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• FDG-PET/CT-based nodal target volume definition improves regional control and survival. • No isolated recurrences in the electively treated neck occurred with FDG-PET/CT-based nodal target volume definition. • FDG-PET/CT-based nodal target volume definition causes target volume transformation. • FDG-PET/CT can guide gradient dose prescription with de-escalation of the elective dose. Multimodality imaging including 18F-FDG-PET has improved the detection threshold of nodal metastases in head and neck squamous cell carcinoma (HNSCC). The aim of this retrospective analysis is to investigate the impact of FDG-PET/CT-based nodal target volume definition (FDG-PET/CT-based NTV) on radiotherapy outcomes, compared to conventional CT-based nodal target volume definition (CT-based NTV). Six-hundred-thirty-three patients treated for HNSCC with definitive (chemo)radiotherapy using IMRT/VMAT techniques between 2008 and 2017 were analyzed. FDG-PET/CT-based NTV was performed in 46% of the patients. The median follow-up was 31 months. Diagnostic imaging depicting the regional recurrence was co-registered with the initial CT-scan to reconstruct the exact site of the recurrence. Multivariate Cox regression analysis was performed to identify variables associated with radiotherapy outcome. FDG-PET/CT-based NTV improved control of disease in the CTV elective-nodal (HR: 0.33, p = 0.026), overall regional control (HR: 0.62, p = 0.027) and overall survival (HR: 0.71, p = 0.033) compared to CT-based NTV. The risk for recurrence in the CTV elective-nodal was increased in case of synchronous local recurrence of the primary tumor (HR: 12.4, p < 0.001). FDG-PET/CT-based NTV significantly improved control of disease in the CTV elective-nodal , overall regional control and overall survival compared to CT-based NTV. A significant proportion of CTV elective-nodal recurrences are potentially new nodal manifestations from a synchronous local recurrent primary tumor. These results support the concept of target volume transformation and give an indication of the potential of FDG-PET to guide gradual radiotherapy dose de-escalation in elective neck treatment in HNSCC. [ABSTRACT FROM AUTHOR]

Abstract Background In quantitative FDG-PET data analysis, normalization of the standardized uptake value (SUV) with an internal image-derived standard improves its reproducibility. In this study, the cervical spinal cord is proposed as an internal standard that is within the field of view of the radiotherapy planning PET/CT-scan in head and neck cancer. The aim is to evaluate if the tumor to cervical spinal cord standardized uptake ratio (SUR) can improve the reproducibility of a model to determine the metabolic tumor volume (MTV) on FDG-PET/CT in a multicenter setting. Materials and methods Ninety-five radiotherapy planning FDG-PET/CT-scans of patients with head and neck cancer were analyzed using the Bland–Altman method to evaluate differences in FDG-uptake in the cervical spinal cord and the mediastinal blood pool. Non-linear regression analysis was used to determine the optimal MTV using the gross tumor volume (GTV) as ground truth and a spatial overlap-index as statistical validation metric. Reproducibility was evaluated using the Bland-Altman method and external validation was performed in an independent dataset consisting of 62 patients. Results Bland–Altman's analyses demonstrated equivalence of FDG-uptake in the mediastinal blood pool and the cervical spinal cord. Reproducibility of the models improved when using SUR instead of SUV. These results were confirmed in the validation cohort. Conclusion The use of the tumor to cervical spinal cord SUR instead of SUV improves the reproducibility of a model to determine the MTV on FDG-PET/CT in a multicenter setting. This study indicates that SUR may be preferred over SUV based approaches. [ABSTRACT FROM AUTHOR]

