Search

Cu2ZnSnS4 (CZTS), a quaternary material formed of Earth-abundant elements, is promising in thin-film solar cell devices, as absorbing layer. The high efficiency of solar energy conversion (>12%) recorded in chalcogen-doped Cu2ZnSnS4 renders it an attractive material for the analysis of the structural stability, electronic band structures, and optical characteristics of Cu2ZnSn(SxTe1-x)4 alloys (0 ≤ x ≤ 1) by first-principles calculations. By employing full-potential linearized augmented plane-wave (FP-LAPW) methodology, the acquired results indicate that CZTS and Cu2ZnSnTe4 (CZTTe) parent compounds possess wide and narrow direct band gaps, respectively. The optical characteristics of Cu2ZnSn(SxTe1-x)4 alloys and their bulk counterparts were computed in terms of the complex dielectric function, which allows the examination of the optical absorption, reflectivity, and refractive index of these ultimate alloys. It is inferred that the S/Te compositional ratio in Cu2ZnSn(SxTe1-x)4 has a significant influence on the optical absorption of electromagnetic radiation in the visible to the infrared (IR) regimes. Our results indicate that the increase of Te concentration leads to a red shift of the major feature peaks in the optical absorption spectra. Because of their direct band gap and remarkable optical absorption, Cu2ZnSn(SxTe1-x)4 alloys with S/Te compositional ratios under 0.5 could be useful materials in thin-film solar cell devices, as absorbing layers. This theoretical report is expected to provide relevant information for future experimental works involving the design of novel solar cell materials based on CZTST systems.

Purpose Local therapy for patients with nonspine bone metastases is evolving, with data supporting the use of single-fraction treatments, and more recently, showing possible benefit from stereotactic body radiation therapy (SBRT). However, the rate of local salvage therapy (LST) after each technique has not been characterized in real-world clinic settings where patients are selected at physician discretion. We examined rates of LST in patients with nonspine bone metastases. Methods and Materials We reviewed records of RT for nonspine bone metastases at our institution from January 1, 2016, to December 31, 2018. We defined LST as the first occurrence of RT or surgery for oncologic progression to a bone metastasis after initial RT. Cumulative incidence functions for retreatment were generated. We conducted multivariate analysis to identify variables associated with LST. Results A total of 1754 patients were analyzed, with median follow-up of 16.2 months (range, 0-36.8 months). Of all episodes of RT, 51.5% were multifraction external beam radiation therapy (EBRT), 7.0% were single-fraction EBRT, and 41.4% were SBRT. Altogether, 88 patients (5.0%) required LST, with an incidence at 6 months of 2.5%. Incidence of LST at 6 months was 2.1% for SBRT, 5.3% for single-fraction conventional regimens, and 2.4% for multifraction conventional regimens (P = .26). Patients of younger age, who had a higher Karnofsky performance status, and/or who had lesions in the pelvis had a higher risk of retreatment. Conclusions In this large institutional cohort, the rate of LST was low, with no difference between RT techniques. The findings indicated that SBRT for patients at high risk for treatment failure may reduce the rate of retreatment overall. When treatment modality was selected based on patient characteristics, rates of LST were lower than when treatment was randomly selected.

In this work, pristine, S- and P-doped monolayer graphene are studied by employing full-potential linear augmented plane-wave method within the framework of density functional theory. One and two C atom in the 2 × 2 supercell of monolayer graphene are replaced by S or P atoms to explore the impact of increasing doping concentration of these reactive nonmetal dopants on the electronic and optical properties. It is found that the incorporation of single S and P dopants in monolayer graphene causes the conduction band minimum at the high symmetry K-point to shift below the Fermi level along with opening the energy states at the Dirac cone; transforming the semi-metallic nature of pristine graphene to an extrinsic n-type semiconductor. Furthermore, we show that increasing the doping concentration of S and P atoms by doping them in nearest-neighbour sites in the honeycomb graphene lattice causes conduction band states to overlap with the valence band of the undoped system; allowing the re-emergence of Dirac cone. The effect of increasing S and P doping concentration on the optical properties of graphene are also studied. Our results indicate that overall absorption spectra of monolayer graphene is red shifted towards lower energy photons upon doping with P and S atoms, while refraction index, extinction coefficient and reflectivity of monolayer graphene are also significantly altered. The electron energy loss function and X-ray absorption spectroscopy results for the S- and P-doped monolayer graphene also show significant changes when compared with pristine system owing to the shifts in the π* and σ* anti-bonding states. Our results provide useful information for tailoring the electronic structure and optical properties of monolayer graphene through S and P doping for its applications in contemporary nano-electronic technologies.

