Regional Failure Research Articles

Sinonasal Mucosal Melanoma Survival Outcomes, Recurrence Patterns, and Prognostic Factors: A Systematic Literature Review and Meta-analysis of Publications after 2000

Abstract Background Sinonasal mucosal melanoma (SNMM) comprises <1% of all head and neck cancers but has one of the highest 5-year mortalities. Methods A systematic review and analysis using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta- Analyses) guidelines was conducted on SNMM survival, recurrence, and prognostic factors. Results A total of 2,379 abstracts were reviewed resulting in 90 studies describing 3347 SNMM patients. Patients were 49.65% male and 66.5 years old. Surgery plus radiation therapy, followed by surgery only, then radiation only were the most common treatments. Chemotherapy and immunotherapy were used in 418 patients and 101 respectively. The 2-, 3-, and 5-year overall survivals are 55.97, 40.09, and 30.35%, respectively. The 5-year disease-free survival and disease-specific survival are 25.56 and 38.04%. The 5-year local, regional, and distant recurrence-free survivals are 42.35, 81.64, and 44.65%. Mean survival after diagnosis was 26.99 months. Local (n = 650), regional (n = 226), and distant (n = 723) failure presented after 19.36, 6.35, and 12.42 months. Sites of metastasis were lung, liver, bone, brain, skin, kidney, and adrenal glands. Distant metastases, disease in the paranasal sinuses, and higher stage were noted to have worse survival outcomes. Positive margins did not significantly impact overall survival in 11/12 studies. Conclusion Overall survival over 20 years has remained poor with 70% of patients deceased in 5 years. About half of patients will develop distant failure and will thereafter rapidly decline. These data indicate need for advances in treatment of SNMM and new efforts with targeted immunotherapy offer a promising avenue toward improving survival outcomes.

A Comparison of Stereotactic Radiation Therapy in Elderly Patients with Central or Peripheral Stage I-II (T1-3 N0 M0) Non-Small Cell Lung Cancer.

The objective of this study was to compare the clinical outcomes of stereotactic body radiation therapy (SBRT) in elderly patients aged 65 or older with clinical stage I-II non-small-cell lung cancer (NSCLC), specifically examining the differences between centrally located lung tumors and peripherally located lung tumors. From April 2009 to January 2020, a total of 136 patients with 136 tumors (65 central, 71 peripheral; NSCLC) at an early stage (T1-3N0M0) were treated with SBRT at a single institution. Central/peripheral location was assessed retrospectively on planning CT scans. A propensity score matching analysis was utilized to compare the two groups. In addition, the prognosis and related toxicity were compared between the two study arms. A total of 33 central tumors and 33 peripheral tumors were matched and analyzed. The results showed no significant differences in overall survival (OS) and progression-free survival (PFS) between the two groups. The 2-year OS was 71.88% (95% CI, 57.87%-89.27%) in the central lung cancer group, while it was 93.94% (95% CI, 86.14%-100.00%) in the peripheral lung cancer group (P=0.462). The 2-year PFS was 43.75% in the central lung cancer group, while it was 78.79% in the peripheral lung cancer group (P=0.279). Further subgroup analysis indicated that the location of peripheral tumor have a positive impact on OS in patients with adenocarcinoma. The occurrence of local failure, regional failure, or distant failure was comparable between central and peripheral tumors. There was no statistically significant difference in toxicity between the central and the peripheral tumor groups. The outcomes of SBRT for central tumors versus peripheral lung tumors in elderly patients with early-stage NSCLC were similar. SBRT demonstrated a similar level of safety in terms of toxicity for both central and peripheral lung tumors.

