Initial Observation among Patients with Vestibular Schwannoma

2020 ◽  
Author(s):  
Henry Ruiz-Garcia ◽  
Jennifer Peterson ◽  
Janet Leon ◽  
Timothy Malouff ◽  
Laura Vallow ◽  
...  
Keyword(s):  
Tumor Progression ◽  
Local Control ◽  
Cox Regression ◽  
Multivariable Analysis ◽  
Internal Auditory Canal ◽  
Local Therapy ◽  
Definitive Treatment ◽  
Tumor Control ◽  
Presenting Symptoms ◽  
Initial Observation

Abstract Introduction Vestibular schwannomas (VS) are slow growing tumors. Although there are a wide variety of available treatment options, these tumors are often initially observed. We aimed to establish the presenting symptoms and outcomes of patients treated with initial observation at our institution. Methods The medical records of patients with radiographically diagnosed VS were reviewed from 1989 to 2018. Actuarial estimates of radiographic tumor control and freedom of local therapy were calculated and compared using Cox regression analyses. Results A total of 360 patients were diagnosed with VS at our institution from 1989 through 2018 with a median age of 59.9 years. After radiographic diagnosis, 243 patients (67.5%) opted for initial observation. Local control at 1, 5, and 10 years was 91, 67, and 58%, respectively. On multivariable analysis, factors associated with shorter time to radiographic tumor progression included younger patient age (p = 0.016) and tumors with an extracanalicular component (p = 0.032). Regarding time until definitive treatment only larger baseline American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) tumor size predicted for earlier initiation of therapy (p < 0.001), although this was restricted to tumors with an extracanalicular component (p = 0.004), as opposed to purely internal auditory canal tumors (p = 0.839). Conclusions Many patients who were initially observed continued to have satisfactory local control rates at 10 years. In patients with extracanalicular tumors, larger AAO-HNS tumor measurements were associated with earlier radiographic tumor progression and shorter time to local therapy, with 7 mm serving as a potential threshold value for extracanalicular tumors. Younger patients and tumors with primarily an extracanalicular portion may warrant closer observation.

Patterns of Care and Survival of Cutaneous Angiosarcoma of the Head and Neck

2020 ◽  
Vol 162 (6) ◽  
pp. 881-887 ◽  
Author(s):  
Clifford Chang ◽  
S. Peter Wu ◽  
Kenneth Hu ◽  
Zujun Li ◽  
David Schreiber ◽  
...  
Keyword(s):  
Head And Neck ◽  
Cox Regression ◽  
Multivariable Analysis ◽  
Multimodality Treatment ◽  
The Elderly ◽  
Hazard Ratio ◽  
Patterns Of Care ◽  
Definitive Treatment ◽  
National Cancer Database ◽  
Curative Intent

Objective To analyze the patterns of care and survival of cutaneous angiosarcomas of the head and neck. Study Design Retrospective cohort study. Setting National Cancer Database. Methods The National Cancer Database was queried to select patients with cutaneous angiosarcoma of the head and neck between 2004 and 2015. For survival analysis, patients were included only if they received definitive treatment and complete data. Prognostic factors were analyzed by univariate and multivariable Cox regression. Results We identified 693 patients diagnosed with head and neck angiosarcomas during the study period. The majority were male (n = 489, 70.6%) and elderly (median, 77 years). A total of 421 patients (60.8%) met the criteria for survival analyses. These patients were treated with surgery and radiation (n = 178, 42.3%), surgery alone (n = 138, 32.8%), triple-modality therapy (n = 48, 11.4%), surgery and chemotherapy (n = 29, 6.9%), and chemoradiation (n = 28, 6.7%). With a median follow-up of 29 months, the 3-year survival was 50.1%. Patients undergoing surgery had better median survival than those who did not (38.1 vs 21.0 months, P = .04). Age, comorbidity, tumor size, and surgical margins were significant factors in univariate analyses. On multivariable analysis, age ≥75 years (hazard ratio, 2.65; 95% CI, 1.80-3.88; P < .001) and positive margins (hazard ratio, 1.91; 95% CI, 1.44-2.51; P < .001) predicted worse overall survival. Conclusion Angiosarcoma of head and neck is a rare malignancy that affects the elderly. Surgical treatment with negative margins is associated with improved survival. Even with curative-intent multimodality treatment, the survival of patients aged ≥75 years is limited.