An inorganic perovskite type spin gapless semiconductor RbVF3 under high pressure was predicted by the first principle calculation. In order to examine the formation process and structural stability of RbVF3, the electronic structures, magnetic and mechanical properties of RbVF3 under external pressure are studied. The results show that RbVF3 undergoes phase transitions from magnetic semiconductor to spin gapless semiconductor to half-metal to metal under pressure. The formation of spin gapless semiconductor is mainly caused by the movement of the spin state. Born-Huang criteria under pressure indicate that RbVF3 has stable mechanical properties in magnetic semiconductor, spin gapless semiconductor and half-metal.

Although cancer is highly heterogeneous, all metastatic cancer is considered American Joint Committee on Cancer (AJCC) Stage IV disease. The purpose of this project was to redefine staging of metastatic cancer. Internal validation of nationally representative patient data from the National Cancer Database (n = 461 357; 2010-2013), and external validation using the Surveillance, Epidemiology and End Results database (n = 106 595; 2014-2015) were assessed using the concordance index for evaluation of survival prediction. A Cox proportional hazards model was used for overall survival by considering identified phenotypes (latent classes) and other confounding variables. Latent class analysis was performed for phenotype identification, where Bayesian information criterion (BIC) and sample-size-adjusted BIC were used to select the optimal number of distinct clusters. Kappa coefficients assessed external cluster validation. Latent class analysis identified five metastatic phenotypes with differences in overall survival (P

Purpose/Objective(s) We hypothesize that there is an oligoprogressive state in metastatic cancer, in which disease control can be improved with local therapy to progressive lesions only. This study therefore evaluated the impact of stereotactic body radiotherapy (SBRT) to sites of oligoprogression in patients with metastatic non-small-cell lung cancer (NSCLC) and breast cancer with 1-5 progressive lesions. Materials/Methods We enrolled patients with metastatic NSCLC or breast cancer who received ≥ 1 line of systemic therapy and had oligoprogressive lesions amenable to SBRT. There was no upper limit of non-progressive lesions. Oligoprogression was defined as Response Evaluation or Positron Emission Tomography Response Criteria in Solid Tumors documented progression ≤ 5 individual lesions. Stratification factors included number of progressive sites (1 vs. 2-5), prior systemic therapy (immunotherapy vs. other), primary tumor (NSCLC vs. breast), and tumor marker status (driver mutation and hormone receptor status). Patients were randomized 1:1 between SBRT to all progressive sites plus palliative standard of care (SOC) vs. palliative SOC only. Systemic therapy was per physician's discretion. The primary endpoint was progression-free survival (PFS). We used a randomized phase II design with a one-sided alpha of 0.05 and a power of 0.80, yielding a target accrual of 160 patients. PFS was compared using one-sided stratified log-rank test. One interim analysis was planned. Results From January 2019 to May 2021, 102 patients were randomized - 58 NSCLC (30 in the SBRT arm) and 44 breast (22 in each arm). Median age was 67. Most patients (75%) had > 1 site of oligoprogression and 47% had > 5 total metastatic lesions. Fifty-five (54%) patients received immunotherapy. The majority of NSCLC (86%) did not harbor an actionable driver mutation and 32% of breast cancer were triple negative. Baseline factors were balanced between arms. At a median follow-up of 51 weeks, 71 patients progressed and 30 died. Median PFS was 22 weeks in the SBRT arm vs. 10 weeks in the palliative SOC arm (p=0.005). This was driven entirely by the PFS benefit from SBRT in the NSCLC patients (44 weeks with SBRT vs. 9 weeks with SOC; p=0.004). No difference in median PFS was seen in the breast cohort (18 weeks with SBRT vs. 17 weeks with SOC; p=0.5). In multivariable Cox model inclusive of stratification factors, age, sex, lines of systemic therapy, and change of systemic therapy, the PFS benefit of SBRT remained substantial in the NSCLC cohort (Hazard Ratio: 0.38; 95% CI: 0.18-77; p=0.007). Grade ≥2 adverse events occurred in 8 patients in the SBRT arm, including 1 grade 3 pneumonitis. Conclusion Inthis pre-planned interim analysis of the first and largest randomized trial of radiotherapy for oligoprogressive metastatic NSCLC and breast cancer, we demonstrated the benefit of SBRT to sites of oligoprogression on overall PFS, meeting the primary endpoint. The mechanism of the differential benefits between NSCLC and breast cohorts merits further evaluation.

