Radiation dose reduction during venous access port implantation: the importance of upgrading equipment and radiation-protection training.

BACKGROUND: Implantable central venous port systems are widely used in oncology. We upgraded our fluoroscopy machines, and all anesthetists completed two training courses focusing on the risks of ionizing radiation for patients and health workers. AIMS: This study aimed to evaluate the impact of upgrading the machines and the radiation-protection training on ionizing radiation exposure during venous port system implantation. METHODS: We retrospectively analyzed consecutive venous port implantations between 2019 and 2022. The older fluoroscopy machines were replaced by two new machines. A first training session about health worker radioprotection was organized. The medical staff completed a second training course focused on protecting patients from ionizing radiation. We defined four distinct time intervals (TI): venous port implantations performed with the old equipment, the new fluoroscopy machines, after the first training course, and after the second training course. The air kerma-area product (KAP) was compared between these four TI and fluoroscopy times and the number of exposures only with the new machines. RESULTS: We analyzed 2587 procedures. A 93% decrease in the median KAP between the first and last TI was noted (median KAP = 323.0 mGy.cm2 vs. 24.0 mGy.cm2, p < 0.0001). A decrease in the KAP was observed for each of the 11 anesthetists. We also noted a significant decrease in the time of fluoroscopy and the number of exposures. CONCLUSIONS: Upgrading the fluoroscopy equipment and completing two dedicated training courses allowed for a drastic decrease patient exposure to ionizing radiation during venous access port implantation by non-radiologist practitioners.

Assessing Long-term Treatment Benefits Using Complementary Statistical Approaches: An In Silico Analysis of the Phase III Keynote-045 and Checkmate-214 Immune Checkpoint Inhibitor Trials.

BACKGROUND: The Keynote-045 trial illustrates that the long-term benefit (LTB) of treatment does not always translate to improved progression-free survival (PFS). Milestone survival and flexible parametric survival model with cure (FPCM) have been proposed as complementary statistical approaches to more comprehensively evaluate LTBs of treatments. OBJECTIVE: The current study compares milestone survival and FPCM analyses to evaluate treatment effects of immune checkpoint inhibitor (ICI) phase III trials. DESIGN, SETTING, AND PARTICIPANTS: Individual patient data, from initial and follow-up analyses of Keynote-045 (urothelial cancer) and Checkmate-214 (advanced renal cell carcinoma), were reconstructed for PFS. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Each trial was reanalyzed using the Cox proportional hazard regression and two complementary methods (milestone survival and FPCM) to estimate treatment impact on the LTB. RESULTS AND LIMITATIONS: For each trial, there was evidence of nonproportional hazards. For the long-term analysis of the Keynote-045 trial, FPCM identified a time-dependent effect on PFS, but the Cox model found no statistical difference in PFS (hazard ratio, 0.90; 95% confidence interval, 0.75-1.08). Milestone survival and FPCM identified improvements in the LTB fractions. This was consistent with the results from the reanalysis of Keynote-045, based on the shorter follow-up, although the LTB fraction was not retained. The increase in PFS in Checkmate-214 was identified by both Cox model and FPCM. Experimental treatment-dependent improvement in the LTB fraction was demonstrated using milestone survival and FPCM. The LTB fraction estimated with FPCM was consistent with the results from the reanalysis of the shorter follow-up period. CONCLUSIONS: Although ICIs show substantial shifts toward LTBs in terms of PFS, based on a conventional Kaplan-Meier or Cox model analysis, our approach provides an alternative assessment of benefit-risk ratios for new therapeutics and facilitates communicating risk to patients. Kidney patients treated with ICIs can be counseled that they are potentially cured, but future work will need to definitively validate this conclusion. PATIENT SUMMARY: Although immune checkpoint inhibitor treatments show substantial shifts toward long-term benefits in terms of progression-free survival, a more rigorous attempt to quantify this shift, rather than simply using a Kaplan-Meier estimate or comparing progression-free survival curves using the classic Cox model, is warranted. Our results suggest that advanced renal cell carcinoma patients who had not received a previous treatment are functionally cured by nivolumab and ipilimumab, which is not the case for second-line urothelial carcinoma.