Predictors of tumor progression among children with gangliogliomas

2009 ◽  
Vol 3 (6) ◽  
pp. 461-466 ◽  
Author(s):  
Mostafa El Khashab ◽  
Lynn Gargan ◽  
Linda Margraf ◽  
Korgun Koral ◽  
Farideh Nejat ◽  
...  
Keyword(s):  
Risk Factors ◽  
Tumor Progression ◽  
Cox Regression ◽  
Tumor Resection ◽  
Progression Free Survival ◽  
Initial Presentation ◽  
Subtotal Resection ◽  
Low Grade ◽  
Cox Regression Analysis ◽  
Presenting Symptoms

Object Few reports describe the outcome and prognostic factors for children with gangliogliomas. The objective of this report was to describe the progression-free survival (PFS) for children with low-grade gangliogliomas and identify risk factors for tumor progression. Methods A retrospective study was performed in children with low-grade gangliogliomas who were evaluated and treated in the neuro-oncology department between 1986 and 2006 to determine risk factors for subsequent tumor progression. Results A total of 38 children with newly diagnosed gangliogliomas were included in this report. Thirty-four children were treated with surgery alone, 3 with subtotal resection and radiation therapy, and 1 with subtotal resection and chemotherapy. The follow-up ranged from 4 months to 15.8 years (mean 5.7 ± 4.2 years [± SD]). Seven children have experienced tumor progression, and 1 child died after his tumor subsequently underwent malignant transformation. The 5-year PFS was calculated to be 81.2% using Kaplan-Meier survival analysis. Initial presentation with seizures (p = 0.004), tumor location in the cerebral hemisphere (p = 0.020), and complete tumor resection (p = 0.035) were associated with prolonged PFS. Further analysis of the above significant variables by a Cox regression model identified initial presentation with seizures as being associated with prolonged PFS (p = 0.028). Conclusions The PFS and overall survival of children with gangliogliomas are good. Tumors located in the cerebral hemispheres, the achievement of total resection, and seizures at presentation were associated with prolonged PFS. Cox regression analysis identified presenting symptoms including seizures as significant predictive factors of PFS. Prospective studies with larger numbers of children are needed to define the significant factors of tumor progression.

Importance of the biologic effective dose in achieving local control of adrenal tumors treated with stereotactic radiosurgery.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e21114-e21114
Author(s):  
Hema Rai ◽  
Amishi Desai ◽  
Matthew R. Witten ◽  
Jonathan A. Haas ◽  
Jeffrey Gary Schneider
Keyword(s):  
Stereotactic Radiosurgery ◽  
Local Control ◽  
Adrenal Tumor ◽  
Local Treatment ◽  
Adrenal Metastasis ◽  
Definitive Treatment ◽  
Adrenal Tumors ◽  
Tumor Control ◽  
Term Survival ◽  
Primary Tumor Site

e21114 Background: Adrenalectomy achieves long term survival in ~ 25% of patients with solitary adrenal metastasis (SAM). Stereotactic radiosurgery (SRS) represents a potential non-surgical alternative to this same endpoint, but reported local control rates vary from 45% to 96%. SRS delivers a range of biologic effective doses (BED) dependent upon fraction size, number and schedule. We herein review our experience with SRS for adrenal metastasis to evaluate the interaction between BED and local adrenal tumor control. Methods: The Winthrop SRS data base was queried to identify 14 patients undergoing SRS for malignant adrenal tumors from 2006 to 2011. Patients were characterized by their primary tumor site, stage at diagnosis and the time to adrenal involvement. BED was calculated for each patient. Local adrenal tumor control and durability of response were also recorded. Results: Calculated BEDs ranged from 4,667 cGy to13,000 cGy. Of the factors examined, BED was the single most important predictor of local adrenal tumor control. According to best adrenal tumor response, mean BEDs were: 10,053 cGy for radiographic regression of disease; 8,115 cGy for stable disease, and 6,667 cGy for progression of disease (p = 0.0465, by one-tail test). No solid tumor patient responded to SRS with BED < 8,800 cGy and no patient immediately progressed through SRS with BED > 6,667 cGy. Duration of adrenal tumor control also correlated with calculated mean BED which was: 9,676 cGy for never locally failing (n=6) and 7,600 cGy for ever locally failing tumors (n=5). However, eventual local treatment failure was seen in one of three patients receiving even the highest calculated BED (13,000 cGy). Conclusions: Because eventual local failures are observed with SRS even at the highest examined BED, adrenalectomy rather than SRS should remain the standard of care for patients with potentially curable SAM. SRS remains an acceptable alternative to adrenalectomy for palliation of symptomatic adrenal tumors or for the definitive treatment of SAM in non-surgical candidates. When given for these purposes, our data support the use of SRS regimens delivering a minimum BED of 8,800 cGy.

