Attention deficit hyperactivity disorder and restless leg syndrome across the lifespan: A systematic review and meta-analysis.

This systematic review aims to assess the association between attention deficit hyperactivity disorder (ADHD) and restless legs syndrome (RLS) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Databases were searched for original articles that reported prevalence data on ADHD and RLS until January 24th, 2023. Two independent reviewers evaluated the quality of the articles using the National Institutes of Health assessment tool. Among the 208 articles identified between 1996 and 2022, 29 were included. In large general population studies, 2.6-15.3% of participants met the RLS criteria, of which 3.2-17.4% presented with ADHD. In the ADHD group, RLS symptoms ranged from 11 to 42.9% in children and 20-33.0% in adults. This suggests a strong co-occurrence between RLS and ADHD. A common characteristic of these conditions is sleep fragmentation, as discussed in the reviewed papers. Although large-scale studies with comparable diagnostic criteria across the lifespan are required, our findings may advocate a possible common physiological pathway, including sleep fragmentation and dopaminergic system impairment.

A systematic review and meta-analysis of the cyclic alternating pattern across the lifespan.

BACKGROUND: Cyclic alternating pattern (CAP) is the electroencephalogram (EEG) pattern described as a marker of sleep instability and assessed by NREM transient episodes in sleep EEG. It has been associated with brain maturation. The aim of this review was to evaluate the normative data of CAP parameters according to the aging process in healthy subjects through a systematic review and meta-analysis. METHODS: Two authors independently searched databases using PRISMA guidelines. Discrepancies were reconciled by a third reviewer. Subgroup analysis and tests for heterogeneity were conducted. RESULTS: Of 286 studies, 10 submitted a total of 168 healthy individuals to CAP analysis. Scoring of CAP can begin at 3 months of life, when K-complexes, delta bursts, or spindles can be recognized. Rate of CAP increased with age, mainly during the first 2 years of life, then decreased in adolescence, and increased in the elderly. The A1 CAP subtype and CAP rate were high in school-aged children during slow-wave sleep (SWS). A1 CAP subtypes were significantly more numerous in adolescents compared with other groups, while the elderly showed the highest amounts of A2 and A3 CAP subtypes. Our meta-analysis registered the lowest CAP rate in infants younger than 2 years old and the highest in the elderly. CONCLUSIONS: This review summarized the normative data of CAP in NREM sleep during the aging process. The CAP rate increased with age and sleep depth, especially during SWS. Parameters of CAP may reflect gender hormonal effects and neuroplasticity. More reports on CAP subtypes are needed for their reference values establishment.

Spiramyin-loaded PLGA implants for the treatment of ocular toxoplasmosis: development, characterization, biocompatibility, and anti-toxoplasma activity.

Ocular toxoplasmosis is the major cause of infectious posterior uveitis worldwide, inducing visual field defect and/or blindness. Despite the severity of this disease, an effective treatment is still lacking. In this study, spiramycin-loaded PLGA implants were developed aiming at the treatment of ocular toxoplasmosis. Implants were manufactured by a hot-molding technique, characterized by Fourier Transform Infrared Spectroscopy, X-Ray Diffraction, Differential Scanning Calorimetry, Scanning Electron Microscopy; evaluated in terms of ocular biocompatibility by immunofluorescence, flow cytometry, cell migration, Hen's egg test-chorioallantoic membrane (HET-CAM) irritation test; and investigated in terms of in vitro efficacy against Toxoplasma gondii . Characterization techniques indicated that spiramycin was dispersed into the polymeric chains and both substances preserved their physical structures in implants. The HET-CAM test indicated that implants did not induce hemorrhage or coagulation, being non-irritant to the CAM. ARPE-19 cells showed viability by MTT assay, and normality in cell cycle kinetics and morphology, without stimulating cell death by apoptosis. Finally, they were highly effective against intracellular parasites without inducing human retinal pigment epithelial cell death. In conclusion, spiramycin-loaded PLGA implants represent a promising therapeutic alternative for the local treatment of ocular toxoplasmosis.

Social media for students' sleep health promotion - a health intervention report during COVID -19.

