Engineering metal-carbide hydrogen traps in steels.

Hydrogen embrittlement reduces the durability of the structural steels required for the hydrogen economy. Understanding how hydrogen interacts with the materials plays a crucial role in managing the embrittlement problems. Theoretical models have indicated that carbon vacancies in metal carbide precipitates are effective hydrogen traps in steels. Increasing the number of carbon vacancies in individual metal carbides is important since the overall hydrogen trapping capacity can be leveraged by introducing abundant metal carbides in steels. To verify this concept, we compare a reference steel containing titanium carbides (TiCs), which lack carbon vacancies, with an experimental steel added with molybdenum (Mo), which form Ti-Mo carbides comprising more carbon vacancies than TiCs. We employ theoretical and experimental techniques to examine the hydrogen trapping behavior of the carbides, demonstrating adding Mo alters the hydrogen trapping mechanism, enabling hydrogen to access carbon vacancy traps within the carbides, leading to an increase in trapping capacity.

Prognostication and optimal criteria of circumferential margin involvement for esophageal cancer after chemoradiation and esophagectomy.

Purpose: Circumferential radial margin (CRM) involvement by tumor after resection for esophageal cancer has been suggested as a significant prognostic factor. However, the prognostic value of CRM involvement after surgery with neoadjuvant concurrent chemoradiotherapy (CCRT) is unclear. This study aimed to evaluate the prognostic value of and survival outcomes in CRM involvement as defined by the Royal College of Pathologists (RCP) and the College of American Pathologists (CAP) for patients with esophageal cancer undergoing neoadjuvant CCRT and esophagectomy. Methods: A total of 299 patients with esophageal cancer who underwent neoadjuvant CCRT followed by esophagectomy between 2006 and 2016 were enrolled in our study. The CRM status of the specimens obtained was determined pathologically according to both the CAP and RCP criteria. Survival analyses were performed and compared according to the two criteria. Results: Positive CRM was found in 102 (34.1%) and 40 (13.3%) patients according to RCP and CAP criteria, respectively. The overall and progression-free survival rates were significantly lower in the CRM-positive group than in the CRM-negative group according to both the RCP and CAP criteria. However, under multivariate analysis, in addition to pathological T and N staging of the tumor, only CAP-defined CRM positivity was a significant prognostic factor with adjusted hazard ratios of 2.64 (1.56-4.46) and 2.25 (1.34-3.78) for overall and progression-free survival, respectively (P < 0.001). Conclusion: In patients with esophageal cancer undergoing neoadjuvant CRT followed by esophagectomy, CAP-defined CRM positivity is an independent predictor of survival. Adjuvant therapy should be offered to patients with positive CRM.

Propensity score matching analysis comparing radical prostatectomy and radiotherapy with androgen deprivation therapy in locally advanced prostate cancer.

To compare clinical outcomes between the use of robotic-assisted laparoscopic radical prostatectomy (RP) and radiotherapy (RT) with long-term androgen deprivation therapy (ADT) in locally advanced prostate cancer (PC), 315 patients with locally advanced PC (clinical T-stage 3/4) were considered for analysis retrospectively. Propensity score-matching at a 1:1 ratio was performed. The median follow-up period was 59.2 months (IQR 39.8-87.4). There were 117 (37.1%) patients in the RP group and 198 (62.9%) patients in the RT group. RT patients were older and had higher PSA at diagnosis, higher Gleason score grade group and more advanced T-stage (all p < 0.001). After propensity score-matching, there were 68 patients in each group. Among locally advanced PC patients, treatment with RP had a higher risk of biochemical recurrence compared to the RT group. In multivariate Cox regression analysis, treatment with RT plus ADT significantly decreased the risk of biochemical failure (HR 0.162, p < 0.001), but there was no significant difference in local recurrence, distant metastasis and overall survival (p = 0.470, p = 0.268 and p = 0.509, respectively). This information supported a clinical benefit in BCR control for patients undergoing RT plus long-term ADT compared to RP.

