Citations

Abstract Background While the radiation dose to left anterior descending (LAD) artery is associated with overall survival (OS) in NSCLC patients, manual segmentation is labor‐intensive. Several auto‐segmentation models were developed on average 4DCT with promising geometric agreement, yet their feasibility in clinical outcome analysis on lung CT remains unclear. Purpose This study evaluates whether automated LAD segmentation can reproduce, at the group level, the established dose‐survival association in a multi‐institutional clinical trial dataset. Methods Three deep learning‐based auto‐segmentation (DLAS) models for automatic segmentation of the LAD coronary artery were applied to 460 patients from the NRG Oncology/RTOG 0617 dataset. Kaplan–Meier curves and Cox proportional hazard ratio (HR) were calculated using each model's segmentation. The LAD V15 Gy was used to stratify patients into high‐and low‐risk groups, and the cut‐off values were determined by minimizing mean absolute error (MAE) between DLAS‐derived and manual OS curves. Results All three models demonstrated significantly different OS curves between the high risk and low risk groups ( p < 0.05). The HR was 1.40 (95% CI: 1.02–1.93; p = 0.0381; MAE = 7.1%), 1.32 (95% CI: 1.03–1.68; p = 0.0258; MAE = 9.6%), and 1.37 (95% CI: 1.03–1.84; p = 0.0331; MAE = 7.9%) for the three models using a common V15 Gy ≥ 10% cut‐off. After optimizing the cut‐off, one model aligned well with what was derived from manual segmentation (MAE = 4.3%). Conclusion Among the evaluated models, one DL model showed the strongest performance of survival groups separation and achieved group‐level overall survival stratification comparable to that previously reported using manual contours in the multi‐institutional cohort. Further validation with paired manual contours and pre‐specified cutoffs is warranted.

Abstract Purpose To evaluate dosimetric properties of intensity‐modulated proton therapy (IMPT) for simulated treatment planning in patients with atrial fibrillation (AF) targeting left atrial‐pulmonary vein junction (LA‐PVJ), in comparison with volumetric‐modulated arc therapy (VMAT) and helical tomotherapy (TOMO). Methods Ten thoracic 4D‐CT scans with respiratory motion and one with cardiac motion were used for the study. Ten respiratory 4D‐CTs were planned with VMAT, TOMO, and IMPT for simulated AF. Targets at the LA‐PVJ were defined as wide‐area circumferential ablation line. A single fraction of 25 Gy was prescribed to all plans. The interplay effects from cardiac motion were evaluated based on the cardiac 4D‐CT scan. Dose‐volume histograms (DVHs) of the ITV and normal tissues were compared. Statistical analysis was evaluated via one‐way Repeated‐Measures ANOVA and Friedman’s test with Bonferroni’s multiple comparisons test. Results The median volume of ITV was 8.72cc. All plans had adequate target coverage (V 23.75Gy ≥ 99%). Compared with VMAT and TOMO, IMPT resulted in significantly lower dose of most normal tissues. For VMAT, TOMO, and IMPT plans, D mean of the whole heart was 5.52 ± 0.90 Gy, 5.89 ± 0.78 Gy, and 3.01 ± 0.57 Gy ( P < 0.001), mean dose of pericardium was 4.74 ± 0.76 Gy, 4.98 ± 0.62 Gy, and 2.59 ± 0.44 Gy ( P < 0.001), and D 0.03cc of left circumflex artery (LCX) was 13.96 ± 5.45 Gy, 14.34 ± 5.91 Gy, and 8.43 ± 7.24 Gy ( P < 0.001), respectively. However, no significant advantage for one technique over the others was observed when examining the D 0.03cc of esophagus and main bronchi. Conclusions IMPT targeting LA‐PVJ for patients with AF has high potential to reduce dose to surrounding tissues compared to VMAT or TOMO. Motion mitigation techniques are critical for a particle‐therapy approach.

Introduction: Central venous access using peripherally inserted central catheters is frequently used for patients receiving intravenous medications in the hospital or outpatients. Although there are several benefits of peripherally inserted central catheters, such as ease of insertion, low procedure-related risk and higher patient satisfaction, there are complications associated with peripherally inserted central catheter use. Despite some studies evaluating peripherally inserted central catheter line–related complications, the factors associated with peripherally inserted central catheter–related deep venous thrombosis in critically ill medical-surgical patients are poorly described. The objective of this case-control study was to identify the risk factors associated with peripherally inserted central catheter line–related deep venous thrombosis in critically ill medical-surgical intensive care unit patients in a community hospital. Methods: We abstracted relevant clinical data from 21 cases with symptomatic peripherally inserted central catheter–related deep venous thrombosis and 42 controls with peripherally inserted central catheters but no deep venous thrombosis. Results: Of the factors evaluated, female gender, the use of triple lumen peripherally inserted central catheters, larger outer diameter, and open (vs valve) peripherally inserted central catheters were associated with venous thrombosis. In this retrospective study, we did not identify any association of peripherally inserted central catheter–related deep venous thrombosis with a prior history of deep venous thrombosis, use of alteplase, antiplatelet therapy, prophylactic or therapeutic anticoagulation, international normalized ratio, platelet count and the use of peripherally inserted central catheters for total parenteral nutrition. Conclusion: Our study indicates that the catheter size relative to the diameter of the vein could be an important risk factor for the development of peripherally inserted central catheter–related deep venous thrombosis. The study findings should be confirmed in a larger study designed to identify risk factors of peripherally inserted central catheter–related deep venous thrombosis. In the meantime, the peripherally inserted central catheter lines should be used judiciously in critically ill patients.