The COVID-19 pandemic has affected sleep health. Students' sleep health is essential for the performance of neuro-cognitive processes, as well as mental and physical balance. We assume the COVID19 pandemic has modified some sleep habits by prompting environmental and social interaction changes. In this study we surveyed a sample of 300 Brazilian students, with internet access, resident in the Federal District. They completed a questionnaire over two weeks in March 2020, i.e. the second and third week of the social isolation policy enacted in the Federal District due to COVID19. Valid responses from students aged18-24 years were analyzed. The sample was mostly female; 76,3% reported somnolence during the day, 70,2% anxiety and 87,8% worse sleep associated with stress and/or anxiety, which indicated the variables for an educational health intervention design in this context. Further, 53.2% made no effort to avoid screens before sleeping; 73.9% to avoid using the bed for work or watching television and 83.1% to avoid consuming heavy foods before sleeping. We then created an Instagram profile, @comodormimos, which focused on the main sleep issues revealed by participants in the survey. Posts on the profile were based on sleep-related subjects: sleep processes, sleep hygiene practices for students; sleep stages, function and regulation; and sleep-wake circadian rhythms. The profile gained 307 followers, mostly women (61,7%), 18-24 years old. We concluded that the Covid-10 pandemic period increased harmful sleep behavior in students. Further studies are needed to understand the impact of the COVID-19 pandemic on student sleep health.

A dynamical (e,2e) investigation into the ionization of the outermost orbitals of R-carvone.

We report an experimental and theoretical investigation into the dynamics of electron-impact ionization of R-carvone. Experimental triple differential cross sections are obtained in asymmetric coplanar kinematic conditions for the ionization of the unresolved combination of the three outermost molecular orbitals (41a-39a) of R-carvone. These cross sections are compared with theoretical cross sections calculated within a molecular 3-body distorted wave (M3DW) framework employing either a proper orientation average or orbital average to account for the random orientation of the molecule probed in the experiment. Here, we observe that the overall scattering behavior observed in the experiment is fairly well reproduced within the M3DW framework when implementing the proper average over orientations. The character of the ionized orbitals also provides some qualitative explanation for the observed scattering behavior. This represents substantial progress when trying to describe the scattering dynamics observed for larger molecules under intermediate-impact energy and asymmetric energy sharing scattering conditions.

Obstructive sleep apnea in patients with chronic rhinosinusitis with nasal polyps: a cross-sectional study.

INTRODUCTION: Adults with chronic rhinosinusitis with nasal polyps (CRSwNP) often suffer from sleep disruption and sleep apnea. As the apneic profile of CRSwNP may differ from obstructive sleep apnea (OSA) classic patients without nasal polyps (NP), it may prove useful to define a new profile for OSA screening in these patients. The aim of the current study was to compare baseline characteristics and apneic profile of OSA patients with CRSwNP to OSA patients without NP. MATERIALS AND METHODS: Thirty-one apneic patients with CRSwNP and 62 apneic cases without NP were included in our study. Both groups underwent nasal endoscopy, Epworth Sleepiness Scale (ESS) evaluation, and overnight polysomnography (PSG). We additionally accessed anthropometric characteristics such as snoring, tiredness, observed apnea, high blood pressure, body mass index (BMI), age, neck circumference, male gender, and OSA risk via the STOP-Bang questionnaire. RESULTS: Although the patients were matched according to age and gender, the median BMI and STOP-Bang score were significantly higher in patients with OSA than in those with OSA and CRSwNP. Notably, the median ESS showed low somnolence and a low median apnea-hypopnea index in patients with CRSwNP, despite the fact that the lowest median oxygen saturation was not significantly different between groups. CONCLUSIONS: Anthropometric characteristics in individuals with apnea caused by CRSwNP were significantly different from those in individuals with typical. This finding will improve screening and treatment of apneic patients CRSwNP.

Tooth crown mesiodistal measurements for the determination of sexual dimorphism across a range of populations: A systematic review and meta-analysis.

