Salivary gland-sparing other than parotid-sparing in definitive head-and-neck intensity-modulated radiotherapy does not seem to jeopardize local control.

International audienceBACKGROUND: The objective was to analyze locoregional (LR) failure patterns in patients with head-and-neck cancer (HNC) treated using intensity-modulated radiotherapy (IMRT) with whole salivary gland-sparing: parotid (PG), submandibular (SMG), and accessory salivary glands represented by the oral cavity (OC). METHODS: Seventy consecutive patients with Stage I-II (23%) or III/IV (77%) HNC treated by definitive IMRT were included. For all LR failure patients, the FDG-PET and CT scans documenting recurrence were rigidly registered to the initial treatment planning CT. Failure volumes (Vf) were delineated based on clinical, radiological, and histological data. The percentage of Vf covered by 95% of the prescription isodose (Vf-V95) was analyzed. Failures were classified as "in-field" if Vf--V95 >= 95%, "marginal" if 20% < Vf-V95 < 95%, and "out-of-field" if Vf-V95 <=20%. Correlation between Vf-V95 and mean doses (Dmean) in the PG, SMG, and OC was assessed using Spearman's rank-order correlation test. The salivary gland dose impact on the LR recurrence risk was assessed by Cox analysis. RESULTS: The median follow-up was 20 months (6--35). Contralateral and ipsilateral PGs were spared in 98% and 54% of patients, respectively, and contralateral and ipsilateral SMG in 26% and 7%, respectively. The OC was spared to a dose <=40 Gy in 26 patients (37%). The 2-year LR control rate was 76.5%. One recurrence was "marginal", and 12 were "in-field". No recurrence was observed in vicinity of spared structures. Vf-V95 was not significantly correlated with Dmean in PG, SMG, and OC. The LR recurrence risk was not increased by lower Dmean in the salivary glands, but by T (p = 0.04) and N stages (p = 0.03). CONCLUSION: Over 92% of LR failures occurred "in-field" within the high dose region when using IMRT with a whole salivary gland-sparing strategy. Sparing SMG and OC in addition to PG thus appears a safe strategy

Evaluation Of A Group Cognitive-Behavioral Depression Prevention Program For Young Adolescents: A Randomized Effectiveness Trial

Depression is a common psychological problem in adolescence. Recent research suggests that group cognitive-behavioral interventions can reduce and prevent symptoms of depression in youth. Few studies have tested the effectiveness of such interventions when delivered by school teachers and counselors (as opposed to research team staff). We evaluated the effectiveness of the Penn Resiliency Program for adolescents (PRP-A), a school-based group intervention that targets cognitive behavioral risk factors for depression. We randomly assigned 408 middle school students (ages 10–15) to one of three conditions: PRP-A, PRP-AP (in which adolescents participated in PRP-A and parents were invited to attend a parent intervention component), or a school-as-usual control. Adolescents completed measures of depression and anxiety symptoms, cognitive style, and coping at baseline, immediately after the intervention, and at 6-month follow-up. PRP-A reduced depression symptoms relative to the school as usual control. Baseline levels of hopelessness moderated intervention effects. Among participants with average and high levels of hopelessness, PRP (A and AP) significantly improved depression symptoms, anxiety symptoms, hopelessness, and active coping relative to control. Among participants with low baseline hopelessness, we found no intervention effects. PRP-AP was not more effective than PRP-A alone. We found no intervention effects on clinical levels of depression or anxiety. These findings suggest that cognitive-behavioral interventions can be beneficial when delivered by school teachers and counselors. These interventions may be most helpful to students with elevated hopelessness

Assessment and topographic characterization of locoregional recurrences in head and neck tumours

