Value of pre-treatment 18F-FDG PET/CT radiomics in predicting the prognosis of stage III-IV colorectal cancer

Background and purpose: To investigate the value of radiomics features extracted from pre-treatment 18F-FDG PET/CT in predicting the outcomes of stage III-IV colorectal cancer (CRC), which may assist in clinical management strategies and precise treatment of stage III-IV CRC. Materials and methods: 124 patients with pathologically confirmed stage III-IV CRC who underwent pre-treatment 18F-FDG PET/CT scans were enrolled in this study. The least absolute shrinkage and selection operator Cox regression (LASSO-Cox) was used to select radiomics features, and the radiomics scores (Rad-scores) were calculated to build radiomics models. The performance of radiomics models was represented by the concordance index (C-index) and compared with clinical models and complex model. The bootstrap resampling method was used to create validation sets. Additionally, nomograms were developed based on complex models. Results: The C-indices of the radiomics model for predicting PFS and OS were 0.712 (95%CI: 0.680–0.744) and 0.758 (0.728–0.789), respectively. In the clinical model, these values were 0.690 (0.664–0.0.717) and 0.738 (0.709–0.767), respectively. However, in the complex model were 0.734 (0.705–0.762) and 0.780 (0.754–0.807), respectively. The Kaplan–Meier curves demonstrated that the radiomics model could effectively separate patients with stage III-IV stage CRC into high- and low-risk groups (p < 0.001). Multivariate Cox regression analysis confirmed the independent prognostic value of Rad-scores. Conclusion: Pre-treatment 18F-FDG PET/CT radiomics features can stratify the risk of patients with stage III-IV CRC and accurately predict their outcomes. These findings could be clinically valuable for precision treatment and management decisions in stage III-IV CRC

Unveiling Structurally Engineered Carrier Dynamics in Hybrid Quasi-Two-Dimensional Perovskite Thin Films toward Controllable Emission

Quasi-two-dimensional Ruddlesden–Popper perovskites driving carrier self-separation have rapidly advanced the development of high-performance optoelectronic devices. However, insightful understanding of carrier dynamics in the perovskites is still inadequate. The distribution of multiple perovskite phases, crucial for carrier separation, is controversial. Here we report a systematic study on carrier dynamics of spin-coated (C₆H₅CH₂CH₂NH₃)₂(CH₃NH₃)_<i>n</i>−1Pb_<i>n</i>I_3<i>n</i>+1 (<i>n</i> = 3 and 5) perovskite thin films. Efficient electrons transfer from small-<i>n</i> to large-<i>n</i> perovskite phases, and holes transfer reversely with time scales from ∼0.3 to 30.0 ps. The multiple perovskite phases are arranged perpendicularly to substrate from small to large <i>n</i> and also coexist randomly in the same horizontal planes. Further, the carrier separation dynamics is tailored by engineering the crystalline structure of the perovskite film, which leads to controllable emission properties. These results have important significance for the design of optoelectronic devices from solar cells, light-emitting diodes, lasers, and so forth