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Objectives: Stereotactic body radiotherapy (SBRT) is a treatment option for patients with early-stage non-small cell lung cancer (NSCLC) who are unfit for surgery. Some patients may experience distant metastasis. This study aimed to develop and validate a radiomics model for predicting distant metastasis in patients with early-stage NSCLC treated with SBRT. Methods: Patients at five institutions were enrolled in this study. Radiomics features were extracted based on the PET/CT images. After feature selection in the training set (from Tianjin), CT-based and PET-based radiomics signatures were built. Models based on CT and PET signatures were built and validated using external datasets (from Zhejiang, Zhengzhou, Shandong, and Shanghai). An integrated model that included CT and PET radiomic signatures was developed. The performance of the proposed model was evaluated in terms of its discrimination, calibration, and clinical utility. Multivariate logistic regression was used to calculate the probability of distant metastases. The cutoff value was obtained using the receiver operator characteristic curve (ROC), and the patients were divided into high- and low-risk groups. Kaplan-Meier analysis was used to evaluate the distant metastasis-free survival (DMFS) of different risk groups. Results: In total, 228 patients were enrolled. The median follow-up time was 31.4 (2.0-111.4) months. The model based on CT radiomics signatures had an area under the curve (AUC) of 0.819 in the training set (n = 139) and 0.786 in the external dataset (n = 89). The PET radiomics model had an AUC of 0.763 for the training set and 0.804 for the external dataset. The model combining CT and PET radiomics had an AUC of 0.835 for the training set and 0.819 for the external dataset. The combined model showed a moderate calibration and a positive net benefit. When the probability of distant metastasis was greater than 0.19, the patient was considered to be at high risk. The DMFS of patients with high- and low-risk was significantly stratified (P < 0.001). Conclusions: The proposed PET/CT radiomics model can be used to predict distant metastasis in patients with early-stage NSCLC treated with SBRT and provide a reference for clinical decision-making. Plain language summary: In this study, the model was established by combining CT and PET radiomics signatures in a moderate-quantity training cohort of early-stage NSCLC patients treated with SBRT and was successfully validated in independent cohorts. Physicians could use this easy-to-use model to assess the risk of distant metastasis after SBRT. Identifying subgroups of patients with different risk factors for distant metastasis is useful for guiding personalized treatment approaches. [ABSTRACT FROM AUTHOR]

Replacing internal combustion engine vehicles with electric vehicles is the most direct pathway to decarbonize transportation. This paper investigates the environmental benefits of electric vehicle adoption in Shanghai—China's largest regional electric vehicle market. Using vehicle registration data and well-to-wheel analysis, this paper calculates the potential emissions reductions of carbon dioxide and air pollutants for each electric vehicle model sold in Shanghai in 2018. Our results indicate that electric vehicles have been over-subsidized: The average environmental benefit was less than one-fourth of the mean subsidy received. Also, the environmental benefits were not distributed uniformly: About 80% of electric vehicle models generated less than 20% of the aggregate environmental benefits. Finally, three policy recommendations are provided to improve the environmental benefits of electric vehicle adoption. [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) are the most direct pathway to reduce greenhouse gas emissions in the transportation sector. Regulators worldwide have announced ambitious targets for EV adoption to replace internal combustion engine vehicles (ICEVs). A program of direct financial subsidy is a dominant policy to encourage adoption. This paper investigates an alternative policy based on differential license plate pricing across vehicle types in Shanghai, China's largest regional EV market. Using monthly vehicle registration data from Shanghai, we find that EV sales would increase by 56%–65% if the differential between ICEV and EV license plate costs rises by 1,000 yuan ($150). We compare differential license plate pricing with the purchase subsidy policy. With a fiscal-neutral policy scheme, differential license plate pricing is more effective for promoting EV adoption than direct purchase subsidies. We also discuss the implications of the ongoing policy change where the free license is no longer granted to plug–in hybrid electric vehicle (PHEV) buyers starting in 2023. We show that the new policy scheme could still be more effective than subsidies in encouraging battery electric vehicle (BEV) adoption. The new policy scheme, combined with relaxed price ceilings in the ICEV license auction market, will yield comparable or even larger adoption growth than the previous policy. [ABSTRACT FROM AUTHOR]