137 research outputs found
Secondary surgical management of osteoradionecrosis using three-dimensional isodose curve visualization:a report of three cases
Osteoradionecrosis is defined as bone death secondary to radiotherapy. There is a relationship between the radiation dose received and the occurrence of osteoradionecrosis of the jaws, with the risk increasing above a dose of 60Gy. In cases of class III mandibular osteoradionecrosis, a segmental resection can be indicated. Current practice is to completely remove the affected bone up to the point where the bone looks healthy and is bleeding. Exact resection planning and the use of guided surgery based on imaging of the bone changes have not been reported so far. This article describes a method whereby the radiotherapy dose information is incorporated into the imaging of the affected bone in order to plan a three-dimensional (3D) virtual guided resection and reconstruction of the mandible in osteoradionecrosis. The method enables 3D visualization of each desired dose field in relation to the 3D model of the affected bone. Two types of application - for resection and reconstruction - are described.</p
Managing Dynamic User Communities in a Grid of Autonomous Resources
One of the fundamental concepts in Grid computing is the creation of Virtual
Organizations (VO's): a set of resource consumers and providers that join
forces to solve a common problem. Typical examples of Virtual Organizations
include collaborations formed around the Large Hadron Collider (LHC)
experiments. To date, Grid computing has been applied on a relatively small
scale, linking dozens of users to a dozen resources, and management of these
VO's was a largely manual operation. With the advance of large collaboration,
linking more than 10000 users with a 1000 sites in 150 counties, a
comprehensive, automated management system is required. It should be simple
enough not to deter users, while at the same time ensuring local site autonomy.
The VO Management Service (VOMS), developed by the EU DataGrid and DataTAG
projects[1, 2], is a secured system for managing authorization for users and
resources in virtual organizations. It extends the existing Grid Security
Infrastructure[3] architecture with embedded VO affiliation assertions that can
be independently verified by all VO members and resource providers. Within the
EU DataGrid project, Grid services for job submission, file- and database
access are being equipped with fine- grained authorization systems that take VO
membership into account. These also give resource owners the ability to ensure
site security and enforce local access policies. This paper will describe the
EU DataGrid security architecture, the VO membership service and the local site
enforcement mechanisms Local Centre Authorization Service (LCAS), Local
Credential Mapping Service(LCMAPS) and the Java Trust and Authorization
Manager.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, LaTeX, 5 eps figures. PSN
TUBT00
Onset of hypothyroidism after total laryngectomy:Effects of thyroid gland surgery and preoperative and postoperative radiotherapy
Background: To determine time of onset and risk of hypothyroidism after total laryngectomy (TL) with and without (hemi)thyroidectomy in relation to treatment regimen, that is, preoperative radiotherapy (RT-TL), postoperative radiotherapy (TL-RT), and postoperative re-irradiation (RT-TL-RT). Methods: Retrospective review of 128 patients treated by RT-TL (51 patients), TL-RT (55 patients), and RT-TL-RT (22 patients). Risk of hypothyroidism was determined by multivariable Cox regression analysis and euthyroid survival was calculated using Kaplan-Meier method. Results: Hypothyroidism developed in 69 (54%) patients. The median onset of hypothyroidism was later (P <.01) and the risk of hypothyroidism was lower (hazard ratio 0.49; P =.014) in the TL-RT group compared to both other treatment regimens. Euthyroid survival did not differ between the treatment regimens. Two years euthyroid survival was 24% with and 61% without (hemi)thyroidectomy (P <.001). Conclusions: Patients treated with TL-RT have later onset of hypothyroidism. Higher risk for hypothyroidism is associated with salvage TL after radiotherapy and (hemi)thyroidectomy
Frailty and restrictions in geriatric domains are associated with surgical complications but not with radiation-induced acute toxicity in head and neck cancer patients:A prospective study
OBJECTIVES: We aimed to evaluate the association between frailty screening and geriatric assessment (GA) on short term adverse events in patients treated for head and neck cancer (HNC) for the first time in a prospective study. MATERIALS AND METHODS: Newly diagnosed HNC patients undergoing curative treatment were prospectively included in OncoLifeS, a data biobank. Prior to the start of treatment, frailty was assessed with a GA, Groningen Frailty Indicator (GFI) and Geriatric-8 (G8). The GA included comorbidity (Adult Comorbidity Evaluation - 27), nutritional status (Malnutrition Universal Screening Tool), functional status ((instrumental) Activities of Daily Living), mobility (Timed Up & Go), psychological (Geriatric Depression Scale 15) and cognitive (Mini Mental State Examination) measures. Clinically relevant postoperative complications (Clavien-Dindo ≥ grade 2) and acute radiation-induced toxicity (Common Terminology Criteria for Adverse Events version 4.0 ≥ grade 2) were defined as outcome measures. Univariable and multivariable logistic regression analyses were performed, yielding odds ratios (ORs) and 95% confidence intervals (95%CIs). RESULTS: Of the 369 included patients, 259 patients were eligible for analysis. Postoperative complications occurred in 41/148 (27.7%) patients and acute radiation-induced toxicity was present in 86/160 (53.7%) patients. Number of deficit domains of GA (OR = 1.71, 95%CI = 1.14-2.56), GFI (OR = 2.54, 95%CI = 1.02-6.31) and G8 (OR5.59, 95%CI = 2.14-14.60) were associated with postoperative complications, but not with radiation-induced toxicity. CONCLUSION: Frailty and restrictions in geriatric domains were associated with postoperative complications, but not with radiation-induced acute toxicity in curatively treated HNC patients. The results of this prospective study further emphasizes the importance of geriatric evaluation, particularly before surgery