Abstract Diagnostic imaging continues to evolve, and now has unprecedented accuracy for detecting small nodal metastasis. This influences the tumor load in elective target volumes and subsequently has consequences for the radiotherapy dose required to control disease in these volumes. Small metastases that used to remain subclinical and were included in elective volumes, will nowadays be detected and included in high-dose volumes. Consequentially, high-dose volumes will more often contain low-volume disease. These target volume transformations lead to changes in the tumor burden in elective and “gross” tumor volumes with implications for the radiotherapy dose prescribed to these volumes. For head and neck tumors, nodal staging has evolved from mere palpation to combinations of high-resolution imaging modalities. A traditional nodal gross tumor volume in the neck typically had a minimum diameter of 10–15 mm, while nowadays much smaller tumor deposits are detected in lymph nodes. However, the current dose levels for elective nodal irradiation were empirically determined in the 1950s, and have not changed since. In this report the radiobiological consequences of target volume transformation caused by modern imaging of the neck are evaluated, and theoretically derived reductions of dose in radiotherapy for head and neck cancer are proposed. The concept of target volume transformation and subsequent strategies for dose adaptation applies to many other tumor types as well. Awareness of this concept may result in new strategies for target definition and selection of dose levels with the aim to provide optimal tumor control with less toxicity. [ABSTRACT FROM AUTHOR]

Advances in diagnostic imaging create opportunities for improved therapeutic targeting of cancer but conceptual thinking about radiotherapy target volume definition and dose-prescription is not keeping up. In this opinion paper we discuss how modern imaging can contribute to new concepts for radiotherapy dose-prescription and target volume definition illustrated by the example of head and neck cancer. These new insights have the potential to significantly reduce radiation associated toxicity and may have important impact on the combination of radiotherapy with systemic cancer therapies. [ABSTRACT FROM AUTHOR]

Background: In definitive radiation therapy for head and neck cancer, clinically uninvolved cervical lymph nodes are irradiated with a so-called 'elective dose' in order to achieve control of clinically occult metastases. As a consequence of high-resolution diagnostic imaging, occult tumor volume has significantly decreased in the last decades. Since the elective dose is dependent on occult tumor volume, the currently used elective dose may be higher than necessary. Because bilateral irradiation of the neck contributes to dysphagia, xerostomia and hypothyroidism in a dose dependent way, dose de-escalation to these regions can open a window of opportunity to reduce toxicity and improve quality of life after treatment.Methods: UPGRADE-RT is a multicenter, phase III, single-blinded, randomized controlled trial. Patients to be treated with definitive radiation therapy for a newly diagnosed stage T2-4 N0-2 M0 squamous cell carcinoma of the oropharynx, hypopharynx or larynx are eligible. Exclusion criteria are recurrent disease, oncologic surgery to the head and neck area, concomitant chemotherapy or epidermal growth factor receptor inhibitors. In total, 300 patients will be randomized in a 2:1 ratio to a treatment arm with or without de-escalation of the elective radiation dose and introduction of an intermediate dose-level for selected lymph nodes. Radiation therapy planning FDG-PET/CT-scans will be acquired to guide risk assessment of borderline-sized cervical nodes that can be treated with the intermediate dose level. Treatment will be given with intensity-modulated radiation therapy or volumetric arc therapy with simultaneous-integrated boost using an accelerated fractionation schedule, 33 fractions in 5 weeks. The primary endpoint is 'normalcy of diet' at 1 year after treatment (toxicity). The secondary endpoint is the actuarial rate of recurrence in electively irradiated lymph nodes at 2 years after treatment (safety).Discussion: The objective of the UPGRADE-RT trial is to investigate whether de-escalation of elective radiation dose and the introduction of an intermediate dose-level for borderline sized lymph nodes in the treatment of head and neck cancer will result in less radiation sequelae and improved quality of life after treatment without compromising the recurrence rate in the electively treated neck.Trial Registration: ClinicalTrials.gov Identifier: NCT02442375 . [ABSTRACT FROM AUTHOR]