Purpose/Objective(s) Leptomeningeal metastasis (LM) is associated with limited survival and treatment options for patients with solid tumor malignancies. While photon involved-field radiotherapy (IFRT) is effective for local palliation, it lacks durability. Craniospinal irradiation (CSI), in contrast, treats the entire central nervous system (CNS) compartment, thus potentially improving disease control. We previously reported the safety and tolerability of proton CSI (pCSI) in a completed phase IB study, and we are now reporting the mature survival outcomes of these patients. Materials/Methods We enrolled 24 patients with solid tumor LM to receive hypofractionated pCSI of 30 Gy (RBE) in 10 fractions in this phase I prospective trial between June 2018 and May 2019 (NCT03520504). The primary endpoint is dose-liming toxicity (DLT) within 1 month of treatment. Secondary endpoints, including time to CNS progression (CNS TTP), CNS progression-free survival (PFS), and overall survival (OS), were assessed using Kaplan-Meier analysis with median survival estimates and 95% confidence intervals (CI) reported. Correlations between cerebrospinal fluid (CSF) circulating tumor cells (CTCs) and survival outcomes were evaluated using Kaplan-Meier analysis. An optimal cutoff for CTCs was determined through maximally selected rank statistics using CNS PFS. Results Of the 24 patients enrolled, 3 did not complete treatment due to systemic disease progression and were excluded from this analysis. The majority of patients had metastatic lung (52%) and breast (33%) malignancies. The median age was 52 years (range 30-67 years) and the median Karnofsky performance status was 70 (range 60-90). The majority of patients had LM that progressed on other therapies prior to enrollment (57% vs. 43% of patients with newly diagnosed LM), and all patients with molecularly driven disease had CNS progression on small-molecule tyrosine kinase inhibitors prior to enrollment. Only 1 patient was censored at 24 months of follow-up, while 20 patients were followed until death with a median OS of 9 months (95% CI 6-22 months). The median CNS TTP was 8 months (95% CI 7-18 months), with 5 (24%) patients with durable CNS control for > 12 months after pCSI. The median CNS PFS was 7 months (95% CI 5-13 months). In the 18 patients with CSF CTCs evaluation at baseline, having a pre-pCSI CSF CTCs Conclusion We reported that pCSI is a safe treatment for patients with solid tumor LM. In this analysis, we demonstrated durable disease control and prolonged survival in some patients. Lower CSF CTCs at baseline, a potential biomarker of response, was associated with improved survival outcomes. An ongoing randomized phase II trial will determine the efficacy of pCSI compared to photon IFRT in patients with solid tumor LM.

Purpose/objective(s) Although clinical trial enrollment is critical to development of new cancer therapies, Materials/methods All patients enrolled on radiation oncology therapeutic clinical trials at community-based partner sites from Q2 2018 - Q1 2021 were included in this analysis. Guided by Expert Recommendation for Implementing Change (ERIC), strategies to increase trial enrollment were implemented prior to Q2 2020, and included: 1) altered incentive structure (per-patient cost paid to partner site, leaderboards), 2) building a coalition of physicians in metastatic disease, and 3) practice facilitation. An interrupted time series analysis included a two-tailed student's t-test to compare mean trial enrollments per quarter pre- and post-implementation. Protocol deviations were assessed in quality assurance (QA) review. Results Among 52 total patients enrolled in community-based, partner sites, 28 (54%) identify as Black or Hispanic. The number of clinical trials open to enrollment pre- and post-implementation was 5 vs. 8, respectively, while the number of patients enrolled was 6 vs. 46, respectively, representing an overall increase in mean number of quarterly patient enrollments from 1 to 11 (P Conclusion These implementation strategies were associated with increased therapeutic trial enrollment in community-based partner sites. With high variation in enrollment between physicians and prior research suggesting limited impact of site-level financial incentives, qualitative research will further investigate non-financial incentives and other facilitators to clinical trial enrollment within community-academic partnerships. Over-representation of minority patients further supports the benefit of enrolling patients on clinical trials in the community-based setting.

