Purpose: To describe the site-specific distribution of distant relapse detected by integrated ^18F-FDG PET/contrast-enhanced CT (PET/ceCT) in breast cancer patients and to explore its association with molecular subtype and clinicopathological features. Methods: This retrospective study included 177 postoperative breast cancer patients who underwent PET/ceCT during follow-up/restaging for suspected recurrence. Clinical and pathological data were extracted from a manually curated institutional database, including type of surgery, pathological T stage, pathological nodal status, histology, molecular subtype, PET/ceCT date, and PET/ceCT-detected site of relapse. Site-specific analyses were performed in patients with codable distant relapse. Results: A PET/ceCT relapse-site entry was available in 141/177 patients (79.7%), and 137/177 (77.4%) had codable distant relapse. Molecular subtype was available in 166/177 patients (93.8%). Bone was the most frequent site of distant relapse (81/137, 59.1%), followed by lung (44/137, 32.1%), distant lymph nodes (41/137, 29.9%), and liver (40/137, 29.2%); brain involvement was uncommon (8/137, 5.8%). Single-site and multisite relapse were observed in 70/137 (51.1%) and 67/137 (48.9%) patients, respectively. Bone involvement was significantly more frequent in luminal than in non-luminal tumors (65/101, 64.4% vs 11/29, 37.9%; p=0.018). Conclusion: PET/ceCT disclosed non-random and biologically meaningful patterns of distant relapse in breast cancer. Bone-dominant relapse was the prevailing phenotype overall and was significantly associated with luminal disease, whereas non-luminal tumors showed relatively more visceral and multisite dissemination.

Cardiac positron emission tomography (PET) has undergone substantial development in recent years, moving beyond conventional perfusion imaging toward a multiparametric and increasingly quantitative assessment of cardiovascular disease. This article provides a critical narrative overview of the recent cardiac PET literature, with particular emphasis on studies published over the last five years, and discusses both established tracers and emerging radiopharmaceuticals in contemporary cardiology. Among established applications, 18F-FDG remains relevant for myocardial viability assessment and selected inflammatory indications, although its prognostic and therapeutic implications are less uniform than earlier narratives suggested. For myocardial perfusion imaging, 13N-ammonia and 82Rb PET provide robust assessment of myocardial blood flow and myocardial flow reserve, but their clinical interpretation remains strongly influenced by acquisition protocols, software reproducibility, and methodological standardization. The review also addresses newer tracers, including 68Ga-FAPI for fibroblast activation, 18F-flurpiridaz for high-performance perfusion imaging, 18F-FDOPA for cardiac sympathetic dysfunction, and amyloid-binding PET radiopharmaceuticals for cardiac amyloidosis. Overall, recent evidence supports cardiac PET as a powerful platform for physiologic and molecular imaging, but not as a uniform or methodologically neutral technology. Its current value lies in selective, question-driven clinical use, whereas broader implementation will depend on tracer-specific validation, harmonized quantitative workflows, and clear demonstration of incremental benefit over existing imaging strategies.