Clinical outcomes, patterns of failure, and salvage therapies of a large modern cohort of patients with anal squamous cell carcinoma treated with definitive-intent IMRT

PurposePatterns of failure and salvage therapy options for patients with anal squamous cell carcinoma (ASCC) who recur after definitive-intent intensity-modulated radiotherapy (IMRT) with concurrent chemotherapy are not well described. Patients and MethodsWe identified consecutive patients with ASCC treated with definitive-intent IMRT between July 2005 and December 2019. Relevant patient and tumor parameters, disease outcomes (locoregional failure (LRF), distant failure (DF), progression-free survival (PFS), colostomy-free survival (CFS), and overall survival (OS)), patterns of failure, and salvage therapies were collected. Failures were analyzed by competing risks methods, whereas survival endpoints were estimated by Kaplan-Meier method. Univariate and multivariate analyses were performed. Landmark analyses were conducted by considering whether patients had LRF within 12 months from completing IMRT. Results375 patients were identified with a median follow-up of 6 years. Stage breakdown was 15%, 23%, and 62% for AJCC stage 0-I, II, and III, respectively. Six-year rates of LRF, DF, PFS, CFS, and OS were 12%, 13%, 73%, 76%, and 80%, respectively. Disease recurred in 74 patients. Among the 45 patients with LRF, 39 (87%) failed within the anorectum, with 25 anal canal, 6 anal margin, and 8 rectal recurrences. Only 4 (9%) patients had isolated nodal failure. Patients experiencing LRF had worse six-year OS than patients without LRF (44% versus 86%, P<0.0001). Approximately 30% of patients who underwent salvage therapy were alive ten years after recurrence, compared with none of the patients who were managed with chemotherapy alone or best supportive care. ConclusionsThis large ASCC cohort managed with definitive-intent IMRT demonstrated excellent rates of locoregional control and survival. Isolated regional nodal failures were uncommon, whereas the majority of LRFs occurred within the anorectum, despite dose escalation by tumor stage. We observed poor outcomes for patients experiencing locoregional disease recurrence, even after aggressive salvage treatment.

Analysis of the End-Bearing Capacity of Piles in Sand Under Limited Region Failure by a Mixed Zero-Extension Line Method

Analysis of the End-Bearing Capacity of Piles in Sand Under Limited Region Failure by a Mixed Zero-Extension Line Method

The value of elective neck irradiation in management of esthesioneuroblastoma: a retrospective study based on propensity score matching.

This study aims to assess the clinical efficacy of elective neck irradiation (ENI) in patients with esthesineuroblastoma (ENB), a rare malignant neoplasm, who are clinically node-negative. We conducted a retrospective analysis of 178 patients newly diagnosed with ENB at our institution between 2009 and 2021. Propensity score matching (PSM) was employed to compare node-negative patients treated with and without ENI. We extensively examined survival outcomes and treatment failure. Of the 178 participants, 149 (83.7%) were lymph node-negative and staged in Modified Kadish A-C. 96 patients underwent ENI treatment, while 53 did not. At baseline, patients who received ENI differed from those who did not in terms of radiotherapy technique, staging, orbital invasion, surgical mode, and chemotherapy. After PSM, 43 pairs were available for analysis. ENI was observed to extend overall survival (OS, 5-year 73.9% vs. 84.0%; 3-year 76.9% vs. 97.1%, p = 0.022), progression-free survival (PFS, 5-year 38.5% vs. 84.6%; 3-year 50.5% vs. 94.5%, p < 0.001) and locoregional relapse-free survival (LRFS, 5-year 42.7% vs. 84.6%, p = 0.023; 3-year 57.3% vs. 94.5%, p < 0.001) in node-negative ENI patients. Failure pattern analyses revealed that ENI, which included level Ib, II, VIIa, significantly reduced the treatment failure rate. Furthermore, ENI did not significantly impact the prognosis of T1-2 patients, indicating potential clinical value of ENI in T3-4 patients. Our findings suggested that ENI decreased regional failure and significantly enhanced LRFS and PFS. ENI may be considered as an integral part of the initial treatment strategy for locally advanced node-negative ENB patients.

Involved-field high-dose chemoradiotherapy with respiratory motion management for esophageal squamous cell carcinoma.