Purpose: To provide a comprehensive risk assessment on the patterns of recurrence in electively irradiated lymph node regions after definitive radiation therapy for head and neck cancer.Methods and Materials: Two hundred sixty-four patients with stage cT2-4N0-2M0 squamous cell carcinoma of the oropharynx, larynx, or hypopharynx treated with accelerated intensity modulated radiation therapy between 2008 and 2012 were included. On the radiation therapy planning computed tomography (CT) scans from all patients, 1166 lymph nodes (short-axis diameter ≥5 mm) localized in the elective volume were identified and delineated. The exact sites of regional recurrences were reconstructed and projected on the initial radiation therapy planning CT scan by performing coregistration with diagnostic imaging of the recurrence.Results: The actuarial rate of recurrence in electively irradiated lymph node regions at 2 years was 5.1% (95% confidence interval 2.4%-7.8%). Volumetric analysis showed an increased risk of recurrence with increasing nodal volume. Receiver operating characteristic analysis demonstrated that the summed long- and short-axis diameter is a good alternative for laborious volume calculations, using ≥17 mm as cut-off (hazard ratio 17.8; 95% confidence interval 5.7-55.1; P<.001).Conclusions: An important risk factor was identified that can help clinicians in the pretreatment risk assessment of borderline-sized lymph nodes. Not overtly pathologic nodes with a summed diameter ≥17 mm may require a higher than elective radiation therapy dose. For low-risk elective regions (all nodes <17 mm), the safety of dose de-escalation below the traditional 45 to 50 Gy should be investigated. [ABSTRACT FROM AUTHOR]

Abstract: Context: Some studies report that tumour progression in patients with non–muscle-invasive bladder cancer (NMIBC) is associated with a poor prognosis. However, no systematic evidence is available. Objective: The aim of the study was to systematically review literature to determine the long-term cancer-specific survival in patients with high-risk NMIBC (T1G3, multifocal, highly recurrent, or carcinoma in situ) having tumour progression. Evidence acquisition: A systematic review was conducted by searching PubMed and the Cochrane library for studies published between 2006 and 2011. Additional studies were identified by scanning reference lists of relevant papers. We attempted to retrieve missing data by contacting the corresponding author. Keywords used included bladder cancer, high-risk, high grade, carcinoma in situ, non-muscle invasive bladder cancer, progression, and survival. Studies were included when they met the following criteria: inclusion of at least 75 patients having high-risk NMIBC, patients were initially treated conservatively with transurethral resection of the bladder tumour and intravesical instillations, a median follow-up of at least 48 mo, and reporting data on progression to muscle-invasive bladder cancer (MIBC) and death resulting from bladder cancer (BCa). Evidence synthesis: Literature was systematically reviewed, and 19 trials were included, producing a total of 3088 patients, of which 659 (21%) showed progression to MIBC and 428 (14%) died as a result of BCa after a median follow-up of 48–123 mo. Survival after progression from high-risk NMIBC to MIBC was 35%. Progression to MIBC and BCa-related death in high-risk NMIBC were found to be relatively early events, occurring mainly within 48 mo. Finally, even in cases of early cystectomy in patients with high-risk NMIBC, a relevant proportion of these patients appear not be cured of their disease. Conclusions: This study provides systematically gathered evidence showing a poor prognosis for patients with high-risk NMIBC and tumour progression. [Copyright &y& Elsevier]

Details an architecture for Digital Subscriber Line access facilitating Internet Protocol service guarantees leveraging quality of service mechanisms in transport-technology-specific data plane. Details regarding the Enhanced Resource and Information Control architecture; Creation of an overlay network on a physical network.

Studies the use of approximation of state functions in measurement-based transistor models. Representation of the state functions; Comparison between measurement and simulation; Implementation of the model in commercially available SPICE simulator; Modeling of current and charge functions and second-order effects.

Investigates the correlation between the impedance pattern for automatic noise-parameter determination and the accuracy of extracted parameters using a statistical approach. Selection criterion for the optimum admittance pattern; Simulations.

Presents a modified approach to S-parameter fitting of measured MESFET (metal semiconductor field-effect transistors) data to the Statz's model equations. How problems with measurement noise and calibration error are reduced; Application of the new and old approach on a 6 x 100 um GaAs MESFET; Results obtained.