Longitudinal shear wave elasticity measurements of millimeter-sized biomaterials using a single-element transducer platform.

Temporal variations of the extracellular matrix (ECM) stiffness profoundly impact cellular behaviors, possibly more significantly than the influence of static stiffness. Three-dimensional (3D) cell cultures with tunable matrix stiffness have been utilized to characterize the mechanobiological interactions of elasticity-mediated cellular behaviors. Conventional studies usually perform static interrogations of elasticity at micro-scale resolution. While such studies are essential for investigations of cellular mechanotransduction, few tools are available for depicting the temporal dynamics of the stiffness of the cellular environment, especially for optically turbid millimeter-sized biomaterials. We present a single-element transducer shear wave (SW) elasticity imaging system that is applied to a millimeter-sized, ECM-based cell-laden hydrogel. The single-element ultrasound transducer is used both to generate SWs and to detect their arrival times after being reflected from the side boundaries of the sample. The sample's shear wave speed (SWS) is calculated by applying a time-of-flight algorithm to the reflected SWs. We use this noninvasive and technically straightforward approach to demonstrate that exposing 3D cancer cell cultures to X-ray irradiation induces a temporal change in the SWS. The proposed platform is appropriate for investigating in vitro how a group of cells remodels their surrounding matrix and how changes to their mechanical properties could affect the embedded cells in optically turbid millimeter-sized biomaterials.

The intracranial tumor segmentation challenge: Contour tumors on brain MRI for radiosurgery.

We report the set-up of the Intracranial Tumor Segmentation (ICTS) dataset. This dataset was retrieved from clinical work of radiosurgery, contoured by qualified neurosurgeons and radiation oncologists. It contains contrast-enhanced T1-weighted images of 1500 patients, together with the labels of tumors to be treated. The ICTS image data and manual annotations continue to be publicly available through an online evaluation system as an ongoing benchmarking resource.

Peri-radiosurgical administration of bevacizumab improves radiographic response to single and fractionated stereotactic radiosurgery for large brain metastasis.

INTRODUCTION: Stereotactic radiosurgery (SRS) is a standard of care for brain metastases (BM) patients, yet large BM are at a greater risk for radionecrosis and local progression (LP). Concomitant bevacizumab and radiotherapy has been shown to improve outcomes in primary and metastatic brain tumors. This retrospective study investigated the efficacy and safety of concurrent bevacizumab and SRS for large BM. METHODS: From 2015 to 2019, patients with a BM diameter ≥ 2 cm who received either combination therapy (n = 49, SRS + BVZ group), or SRS alone (n = 73, SRS group) were enrolled. Bevacizumab was given peri-radiosurgically with a 2-week interval. Radiographic response was assessed using the RECIST version 1.1. Competing risk and logistic regression analysis were performed to evaluate prognostic factors. RESULTS: Radiographic response was achieved in 41 patients (84%) in the SRS + BVZ group and 37 patients (51%) in the SRS group (p = 0.001). In the multivariate regression analysis, concurrent bevacizumab was independently associated with a better radiographic response (p = 0.003). The cumulative incidences of LP and ≥ grade 2 radionecrosis at 12 months between the SRS + BVZ group and SRS group were 2% versus 6.8%, and 14.3% versus 14.6%, respectively. For patients with BM size ≥ 3 cm, the cumulative incidence of LP was significantly lower in the SRS + BVZ group (p = 0.03). No ≥ grade 4 toxicity was observed in either group. CONCLUSIONS: Concurrent bevacizumab and SRS for large BM is highly effective, with a better radiographic response and minimal excessive treatment-related toxicities. Peri-radiosurgical bevacizumab preferentially reduced the risk of LP, especially for BM size ≥ 3 cm.