We investigated the clinical outcomes of involved-field high-dose (≥66 Gy) chemoradiotherapy (CRT) combined with respiratory motion management for esophageal squamous cell carcinoma (ESCC). Patients who underwent definitive CRT for histologically confirmed ESCC in our department between 2012 and 2018 were retrospectively analyzed. Respiratory motion management strategies included breath-holding (63%) and mask immobilization (29%) based on individual measurements of respiratory tumor motion using radiographic fluoroscopy with endoscopically placed clip markers as landmarks. We evaluated patient characteristics, treatment efficacy, failure patterns, and toxicities. We enrolled 35 patients with a prescribed dose of 66-70 Gy in 33-35 fractions. The overall response rate within 6 months post-CRT was 94.3%; the median follow-up period for survivors was 43 months. The 2-year overall survival (OS), progression-free survival, and locoregional failure-free survival rates were 51.4%, 42.9%, and 42.9%, respectively. A significant difference in OS was observed between patients with and without esophageal fistulas after CRT (p = 0.002, log-rank test). Disease failure occurred in 16 patients (45.7%), including one (2.9%) with out-of-field regional nodal failure. Major grade 3 or higher toxicities included decreased white blood cell count (48.6%), neutrophil count (34.3%), and esophageal stenosis (31.4%). No grade 3 or higher cardiopulmonary toxicities were observed. Bronchial/tracheal tumor compression and a higher radiotherapy dose (70 Gy) were significantly correlated with esophageal fistulas. Involved-field high-dose CRT with respiratory motion management may be a feasible treatment option for ESCC. However, a comprehensive assessment of esophageal fistula risk is required to identify suitable candidates.

Rainfall water collection and irrigation via stone bud and karren on karst rocky desertification slopes: Application and benefit analysis

Lack of surface water is a key factor leading to agricultural drought in karst regions and exacerbates the karst rocky desertification, which is characterized by high rate of exposed bedrock. With the characteristics of impermeability, runoff collection, and wide distribution, stone bud and karren (SBK), a unique karst landscape type composed of exposed bedrock and gullies, has a great potential to solve water shortage in agricultural irrigation, especially in the rain-rich karst regions of Guizhou Province, China. Using unmanned aerial vehicle images to identify SBK and measured rainfall–runoff data for validation, we applied SBK as a basic unit to harvest rainfall water on rocky desertification slopes and analyzed the benefits of rainfall water collection and irrigation via SBK. The results showed the following: (1) Karrens on rocky desertification slopes could be identified using a method coupling terrain opening difference and depression filling, and the simulated runoff on SBK could achieved the average NSE and R2 of 0.82 and 0.86, with RMSE and RSR less than 0.03 m3 and 0.51, respectively. (2) The exposed bedrock utilization rate and rainfall water collection coefficient of SBK were 0.62 and 0.55, respectively, such that the area ratio of exposed bedrock to the cultivated land meeting irrigation water demand reached 1:3.1, 1:3.7 and 1:7.0 under 90 %, 80 % and 50 % possibilities of irrigation. (3) Implementing SBK for rainfall water harvesting and irrigation could efficiently avoid crop failure in the karst regions where crops faced drought within only one week after rainfall, and was at an affordable cost to local farmers with limited environmental damage. The use of SBK to harvest rainfall water could also alleviate surface water shortages in karst regions caused by problems such as uneven temporal distribution of rainfall and engineering water shortages. Consequently, SBK demonstrate a strong application potential to alleviate agricultural drought in karst rocky desertification regions.

Wind-induced collapse mode and mechanism of super-large hyperbolic steel reticulated shell cooling tower with stiffening rings

With advancement of dry-air cooling technology, it has become feasible to use steel reticulated shell structures in design and construction of industrial cooling towers. Steel reticulated shell cooling towers (SRSCTs) with light weight, high strength, and rapid construction have development potential. Wind-induced collapse accidents in cooling towers frequently occur, characterized by pronounced nonlinear behavior involving significant deformation and material failure. Nevertheless, current stability and collapse analyses of cooling towers based on linear theory and elastic deformation are inadequate and unsafe. Thus, the wind-resistant stability of SRSCTs must be evaluated considering their inherent high flexibility and low damping levels. Considering a 220 m high hyperbolic SRSCT as a case study, a wind-induced collapse FEM simulation and analysis were performed. The average and fluctuating wind loads were measured in a reduced-scale model during wind tunnel tests and used as the time-variant wind pressure in a structural finite-element model. The dynamic performance and buckling collapse analyses of the cooling tower were conducted considering geometric and material nonlinearities. The entire wind-induced failure process of the SRSCT in extreme winds was systematically investigated. The weaknesses in the structural stiffness and the failure process were quantified, with five failure stages and four failure modes. The failure stages included linear elasticity, local member failure, local regional failure, overall structural failure, and collapse. The failure modes included circumferential plastic buckling zone failure, windward buckling failure of the shell, crosswind failure of the stiffening ring (hinged curved-beam mechanism), and windward failure of the stiffening ring (triangular arch-like mechanism). This study confirms that development of plastic buckling zones and formation of plastic hinges, considering geometric and material nonlinearity, are the dominant factor in wind-induced failure and collapse of SRSCTs.