Palliative care and radiation therapy have played an expanding role in the management of patients with advanced cancers. Recent advances in our understanding of oligometastatic disease have led to increasing demand for familiarity with ablative techniques. Recognizing the demands of hospitalized patients for rapid access to care, we created an inpatient radiation oncology consult service (IROC) with consolidated expertise in palliative radiation and ablative techniques. In this quality improvement cohort study, we analyzed inpatient radiation oncology consults placed before and after IROC implementation and found that IROC led to increased delivery of specialty care and decreased hospital length of stay (median 8 days v 7 days, P = .005). This difference was most pronounced for patients for whom radiation therapy was indicated (14.5 v 11 days, P = .007). Our institutional experience demonstrates the value of recognizing metastatic disease as a distinct discipline and providing rapid access to palliative treatments for patients with advanced malignancies.

By using first-principles calculations, we compute the electronic band structures and typical aspects of the optical spectra of hexagonally structured GaN1−xPx alloys. Although a type III–V semiconductor, GaP commonly possesses a zinc-blende structure with an indirect band gap; as such, it may additionally form hexagonal polytypes under specific growth conditions. The electronic structures and optical properties are calculated by combining a non-nitride III–V semiconductor and a nitride III–V semiconductor, as GaP and GaN crystallizing in a 4H polytype, with the N composition ranging between x = 0–1. For all studied materials, the energy gap is found to be direct. The optical properties of the hexagonal materials may illustrate the strong polarization dependence owing to the crystalline anisotropy. This investigation for GaN1−xPx alloys is anticipated to supply paramount information for applications in the visible/ultraviolet spectral regions. At a specific concentration, x, these alloys would be exclusively appealing candidates for solar-cell applications.

Purpose/objective(s) Management of recurrent or new primary intracranial tumors in a previously irradiated area presents a significant challenge. For inoperable patients, reirradiation (re-RT) may provide the best chance for prolonged disease control. However, given concerns for excessive morbidity, re-RT with definitive doses (≥ 45 Gy) is not commonly prescribed. Given its dosimetric advantages over photon-based techniques, we hypothesize that intensity-modulated proton therapy (IMPT) may permit safer dose escalation in the re-RT setting. This study examined feasibility of definitive brain re-RT in a cohort of patients treated with IMPT. Materials/methods The electronic medical record of a pencil beam scanning-only proton center was queried for adult patients who developed in-field recurrence or new primary tumor for which they subsequently received definitive-dose (≥ 45 Gy) re-RT. Dosimetric and clinical characteristics were collected. Survival was examined using the Kaplan-Meier method. Toxicities were assessed using the Common Terminology Criteria for Adverse Events v.5.0. Results Between August 2019 and February 2021, 62 consecutive patients received intracranial re-RT with IMPT. Twelve (18%) were treated to ≥ 45 Gy and were included for analysis. Median age at the time of re-RT was 51.5 years, and 83% of patients had an Eastern Cooperative Oncology Group score of 0. The most common histologies were oligodendroglioma (n = 4), astrocytoma (n = 3), and meningioma (n = 3). Median time from prior radiation course to IMPT was 9.4 years (range, 3.6 - 42.0 years). IMPT was delivered with conventional fractionation in 92% and hypofractionation in 8% of cases. Median equivalent dose in 2 Gy fractions (EQD2) for initial course was 53.1 Gy. Median EQD2 for the re-RT course was 54.0 Gy. The entire re-RT course was completed as planned by 83% of patients. Patients received concurrent temozolomide (66%) or temozolomide plus bevacizumab plus nivolumab (8%). Dosimetric data from the initial course were available for 58% of patients. The median cumulative (initial radiation and re-RT combined) maximum EQD2 doses were 116.8 Gy to brain, 66.2 Gy to brainstem, 67.7 Gy to chiasm, 72.0 Gy to ipsilateral optic nerve, and 54.5 Gy to contralateral optic nerve. At a median follow-up of 5.4 months, 58.3% (n = 7) of patients developed grade 2 toxicities including fatigue (n = 6) and alopecia (n = 5). No grade ≥3 neurotoxicities were documented. Median progression free survival was 7 months; median overall survival was not reached. Conclusion Early results of our single-institution experience suggest a potential for safe intracranial re-RT with definitive-dose IMPT for select patients. Based on these findings, we are activating a prospective study to identify subsets of patients who are best fit for IMPT re-RT and formulate optimal dose regimens and normal tissue composite dose constraints. Author disclosure L. Maillie: None. S. Sharma: None. J.T. Yang: None. N. Ohri: Consultant; Merck, AstraZeneca. I.J. Choi: Employee; New York Proton Center. Travel Expenses; Varian; National Association of Proton Therapy, Proton Collaborative Group. Oversee and provide guidance for new and existing research protocols, ensure best practices for organization research endeavors.; Proton Collaborative Group. B.K. Yeh: None. R.H. Press: None. A. Chhabra: None. M.K. Garg: None. Y. Yamada: Consultant; University of Wollongong. Speaker's Bureau; Varian Medical Systems, BrainLab. Medical advisor; Chordoma Foundation. C.B. Simone: Employee; New York Proton Center. Honoraria; Varian Medical System, Novocure. Travel Expenses; Varian Medical System; Proton Collaborative Group (PCG), Annals of Palliative Medicine, American Society for Radiation Oncology. S. Lazarev: None.

