Radiology. Imaging cancer最新文献

Purpose To evaluate the potential of perfluorobutane-enhanced US as a predictive biomarker for anti-programmed cell death (PD)-1 treatment response by targeting alternatively activated phenotype (M2)-polarized tumor-associated macrophages (TAMs) in hepatocellular carcinoma (HCC). Materials and Methods This study was conducted from June 2021 to February 2025. Male animal models included 4-week-old C57BL/6 mice for HCC models and 2-3-month-old New Zealand white rabbits for VX2 liver tumor models. The phagocytic capacity of M2-polarized TAMs for perfluorobutane microbubbles was evaluated in vitro using transmission microscopy to confirm selective microbubble uptake. In vivo, HCC models were established, including mice with primary HCC induced by Akt/N-ras oncogenes, an orthotopic intrahepatic transplantation mouse model, and a VX2 metastatic tumor rabbit model. Targeted imaging of M2-TAMs in these models was performed using perfluorobutane microsphere-based contrast-enhanced US, and the presence of hyperenhanced rims during the postvascular phase was analyzed to assess their association with M2-TAM accumulation. In addition, an orthotopic liver transplant mouse model was developed, in which contrast-enhanced US was used to depict hyperenhanced rims and analyze their correlation with M2-TAM distribution and the efficacy of anti-PD-1 therapy. Results In vitro studies demonstrated predominant uptake of perfluorobutane microbubbles by M2-TAMs, with 92% (46 of 50) of U937-derived M2 macrophages engulfing the microspheres compared with 0% of M1 macrophages (P < .001). In vivo, the observation of hyperenhanced rims during the postvascular phase of contrast-enhanced US was associated with the presence of M2-TAMs. In orthotopic liver transplant mouse models receiving anti-PD-1 treatment, tumor progression differed between the hyperenhanced rim-positive and rim-negative groups (P < .05). Conclusion Perfluorobutane microbubble-based contrast-enhanced US, which targets M2-TAMs, presents a promising method for predicting the response to anti-PD-1 therapy in HCC. Keywords: Contrast-enhanced Ultrasound, Tumor-associated Macrophages, Anti-PD-1 Treatment, Hepatocellular Carcinoma Supplemental material is available for this article. © RSNA, 2025.

Purpose To evaluate the diagnostic capability of MR histopathology (MRH) for identifying prostate cancer and guiding selection of imaging parameters for clinical MRH acquisition. Materials and Methods This retrospective study was conducted on a dataset of histologic slides of radical prostatectomy specimens with prostate cancer collected between 2009 and 2011. The dataset was used to perform an in silico validation of MRH, a method of assessing tissue texture that trades spatial coherence for spatial resolution surpassing traditional MRH by over an order of magnitude. The MRH measurement process was computationally recreated on the annotated slides, creating a dataset of spectral intensities at submillimeter wavelengths. Novel artificial intelligence analytics methods were developed to classify spectral data as normal or containing prostate cancer, and diagnostically informative parameters were determined. Results A set of spatial frequencies that maximized discriminative ability between healthy and cancerous tissue (area under the receiver operating characteristic curve, 0.79) was identified, thereby informing future clinical implementation. Integrating spatial context into the model denoised the inferential results and improved classification performance (area under the receiver operating characteristic curve, 0.84) and moreover enabled the estimation of lesion size. Conclusion This study demonstrates the feasibility of MRH as a novel method for prostate cancer detection and identifies imaging parameters that may guide clinical implementation. Keywords: MRI, Prostate Cancer, Neural Networks, Histopathology, MR-Spectroscopy, Prostate, Tissue Characterization, Technology Assessment Supplemental material is available for this article. © RSNA, 2025 See also commentary by Fields and Hassan in this issue.

Purpose To determine agreement between conventional staging and whole-body (WB) diffusion-weighted imaging (DWI) MRI in newly diagnosed pediatric sarcomas and to compare the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each approach for lesion detection. Materials and Methods In this prospective single-center study (January 2014-February 2019), 47 participants (25 male participants; median age, 11.7 years [IQR, 7.49-15.63 years]) with Ewing sarcoma (n = 19), osteosarcoma (n = 7), rhabdomyosarcoma (n = 20), or non-rhabdomyosarcoma soft-tissue sarcoma (n = 1) underwent conventional staging and research-only WB MRI (T1-weighted, short tau inversion recovery, DWI). Using biopsy or clinical follow-up as the reference standard, authors determined staging agreement between conventional imaging, including PET/CT, and WB DWI instead of PET/CT. Two radiologists, aware of primary diagnoses but blinded to other information, recorded and scored lesions on a five-point Likert scale. A blinded nuclear medicine radiologist reviewed WB PET/CT images, recorded lesion locations, and scored them using the same method. One radiologist reconciled lesions with anatomic imaging. Primary outcomes were per-participant staging agreement and lesion-level sensitivity, specificity, PPV, and NPV. Statistical analysis used the Wilcoxon rank sum test for continuous variables and the McNemar test for paired proportions; P ≤ .05 indicated significance. Results There was 91.5% agreement among participants when comparing WB DWI and conventional staging (95% CI: 79.6, 97.6). Among 631 unique lesions, WB DWI sensitivity was 65.5% versus 30.2% for PET/CT (P < .001), while PET/CT specificity was 86.7% versus 66.4% for WB DWI (P < .001). WB DWI depicted more than twice as many malignant bone or bone marrow (151 vs 60) and lymph node sites (59 vs 28) as PET/CT. Conclusion WB DWI offered high agreement with conventional staging and higher sensitivity but lower specificity than PET/CT for metastatic lesion detection in pediatric sarcomas. Keywords: Diffusion-weighted MRI, Pediatric, Sarcoma, Staging, Whole-Body Imaging Supplemental material is available for this article. © RSNA, 2025.