Five-Year Prostate-Specific Membrane Antigen Positron Emission Tomography-Based Outcomes of Spot-Scanning Proton Radiation Therapy for Localized Prostate Cancer: A Single Institution Experience

PURPOSE: We report 5-year oncologic outcomes of a prospective series of patients with prostate cancer treated with spot-scanning proton therapy (SSPT).METHODS AND MATERIALS: A prospective registry identified patients with prostate cancer treated with SSPT between January 2016 and December 2018. Five-year overall survival (OS), local control (LC), biochemical failure (BF), regional and distant failures, and adverse events (AEs) were assessed. Biochemical failure was defined as rise in PSA ≥ 2.0 ng/mL above nadir PSA. Baseline-adjusted toxicities were assigned using CTCAE v5.0.RESULTS: With a median follow up of 4.4 years, 284 prostate cancer patients were treated with SSPT. Median total radiation dose was 79.2 Gy over 44 fractions, 70 Gy over 28 fractions, and 38 Gy over 5 fractions for conventional fractionation (CF), hypofractionation (HF), and stereotactic body radiation therapy (SBRT), respectively. Biochemical failure rate for all patients was 6.7%. Five-year LC rates for CF, HF, and SBRT were 100%, 100%, and 97.3%, respectively (p = 0.07). Regional recurrences occurred in 12 (4.2%) patients: 8 treated with CF, 2 with HF, and 2 with SBRT (p = 0.62). Distant failures occurred in 12 patients (4.2%): 5 treated with CF, 7 with HF, and none with SBRT (p = 0.05). Five-year OS for patients treated with CF, HF, and SBRT SSPT were 88.1%, 86.1%, and 97.2%, respectively (p = 0.1). Acute and chronic grade 2+ GI AEs occurred in 8 (2.8%) and 51 (18.0%) patients, respectively. Acute and chronic grade 3+ GI AEs occurred in 3 (1.1%) and 4 (1.4%) patients, respectively. Acute and chronic grade 2+ GU-related AEs were observed in 71 (25%) and 63 (22.2%) patients, respectively. Acute and chronic grade 3+ GU toxicity were observed in 3 (1.1%) and 6 (2.1%) patients, respectively.CONCLUSIONS: SSPT provides high local control rates and excellent oncologic outcomes across different fractionation schedules with low long-term AE rates.

Patterns of treatment failure in patients with sinonasal squamous cell carcinoma after chemoradiotherapy.

To investigate the failure patterns based on precision radiation treatment and to determine the predictive factors of treatment failure for sinonasal squamous cell carcinoma (SNSCC) patients. This was a retrospective study that included 214 cases of treatment failure from 441 consecutive patients. Two experienced radiation oncologists evaluated the tumour volume of cases with local recurrence. The 5-year overall survival (OS), progression-free survival (PFS) rates, and distant-metastasis-free survival (DMFS) were estimated. Investigations were performed on the factors that predicted local failure or distant metastasis. About 140 (31.7%) patients developed local recurrence, 24 (5.4%) experienced regional failure, and 65 (14.7%) underwent distant metastasis. In-field, marginal, and out-of-field failures occurred in 55.7% (78/140), 33.6% (47/140), and 10.7% (15/140) of patients with local recurrence, respectively. In logistic regression analysis, factors statistically significant for total local failure included treatment mode (P < .01), chemotherapy (P < .01), and surgical margins (P < .01). Primary tumours with poor differentiation (P = .018) and R2 resection margin (P = .009) were more prone to develop distant failure. The 5-year OS, PFS, and DMFS rates were 57.8%, 52.0%, and 56.7% for the whole cohort. In univariate and multivariate analysis, the skull base involvement was an independent predictor for poorer OS and PFS; orbital invasion was an independent predictor for poorer OS. Local recurrence and distant metastasis were the most common failure modes. Treatment mode, chemotherapy, and surgical margins were related to local recurrence. Poor differentiation and R2 resection margin were predictors for distant failure. Local recurrence is the most common failure pattern in patients with SNSCC who accepted chemoradiotherapy, and marginal and out-of-field failures occurred in 44.3% of patients with local recurrence.