Predicting Tumor Control After Resection Bed Radiosurgery of Brain Metastases

Neurosurgery ◽  
2013 ◽  
Vol 73 (6) ◽  
pp. 1001-1006 ◽  
Author(s):  
Neal Luther ◽  
Douglas Kondziolka ◽  
Hideyuki Kano ◽  
Seyed H. Mousavi ◽  
Johnathan A. Engh ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Brain Metastasis ◽  
Brain Metastases ◽  
Tumor Progression ◽  
Local Control ◽  
Progression Free Survival ◽  
Tumor Control ◽  
Free Survival ◽  
Whole Brain Radiation ◽  
Brain Radiation

Abstract BACKGROUND: Stereotactic radiosurgery (SRS) to the resection bed of a brain metastasis is an important treatment option. OBJECTIVE: To identify factors associated with tumor progression after SRS of the resection bed of a brain metastasis and to evaluate patterns of failure for patients who eventually had tumor progression. METHODS: We performed a retrospective analysis of 120 patients who underwent tumor bed radiosurgery after an initial gross total resection. The mean imaging follow-up time was 55 weeks. The median margin dose was 16 Gy. Forty-seven patients (39.2%) underwent whole-brain radiation therapy before or shortly after SRS. RESULTS: Local tumor control was achieved in 103 patients (85.8%). Progression-free survival was 96% at 6 months, 87% at 12 months, and 74% at 24 months. Recurrence most commonly occurred deep in the cavity (65%) outside the planned treatment volume (PTV) margin (53%). PTV, cavity diameter, and a margin dose &lt; 16 Gy significantly correlated with local failure. For patients with PTVs ≥ 8.0 cm3, local progression-free survival declined to 93% at 6 months, 83% at 12 months, and 65% at 24 months. Development or progression of distant metastases occurred in 40% of patients. Whole-brain radiation therapy was not associated with improved local control. CONCLUSION: Resection bed SRS for brain metastases provided excellent local control. The cavity PTV is predictive of tumor control. Because failure usually occurs outside the PTV, inclusion of a judicious 2- to 3-mm margin beyond the area of postoperative enhancement may be prudent.

Neurofibromatosis type 2–associated meningiomas: an international multicenter study of outcomes after Gamma Knife stereotactic radiosurgery

2021 ◽  
pp. 1-6
Author(s):  
Nasser Mohammed ◽  
Yi-Chieh Hung ◽  
Zhiyuan Xu ◽  
Tomas Chytka ◽  
Roman Liscak ◽  
...  
Keyword(s):  
Tumor Progression ◽  
Gamma Knife ◽  
Cox Regression ◽  
Neurofibromatosis Type ◽  
Neurofibromatosis Type 2 ◽  
Tumor Control ◽  
Cox Regression Analysis