Frailty is associated with decline in health-related quality of life of patients treated for head and neck cancer
Objective: To determine the effect of frailty on Health Related Quality of Life (HRQoL) after treatment for Head and Neck Cancer (HNC). Materials and methods: Patients were prospectively included in OncoLifeS, a data-biobank. Before treatment, patients underwent geriatric screening, including the Groningen Frailty Indicator (GFI) and Geriatric 8 (G8). Patients' HRQoL was measured using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC-QLQ-C30) at three, six, twelve and twenty four months after treatment. Linear mixed models were used for statistical analysis. All models were adjusted for baseline HRQoL values, relevant confounders at baseline and yielded estimates (beta), 95% confidence intervals and p-values. Results: 288 patients were included. The mean age was 68.4 years and 68.8% were male. During follow-up, 84 patients had tumor recurrence and 66 died. Response to EORTC-QLQ-C30 ranged from 77.3% to 87.8%. Frail patients, defined by GFI, had significantly worse Global Health Status/Quality of Life (GHS/QoL) (beta = -8.70(-13.54;-3.86), p <0.001), physical functioning (beta = -4.55(-8.70;-0.40), p <0.032), emotional functioning (beta = -20.06(-25.65;-15.86), p <0.001), and social functioning (beta = -8.44(-13.91;-2.98), p <0.003) three months after treatment compared to non-frail patients. Furthermore, frail patients had a significantly worse course of GHS/QoL (j3 = -7.47(-11.23;-3.70), p = 0.001), physical functioning (beta = -3.28(-6.26;-0.31), p = 0.031) and role functioning (beta = -7.27(-12.26;-2.28), p = 0.005) over time, compared to non-frail patients. When frailty was determined by G8, frailty was significantly associated with worse GHS/QoL (beta = -6.68(-11.00;-2.37), p = 0.003) and emotional functioning (beta = -5.08(-9.43;-0.73), p = 0.022) three months after treatment. Conclusion: Frail patients are at increased risk for decline in HRQoL, and further deterioration during follow-up after treatment for HNC
Patterns of long-term swallowing dysfunction after definitive radiotherapy or chemoradiation
Objectives: To identify patterns of long-term, radiation-induced swallowing dysfunction after definitive radiotherapy with or without chemotherapy (RT or CHRT) and to determine which factors may explain these patterns over time.Material and methods: The study population consisted of 238 consecutive head and neck cancer patients treated with RT or CHRT. The primary endpoint was >= grade 2 swallowing dysfunction at 6, 12, 18 and 24 months after treatment. Cluster analysis was used to identify different patterns over time. The differences between the mean dose to the swallowing organs at risk for each pattern were determined by using dose maps.Results: The cluster analysis revealed five patterns of swallowing dysfunction: low persistent, intermediate persistent, severe persistent, transient and progressive. Patients with high dose to the upper pharyngeal, laryngeal and lower pharyngeal region had the highest risk of severe persistent swallowing dysfunction. Transient problems mainly occurred after high dose to the laryngeal and lower pharyngeal regions, combined with moderate dose to the upper pharyngeal region. The progressive pattern was mainly seen after moderate dose to the upper pharyngeal region.Conclusions: Various patterns of swallowing dysfunction after definitive RT or CHRT can be identified over time. This could reflect different underlying biological processes. (C) 2015 The Authors. Published by Elsevier Ireland Ltd.</p
Acute symptoms during the course of head and neck radiotherapy or chemoradiation are strong predictors of late dysphagia
AbstractPurposeTo determine if acute symptoms during definitive radiotherapy (RT) or chemoradiation (CHRT) are prognostic factors for late dysphagia in head and neck cancer (HNC).Material and methodsThis prospective cohort study consisted of 260 HNC patients who received definitive RT or CHRT. The primary endpoint was grade 2–4 swallowing dysfunction at 6months after completing RT (SWALM6). During treatment, acute symptoms, including oral mucositis, xerostomia and dysphagia, were scored, and the scores were accumulated weekly and entered into an existing reference model for SWALM6 that consisted of dose–volume variables only.ResultsBoth acute xerostomia and dysphagia were strong prognostic factors for SWALM6. When acute scores were added as variables to the reference model, model performance increased as the course of treatment progressed: the AUC rose from 0.78 at the baseline to 0.85 in week 6. New models built for weeks 3–6 were significantly better able to identify patients with and without late dysphagia.ConclusionAcute xerostomia and dysphagia during the course of RT are strong prognostic factors for late dysphagia. Including accumulated acute symptom scores on a weekly basis in prediction models for late dysphagia significantly improves the identification of high-risk and low-risk patients at an early stage during treatment and might facilitate individualized treatment adaptation