Comparison of Dental Findings with Computed Tomographic and Clinical Examination in Patients with End-Stage Heart Failure.

Background: This study aimed to evaluate the diagnostic value of pre-existing computed tomography (CT) examinations for the detection of dental pathologies compared with clinical dental examination in patients with end-stage heart failure. Methods: For this purpose, 59 patients with end-stage heart failure and pre-existing non-dental CT images of the craniofacial region were included. Virtual orthopantomograms (vOPG) were reconstructed. Dental pathologies were analyzed in vOPG and source-CT images. Imaging and clinical findings less than 6 months apart were compared (n = 24). Results: The subjective image quality of vOPG was more often rated as insufficient than CT (66%; 20%; p < 0.01). Depending on examination (CT, vOPG or clinic), between 33% and 92% of the patients could require dental intervention such as treatment of caries and periodontitis or tooth extraction. vOPG led to a higher (80%) prevalence of teeth requiring treatment than CT (39%; p < 0.01). The prevalence of teeth requiring treatment was similar in CT (29%) and clinic (29%; p = 1.00) but higher in vOPG (63%; p < 0.01). CT (stage 3 or 4: 42%) and vOPG (38%) underestimated the stage of periodontitis (clinic: 75%; p < 0.01). Conclusions: In conclusion, available CT images including the craniofacial region from patients with end-stage heart failure may contain valuable information regarding oral health status. The assessability of vOPGs might be insufficient and must be interpreted with caution.

Unilateral Neck Treatment with either Surgery and/or Radiotherapy for Squamous Cell Carcinoma for the Tonsil

Introduction: Strategies for treatment of tonsil carcinoma are under active investigation. Limiting surgical and radiation treatment volumes to the primary tumor and ipsilateral neck in appropriately selected patients are one such approach. Here, we present our institutional experience with treatment through ipsilateral surgical or radiotherapeutic neck management. Methods: We retrospectively reviewed our institutional database of patients with tonsil carcinoma treated from 2012 to 2020. Patients were included for analysis if they received definitive radiation therapy (RT), definitive surgery (S), or surgery with postoperative radiation therapy (S-PORT) and whose treatment volumes were limited to the primary tumor and involved/elective ipsilateral neck. Patients who received radiation and/or surgery to the contralateral neck (including those with bilateral nodal involvement), as well as patients with metastatic disease, were excluded. Clinical factors including T- and N-stage (AJCC 7th edition), and HPV status (by p16 and/or HPV DNA PCR) were recorded, as were pathologic factors (when applicable) including margin status, extracapsular extension (ECE), lymphovascular invasion (LVSI), and perineural invasion (PNI). Overall survival (OS), progression-free survival (PFS), and locoregional control (LRC) at 2 years were estimated using the Kaplan-Meier method. Results: In total, 71 patients were treated with unilateral neck approaches: S (n = 49), RT (n = 10), and S+PORT (n = 12). Among these patients, 32, 36, and 3 had T1, T2, and T3 disease, respectively. N-stage was N0, N1, N2a, N2b, and N3 in 22, 20, 5, 23, and 1 patient(s), respectively. Concurrent chemotherapy was administered in 12 patients. From those with recorded risk factors, 86% were HPV positive, 20% had LVSI, 7% had PNI, 13% had ECE, and 5% had positive margins. From a median follow-up of 27 months, local, regional, and distant failures occurred in 5, 6, and 5 patients, respectively. No contralateral neck failures were recorded. At 2 years, OS, PFS, and LRC were 92% (95% CI 85–99%), 85% (95% CI 75–95%), and 88% (95% CI 80–98%), respectively. Conclusions: In patients with early T-stage tonsil carcinoma, treatment of the primary tumor and ipsilateral neck is associated with acceptable OS, PFS, and LRC. In this population, the risk of contralateral neck failure is likely very low regardless of primary treatment modality. Additional prospective studies are needed to determine the impact of limiting treatment extent, either surgical or radiotherapeutic, to the unilateral neck.