Randomized multi-reader evaluation of automated detection and segmentation of brain tumors in stereotactic radiosurgery with deep neural networks.

BACKGROUND: Stereotactic radiosurgery (SRS), a validated treatment for brain tumors, requires accurate tumor contouring. This manual segmentation process is time-consuming and prone to substantial inter-practitioner variability. Artificial intelligence (AI) with deep neural networks have increasingly been proposed for use in lesion detection and segmentation but have seldom been validated in a clinical setting. METHODS: We conducted a randomized, cross-modal, multi-reader, multispecialty, multi-case study to evaluate the impact of AI assistance on brain tumor SRS. A state-of-the-art auto-contouring algorithm built on multi-modality imaging and ensemble neural networks was integrated into the clinical workflow. Nine medical professionals contoured the same case series in two reader modes (assisted or unassisted) with a memory washout period of 6 weeks between each section. The case series consisted of 10 algorithm-unseen cases, including five cases of brain metastases, three of meningiomas, and two of acoustic neuromas. Among the nine readers, three experienced experts determined the ground truths of tumor contours. RESULTS: With the AI assistance, the inter-reader agreement significantly increased (Dice similarity coefficient [DSC] from 0.86 to 0.90, P < 0.001). Algorithm-assisted physicians demonstrated a higher sensitivity for lesion detection than unassisted physicians (91.3% vs 82.6%, P = .030). AI assistance improved contouring accuracy, with an average increase in DSC of 0.028, especially for physicians with less SRS experience (average DSC from 0.847 to 0.865, P = .002). In addition, AI assistance improved efficiency with a median of 30.8% time-saving. Less-experienced clinicians gained prominent improvement on contouring accuracy but less benefit in reduction of working hours. By contrast, SRS specialists had a relatively minor advantage in DSC, but greater time-saving with the aid of AI. CONCLUSIONS: Deep learning neural networks can be optimally utilized to improve accuracy and efficiency for the clinical workflow in brain tumor SRS.

Enhanced Radiosensitization for Cancer Treatment with Gold Nanoparticles through Sonoporation.

We demonstrate the megavoltage (MV) radiosensitization of a human liver cancer line by combining gold-nanoparticle-encapsulated microbubbles (AuMBs) with ultrasound. Microbubbles-mediated sonoporation was administered for 5 min, at 2 h prior to applying radiotherapy. The intracellular concentration of gold nanoparticles (AuNPs) increased with the inertial cavitation of AuMBs in a dose-dependent manner. A higher inertial cavitation dose was also associated with more DNA damage, higher levels of apoptosis markers, and inferior cell surviving fractions after MV X-ray irradiation. The dose-modifying ratio in a clonogenic assay was 1.56 ± 0.45 for a 10% surviving fraction. In a xenograft mouse model, combining vascular endothelial growth factor receptor 2 (VEGFR2)-targeted AuMBs with sonoporation significantly delayed tumor regrowth. A strategy involving the spatially and temporally controlled release of AuNPs followed by clinically utilized MV irradiation shows promising results that make it worthy of further translational investigations.

Improved prognosis with induction chemotherapy in pathological complete responders after trimodality treatment for esophageal squamous cell carcinoma: Hypothesis generating for adjuvant treatment.