Background: The EANM Research Ltd. (EARL) guidelines give recommendations for harmonization of [18F]FDG PET-CT image acquisition and reconstruction, aiming to ensure reproducibility of quantitative data between PET scanners. Recent technological advancements in PET-CT imaging resulted in an updated version of the EARL guidelines (EARL2). The aim of this study is to compare quantitative [18F]FDG uptake metrics of the primary tumor and lymph nodes in patients with head and neck squamous cell carcinoma (HNSCC) on EARL2 versus EARL1 reconstructed images and to describe clinical implications for nodal staging and treatment. Methods: Forty-nine consecutive patients with HNSCC were included. For all, both EARL1 and EARL2 images were reconstructed from a singular [18F]FDG PET-CT scan. Primary tumors and non-necrotic lymph nodes ≥ 5 mm were delineated on CT-scan. In the quantitative analysis, maximum standardized uptake values (SUVmax) and standardized uptake ratios (SURmax, i.e., SUVmax normalized to cervical spinal cord uptake) were calculated for all lesions on EARL1 and EARL2 reconstructions. Metabolic tumor volume (MTV) and total lesion glycolysis were compared between EARL1 and EARL2 using different segmentation methods (adaptive threshold; SUV2.5/3.5/4.5; SUR2.5/3.5/4.5; MAX40%/50%). In the qualitative analysis, each lymph node was scored independently by two nuclear medicine physicians on both EARL1 and EARL2 images on different occasions using a 4-point scale. Results: There was a significant increase in SUVmax (16.5%) and SURmax (9.6%) of primary tumor and lymph nodes on EARL2 versus EARL1 imaging (p < 0.001). The proportional difference of both SUVmax and SURmax between EARL2 and EARL1 decreased with increasing tumor volume (p < 0.001). Absolute differences in MTVs between both reconstructions were small (< 1.0 cm3), independent of the segmentation method. MTVs decreased on EARL2 using relative threshold methods (adaptive threshold; MAX40%/50%) and increased using static SUV or SUR thresholds. With visual scoring of lymph nodes 38% (11/29) of nodes with score 2 on EARL1 were upstaged to score 3 on EARL2, which resulted in an alteration of nodal stage in 18% (6/33) of the patients. Conclusions: Using the EARL2 method for PET image reconstruction resulted in higher SUVmax and SURmax compared to EARL1, with nodal upstaging in a significant number of patients. [ABSTRACT FROM AUTHOR]

in the last few years a number of applications have emerged that can benefit from network-layer signaling (i.e., the installation, maintenance, and removal of control state in network elements). These applications include path-coupled and path-decoupled quality of service management and resource allocation, as well as network debugging, NAT, and firewall control. These applications call for an extensible and securable signaling protocol. This article discusses some of the recent standardization efforts in the IETF for a new extensible IP signaling protocol suite (NSIS). We describe the design of the NSIS protocol suite, and compare it with RSVP, the current Internet QoS signaling protocol. [ABSTRACT FROM AUTHOR]

In this paper, an off-line traffic engineering algorithm is presented that optimizes the single-path routing of Label Switched Paths in a Differentiated Services IP domain by means of explicit, Multi-Protocol Label Switching controlled nonshortest paths. This algorithm allows traffic engineering up to 2500 traffic trunks in flat networks with sizes up to 150 nodes while supporting protection, pre-emption, quality-of-service, oversubscription, and resource class affinity. The algorithm with proper extensions can be applied to hierarchical networks, thus increasing the scalability properties for network size with a factor of about 50. First the single-area algorithm is detailed, then the concept and implementation of hierarchy is introduced for inter-area traffic engineering. These topics are illustrated with simulation results. KEY WORDS: Traffic engineering; hierarchy; differentiated services; quality-of-service; explicit routing. [ABSTRACT FROM AUTHOR]