Purpose: To evaluate the differences between three methods of classification of recurrences in patients with head and neck tumours treated with Radiation Therapy (RT). Materials and methods: 367 patients with head and neck tumours were included in the study. Tumour recurrences were delineated in the CT images taken during patient follow-up and deformable registration was used to transfer this volume into the planning CT. The methods used to classify recurrences were: methodCTV quantified the intersection volume between the recurrence and the Clinical Target Volume (CTV); methodTV quantified the intersection between the Treated Volume and the recurrence (for method CTV and TV, recurrences were classified in-field if more than 95% of their volume were inside the volume of interest, marginal if the intersection was between 20-95% and outfield otherwise); and methodCOM was based on the position of the Centre Of Mass of the recurrence. A dose assessment in the recurrence volume was also made. Results: The 2-year Kaplan-Meier locoregional recurrence incidence was 10%. Tumour recurrences occurred in 22 patients in a mean time of 16.5 ± 9.4 months resulting in 28 recurrence volumes. The percentage of in-field recurrences for methods CTV, TV and COM was 7%, 43% and 50%, respectively. Agreement between the three methods in characterizing individually in-field and marginal recurrences was found only in six cases. Methods CTV and COM agreed in 14. The percentage of outfield recurrences was 29% using all methods. For local recurrences (in-field or marginal to gross disease) the average difference between the prescribed dose and D 98% in the recurrence volume was -5.2 ± 3.5% (range: -10.1%-0.9%). Conclusions: The classification of in-field and marginal recurrences is very dependent on the method used to characterize recurrences. Using methods TV and COM the largest percentage of tumour recurrences occurred in-field in tissues irradiated with high doses. Keywords: Head and neck tumours, Radiation therapy, Characterization of tumour recurrences, Geometric methods, Dosimetric assessmen

The constitution of racial power: A nonracialist analysis

The body of theoretical works that theorize empirical political power have largely declined addressing “racism”. Political theorists have collectively failed to arrive at a coherent and consistent definition of the term “race”. Obversely, the scholarship that makes focused normative evaluations of racialist politics has at times neglected to make a more sophisticated conception of “power” central to their analyses. This lack of conceptual precision has created an unfortunate tendency toward an uncritical deployment of “racialist” terms and “presentist” historiographies. Terms such as “negro”, “white”, “African”, “Asian”, “black”, are often provided without an accompanied explanation or justification for their usage. Typical “histories” of “racism” tend to betray a general incapacity to visualize or bring to life the nonracialist or pre-racialist character of societies in the “Old World”. Moreover, political psychologists that do address “racism” tend to contextualize this phenomenon using passively-constructed language that presents scenarios of an unfortunate racist political behavior motivated by antipathy. These analytical limitations imply a reduced capacity within the “humanities” or “social sciences” to create a nonracialist vision and conceptual language through which the analytical and normative dimensions of “race” can be fully assessed. The practice of uncritically reproducing racialist terms undermines the central goal of practicing critique itself—namely that of achieving autonomy from “truth” claims that constitute the subject within authoritarian power relations. In response, this thesis advances the following claims: (a) prior to the advent of “modern racism”, around the globe, and in the geographic spaces of “western Eurasia”, the range of “morphological” characteristics was heterogeneous and reflected the cyclical explorations, invasions, and colonization from peoples who were home to what is now known as “Africa”, the “Near East”, and “Asia” into those spaces; (b) the term “race” has undergone specific and radically transformative phases in which its meanings have been re-constituted from mere “kinship” to “meta-ancestry”, “morphology”, “anthropology” and “bio-genetics”; (c) the contemporary meaning of “race” is best conceptualized as a mosaic of constructed micro-differences (e.g. social relations, cognitive-linguistic framework, appearance, ancestry, and self- identification) reified as the markers of intrinsic “racial” distinction, which the subject measures according to a weighted-scale that she uses to ultimately assign self, group, and other membership in one (or more) “racial” group(s); and (d) racial power entails a nexus of power-knowledge whereby an authority is enabled to exercise political power to confer greater enabled agency to the social agent by virtue of discourses developed by credentialed “experts” working within a field of authoritative knowledge that objectifies that social agent as occupying a subject position that is imbued with empowerment. The intended goal of this thesis is to provide an analytic guidepost for those next generation political theorists whose analytical and normative discourses on “race” will explore the pathways to a radical transformative politics based on epistemic pluralism and autonomy

Redes ROADM como futuro de las redes DWDM en Guatemala.

Presenta la solución que ofrecen las redes ROADM en las redes de transmisión óptica, en especial sobre las redes DWDM