PURPOSE: To compare the locations of recurrences and survival outcomes in esophageal squamous cell carcinoma (ESCC) patients with pathological complete response (pCR) after neoadjuvant concurrent chemoradiotherapy (CCRT) with or without preceding induction chemotherapy (IC) followed by esophagectomy. METHODS: Among 276 patients with locally advanced ESCC undergoing trimodality treatment during 2004-2014, 94 (34.1%) with pCR were eligible. The cohort included 26 patients undergoing IC before CCRT (IC group), and 68 patients who did not receive IC (non-IC group). RESULTS: At a median follow-up of 51.4 months (95% confidence interval; 42.9-62.1), 19 patients experienced recurrences. There was a trend toward fewer distant failures in the IC group (0% vs.14.7%, p = 0.057), while locoregional recurrence was similar (7.7% vs. 7.4%). IC was associated with significantly improved survivals with the 5-year RFS and OS rates for the IC group of 85.1% and 90.5%, respectively, compared to of 46.2% and 48.1% for the non-IC group (p = 0.008 for RFS, and p = 0.015 for OS). By multivariable analyses, IC remained the only significant factor associated with survivals (HR:0.18 for RFS, p = 0.020 and HR:0.18 for OS, p = 0.025). The effect of IC in the whole cohort, irrespective of pathological response, was also assessed. Patients with non-pCR in the IC group had a trend toward worse survivals compared to the non-IC group CONCLUSIONS: In ESCC patients with pCR after trimodality treatment, IC was associated with favorable survivals. The benefits of IC might be a hypothesis generation for adjuvant treatment for patients with pCR.

Maximizing Benefits from Maintenance Pemetrexed with Stereotactic Ablative Radiotherapy in Oligoprogressive Non-Squamous Non-Small Cell Lung Cancer.

Maintenance pemetrexed offers survival benefit with well-tolerated toxicities for advanced non-squamous non-small cell lung cancer (NSCLC). We present 3 consecutively enrolled patients with advanced non-squamous NSCLC, receiving stereotactic ablative radiotherapy (SABR) for oligoprogressive disease during maintenance pemetrexed. All of them had sustained local control of thoracic oligoprogression after the SABR, while maintenance pemetrexed were kept for additionally long progression-free interval. SABR targeting oligoprogression with continued pemetrexed is an effective and safe approach to extend exposure of maintenance pemetrexed, thus maximizing the benefit from it.

Serum Transforming Growth Factor-ß1 Change After Neoadjuvant Chemoradiation Therapy Is Associated With Postoperative Pulmonary Complications in Esophageal Cancer Patients Undergoing Combined Modality Therapy.

PURPOSE: Our aim was to investigate the association of clinical factors, dosimetric parameters, and biomarkers with postoperative pulmonary complications (PPCs) in patients with locally advanced esophageal squamous cell carcinoma (ESCC) treated by neoadjuvant concurrent chemoradiation therapy (CCRT) under strict pulmonary dose constraints and esophagectomy. METHODS AND MATERIALS: We prospectively enrolled 112 patients undergoing trimodality treatment (including radiation therapy [40 Gy], concurrent taxane-/5-fluorouracil-based regimens, and radical esophagectomy) for ESCC. A PPC was defined as pneumonia or acute respiratory distress syndrome within 30 days after surgery. Serum samples were collected before and within 1 month after CCRT. The association of serum biomarkers with PPCs was detected by proximity ligation assay (PLA) and verified by enzyme-linked immunosorbent assay. Associations of clinical factors, lung dosimetric parameters, and biomarkers with PPC were tested statistically. RESULTS: Thirty-three patients (29.5%) had PPCs. None of the dosimetric parameters was associated with PPCs. Preoperative functional vital capacity (FVC) was significantly associated with PPCs (P=.004). Of the 15 PLA-screened biomarkers, posttreatment transforming growth factor-ß1 (TGF-ß1) was borderline significantly associated with PPCs (P=.087). Patients with PPCs had significantly larger pre-CCRT to post-CCRT decrease in serum TGF-ß1 concentration (-11,310 vs -5332 pg/mL, P=.005) and higher pre-CCRT to post-CCRT percent decline in serum TGF-ß1 concentration (-37.4% vs -25.0%, P=.009) than patients without PPCs. On multivariate analysis, preoperative FVC (P=.003) and decrease in TGF-ß1 >7040 pg/mL (P=.014) were independent factors associated with PPCs. CONCLUSIONS: Preoperative FVC and decrease in serum TGF-ß1 level after dose-limited CCRT to the lung are associated with the development of PPCs.