OBJECTIVE: The aim of this study was to determine whether the tooth crown sexual dimorphism pattern reported in previous small studies can be generalized for a broader range of populations. LITERATURE REVIEW: A systematic literature review was performed by two independent examiners. The following databases were searched from October 2015 to July 2016: PubMed, Scopus, Lilacs, ScienceDirect, Medline, and Cochrane Reviews. No language restrictions were applied to the search. SELECTION CRITERIA: The inclusion criteria comprised original studies investigating mesiodistal permanent teeth that reported the sample population and standard deviation. All right-sided teeth, except the third molars, were measured and separated by sex in the included studies. Thirty-one studies were included in the quantitative data synthesis and meta-analysis. Studies of non-human teeth, skeletal remains, or an overly specific study population were excluded. MAIN RESULTS: Thirty-one trials, involving 6481 participants, provided data for the meta-analysis of teeth. Sexual dimorphism in mesiodistal crowns was found in all teeth across a range of populations, principally in lower canines (5.73%) and maxillary canines (4.72%), followed by the lower second molars (3.54%) and upper second molars(3.20%), and finally in the lower first molars(3.14%) and upper first molars(2.64%). CONCLUSIONS: A small degree of sexual dimorphism exists in all human teeth. Second molars and canines show the greatest sexual dimorphism. Additionally, smaller racial differences are present in mesiodistal crowns among groups living in different geographic areas; however, it is not possible to establish a single value applicable for all populations.

Electron scattering from 1-butanol at intermediate impact energies: Total cross sections.

We report experimental measurements of the absolute total cross sections (TCSs) for electron scattering from 1-butanol at impact energies in the range 80-400 eV. Those measurements were conducted by considering the attenuation of a collimated electron beam, at a given energy, through a gas cell containing 1-butanol, at a given pressure, and through application of the Beer-Lambert law to derive the required TCS. We also report theoretical results using the Independent-Atom Model with Screening Corrected Additivity Rule and Interference approach. Those results include the TCS, the elastic integral cross section (ICS), the ionization total ICS, and the sum over all excitation process ICSs with agreement at the TCS level between our measured and calculated results being encouraging.

Visual and automatic classification of the cyclic alternating pattern in electroencephalography during sleep.

Cyclic alternating pattern (CAP) is a neurophysiological pattern that can be visually scored by international criteria. The aim of this study was to verify the feasibility of visual CAP scoring using only one channel of sleep electroencephalogram (EEG) to evaluate the inter-scorer agreement in a variety of recordings, and to compare agreement between visual scoring and automatic scoring systems. Sixteen hours of single-channel European data format recordings from four different sleep laboratories with either C4-A1 or C3-A2 channels and with different sampling frequencies were used in this study. Seven independent scorers applied visual scoring according to international criteria. Two automatic blind scorings were also evaluated. Event-based inter-scorer agreement analysis was performed. The pairwise inter-scorer agreement (PWISA) was between 55.5 and 84.3%. The average PWISA was above 60% for all scorers and the global average was 69.9%. Automatic scoring systems showed similar results to those of visual scoring. The study showed that CAP could be scored using only one EEG channel. Therefore, CAP scoring might also be integrated in sleep scoring features and automatic scoring systems having similar performances to visual sleep scoring systems.

Natural factors regulating mustard aphid dynamics in cabbage.

Lipaphis erysimi (L.) Kaltenbach (Hemiptera: Aphididae) is one of the most important pests of brassica crops, mainly causing losses due to sap sucking, toxin injection and viral transmission. Knowledge about the main natural factors that regulate populations of this pest, as well as its critical mortality stage, is crucial for the development of integrated pest management of L. erysimi. Here, we determined the critical stage and key mortality factors for L. erysimi in cabbage using an ecological life table. Causes of mortality at each stage of L. erysimi development were monitored daily in the field for seven seasons. From the experimental data, we determined the key factor and critical stage of mortality through correlation and regression analyses. The nymphal stage, especially first instar nymphs, was critical for L. erysimi mortality. The key mortality factors were, in descending order of importance, physiological disturbances and predation by Syrphidae, Coccinellidae and Solenopsis ants. Therefore, control measures should target early stages of L. erysimi and the use of cabbage cultivars that have negative effects against L. erysimi may be a promising strategy for its management. Our results may be useful for plant geneticists who could develop new cabbage cultivars based on these findings. In addition, conservation measures of the main predators of L. erysimi may contribute to the natural control of this pest.

