Background: While prostate-specific membrane antigen (PSMA)-targeted imaging has revolutionized metastatic detection, unspecific bone uptake (UBU)—particularly in the ribs—is a common but diagnostically challenging finding in prostate cancer (PCa) patients. This review aims to synthesize current evidence on PSMA-avid rib lesions in PCa and to propose a structured approach for differentiating true metastases from benign mimics. Methods: A comprehensive literature search across PubMed, EMBASE, Scopus, and Web of Science identified relevant studies on PSMA imaging interpretation, tracer-specific patterns, rib lesion morphology, and clinical correlates. Data on uptake intensity, CT features, lesion number, location, tracer type, patient-specific risk factors, and follow-up behavior were extracted and analyzed. Results: Most solitary rib lesions are benign, particularly in low-risk patients or when located in the anterior/lateral arcs. Metastatic lesions are more likely to present as multiple foci, show cortical destruction on CT, exhibit high uptake intensity, and occur in patients with elevated PSA, high Gleason score, or ongoing androgen deprivation. ¹⁸F-PSMA-1007 is especially prone to UBU in the ribs compared to ⁶⁸Ga-PSMA-11. Based on these variables, we propose a clinical decision tree to guide interpretation of PSMA-avid rib lesions. Conclusions: Accurate interpretation of rib lesions on PSMA PET/CT requires a multimodal, context-sensitive approach. Our diagnostic decision tree guides precise differentiation of benign versus metastatic rib lesions, enhancing staging accuracy and clinical decision-making. Biomarker-guided therapies offer potential for personalized treatment, though rib-specific validation remains a critical need.

Renal scintigraphy is a diagnostic imaging technique that employs radiopharmaceuticals to evaluate renal function. This atlas underscores critical pearls and pitfalls in the interpretation of renal scintigraphy, emphasizing factors that may affect diagnostic accuracy and influence clinical decision-making. In addition, the cases presented highlight the significance of SPECT/CT imaging in enhancing diagnostic precision. Understanding these patterns is vital for optimizing the interpretation and clinical utility of renal scans. In this paper, we presented patients with horseshoe kidneys, crossed ectopia, cortical defects, fetal lobulations, and duplex kidneys.

A 66-year-old man with inoperable malignant scalp melanoma, refractory to immunotherapy, underwent ^99m Tc-HYNIC-TOC SPECT/CT for evaluating the possibility of radioligand therapy with ¹⁷⁷ Lu-DOTATATE, which demonstrated no tracer uptake in scalp lesions, precluding ¹⁷⁷ Lu-DOTATATE therapy. Subsequent disease progression prompted ^99m Tc-FAPI-46 SPECT/CT, which showed intense tracer uptake in lesions and prompted radioligand therapy with ¹⁷⁷ Lu-FAPI-2286. After 4 cycles of treatment, all lesions showed regression and he was referred for tumor resection. This case illustrates the clinical utility of FAPI-based theranostic and shows ^99m Tc-FAPI SPECT/CT can directly inform targeted radioligand therapy using ¹⁷⁷ Lu-FAPI, thereby expanding therapeutic options in melanoma management.

This report evaluates ^99m Tc-FAPI-46 SPECT/CT in 2 young men with advanced metastatic Ewing sarcoma, demonstrating high tumor-to-background contrast and broad lesion detectability for skeletal and soft-tissue lesions. Case 1 showed widespread FAPI uptake throughout multiple osteoblastic skeletal metastases alongside avid pleural metastatic lesions. Case 2 exhibited intense FAPI avidity across several aggressive sites, including a recurrent spinal tumor, an invasive neck mass, and extensive lytic bone lesions, while demonstrating discordant thoracic uptake. Overall, FAPI-46 SPECT/CT serves as a powerful molecular imaging tool, providing excellent visualization by effectively mapping active stromal remodeling across diverse metastatic presentations.

A 62-year-old man with newly diagnosed prostate adenocarcinoma underwent initial staging with ^99m Tc-PSMA and ^99m Tc-MDP whole-body scans. The bone scan revealed a small zone of tracer activity superior to the left kidney. Subsequent ^99m Tc-PSMA SPECT/CT revealed a fluid density collection in the left perinephric and pararenal space, extending from the left subdiaphragmatic area to the pelvic inlet. PSMA tracer activity was seen around the left kidney. Contrast-enhanced CT confirmed a perinephric fluid collection consistent with urinoma. This case underscores the importance of recognizing atypical patterns of ^99m Tc-PSMA uptake to improve diagnostic accuracy, avoid misinterpretation, and ensure appropriate patient management.