Can quantitative parameters of spectral computed tomography predict lymphatic metastasis in lung cancer? A systematic review and meta-analysis

Spectral computed tomography in the assessment of metastatic lymph nodes in cervical cancer patients treated with definitive radiotherapy: a single-center, prospective study

Identifying metastatic lymph nodes (LNs) in patients with cervical cancer treated with definitive radiotherapy may inform treatment strategy and determine prognosis, but available methods have limitations, especially in developing regions. Herein, we aimed to evaluate the performance of quantitative parameters in spectral computed tomography (CT) scanning in this context, focusing on its complementary role alongside conventional diagnostic approaches like 18-fluorine-fuorodeoxyglucose positron emission tomography computed tomography (18 F FDG-PET/CT). Patients with cervical cancer, who underwent pretreatment spectral CT simulation scanning and planned radiotherapy, were enrolled in this prospective study. The LNs were categorized as "metastatic" and "non-metastatic", based on a procedure that included 18 F FDG-PET/CT as well as CT, magnetic resonance imaging, Node Reporting and Data System and follow-up results. Iodine concentrations (IC), normalized IC (NIC), effective atom number (effZ), and spectral curve slope (λHU) in the arterial (AP) and venous (VP) phases, were compared between metastatic and non-metastatic LNs. IC were derived from iodine-based material decomposition through manual delineation and normalized to the iodine concentration in the adjacent artery (NIC). effZ and λHU were calculated based on the effective atom number image and virtual monochromatic images. Univariate and multivariate logistic regression analyses were used to determine spectral CT factors independently associated with LNs metastasis, and their diagnostic efficacies were assessed using the area under the curve (AUC) analysis. The diagnostic efficiency of 18 F FDG-PET/CT and spectral CT was compared. A total of 115 metastatic and 97 non-metastatic LNs were detected, and spectral CT parameters (IC, NIC, effZ, λHU) significantly differed between the two groups. In univariate and multivariable logistic regression analysis, λHU in the AP and NIC in the VP were independent predictors for metastatic LNs and their combination improved AUC to 0.923, with a sensitivity of 84.4%, and a specificity of 85.6%. Spectral CT could achieve similar sensitivity as 18 FFDG-PET/CT in total LNs, and, more importantly, a higher sensitivity (95.5% vs. 59.1%) and diagnostic accuracy (92.9% vs. 67.9%) for para-aortic LNs. Quantitative spectral CT parameters can help distinguish metastatic from non-metastatic LNs in patients with cervical cancer treated with definitive radiotherapy. Combination of λHU in AP and NIC in VP further improves diagnostic performance. Spectral CT, while promising, complements rather than replaces PET/CT, especially for diagnosing para-aortic LNs, where PET/CT may have limitations. It could be a valuable adjunct to conventional imaging, particularly in settings with limited access to advanced tools.

Dual-Energy Computed Tomography in Detecting and Predicting Lymph Node Metastasis in Malignant Tumor Patients: A Comprehensive Review

The accurate and timely assessment of lymph node involvement is paramount in the management of patients with malignant tumors, owing to its direct correlation with cancer staging, therapeutic strategy formulation, and prognostication. Dual-energy computed tomography (DECT), as a burgeoning imaging modality, has shown promising results in the diagnosis and prediction of preoperative metastatic lymph nodes in recent years. This article aims to explore the application of DECT in identifying metastatic lymph nodes (LNs) across various cancer types, including but not limited to thyroid carcinoma (focusing on papillary thyroid carcinoma), lung cancer, and colorectal cancer. Through this narrative review, we aim to elucidate the clinical relevance and utility of DECT in the detection and predictive assessment of lymph node metastasis in malignant tumors, thereby contributing to the broader academic discourse in oncologic radiology and diagnostic precision.