Visual and automatic classification of the cyclic alternating pattern in electroencephalography during sleep

Cyclic alternating pattern (CAP) is a neurophysiological pattern that can be visually scored by international criteria. The aim of this study was to verify the feasibility of visual CAP scoring using only one channel of sleep electroencephalogram (EEG) to evaluate the inter-scorer agreement in a variety of recordings, and to compare agreement between visual scoring and automatic scoring systems. Sixteen hours of single-channel European data format recordings from four different sleep laboratories with either C4-A1 or C3-A2 channels and with different sampling frequencies were used in this study. Seven independent scorers applied visual scoring according to international criteria. Two automatic blind scorings were also evaluated. Event-based inter-scorer agreement analysis was performed. The pairwise inter-scorer agreement (PWISA) was between 55.5 and 84.3%. The average PWISA was above 60% for all scorers and the global average was 69.9%. Automatic scoring systems showed similar results to those of visual scoring. The study showed that CAP could be scored using only one EEG channel. Therefore, CAP scoring might also be integrated in sleep scoring features and automatic scoring systems having similar performances to visual sleep scoring systems.

Effect of watershed land use on water quality: a case study in Córrego da Olaria Basin, São Paulo State, Brazil / Efeito do uso do solo em sub-bacias na qualidade da água: um estudo de caso na Bacia do Córrego da Olaria, Estado de São Paulo, Brasil

Abstract The water quality is related to the hydrologic and limnologic properties of ground and surface water, and significant efforts have been made to monitor water sources to understand the effects of land use changes in agricultural areas, with significant socioeconomic activities. The objective of this study was to evaluate the qualitative aspects of surface water in subbasins related to land use. Samples were analyzed in terms of physical and chemical parameters on monthly discrete water quality sampling in four representative sites at first order subbasin streams, located at the Polo Regional Centro Norte, Pindorama County, State of São Paulo, Brazil. The land use classification was made by visual detection technique in a multispectral satellite data obtained from LandSat8- spectral bands of the OLI sensor. The watershed was classified into major land cover/use classes and overlay maps generated in ArcGIS 10 indicated a significant shift from natural vegetation to agriculture activities. Water quality monitoring was according to the brazilian protocol and the results were submitted to analysis of variance (ANOVA). The values obtained differ significantly at each sampling point - subbasins, reflecting the effects of land use on water quality. Soil conservation management is important to optimize soil use in order to contribute to the control of water pollution and the formulation of a public policy is necessary for the conservation of water and soil resources.

Resumo A qualidade da água está relacionada com as propriedades hidrológicas e limnológicas das águas subterrâneas e superficiais, e esforços significativos devem ser realizados para monitorar as nascentes no intuito de compreender os efeitos das mudanças no uso da terra em áreas agrícolas, com atividades socioeconômicas significativas. O objetivo deste estudo foi avaliar os aspectos qualitativos das águas superficiais de bacias hidrográficas e correlacionar com o uso do solo. As amostras foram analisadas em termos dos parâmetros físicos e químicos na amostragem mensal discreta da qualidade da água, em quatro locais representativos de nascentes em microbacias de primeira ordem, localizadas no Polo Regional Centro Norte, Pindorama, Estado de São Paulo, Brasil. A classificação do uso do solo foi feita por técnica de detecção visual em uma imagem multiespectral de satélite LandSat8- bandas espectrais, sensor OLI. O uso do solo foi classificado nas principais classes de uso e os mapas de sobreposição gerados no ArcGIS 10 indicaram uma mudança significativa da vegetação natural para as atividades agrícolas. O monitoramento da qualidade da água foi realizado de acordo com o protocolo brasileiro e os resultados foram submetidos à análise de variância (ANOVA). Os valores obtidos diferem significativamente em cada ponto de amostragem, refletindo os efeitos do uso do solo sobre a qualidade da água. A gestão do solo e da água é importante para aperfeiçoar as práticas agrícolas, no intuito de contribuir para o controle da poluição da água e para a formulação de uma política pública necessária para a conservação dos recursos hídricos e do solo.

Effect of watershed land use on water quality: a case study in Córrego da Olaria Basin, São Paulo State, Brazil.

The water quality is related to the hydrologic and limnologic properties of ground and surface water, and significant efforts have been made to monitor water sources to understand the effects of land use changes in agricultural areas, with significant socioeconomic activities. The objective of this study was to evaluate the qualitative aspects of surface water in subbasins related to land use. Samples were analyzed in terms of physical and chemical parameters on monthly discrete water quality sampling in four representative sites at first order subbasin streams, located at the Polo Regional Centro Norte, Pindorama County, State of São Paulo, Brazil. The land use classification was made by visual detection technique in a multispectral satellite data obtained from LandSat8- spectral bands of the OLI sensor. The watershed was classified into major land cover/use classes and overlay maps generated in ArcGIS 10 indicated a significant shift from natural vegetation to agriculture activities. Water quality monitoring was according to the brazilian protocol and the results were submitted to analysis of variance (ANOVA). The values obtained differ significantly at each sampling point - subbasins, reflecting the effects of land use on water quality. Soil conservation management is important to optimize soil use in order to contribute to the control of water pollution and the formulation of a public policy is necessary for the conservation of water and soil resources.

