Parent, Ephraim E.

Abstract Background. Cardiovascular disease is a leading cause of death among women with breast cancer, and the 2026 ACC/AHA dyslipidemia guideline endorses coronary artery calcium (CAC) scoring to guide statin therapy before cardiotoxic treatment. Breast cancer patients routinely undergo staging 18 F-fluorodeoxyglucose PET/CT, whose low- dose CT visualizes the coronary arteries, thus enabling CAC quantification at no additional cost or radiation. Methods In this single-center retrospective study, consecutive women with newly diagnosed breast cancer undergoing staging 18 F-FDG PET/CT (2009–2021) had semi- automated Agatston CAC scoring performed on the low-dose CT and were stratified by CAC presence (CAC-P) versus absence (CAC-A). We assessed a composite of cardiac diagnostic testing (stress testing, coronary CT angiography, invasive angiography), clinical events, and reclassification of statin eligibility per ACC/AHA guideline thresholds in a prevention-eligible subgroup. Results Among 276 women (mean age 55.5 years; median follow-up 7.1 years), CAC was present in 68 (25%) but was clinically reported in only 5.4%. CAC-P was associated with more cardiac testing (34% vs 12%; age-adjusted hazard ratio 2.75, 95% CI 1.43–5.28) and, though underpowered, with more atherosclerotic events (7.4% vs 1.4%), but not with the all-cause composite. In the prevention-eligible subgroup (n=39), CAC scoring would have changed statin eligibility in 64%, initiating therapy in 62% of CAC-P women and supporting de-prescribing in 67% of CAC-A women. Conclusions CAC can be feasibly quantified from staging PET/CT in women with breast cancer and would frequently reclassify statin eligibility at no additional cost or radiation, yet is rarely reported.

Abstract INTRODUCTION Anti—amyloid‐β (Aβ) therapies are reshaping Alzheimer's disease (AD) management. Understanding changes in real‐world patterns of diagnostic testing and infusion chair usage is essential for optimizing access to care. METHODS Retrospective analysis of Mayo Clinic enterprise electronic health records (Jan 2019–Mar 2025) assessed trends in AD‐relevant brain imaging, fluid biomarkers, apolipoprotein E (APOE) testing, and lecanemab infusions. Rates of amyloid‐beta (Aβ) positivity by sex and age, APOE genotype frequencies, and lecanemab treatment initiation and discontinuation were evaluated. RESULTS Following national insurance coverage changes, lecanemab infusions grew by 110 infusions per quarter to 605 in Q1 2025. Aβ positron emission tomography scans increased (+22/quarter), cerebrospinal fluid biomarker orders declined (−25/quarter), and plasma p‐tau 217 orders rapidly increased (+238/quarter). Females were more likely to be Aβ positive ( p < 0.006). APOE ‐ε4 homozygotes were less likely to initiate lecanemab (HR = 0.11, p < 0.001). DISCUSSION The adoption of anti‐Aβ therapies coincided with a rapid shift in diagnostic workflows.