PURPOSE/OBJECTIVE(S) Staging for metastatic disease is unreliable; there is usually only one category of Stage IV in the American Joint Commission on Cancer (AJCC) 8th edition, but survival can range from weeks to years. We hypothesize that prognostication can be improved for metastatic disease by using common clinical covariates in a pan-cancer phenotype staging system. MATERIALS/METHODS Latent class analysis was performed to explore the phenotypes using nationally representative patient data from the National Cancer Database (NCDB; n = 461,357, years 2010-2013, for the training cohort) and the Surveillance, Epidemiology, and End Results database (SEER; n = 106,595, years 2014-2015, for the validation cohort). The optimal number of clusters was determined based on Bayesian information criterion (BIC) and sample-size-adjusted BIC. Kappa coefficients were used to assess external validation. In addition, we used a Cox proportional hazards model with latent classification for survival prediction. Internal validation of the NCDB and the external validation of the training set of SEER were assessed using the concordance (C)-index. RESULTS Of the 461,357 patients included from the NCDB (median age 65), latent class analysis identified five metastatic phenotypes: (Stage IVA) nearly-exclusive bone-only metastases, commonly seen in lung, breast, and prostate cancer (n = 59,049, 12.8%; median survival = 12.7 months); (IVB) predominant lung metastases, commonly seen in breast, stomach, kidney, ovary, uterus, thyroid, cervix, and soft tissue cancer (n = 62,491, 13.6%; median survival = 11.4 months); (IVC) predominant liver/lung metastases, commonly seen in colon, rectum, pancreas, lung, esophagus, and stomach cancer (n = 130,014, 28.2%; median survival = 7.0 months); (IVD) bone/liver/lung metastases predominant over brain, commonly seen in lung and breast cancer (n = 61,004, 13.2%; median survival = 5.9 months); (IVE) brain/lung metastases predominant over bone/liver, commonly seen in lung cancer and melanoma (n = 148,799, 32.3%; median survival = 5.7 months). These phenotypes had differences in overall survival, and long-term survivors were identified in Stages IVA-B (P < 0.0001). A pan-cancer nomogram model to predict survival (STARS; based on Site, Tumor, Age, Race, Sex) was created and validated. STARS has 13% better prognostication than AJCC: C-index at 1 month of 0.69 (95% CI 0.68-0.69) vs 0.61 (95% CI 0.60-0.61). CONCLUSION We created and validated a novel pan-cancer staging system for metastatic disease, termed STARS, which is significantly more prognostic than AJCC staging. STARS is innovative because: (1) it takes a global approach, not just focusing on primary tumor, (2) it can be used in all communities, since it relies on readily available, inexpensive predictors; (3) it is simple and allows for rapid validation.