Total cross sections for electron scattering by 1-propanol at impact energies in the range 40-500 eV.

Absolute total cross section (TCS) measurements for electron scattering from 1-propanol molecules are reported for impact energies from 40 to 500 eV. These measurements were obtained using a new apparatus developed at Juiz de Fora Federal University-Brazil, which is based on the measurement of the attenuation of a collimated electron beam through a gas cell containing the molecules to be studied at a given pressure. Besides these experimental measurements, we have also calculated TCS using the Independent-Atom Model with Screening Corrected Additivity Rule and Interference (IAM-SCAR+I) approach with the level of agreement between them being typically found to be very good.

Microglia-glioblastoma interactions: New role for Wnt signaling.

Glioblastoma, the most aggressive and fatal type of brain tumor, is capable of interacting with brain immune cells such as microglia, which contributes to the growth of these tumors. Various molecules, including growth factors and cytokines, have been identified as regulators of microglia-glioblastoma interaction. Recent studies suggest that the Wnt family of lipoglycoproteins plays an important role, not only in biological events during development, but also in cancer progression, and can be part of microglia recruitment to glioblastoma as well as of tumor growth and invasion. Here, we discuss recent interesting findings that support a role for Wnt signaling pathways in the microglia-glioblastoma crosstalk.

Optimization of Image Quality and Dose in Digital Mammography.

Nowadays, the optimization in digital mammography is one of the most important challenges in diagnostic radiology. The new digital technology has introduced additional elements to be considered in this scenario. A major goal of mammography is related to the detection of structures on the order of micrometers (µm) and the need to distinguish the different types of tissues, with very close density values. The diagnosis in mammography faces the difficulty that the breast tissues and pathological findings have very close linear attenuation coefficients within the energy range used in mammography. The aim of this study was to develop a methodology for optimizing exposure parameters of digital mammography based on a new Figure of Merit: FOM ≡ (IQFinv)2/AGD, considering the image quality and dose. The study was conducted using the digital mammography Senographe DS/GE, and CDMAM and TORMAM phantoms. The characterization of clinical practice, carried out in the mammography system under study, was performed considering different breast thicknesses, the technical parameters of exposure, and processing options of images used by the equipment's automatic exposure system. The results showed a difference between the values of the optimized parameters and those ones chosen by the automatic system of the mammography unit, specifically for small breast. The optimized exposure parameters showed better results than those obtained by the automatic system of the mammography, for the image quality parameters and its impact on detection of breast structures when analyzed by radiologists.

Treatment failure prediction for head-and-neck cancer radiation therapy.

PURPOSE: Treatment outcome prediction is an important emerging topic in oncologic care. To support radiation oncologists on their decisions, with individualized, tailored treatment regimens increasingly becoming the standard of care, accurate tools to predict tumour response to treatment are needed. The goal of this work is to identify the most determinant factor(s) for treatment response aiming to develop prediction models that robustly estimate tumour response to radiation therapy in patients with head-and-neck cancer. PATIENTS AND METHODS: A population-based cohort study was performed on 92 patients with head-and-neck cancer treated with radiation from 2007 until 2014 at the Portuguese Institute of Oncology of Coimbra (IPOCFG). Correlation analysis and multivariate binary logistic regression analysis were conducted in order to explore the predictive power of the considered predictors. Performance of the models is expressed as the area under the curve (AUC) of the receiver operating characteristics (ROC) curve. A nomogram to predict treatment failure was developed. RESULTS: Significant prognostic factors for treatment failure, after multivariate regression, were older age, non-concomitant radiation therapy and larger primary tumour volume. A regression model with these predictors revealed an AUC of .78 for an independent data set. CONCLUSION: For patients with head-and-neck cancer treated with definitive radiation, we have developed a prediction nomogram based on models that presented good discriminative ability in making predictions of tumour response to treatment. The probability of treatment failure is higher for older patients with larger tumours treated with non-concomitant radiation.