Outcomes for patients with perineal and perianal rhabdomyosarcoma: A report from the Children's Oncology Group Soft Tissue Sarcoma Committee.

To describe clinical features, risk factors, and outcomes of patients with perineal and perianal rhabdomyosarcoma. The records of 51 patients (38 perineal and 13 perianal) enrolled on Children's Oncology Group clinical trials between 1997 and 2012 were reviewed. At presentation, 53% were female, 65% were older than 10years of age, 76% were alveolar histology, 76% were more than 5cm, 84% were invasive, 65% were regional node positive by imaging, 49% were metastatic, only 16% were grossly resected upfront, and 25% of patients had a delayed excision. At a median follow-up of 6.13years, estimated 5-year event-free survival (EFS) was 38% [22.17%-53.38%], and overall survival (OS) was 42% [26.66%-58.21%]. The rates of local, regional, and distant failure were 15.6%, 13.7%, 43.1%, respectively; all failures ultimately died. By univariate analysis, only age more than 10years negatively impacted 5-year EFS (p=.023) and OS (p=.09), and IRS Group also impacted OS (p=.043). In Cox proportional hazards model, neither of these variables were significant after adjusting for other factors. Patients with perineal and perianal rhabdomyosarcoma have a poor overall prognosis, probably related to poor patient and disease characteristics at presentation.

Image stitching algorithm for super-resolution localization microscopy combined with fluorescence noise prior.

Super-resolution panoramic pathological imaging provides a powerful tool for biologists to observe the ultrastructure of samples. Localization data can maintain the essential ultrastructural information of biological samples with a small storage space, and also provides a new opportunity for stitching super-resolution images. However, the existing image stitching methods based on localization data cannot accurately calculate the registration offset of sample regions with no or few structural points and thus lead to registration errors. Here, we proposed a stitching framework called PNanoStitcher. The framework fully utilizes the distribution characteristics of the background fluorescence noise in the stitching region and solves the stitching failure in sample regions with no or few structural points. We verified our method using both simulated and experimental datasets, and compared it with existing stitching methods. PNanoStitcher achieved superior stitching results on biological samples with no structural and few structural regions. The study provides an important driving force for the development of super-resolution digital pathology.

Medicines for reduced ejection fraction heart failure in Central region of Portugal’s primary care: a 2022 observational study

Objective: To evaluate the accordance of prognostic medicines prescription (PMP), for persons with chronic heart failure with reduced ejection fraction (P-CHFrEF), attended in primary health care units in Central Portugal, with the European Society of Cardiology (ESC) 2021 August, guidelines. To know about mean age, median time since the diagnosis and last echocardiogram performance in P-CHFrEF. Methods: Observational, cross-sectional study of a random size representative sample, 95% confidence interval, and 8% error margin of the P-CHFrEF of a population on 31st December 2021. Age, gender, year of International Classification for Primary Care-2 (ICPC-2, K-77) problem classification input data, years since the last echocardiogram, ongoing PMP and the use of other chronic heart failure (CHF) drugs were gathered. Data were obtained from 11 Portugal Primary Health Care Units, invited by convenience, after an Ethics Committee approval. Results: From a universe of n=2,381 persons with CHF, n=453 (19.0%) P-CHFrEF was found. A size representative sample of P-CHFrEF of n=133 (5.6%), n=95 males (71.4%) was studied. Prescription of a renin-angiotensin system inhibitor (RAAS-I) was ongoing in 91.0%, beta-blocker (BB) in 75.2%, mineralocorticoid antagonists (MRA) in 40.6%, inhibitors of the sodium-glucose cotransporter-2 (SGLT2i) in 44.4%, neprilisine inhibitors 38.3% and loop diuretics in 72.2%. The optimized medical quadruple therapy was established in 28 patients (21.1%) and the triple one in 38 (28.6 %). Mean age was of 74.3±11.6 years, males 73.4±11.0 and females 76.6±12.9, p=0.088. The median time since the diagnosis was 6.0 for men and 4.0 for women, p=0.031. The median time since the last echocardiogram was 3.0, p=0.750 between genders. Conclusion: According to the 2021 ESC guidelines, prognostic modifying medicines were underused for 50.4% of P-CHFrEF. Even with these results, a reflection must be made, on the barriers physicians encounter, to comply with the ESC guidelines in such patients.