OBJECTIVE The management of neurofibromatosis type 2 (NF2)–associated meningiomas is challenging. The role of Gamma Knife radiosurgery (GKRS) in the treatment of these tumors remains to be fully defined. In this study, the authors aimed to examine the role of GKRS in the treatment of NF2-associated meningiomas and to evaluate the outcomes and complications after treatment. METHODS Seven international medical centers contributed data for this retrospective cohort. Tumor progression was defined as a ≥ 20% increase from the baseline value. The clinical features, treatment details, outcomes, and complications were studied. The median follow-up was 8.5 years (range 0.6–25.5 years) from the time of initial GKRS. Shared frailty Cox regression was used for analysis. RESULTS A total of 204 meningiomas in 39 patients treated with GKRS were analyzed. Cox regression analysis showed that increasing the maximum dose (p = 0.02; HR 12.2, 95% CI 1.287–116.7) and a lower number of meningiomas at presentation (p = 0.03; HR 0.9, 95% CI 0.821–0.990) were predictive of better tumor control in both univariable and multivariable settings. Age at onset, sex, margin dose, location, and presence of neurological deficit were not predictive of tumor progression. The cumulative 10-year progression-free survival was 94.8%. Radiation-induced adverse effects were noted in 4 patients (10%); these were transient and managed medically. No post-GKRS malignant transformation was noted in 287 person-years of follow-up. CONCLUSIONS GKRS achieved effective tumor control with a low and generally acceptable rate of complications in NF2-associated meningiomas. There did not appear to be an appreciable risk of post–GKRS-induced malignancy in patients with NF2-treated meningiomas.

Definitive thoracic radiotherapy in oligometastatic stage IV non-small cell lung cancer (NSCLC).

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e18032-e18032
Author(s):  
Annemarie Therese Fernandes ◽  
Eric Xanthopoulos ◽  
Elizabeth Handorf ◽  
Surbhi Grover ◽  
Sonam Sharma ◽  
...  
Keyword(s):  
Overall Survival ◽  
Median Survival ◽  
Local Control ◽  
Performance Status ◽  
Multivariable Analysis ◽  
Stage Iv ◽  
Local Failure ◽  
Tumor Control ◽  
Intrathoracic Tumor ◽  
And Gender

e18032 Background: Intrathoracic tumor control in patients (pts) with metastatic NSCLC is controversial as most die of distant disease. But a subset of good performance status pts with minimal burden of extrathoracic disease may benefit aggressive treatment. We report outcomes in a subset of pts with oligometastatic NSCLC treated with definitive radiotherapy (RT) to the primary tumor. Methods: We identified29 stage IV pts from 01/04 - 08/10 who had ECOG ≤2 and ≤4 metastases who received ≥50 Gy thoracic RT with chemotherapy. Pts were assessed for local control, overall survival and toxicity. An exploratory analysis was performed matching these pts to pts receiving chemotherapy (CT) alone. Results: In the 29 chemoradiotherapy (CRT) pts, median age was 57 yrs, 72% had ECOG 1 and 91% were staged with PET. Median survival was 22 months. Eight patients had grade 2+ pneumonitis. Nineteen patients had grade 2+ esophagitis. Next, 2 CT pts were matched with each CRT pt on 4 factors: age, ECOG, and presence of multi-organ or contralateral lung disease. We excluded 4 CRT pts who did not match 2 CT controls. Median survival was 22 vs 9 months (p <0.01) for patients given CRT vs CT. Median time to local failure was 18 vs 6 months (p = 0.01). Median survival in locally controlled pts was 39 vs 19 months in pts with local failure (p = 0.02). On multivariable analysis, radiation (p <0.01, OR = 0.33), multiple metastatic organs at diagnosis (p <0.01, OR = 2.14), and gender (p <0.01, OR = 0.41) were associated with overall survival. Conclusions: Treatment ofNSCLC patients with oligometastatic disease with definitive dose radiation therapy may provide a local control and overall survival benefit in a subset of patients with minimal extrathoracic burden of disease.

Combination therapy with TACE + ablation versus TACE + SBRT for hepatocellular carcinoma (HCC): Comparative analysis with propensity score-weighted cohorts.