Purpose/Objective(s) Local therapy for patients with non-spine bone metastases is evolving, with recent data suggesting that stereotactic body radiotherapy (SBRT) may improve pain response in the palliative setting. However, the rate of local salvage therapy (LST) after SBRT compared to conventional RT is unknown. We therefore characterized rates and risk factors for LST in patients with non-spine bone metastases. Materials/Methods We reviewed records of all courses of RT for non-spine bone metastases at our institution from 1/1/2016 to 12/31/2018. LST was defined as the first occurrence of either RT or surgery for progression to a bone metastasis following initial RT. Functions of the cumulative incidence of re-treatment were generated for each RT technique. We identified associations with various predictors using the Fine and Gray method for competing risk regression. Results Of the 1,754 patients included, 2,648 bone metastases were treated with RT and analyzed with a median follow up of 15 months (IQR = 6.4 – 25.0 months). 51% of episodes were multi-fraction EBRT, 10% were single fraction EBRT, and 39% were SBRT. Of the treated metastases, 120 (4.5%) episodes required LST (median time to LST = 6.2 months, range = 0.3-35.6 months), with a cumulative incidence at 6 and 12 months of 2.4% and 3.9%, respectively. Cumulative incidence of re-treatment at 6 months was 2.6% for SBRT, 3.5% for single-fraction conventional, and 2.1% for multi-fraction conventional regimens (P = 0.76). On multivariable analysis, younger age, higher Karnofsky performance status (KPS), and location of the metastasis in the pelvis had higher hazard of re-treatment (Table 1). There was no significant difference in hazard of LST among RT techniques (P = 0.44), nor was there a significant interaction between RT technique and radioresistant histology (P = 0.33). Conclusion In our large institutional cohort, the rate of LST was low, with no difference between RT techniques. Our results suggest that judicious selection of patients at high risk for eventual treatment failure (i.e., those with longer expected survival) for SBRT may reduce the rate of retreatment rate in the population. When patients are appropriately selected for single fraction conventional RT, such as those who are older or have poor KPS, rates of LST remain low. Further studies to validate our findings are warranted to help clinicians to select the appropriate treatment technique for patients with bone metastases.

Purpose/objective(s) Palliative radiation therapy (RT) can be an effective tool for bone metastases. NCCN guidelines recommend imaging every 3 months after RT for spine metastases (SM), yet no standard surveillance guidelines exist after RT for non-spine bone metastases (NSBM). We sought to evaluate factors associated with radiation oncology-specific follow-up after palliative RT. Materials/methods In a large single-institution retrospective cohort analysis, we identified all patients receiving RT for bone metastases by ICD-10 codes and RT prescription from 2017-2019. Demographic, clinical, and RT data were collected. Overall survival (OS) was calculated using Kaplan-Meier analysis. Factors associated with urgent care (UC) evaluation and radiation oncology follow-up were evaluated with multivariable logistic regression among patients surviving or followed to 3 months post-RT. Results Overall, 3082 patients (39% NSBM, 61% SM) received RT for bone metastases. Within 3 months of RT, 49% had radiation oncology follow-up, 79% underwent imaging, and 27% were seen in the UC. For patients with NSBM, follow-up CT was most common (55%) while for SM, MRI and CT were common (both 54%). Median OS was 10.0 months for SM (95% CI 8.9-11.0) and 13.5 months for NSBM (95% CI 11.5-15.5), with 1343 (71%) SM patients and 923 (77%) NSBM patients surviving to > = 3 months post-RT. Of the 2266 3-month survivors (41% NSBM, 59% SM), 1619 (71%) had radiation oncology follow-up, with higher performance status (OR 2.1, 95% CI 1.44-3.05) and younger patients ( Conclusion After RT for bone metastases, most patients had radiation oncology-specific surveillance, which was associated with younger age and improved performance status. Most patients survived to 3 months post-RT, with a substantial minority receiving a second RT course. Patients with NSBM had longer survival and different time-to-follow-up compared to SM, highlighting the need for further clarification on what the optimal follow-up should be for NSBM. Race was a predictor of UC visits, likely reflecting health disparities that require further investigation. These data support radiation oncology specific follow-up after RT, particularly among younger patients and those with higher performance status with specific attention to racial disparities.

Purpose We report on the clinical performance of a fully automated approach to treatment planning based on a Pareto optimal, constrained hierarchical optimization algorithm, named Expedited Constrained Hierarchical Optimization (ECHO). Methods and materials From April 2017 to October 2018, ECHO produced 640 treated plans for 523 patients who underwent stereotactic body radiation therapy (RT) for paraspinal and other metastatic tumors. A total of 182 plans were for 24 Gy in a single fraction, 387 plans were for 27 Gy in 3 fractions, and the remainder were for other prescriptions or fractionations. Of the plans, 84.5% were for paraspinal tumors, with 69, 302, and 170 in the cervical, thoracic, and lumbosacral spine, respectively. For each case, after contouring, a template plan using 9 intensity modulated RT fields based on disease site and tumor location was sent to ECHO through an application program interface plug-in from the treatment planning system. ECHO returned a plan that satisfied all critical structure hard constraints with optimal target volume coverage and the lowest achievable normal tissue doses. Upon ECHO completion, the planner received an e-mail indicating the plan was ready for review. The plan was accepted if all clinical criteria were met. Otherwise, a limited number of parameters could be adjusted for another ECHO run. Results The median planning target volume size was 84.3 cm3 (range, 6.9-633.2). The median time to produce 1 ECHO plan was 63.5 minutes (range, 11-340 minutes) and was largely dependent on the field sizes. Of the cases, 79.7% required 1 run to produce a clinically accepted plan, 13.3% required 1 additional run with minimal parameter adjustments, and 7.0% required ≥2 additional runs with significant parameter modifications. All plans met or bettered the institutional clinical criteria. Conclusions We successfully implemented automated stereotactic body RT paraspinal and other metastatic tumors planning. ECHO produced high-quality plans, improved planning efficiency and robustness, and enabled expedited treatment planning at our clinic.