Effect analysis of 847 nasopharyngeal carcinoma cases treated with intensity modulated radiation: Experience and suggestions

ObjectivesTo identify the failure patterns and prognostic factors of nonmetastatic nasopharyngeal carcinoma (NPC) in the intensity-modulated radiotherapy (IMRT) era. MethodsData on 847 patients with newly diagnosed, non-disseminated NPC treated by IMRT between 2012 and 2016 were retrospectively reviewed. Survival outcome, failure patterns and prognosis factors were analyzed. ResultsThe 5-year local relapse-free survival, nodal relapse-free survival, distant metastasis-free survival, disease-free survival, and overall survival rates were 94.3%, 95.3%, 84.8%, 76.5% and 85.7%, respectively. The major local recurrence sites were the nasopharynx (91.5%, 43/47) and skull base (68.1%, 32/47); 39 patients had in-field failures, four had marginal failures, and four had out-field failures. Level IIb (62.2%, 23/37) was the most frequent regional recurrence site, followed by IIa (35.1%, 13/37) and retropharyngeal region (32.4%, 12/37); 35 cases had in-field failure alone, one had out-field failure alone, and one had both in- and out-field failure. TNM stage was the most significant factor for prognosis prediction. 402 (47.5%) patients had acute adverse events of grade 3 or 4; leukopenia (31.5%) and mucositis (26.7%) was the most common hematological and non-hematological event, respectively. Late complications were slight or moderate damages; xerostomia (647/847, 76.4%) and hearing impairment (422/847, 49.8%) remained the most troublesome. ConclusionNPC patients treated with IMRT obtained satisfactory survival outcomes. The key failure pattern was distant metastasis. The main pattern of local–regional failure was in-field failure. Screening high risk patients with distant metastases and optimizing radiotherapy targets should be studied.

Pathologic Substrates of Structural Brain Network Resilience and Topology in Parkinson Disease Decedents.

In Parkinson disease (PD), α-synuclein spreading through connected brain regions leads to neuronal loss and brain network disruptions. With diffusion-weighted imaging (DWI), it is possible to capture conventional measures of brain network organization and more advanced measures of brain network resilience. We aimed to investigate which neuropathologic processes contribute to regional network topologic changes and brain network resilience in PD. Using a combined postmortem MRI and histopathology approach, PD and control brain donors with available postmortem in situ 3D T1-weighted MRI, DWI, and brain tissue were selected from the Netherlands Brain Bank and Normal Aging Brain Collection Amsterdam. Probabilistic tractography was performed, and conventional network topologic measures of regional eigenvector centrality and clustering coefficient, and brain network resilience (change in global efficiency upon regional node failure) were calculated. PSer129 α-synuclein, phosphorylated-tau, β-amyloid, neurofilament light-chain immunoreactivity, and synaptophysin density were quantified in 8 cortical regions. Group differences and correlations were assessed with rank-based nonparametric tests, with age, sex, and postmortem delay as covariates. Nineteen clinically defined and pathology-confirmed PD (7 F/12 M, 81 ± 7 years) and 15 control (8 F/7 M, 73 ± 9 years) donors were included. With regional conventional measures, we found lower eigenvector centrality only in the parahippocampal gyrus in PD (d = -1.08, 95% CI 0.003-0.010, p = 0.021), which did not associate with underlying pathology. No differences were found in regional clustering coefficient. With the more advanced measure of brain network resilience, we found that the PD brain network was less resilient to node failure of the dorsal anterior insula compared with the control brain network (d = -1.00, 95% CI 0.0012-0.0015, p = 0.018). This change was not directly driven by neuropathologic processes within the dorsal anterior insula or in connected regions but was associated with higher Braak α-synuclein staging (rs = -0.40, p = 0.036). Although our cohort might suffer from selection bias, our results highlight that regional network disturbances are more complex to interpret than previously believed. Regional neuropathologic processes did not drive regional topologic changes, but a global increase in α-synuclein pathology had a widespread effect on brain network reorganization in PD.