Abstract Background: 18F-Fluoroestradiol (FES) positron emission tomography (PET) is approved for non-invasive detection of estrogen receptor (ER)-positive breast cancer (BC) and recent updates to the National Comprehensive Cancer Center Network clinical practice guidelines include FES-PET for staging recurrent/metastatic ILC. Given the wide range of FES-PET indications, we retrospectively reviewed the management of ER+ BC patients after FES-PET at Mayo Clinic. Methods: We identified ER+ BC patients who underwent FES-PET from April 2021 to June 2025 across the Mayo Clinic. BC context at the time of FES-PET requisition was categorized as early (EBC), locally recurrent (LRBC), or metastatic (MBC). Management changes were classified as either affecting BC or non-BC care (not mutually exclusive). For pts who underwent 18F-flurodeoxyglucose (FDG) PET-CT and had a discrepant result with FES-PET, we assessed the clinical impact of these discrepancies. Finally, we examined the change in clinical management when FES-PET was ordered to investigate rising tumor markers CA 15-3 or CA 27.29. Results: 166 pts underwent ≥1 FES-PET scan. At diagnosis, 57% had invasive lobular carcinoma (ILC), 33% invasive ductal carcinoma (IDC), and 5.4% mixed histology. ER expression ≥ 50% was observed in 81.4% and 1.2% were HER2+. Overall, FES-PET led to a change in management in 54.5% (n=90) of pts with 43.0% (n=71) experiencing a change in BC care and 16.4% (n=27) in non-BC care. Changes in BC care occurred in 36% of EBC, 68% of LRBC, and 43.7% of MBC. The most common BC management changes after FES-PET were change in treatment strategy in 23.6% (n=39), additional BC-related imaging including further FES-PET scans in 23.0% (n=38), upstaging in 10.3% (n=17), change in surgical planning in 10.3% (n=17), local therapy in 4.2% (n=7), and biopsy avoidance in 3% (n=5). Surgical planning changes were mostly deciding to proceed with curative intent surgery (n=11), though some surgeries were aborted upon FES-PET upstaging (n=6). Non-BC management changes included additional imaging to evaluate incidental findings in 11.5% (n=19) and procedures in 6.7% (n=11), including 5 biopsies, 2 bronchoscopies, 2 endoscopies, 1 hysterectomy, and 1 cholecystectomy. FDG/FES discordancy was observed in 22.3% of the overall population (n=37). The most common pattern was FDG-/FES+ (n=19), leading to upstaging of BC in 8 and the sole use of FES-PET for future restaging in 13 BC patients. The second most common pattern was FDG+/FES- (n=18), attributed to non-BC related FDG uptake in 11 (false-positive FDG) or post-treatment ER loss in 7. Three FDG+/FES- patients were found to have additional cancers: two non-small cell lung cancers and one lymphoma. Non-malignant causes of false positive FDG were inflammation (n=3), silicone implants (n=1), thymic hyperplasia (n=1), and unknown (n=5). Six patients initially upstaged with FDG-PET imaging proceeded to curative-intent surgery after negative FES-PET confirmatory scans (FDG+/FES-). When FES-PET was ordered to investigate rising CA 15-3 or CA 27.29 tumor markers, this led to upstaging/progression in 3 of 21 cases (1 EBC, 2 MBC). The mean tumor marker increase was 57.0% in patients with upstaging/progression versus 19.0% in those without (p=0.02, two-tailed Student’s t-test). Conclusions: FES-PET altered clinical management in approximately half of BC cases in this study. Changes in BC-specific management were most frequent in LRBC, followed by MBC and EBC. One in six patients had a non-BC clinical management change after FES-PET. FDG/FES discordance provided value in upstaging FDG non-avid cancers and downstaging FDG-avid lesions unrelated to BC, influencing curative treatment decisions. FES-PET ordered for rising tumor markers rarely changed management, though larger tumor marker increases were associated with upstaging or progression. Citation Format: N. Wiest, K. Bullock, T. Pai, M. Kornas, B. McKinley, E. Parent, P. Advani. FES-PET imaging in estrogen receptor-positive breast cancer: implications for clinical management [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS1-06-16.

Abstract Background: Assessing invasive lobular carcinoma (ILC) with standard-of-care (SOC) imaging, such as 18F-fluorodeoxyglucose (FDG) PET-computed tomography (CT), is challenging. In May 2025, National Comprehensive Cancer Center Network guidelines added FES PET for recurrent/metastatic ILC staging. However, perceptions of the value added by FES PET to SOC imaging may vary, as only small ILC cohorts have been published. We evaluated FES PET’s clinical utility in the largest-studied cohort, to our knowledge, of ILC pts who have undergone FES PET. Methods: We identified all ILC pts who had an FES PET [PET-magnetic resonance (MR) or PET-CT)] between April 1, 2021, and May 1, 2025, at Mayo Clinic. Clinical and radiological data, including indications and management (mgmt) changes related to pts’ first FES PET, were obtained from clinical records. FES and SOC FDG PET were compared. Data were summarized with descriptive statistics. Results: 102 female pts were included: 88% White and 4.9% Black. Median age at initial breast cancer (BC) diagnosis was 57 (range, 36-79). At initial ILC diagnosis, most tumors were strongly estrogen receptor (ER) positive. Highest tumor grade was 1 in 25% of pts and 2 in 57%, with grade not documented in 19%; none had documented grade 3 ILC. Initial clinical prognostic stage was as follows: 26% stage 1, 21% stage 2, 10% stage 3, and 16% stage 4. At the time of FES PET, 37% had biopsy-confirmed metastatic ILC at the time of FES PET. The most common indications for FES PET were (re)staging ILC (49%), detecting suspected metastatic/recurrent BC (30%), and evaluating rising tumor markers like CA 15-3 or CA 27.29 (15%). 16% of pts were upstaged due to the FES PET result: 14 pts to stage 4 and 2 pts to stage 3. FES PET led to a mgmt change in 38 pts (37%), for whom the most common FES PET indications were (re)staging ILC (21 pts), detecting suspected recurrent/metastatic BC (11 pts), and detecting ER expression when biopsy was not feasible/nondiagnostic (7 pts). 19 scans (50%) led to a systemic therapy (tx) decision, 10 (26%) to a biopsy, 4 (11%) to additional imaging like MRI, 3 (8%) to locoregional tx, and 2 (5%) to a non-oncologic specialty referral to evaluate a suspected new metastasis. 11 pts had stage 4 BC pre-FES PET; their FES PET was ordered primarily for restaging (5 pts) or detecting ER expression (5 pts). Notably, of the 19 pts with a systemic tx-related change, 4 began a triple-negative BC regimen due to low FES uptake on the scan. Of the 15 pts who had FES PET to evaluate a rising tumor marker, a direct change in systemic tx occurred in 2 pts. 63/102 pts (62%) had FDG PET-CT prior to FES PET. Of these, 57% had discordant FDG and FES PET results. 39% had a higher number of avid metastatic lesions on FES PET as compared to FDG PET, primarily in the bone (8 pts) and lymph nodes (4 pts). 25% had bone, nodal, or soft tissue metastatic lesions that were FDG but not FES avid. 13 pts had FES PET-MRI; 9 of these had a prior FDG PET-CT. 2 PET-MRI pts had FES-avid metastatic lesions in unusual sites (brain, peritoneum) that were not FDG avid. Among the 38 pts with a mgmt change due to their FES PET result, 63% had prior FDG PET; 32% of the 38 pts had FES-avid metastatic lesions that were not seen on FDG PET, and 8% had FDG-avid but not FES-avid lesions. Conclusions: FES PET was useful for evaluating not only stage 4, but also early-stage ILC, with 1/3 of pts with an FES PET-driven mgmt change having early-stage BC. FES PET was most helpful for ILC (re)staging, detection of suspected recurrent/metastatic BC, and detection of ER expression when biopsy was not feasible/nondiagnostic. FES PET added clinically meaningful information beyond SOC imaging, with detection of FES-avid but not FDG-avid metastatic lesions in 1/3 of pts with an FES PET-driven mgmt change. Notably, FES PET-MRI demonstrated potential superiority over FDG PET in identifying atypical ILC metastases. Citation Format: T. Pai, C. Bullock, N. Wiest, E. Parent, P. Advani. Clinical utility of 18F-fluoroestradiol positron emission tomography (FES PET) in patients (pts) with lobular breast cancer [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PD9-09.

