmacokinetic and pharmacodynamic profile of tolvaptan. This paper is a review of both these clinical studies, as well as previous literature, in order to help guide appropriate clinical use of tolvaptan in patients. With appropriate monitoring of serum sodium, tolvaptan may be safely dose escalated from 15 mg once daily to a maximum effective dose of 60 mg once daily for multiple days, to achieve optimal aqauretic effects. In terms of drug interactions, co-administration of moderate to potent CYP3A4 inhibitors and inducers should be avoided. Tolvaptan should also be co-administered with caution and proper monitoring in the presence of P-glycoprotein substrate and strong inhibitors. Co-administration of tolvaptan with diuretic therapy did not appear to alter the aquaretic effect of tolvaptan; and was shown to be safe and well tolerated.