2019 ◽  
Vol 37 (4_suppl) ◽  
pp. 443-443 ◽  
Author(s):  
Nima Nabavizadeh ◽  
Younes Jahangiri ◽  
Ramtin Rahmani ◽  
Catherine Degnin ◽  
Yiyi Chen ◽  
...  
Keyword(s):  
Liver Disease ◽  
Propensity Score ◽  
Liver Transplant ◽  
Cox Regression ◽  
Multivariable Analysis ◽  
Local Tumor Control ◽  
Post Treatment ◽  
Tumor Control ◽  
Local Tumor ◽  
Bridge To Transplant

443 Background: To assess the relative efficacy and toxicity associated with TACE+Ablation (Ablation) or TACE+SBRT (SBRT) in a large cohort of patients with unresectable HCC. Methods: Patients with HCC undergoing Ablation or SBRT from 2006-2016 with available follow up were included. Treatment groups were different at baseline regarding tumor stage (BCLC A, B and C: 96%, 4%, 0% (Ablation) vs. 73%, 14% and 13% (SBRT), P < 0.001) and severity of liver disease (CTP A, B, and C: 55%, 45% and 0% (Ablation) vs. 50%, 41%, and 9% (SBRT), P = 0.007). Propensity scores were calculated with age, sex, BCLC stage, CTP class, etiology of liver disease, tumor number, and diameter to balance the cohorts. Average treatment effects on survival with multivariable propensity score-weighted competing risk Cox regression models were evaluated, with BCLC stage, number of treated tumors and liver transplant as additionally controlled variables. Primary outcome was overall survival (OS). Secondary outcomes were progression-free survival (PFS), local tumor control and hepatotoxicity. Treatment-related hepatotoxicity was defined as a two point change in CTP within six months after treatment. Results: 192 subjects were included (101 Ablation, 91 SBRT; median age=60 years, 75% men). Liver disease included HCV (78%), alcohol (35%) and NASH (8%). Liver transplant-adjusted 1- and 2-year OS rates were significantly greater for Ablation vs SBRT (88% vs. 75% and 77% vs. 50%, P<0.001). 1-and 2-year PFS rates were significantly greater for Ablation vs. SBRT (84% vs. 65% and 75% vs. 51%, P < 0.001). 1- and 2- year local tumor control rates were similar with both strategies (99% vs. 91% and 94% vs. 87%, P=0.298). Propensity score-weighted multivariable analysis showed significantly higher OS (sHR: 2.31, P = 0.006) and PFS rates (sHR:1.75, P = 0.008) with Ablation compared to SBRT. Ablation was also associated with lower post-treatment hepatotoxicity compared with SBRT (5% vs. 12%, P = 0.001). Conclusions: TACE+Ablation demonstrated higher OS/PFS and lower post-treatment hepatotoxicity compared with TACE+SBRT. Local disease control up to two years was equivocal, potentially suggesting equipoise for bridge to transplant.

scholarly journals Genotype-targeted local therapy of glioma

2018 ◽  
Vol 115 (36) ◽  
pp. E8388-E8394 ◽  
Author(s):  
Ganesh M. Shankar ◽  
Ameya R. Kirtane ◽  
Julie J. Miller ◽  
Hormoz Mazdiyasni ◽  
Jaimie Rogner ◽  
...  
Keyword(s):  
Local Control ◽  
Specific Treatment ◽  
Local Therapy ◽  
Systemic Toxicity ◽  
Tumor Control ◽  
Lower Grade ◽  
Isocitrate Dehydrogenase 1 ◽  
Nicotinamide Phosphoribosyltransferase

Aggressive neurosurgical resection to achieve sustained local control is essential for prolonging survival in patients with lower-grade glioma. However, progression in many of these patients is characterized by local regrowth. Most lower-grade gliomas harbor isocitrate dehydrogenase 1 (IDH1) or IDH2 mutations, which sensitize to metabolism-altering agents. To improve local control of IDH mutant gliomas while avoiding systemic toxicity associated with metabolic therapies, we developed a precision intraoperative treatment that couples a rapid multiplexed genotyping tool with a sustained release microparticle (MP) drug delivery system containing an IDH-directed nicotinamide phosphoribosyltransferase (NAMPT) inhibitor (GMX-1778). We validated our genetic diagnostic tool on clinically annotated tumor specimens. GMX-1778 MPs showed mutant IDH genotype-specific toxicity in vitro and in vivo, inducing regression of orthotopic IDH mutant glioma murine models. Our strategy enables immediate intraoperative genotyping and local application of a genotype-specific treatment in surgical scenarios where local tumor control is paramount and systemic toxicity is therapeutically limiting.

scholarly journals Clinical features and prognostic analysis of patients with Aspergillus isolation during acute exacerbation of chronic obstructive pulmonary disease