Objectives: The practice parameter was revised collaboratively by the American College of Radiology (ACR), the American Brachytherapy Society (ABS), the American College of Nuclear Medicine (ACNM), the American Radium Society (ARS), the Society of Interventional Radiology (SIR), and the Society of Nuclear Medicine and Molecular Imaging (SNMMI). This document summarizes current evidence-based guidelines for the administration of Yttrium radioembolic therapy to the liver, including training requirements, evidence-based guidelines for administration, and safe practice for administration. Methods: This practice parameter was revised according to the process described under the heading The Process for Developing ACR Practice Parameters and Technical Standards on the ACR website (https://www.acr.org/ClinicalResources/Practice-Parameters-and-Technical-Standards) by the Committee on Practice Parameters—Interventional and Cardiovascular Radiology of the ACR Commission on Interventional and Cardiovascular, Committee on Practice Parameters and Technical Standards—Nuclear Medicine and Molecular Imaging of the ACR Commission on Nuclear Medicine and Molecular Imaging and the Committee on Practice Parameters—Radiation Oncology of the ACR Commission on Radiation Oncology in collaboration with the ABS, the ACNM, the ARS, the SIR, and the SNMMI. Results: This review seeks not to be a comprehensive discussion of radiotherapy to the liver, but rather, seeks to provide a parameter for safe and effective therapy. We discuss the qualifications of physicians involved in this therapy, basic indications, contraindications, procedural work-up, safe-handling, and regulatory requirement for the administration of selective internal radiation therapy to patients that are likely to benefit. The goal of this document is not to define which patients are best treated by these therapies, as this is best determined for individual patients after multidisciplinary review. A consistent and evidence-based approach to therapy, however, would benefit all patients who are offered this therapy. This document seeks to provide a framework for current best practices for the administration of the 2 currently available radioembolization devices. Conclusions: As Yttrium-90 radiotherapy to the liver occupies a growing role in the treatment of primary and metastatic liver cancer, this review seeks to assist clinicians of all involved specialties to optimize the efficacy and safety of these procedures.

Following lung cancer, prostate cancer is the leading cause of cancer death in men. High-risk localized tumor burden or metastatic disease often progresses, refractory to initial treatment regimens. There is ongoing development of technology to appropriately identify high-risk patients, stage them correctly, and offer appropriate treatments to obtain the best clinical outcomes. Prostate cancer-specific membrane antigen (PSMA) is a transmembrane glutamate carboxypeptidase, which helps regulate folate absorption, and its overexpression is pathologically directly proportional and associated with prostate cancer. Increased PSMA expression is a known independent risk factor for poorer survival, and most metastatic lesions in CRPC are PSMA positive. Over the last decade, several PSMA-based PET radiopharmaceuticals have demonstrated superior sensitivities and specificities compared to traditional imaging methods. These outcomes have been demonstrated by several large clinical trials. As the data emerges, these diagnostics are being integrated into standard of care protocol to facilitate nuanced identification of malignant lesions. PSMA is also being targeted through several therapeutics, including radioligands and immunotherapies such as CAR-T, BiTEs, and ADCs. This review will discuss the landscape of PSMA-based theranostics in the context of prostate cancer.