Theoretical and experimental differential cross sections for electron impact excitation of the electronic bands of furfural.

We report results from a joint experimental and theoretical investigation into electron scattering from the important industrial species furfural (C5H4O2). Specifically, differential cross sections (DCSs) have been measured and calculated for the electron-impact excitation of the electronic states of C5H4O2. The measurements were carried out at energies in the range 20-40 eV, and for scattered-electron angles between 10° and 90°. The energy resolution of those experiments was typically ∼80 meV. Corresponding Schwinger multichannel method with pseudo-potential calculations, for energies between 6-50 eV and with and without Born-closure, were also performed for a sub-set of the excited electronic-states that were accessed in the measurements. Those calculations were undertaken at the static exchange plus polarisation-level using a minimum orbital basis for single configuration interaction (MOB-SCI) approach. Agreement between the measured and calculated DCSs was qualitatively quite good, although to obtain quantitative accord, the theory would need to incorporate even more channels into the MOB-SCI. The role of multichannel coupling on the computed electronic-state DCSs is also explored in some detail.

Adenosine diphosphate involvement in THP-1 maturation triggered by the contact allergen 1-fluoro-2,4-dinitrobenzene.

Dendritic cells' (DC) activation is considered a key event in the adverse outcome pathway for skin sensitization elicited by covalent binding of chemicals to proteins. The mechanisms underlying DC activation by contact sensitizers are not completely understood. However, several "danger signals" are pointed as relevant effectors. Among these extra-cellular early danger signals, purines may be crucial for the development of xenoinflammation and several reports indicate their involvement in contact allergic reactions. In the present work we used the DC-surrogate monocytic cell line THP-1, cultured alone or co-cultured with the human keratinocyte cell line HaCaT, to explore the contribution of extracellular adenine nucleotides to THP-1 maturation triggered by the extreme contact sensitizer, 1-fluoro-2,4-dinitrobenzene (DNFB). We found that THP-1 maturation induced by DNFB is impaired after purinergic signaling inhibition, and that the transcription of the purinergic metabotropic receptors P2Y2 and P2Y11 is modulated by the sensitizer. We also detected that THP-1 cells only partially hydrolyse extracellular adenosine triphosphate, leading to accumulation of the mono-phosphate derivative, AMP. We detected different and non-overlapping activation patterns of mitogen activated protein kinases by DNFB and extracellular nucleotides. Overall, our results indicate that THP-1 maturation induced by DNFB is strongly modulated by extracellular adenine nucleotides through metabotropic purinergic receptors. This knowledge unveils a molecular toxicity pathway evoked by sensitizers and involved in THP-1 maturation, a DC-surrogate cell line thoroughly used in in vitro tests for the identification of skin allergens.

Compliance to radiation therapy of head and neck cancer patients and impact on treatment outcome.

AIMS: The aims of the study were to evaluate head and neck cancer (HNC) patient's compliance to the planned radiation therapy (RT) using the department policy established in 2005 at IPOCFG and to estimate the impact on treatment outcome due to failure in receiving RT as prescribed. MATERIALS AND METHODS: 359 HNC patients irradiated from 2007 to 2013 were included in this study. Patient cohort was divided into Group 1: patients receiving RT as prescribed and Group 2: patients that interrupted or suspended RT. Group Tox is the subgroup of patients that interrupted RT due to toxicity or intercurrent disease. Number and causes for treatment interruptions were assessed. The cumulative incidence of locoregional control (LRC), disease-free survival (DFS) and overall survival for Groups 1 and 2 was determined. Cox regression was performed to investigate potential hazard factors and logistic regression was made to determine risk factors related to treatment interruptions. RESULTS: Major causes for treatment interruptions were toxicity plus intercurrent disease (41.7 %) and public holidays (30.1 %). 10.3 % of the patients interrupted 3-9 days. Significant differences in survival distributions of the LRC between Groups 1 and 2, of up to 19 %, were found in the subgroup of patients with N2-3 tumours, for post-operative RT and for concomitant RT. Treatment breaks larger than two days had an almost fourfold increased risk of poorer LRC and DFS. CONCLUSIONS: Twin accelerators and treating on public holidays are effective measures minimizing RT breaks. For HNC, patient compliance is mostly limited by RT side-effects. Efforts to maintain RT biological effective dose in HNC must be always undertaken.