Association of Deficits Identified by Geriatric Assessment With Deterioration of Health-Related Quality of Life in Patients Treated for Head and Neck Cancer
This cohort study assesses the association of single and accumulated geriatric deficits with health-related quality of life decline after treatment for head and neck cancer. Question Are pretreatment geriatric deficits associated with quality of life after treatment for head and neck cancer? Findings In this cohort study including 283 patients, items of geriatric assessment within all domains (physical, functional, psychological, social) were associated with decline of quality of life after treatment. The accumulation of domains with geriatric deficits was a major significant factor for deterioration at both short- and long-term follow-up after treatment. Meaning Deficits in individual and accumulated geriatric domains are associated with decline in quality of life; this knowledge may aid decision-making, indicate interventions, and reduce loss of quality of life. Importance Accumulation of geriatric deficits, leading to an increased frailty state, makes patients susceptible for decline in health-related quality of life (HRQOL) after treatment for head and neck cancer (HNC). Objective To assess the association of single and accumulated geriatric deficits with HRQOL decline in patients after treatment for HNC. Design, Setting, and Participants Between October 2014 and May 2016, patients at a tertiary referral center were included in the Oncological Life Study (OncoLifeS), a prospective data biobank, and followed up for 2 years. A consecutive series of 369 patients with HNC underwent geriatric assessment at baseline; a cohort of 283 patients remained eligible for analysis, and after 2 years, 189 patients remained in the study. Analysis was performed between March and November 2020. Interventions or Exposures Geriatric assessment included scoring of the Adult Comorbidity Evaluation 27, polypharmacy, Malnutrition Universal Screening Tool, Activities of Daily Living, Instrumental Activities of Daily Living (IADL), Timed Up & Go, Mini-Mental State Examination, 15-item Geriatric Depression Scale, marital status, and living situation. Main Outcomes and Measures The primary outcome measure was the Global Health Status/Quality of Life (GHS/QOL) scale of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30. Differences between patients were evaluated using linear mixed models at 3 months after treatment (main effects, beta [95% CI]) and declining course per year during follow-up (interaction x time, beta [95% CI]), adjusted for baseline GHS/QOL scores, and age, sex, stage, and treatment modality. Results Among the 283 patients eligible for analysis, the mean (SD) age was 68.3 (10.9) years, and 193 (68.2%) were male. Severe comorbidity (beta = -7.00 [-12.43 to 1.56]), risk of malnutrition (beta = -6.18 [-11.55 to -0.81]), and IADL restrictions (beta = -10.48 [-16.39 to -4.57]) were associated with increased GHS/QOL decline at 3 months after treatment. Severe comorbidity (beta = -4.90 [-9.70 to -0.10]), IADL restrictions (beta = -5.36 [-10.50 to -0.22]), restricted mobility (beta = -6.78 [-12.81 to -0.75]), signs of depression (beta = -7.08 [-13.10 to -1.06]), and living with assistance or in a nursing home (beta = -8.74 [-15.75 to -1.73]) were associated with further GHS/QOL decline during follow-up. Accumulation of domains with geriatric deficits was a major significant factor for GHS/QOL decline at 3 months after treatment (per deficient domain beta = -3.17 [-5.04 to -1.30]) and deterioration during follow-up (per domain per year beta = -2.74 [-4.28 to -1.20]). Conclusions and Relevance In this prospective cohort study, geriatric deficits were significantly associated with HRQOL decline after treatment for HNC. Therefore, geriatric assessment may aid decision-making, indicate interventions, and reduce loss of HRQOL
Improving the prediction of overall survival for head and neck cancer patients using image biomarkers in combination with clinical parameters
Purpose: To develop and validate prediction models of overall survival (OS) for head and neck cancer (HNC) patients based on image biomarkers (IBMs) of the primary tumor and positive lymph nodes (Ln) in combination with clinical parameters. Material and methods: The study cohort was composed of 289 nasopharyngeal cancer (NPC) patients from China and 298 HNC patients from the Netherlands. Multivariable Cox-regression analysis was performed to select clinical parameters from the NPC and HNC datasets, and IBMs from the NPC dataset. Final prediction models were based on both IBMs and clinical parameters. Results: Multivariable Cox-regression analysis identified three independent IBMs (tumor Volume density, Run Length Non-uniformity and Ln Major-axis-length). This IBM model showed a concordance (c)-index of 0.72 (95%Cl: 0.65-0.79) for the NPC dataset, which performed reasonably with a c-index of 0.67 (95%Cl: 0.62-0.72) in the external validation HNC dataset. When IBMs were added in clinical models, the c-index of the NPC and HNC datasets improved to 0.75 (95%Cl: 0.68-0.82; p = 0.019) and 0.75 (95%Cl: 0.70-0.81; p <0.001), respectively. Conclusion: The addition of IBMs from the primary tumor and Ln improved the prognostic performance of the models containing clinical factors only. These combined models may improve pre-treatment individualized prediction of OS for HNC patients. (C) 2017 The Authors. Published by Elsevier Ireland Ltd
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