In-plane compressive behavior of cross-laminated bamboo and timber with variable heights

This paper investigates the in-plane compressive behavior of 5-layer cross-laminated bamboo and timber (CLBT) wall elements with variable heights. Five different heights of CLBT specimens, ranging 400 mm – 3800 mm, were designed for the experiment, with conventional 5-layer cross-laminated timber (CLT) specimens used as controls. Theoretical calculations based on timber structure design codes were employed to analyze the ultimate bearing capacity in compression, complemented by finite element simulations based on Abaqus that also explored the failure characteristics. The results indicated that CLBT wall panels had significantly better compressive performance compared to those of CLT wall panels. For wall panels of around 3.0 m and 6.0 m in height, the compressive strength of the CLBT was approximately 65 % and 40 % higher than that of the CLT, respectively. For specimens showing buckling instability, CLBT demonstrated more concentrated failure in the end regions, contrasting with CLT, which failed primarily in the central region. The outcomes of this study clearly delineate the superiority of CLBT over CLT when used as wall panels, providing valuable references for their potential engineering applications.

Causes of Safety Barrier Failures at Oil and Gas Facilities in Nigeria: A Technical Approach

This study investigates the company-controlled causes of barrier failure in Niger Delta region of Nigeria. Also, it focuses on oil and gas facilities and their operations involving hydrocarbon handling. Safety Barriers in the oil and gas industry are crucial safety systems designed to prevent hazards and mitigate the consequences of incidents. These barriers, encompassing technical, operational, and organizational elements, play a significant role in handling hazardous substances and preventing their unintended release. Despite their importance, barrier failures have been identified as major causes of process safety incidents globally, including Niger Delta region of Nigeria. A cross-sectional research design, using a questionnaire to collect primary data from 132 personnel across 12 facilities, was employed. Statistical data analyses were carried out using XLSTAT Version 2016. Findings indicate that process upsets and technical/physical failures are significant risk influencing factors, while human and operational errors, though present, are less impactful. Key technical failures include degradation of valve sealing and flange gaskets, while process upsets often result from overpressure and malfunctioning transmitters. The study highlights the need for improved risk reduction strategies and periodic training to enhance safety practices in the Niger Delta's oil and gas industry. Recommendations include increasing technical components of risk strategies and ensuring regular maintenance and compliance with safety regulations; that is, proactive maintenance strategies to mitigate the identified risks.

Two-scale concurrent simulations for crack propagation using FEM–DEM bridging coupling

The Discrete element method (DEM) is a robust numerical tool for simulating crack propagation and wear in granular materials. However, the computational cost associated with DEM hinders its applicability to large domains. To address this limitation, we employ DEM to model regions experiencing crack propagation and wear, and utilize the finite element method (FEM) to model regions experiencing small deformation, thus reducing the computational burden. The two domains are linked using a FEM–DEM coupling, which considers an overlapping region where the deformation of the two domains is reconciled. We employ a “strong coupling” formulation, in which each DEM particle in the overlapping region is constrained to an equivalent position obtained by nodal interpolation in the finite element. While the coupling method has been proved capable of handling propagation of small-amplitude waves between domains, we examine in this paper its accuracy to efficiently model for material failure events. We investigate two cases of material failure in the DEM region: the first one involves mode I crack propagation, and the second one focuses on rough surfaces’ shearing leading to debris creation. For each, we consider several DEM domain sizes, representing different distances between the coupling region and the DEM undergoing inelasticity and fracture. The accuracy of the coupling approach is evaluated by comparing it with a pure DEM simulation, and the results demonstrate its effectiveness in accurately capturing the behavior of the pure DEM, regardless of the placement of the coupling region.