The Role of Physician-Driven Device Preference in the Cost Variation of Common Interventional Radiology Procedures.

PURPOSE: To analyze the impact of physician-specific equipment preference on cost variation for procedures typically performed by interventional radiologists at a tertiary care academic hospital. MATERIALS AND METHODS: From October 2017 to October 2019, data on all expendable items used by 9 interventional radiologists for 11 common interventional radiology procedure categories were compiled from the hospital analytics system. This search yielded a final dataset of 44,654 items used in 2,121 procedures of 11 different categories. The mean cost per case for each physician as well as the mean, standard deviation, and coefficient of variation (CV) of the mean cost per case across physicians were calculated. The proportion of spending by item type was compared across physicians for 2 high-variation, high-volume procedures. The relationship between the mean cost per case and case volume was examined using linear regression. RESULTS: There was a high variability within each procedure, with the highest and the lowest CV for radioembolization administration (56.6%) and transjugular liver biopsy (4.9%), respectively. Variation in transarterial chemoembolization cost was mainly driven by microcatheters/microwires, while for nephrostomy, the main drivers were catheters/wires and access sets. Mean spending by physician was not significantly correlated with case volume (P =.584). CONCLUSIONS: Physicians vary in their item selection even for standard procedures. While the financial impact of these differences vary across procedures, these findings suggest that standardization may offer an opportunity for cost savings.

The Epithelial to Mesenchymal Transition Promotes Glutamine Independence by Suppressing GLS2 Expression.

Identifying bioenergetics that facilitate the epithelial to mesenchymal transition (EMT) in breast cancer cells may uncover targets to treat incurable metastatic disease. Metastasis is the number one cause of cancer-related deaths; therefore, it is urgent to identify new treatment strategies to prevent the initiation of metastasis. To characterize the bioenergetics of EMT, we compared metabolic activities and gene expression in cells induced to differentiate into the mesenchymal state with their epithelial counterparts. We found that levels of GLS2, which encodes a glutaminase, are inversely associated with EMT. GLS2 down-regulation was correlated with reduced mitochondrial activity and glutamine independence even in low-glucose conditions. Restoration of GLS2 expression in GLS2-negative breast cancer cells rescued mitochondrial activity, enhanced glutamine utilization, and inhibited stem-cell properties. Additionally, inhibition of expression of the transcription factor FOXC2, a critical regulator of EMT in GLS2-negative cells, restored GLS2 expression and glutamine utilization. Furthermore, in breast cancer patients, high GLS2 expression is associated with improved survival. These findings suggest that epithelial cancer cells rely on glutamine and that cells induced to undergo EMT become glutamine independent. Moreover, the inhibition of EMT leads to a GLS2-directed metabolic shift in mesenchymal cancer cells, which may make these cells susceptible to chemotherapies.