2011 Background: Leptomeningeal metastasis (LM) involves seeding of tumor cells to the cerebrospinal fluid (CSF) and the leptomeninges. Proton craniospinal irradiation (pCSI) has been shown to be potentially effective for patients with solid tumor LM. We evaluated whether CSF circulating tumor cells (CSF-CTC) and neuroimaging correlate with outcomes in patients with LM treated with pCSI. Methods: We reviewed a single-institution retrospective database of patients treated with pCSI for LM between 2018-2020 who had ≥ 3 months (mos.) follow-up and identified 58 patients. Pre-pCSI CSF-CTC using CellSearch and magnetic resonance imaging (MRI) data, and post-pCSI CSF-CTC nadir before initiation of new cancer-directed therapy were assessed. The optimal cutoff for pre-pCSI CSF-CTC was determined using maximally selected rank statistics. Kaplan Meier analysis was used to identify univariate correlates with CNS progression free survival (CNS PFS) and overall survival (OS), calculated from start of pCSI. Multivariate Cox proportional hazards modeling was used to test independence of univariate associations. Results: The median follow-up for patients who were censored (n = 15, 26%) was 15 mos. (interquartile range (IQR): 9 -21). Most patients were diagnosed with lung (n = 27, 47%) or breast cancer (n = 22, 38%). The median CNS PFS and OS were 6 mos. (IQR: 3 – 9) and 8 mos. (IQR: 5 – 18), respectively. Of the 49 patients with pre-pCSI CSF-CTCs analyzed, CSF-CTCs were identified in 43 (88%). Pre-pCSI CSF-CTC< 53/3mL was associated with improved CNS PFS (11.8 vs 6.0 mos., p = 0.01), and a trend toward improved OS (16.7 vs 7.7 mos., p = 0.08). On pre-pCSI MRI, patients with parenchymal brain metastases (n = 33, 57%) had worse OS (6.7 vs 12.7 mos., p = 0.01) but not CNS PFS. Patients with both brain and spine LM (n = 42, 72%) compared to those only one site or no visible disease (n = 16, 28%) showed worse CNS PFS (5.8 vs 7.5 mos., p = 0.03) and OS (7.7 vs 16.7 mos., p = 0.05). In a multivariate model, pre-pCSI CSF-CTC was significantly associated with CNS PFS (p = 0.03) while brain and spine LM on MRI was not (p = 0.20) No patient had an increase in CSF-CTC immediately post-pCSI, and in those with both detectable pre-pCSI CSF-CTCsand a post-pCSImeasurement(n = 29, 50%), the median decrease at nadir was 37/3mL (range: 0-200) occurring at a median of 1.6 mos. (range: 0.5 -5.2). A decrease in CSF-CTC > 37/3mL was associated with improved CNS PFS (7.1 vs 4.4 mos., p = 0.04) but not OS (12.5 vs.7.7 mos., p = 0.2). Conclusions: Proton CSI is an effective treatment for patients with solid tumor LM and can result in prolonged disease control in some patients. Lower CSF-CTC count prior to pCSI and larger changes after pCSI are predictive of survival outcomes, arguing for early pCSI intervention for solid tumor LMD. Early treatment escalation after pCSI can be considered for patients with high pre-pCSI CSF-CTC and a smaller nadir post-pCSI.

