Journal of nuclear medicine : official publication, Society of Nuclear Medicine最新文献

The aim of this retrospective study was to evaluate the correlation between findings from somatostatin receptor (SSTR) PET/CT and histopathology in patients with suspected intracranial meningiomas. Methods: We conducted a retrospective analysis of 8,077 SSTR imaging studies recorded in our institutional database between 2006 and 2021. In total, 223 SSTR PET/CT scans were performed for suspected meningioma, and 240 lesions were matched with histopathology results within 4 mo. Reports from SSTR PET/CT scans and histopathology were retrospectively reviewed to assess the presence of intracranial meningiomas. The positive and negative predictive values, sensitivity, specificity, and overall diagnostic accuracy of SSTR PET/CT were calculated. The SUV_max, SUV_mean, and SUV_peak were determined for each lesion. Results: In 222 (92.5%) of 240 lesions, meningioma was accurately identified by SSTR PET/CT and confirmed by histopathology. In 7 cases (2.9%), SSTR PET/CT suspected meningioma was not confirmed by histopathology (false-positive). Furthermore, in 11 cases (5%), meningioma was neither suspected by SSTR PET/CT nor confirmed by histopathology (true-negative result). There were no false-negative findings in our cohort. SSTR PET/CT demonstrated a sensitivity of 100% (95% CI, 98.4%-100%) and a specificity of 61.1% (95% CI, 35.8%-82.7%) in detecting meningiomas. Positive predictive value was 96.9% (95% CI, 93.8%-98.8%), and negative predictive value was 100% (95% CI, 71.5%-100%). The overall diagnostic accuracy was 97.1%. The receiver-operating-characteristic analysis for SUV_max in predicting histopathology results showed an area under the curve of 94%, indicating an excellent ability of SUV_max to distinguish between positive and negative histopathologic findings. Conclusion: SSTR PET/CT is a precise imaging modality for detecting intracranial meningiomas, as demonstrated by its high sensitivity. However, in 2.9% of cases, despite a positive PET/CT result, histopathology did not confirm the presence of a meningioma. Integration of MRI, histopathology, and SSTR PET/CT supports informed treatment decisions.

Whole-body CD8⁺ T-cell PET imaging can detect spatial and temporal localization of CD8⁺ T cells. To obtain insight into early CD8⁺ T-cell response to immunotherapy in patients with melanoma, a highly immunogenic tumor, we performed serial PET imaging with the 1-armed CD8 antibody tracer ⁸⁹ZED88082A. Methods: Immunotherapy-naïve adult patients with stage IV melanoma underwent PET scanning 2 d after receiving 10 mg of ⁸⁹ZED88082A intravenously at baseline and 6-8 wk after initiation of standard-of-care immunotherapy. Tracer uptake in lesions, normal lymph nodes, and Waldeyer ring was assessed using SUV_max; other healthy tissue uptake was assessed using SUV_mean Uptake in tumors and healthy lymph nodes was expressed as the geometric mean SUV_max per patient and in healthy tissue as SUV_mean for all patients. Tumor response was evaluated in accordance with iRECIST version 1.1. Tumor tissue was immunohistochemically stained for CD8. Results: Serial imaging was performed for 10 of 11 enrolled patients. The geometric mean tumor SUV_max was 7.2 (95% CI, 5.6-9.4) before treatment and 7.3 (95% CI, 5.7-9.5; P = 0.89) during treatment, with spatial and temporal heterogeneity in tumor uptake. The spleen demonstrated the highest uptake among healthy tissues, and this value remained similar during treatment. After immunotherapy, 2 patients experienced a complete response, 7 a partial response, and 2 progressive disease. Changes in tumor uptake during treatment did occur but did not correlate with tumor response. Nine evaluable pretreatment tumor tissues showed a CD8-inflamed immune phenotype. Conclusion: Lesions demonstrated spatial and temporal heterogeneity in ⁸⁹ZED88082A uptake within and among patients with melanoma.