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yu Gu ◽  
Xianping Ye ◽  
Yu Wang ◽  
Kunlu Shen ◽  
Jinjin Zhong ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Acute Exacerbation ◽  
Clinical Features ◽  
Antifungal Therapy ◽  
Cox Regression ◽  
Multivariable Analysis ◽  
Positive Culture ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease

Abstract Background Lower respiratory tract (LRT) specimen culture is widely performed for the identification of Aspergillus. We investigated the clinical features and prognosis of patients with Aspergillus isolation from LRT specimens during acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods This is a 6-year single-center, real-world study. 75 cases out of 1131 hospitalized AECOPD patients were positive for Aspergillus. These patients were carefully evaluated and finally diagnosed of pulmonary aspergillosis (PA, 60 cases, 80%) or colonization (15 cases, 20%). Comparisons of clinical data were performed between these two groups. A cox regression model was used to confirm prognostic factors of Aspergillus infection. Results The PA group had worse lung function and higher rates of systemic corticosteroid use and broad-spectrum antibiotic use before admission than the colonization group. The PA group had significantly higher in-hospital mortality and 180-day mortality than the colonization group (45% (27/60) vs. 0% (0/15), p = 0.001, and 52.5% (31/59) vs. 6.7% (1/15), p < 0.001, respectively). By multivariable analysis among Aspergillus infection patients, antifungal therapy (HR 0.383, 95% CI 0.163–0.899, p = 0.027) was associated with improved survival, whereas accumulated dose of systemic steroids > 700 mg (HR 2.452, 95% CI 1.134–5.300, p = 0.023) and respiratory failure at admission (HR 5.983, 95% CI 2.487–14.397, p < 0.001) were independently associated with increased mortality. Significant survival differential was observed among PA patients without antifungals and antifungals initiated before and after Aspergillus positive culture (p = 0.001). Conclusions Aspergillus isolation in hospitalized AECOPD patients largely indicated PA. AECOPD patients with PA had worse prognosis than those with Aspergillus colonization. Empirical antifungal therapy is warranted to improve the prognosis for Aspergillus infection.

scholarly journals Primary tumor surgery improves survival in non-metastatic primary urethral carcinoma patients: a large population-based investigation

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jie Wu ◽  
Yu-Chen Wang ◽  
Wen-Jie Luo ◽  
Bo-Dai ◽  
Ding-Wei Ye ◽  
...  
Keyword(s):  
Regression Model ◽  
Competing Risks ◽  
Primary Tumor ◽  
Cox Regression ◽  
Radical Surgery ◽  
Large Population ◽  
Local Therapy ◽  
Primary Site ◽  
Urethral Carcinoma ◽  
The Impact

Abstract Background Primary urethral carcinoma (PUC) is a rare genitourinary malignancy with a relatively poor prognosis. The aim of this study was to examine the impact of surgery on survival of patients diagnosed with PUC. Methods A total of 1544 PUC patients diagnosed between 2004 and 2016 were identified based on the SEER database. The Kaplan-Meier estimate and the Fine and Gray competing risks analysis were performed to assess overall survival (OS) and cancer-specific mortality (CSM). The multivariate Cox regression model and competing risks regression model were used to identify independent risk factors of OS and cancer-specific survival (CSS). Results The 5-yr OS was significantly better in patients who received either local therapy (39.8%) or radical surgery (44.7%) compared to patients receiving no surgery of the primary site (21.5%) (p < 0.001). Both local therapy and radical surgery were each independently associated with decreased CSM, with predicted 5-yr cumulative incidence of 45.4 and 43.3%, respectively, compared to 64.7% for patients receiving no surgery of the primary site (p < 0.001). Multivariate analyses demonstrated that primary site surgery was independently associated with better OS (local therapy, p = 0.037; radical surgery, p < 0.001) and decreased CSM (p = 0.003). Similar results were noted regardless of age, sex, T stage, N stage, and AJCC prognostic groups based on subgroup analysis. However, patients with M1 disease who underwent primary site surgery did not exhibit any survival benefit. Conclusion Surgery for the primary tumor conferred a survival advantage in non-metastatic PUC patients.

Sign in / Sign up

Export Citation Format

Share Document