Background Although brain metastases (BM) are associated with poor prognosis, patients with human epidermal growth factor receptor 2 (HER2) overexpressing (HER2+) breast cancer (BC) with BM who are treated with anti-HER2 therapy have a relatively longer survival after BM diagnosis compared with other subtypes and HER2+ patients previously untreated with anti-HER2 therapy. It is unclear if previously reported prognostic factors are applicable to patients with HER2+ BC in the era of HER2-targeted therapy. Patients and Methods We evaluated 100 consecutive patients with HER2+ BC with BM who underwent radiation therapy as primary BM treatment from January 2001 to December 2011 at Memorial Sloan Kettering Cancer Center by retrospective review. Patient characteristics at the time of BM diagnosis and their associations with time from BM to death were evaluated by Kaplan-Meier curves, log-rank tests, and Cox proportional hazard models. Results Significantly better survival from BM was noted for patients with higher performance status, fewer BM lesions, continued use of HER2-targeted therapy after BM diagnosis, and better controlled extracranial metastatic disease. Absence of neurologic symptoms at BM diagnosis was significantly associated with fewer lesions, decreased use of whole brain radiotherapy, and longer survival in univariate and multivariate analysis (multivariate hazard ratio, 3.69; 95% confidence interval, 1.69-8.07). Conclusion Our finding supports the continued use of HER2-targeted therapy after BM diagnosis. In addition, future research on the clinical impact of detecting asymptomatic BM in patients with HER2+ BC, in terms of improving prognosis, quality of life, and avoidance of whole brain radiotherapy, is warranted.

Electric energy metering system consists of watt-hour meter, voltage transformer and current transformer. Hence, the error of electric energy metering system should be analyzed from the three parts. Aiming at the measurement accuracy of the power metering system under harmonics, the equivalent circuits of electronic watt-hour meter, capacitive voltage transformer and magnetic current transformer under harmonic conditions are built, and the harmonic measurement/metering error and the influencing factors are analyzed. The model of electric energy metering system is set up to analyze its error under harmonic conditions. This article provides a theoretical basis for the quantitative analysis of measurement error of the energy metering system under harmonics.

In the digital era to the core of computer technology, computer music came into being; it brings a series of new topics to disciplines to study. In the field of communication, the computer music technology is an element commonly used in the production of information, which can effectively achieve all kinds of information dissemination by the music computer synthesized. Through reviewing the recent research on computer music technology development and information dissemination effect, this paper analyzes the impact of computer music has on the audience memory in information dissemination. Keywords-computer information technology; information production; communication effect

An experiment to search for double-strangeness nuclei in nuclear emulsion is now being carried on as KEK-PS E373. Preliminary results of the data analysis for the K + spectrometer and the scintillating fiber detectors are presented. Status of the automatic track finding method for the emulsion is reported.

The first real size Resistive Plate Chamber (RPC) prototype of ME2/1 for the forward region of the Compact Muon Solenoid (CMS) detector was constructed at Korea Detector Laboratory (KODEL). The parallel resistive electrodes of the double gap RPC were made of bakelite whose resistivity was 5×10 9 Ω cm . The prototype was tested at the Gamma Irradiation Facility (GIF) of CERN in an environment of the background intensity ranging up to 1 kHz / cm 2 / gap . We report that the full efficiency of 98% has been achieved with time resolution of about 1 ns. These results demonstrate that such a double gap RPC is suitable for the muon trigger in the future experiments.

Game-based Learning, to date, is an emergent solution to raise the learning motivation by involving the entertainment factors into original learning process. However, experiences revealed that learners paid more emphasis on the game-playing than on the pedagogical content. Thus, in this study, the issue to discover the fundamental factors that may cause the increase or loss of motivation will be discussed. The Problem-based strategy was adopted to be the subject of game design and development while the content was based on the historical knowledge in specific area. The ADDIE is adopted to make improvement of the convention of historical knowledge via a Game-based strategy. The issues, both pedagogy and entertainment, are involved to bring up the learning motivation of students of specific domain.

Summary form only given. Human gait is composed of the stance and swing phases. Stance phase, the weight support course for the other leg to move forward, is important phase that needs stability. The objective of this study is to develop a design tool that can help the development of lower limb prosthesis. For the purpose, the stance phase gait of SNS (stance and swing phase) controlled knee prosthesis for transfemoral amputee was modeled and simulated. Large deformation components, such as foot and knee damper, were modeled using the finite element (FE) and used to dynamic gait analysis. Material property of each model is obtained by part experiments and gait simulation result is compared with gait experiments result. The developed FE model could be used to design advanced knee prosthesis and optimized the above knee prosthetic components.