22 research outputs found

    International Guideline on Dose Prioritization and Acceptance Criteria in Radiation Therapy Planning for Nasopharyngeal Carcinoma

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    Purpose: The treatment of nasopharyngeal carcinoma requires high radiation doses. The balance of the risks of local recurrence owing to inadequate tumor coverage versus the potential damage to the adjacent organs at risk (OARs) is of critical importance. With advancements in technology, high target conformality is possible. Nonetheless, to achieve the best possible dose distribution, optimal setting of dose targets and dose prioritization for tumor volumes and various OARs is fundamental. Radiation doses should always be guided by the As Low As Reasonably Practicable principle. There are marked variations in practice. This study aimed to develop a guideline to serve as a global practical reference. Methods and Materials: A literature search on dose tolerances and normal-tissue complications after treatment for nasopharyngeal carcinoma was conducted. In addition, published guidelines and protocols on dose prioritization and constraints were reviewed. A text document and preliminary set of variants was circulated to a panel of international experts with publications or extensive experience in the field. An anonymized voting process was conducted to rank the proposed variants. A summary of the initial voting and different opinions expressed by members were then recirculated to the whole panel for review and reconsideration. Based on the comments of the panel, a refined second proposal was recirculated to the same panel. The current guideline was based on majority voting after repeated iteration for final agreement. Results: Variation in opinion among international experts was repeatedly iterated to develop a guideline describing appropriate dose prioritization and constraints. The percentage of final agreement on the recommended parameters and alternative views is shown. The rationale for the recommendations and the limitations of current evidence are discussed. Conclusions: Through this comprehensive review of available evidence and interactive exchange of vast experience by international experts, a guideline was developed to provide a practical reference for setting dose prioritization and acceptance criteria for tumor volumes and OARs. The final decision on the treatment prescription should be based on the individual clinical situation and the patient's acceptance of optimal balance of risk. (C) 2019 Elsevier Inc. All rights reserved

    International Recommendations on Reirradiation by Intensity Modulated Radiation Therapy for Locally Recurrent Nasopharyngeal Carcinoma

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    Purpose: Reirradiation for locally recurrent nasopharyngeal carcinoma (NPC) is challenging because prior radiation dose delivered in the first course is often close to the tolerance limit of surrounding normal structures. A delicate balance between achieving local salvage and minimizing treatment toxicities is needed. However, high-level evidence is lacking because available reports are mostly retrospective studies on small series of patients. Pragmatic consensus guidelines, based on an extensive literature search and the pooling of opinions by leading specialists, will provide a useful reference to assist decision-making for these difficult decisions. Methods and Materials: A thorough review of available literature on recurrent NPC was conducted. A set of questions and preliminary draft guideline was circulated to a panel of international specialists with extensive experience in this field for voting on controversial areas and comments. A refined second proposal, based on a summary of the initial voting and different opinions expressed, was recirculated to the whole panel for review and reconsideration. The current guideline was based on majority voting after repeated iteration for final agreement. Results: The initial round of questions showed variations in clinical practice even among the specialists, reflecting the lack of high-quality supporting data and the difficulties in formulating clinical decisions. Through exchange of comments and iterative revisions, recommendations with high-to-moderate agreement were formulated on general treatment strategies and details of reirradiation (including patient selection, targets contouring, dose prescription, and constraints). Conclusion: This paper provides useful reference on radical salvage treatment strategies for recurrent NPC and optimization of reirradiation through review of published evidence and consensus building. However, the final decision by the attending clinician must include full consideration of an individual patient's condition, understanding of the delicate balance between risk and benefits, and acceptance of risk of complications. (C) 2021 Elsevier Inc. All rights reserved

    Elizabethkingia anophelis and Association with Tap Water and Handwashing, Singapore

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    We report an Elizabethkingia anophelis case cluster associated with contaminated aerators and tap water in a children’s intensive care unit in Singapore in 2017. We demonstrate a likely transmission route for E. anophelis to patients through acquisition of the bacteria on hands of healthcare workers via handwashing

    An assessment of the magnitude of intra-fraction movement of head-and-neck IMRT cases and its implication on the action-level of the imaging protocol.

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    BACKGROUND AND PURPOSE: A planning margin ⩽3mm is employed in some head-and-neck IMRT cases due to the proximity of critical structures. This study aims to explore the need to redefine the action-level in the head-and-neck imaging protocol in consideration of the intra-fraction movement. MATERIAL AND METHODS: This is a local study of 18 patients treated using the same immobilisation system and setup protocol. Post-treatment orthogonal pair of kilovoltage X-ray images was acquired on the first three days of treatment. 106 sets of pre- and post-treatment kV X-ray images acquired over 53 fractions were analysed against the treatment planning DRR for calculation of intra-fraction movement. RESULTS: Individual mean intra-fraction movement in all directions ranged from -1.8 to 1.1mm. Population mean (median) intra-fraction movement in the x-, y-, and z-planes were -0.1mm (0mm), -0.3mm (-0.3mm) and -0.2mm (-0.2mm) respectively. Intra-fraction movement in all three dimensions, x-, y- and z-planes were considered statistically significant (p<0.05). 7 out of 53 fractions (13.2%) were highlighted as the combined magnitude of the intra-fraction motion with the uncorrected pre-treatment setup errors had exceeded the boundaries of given margins. CONCLUSIONS: 3mm-AL was not adequate to account for intra-fraction movement when the CTV-PTV margin was ⩽3mm and should be excluded from the routine imaging protocol and daily image-guided radiotherapy should be employed. Adjusting the action-level to 2mm would allow a more confident approach in delivery of the prescribed dose in head-and-neck IMRT cases

    Changing self-concept in the time of COVID-19: a close look at physician reflections on social media.

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    BackgroundThe COVID-19 pandemic has changed the healthcare landscape drastically. Stricken by sharp surges in morbidity and mortality with resource and manpower shortages confounding their efforts, the medical community has witnessed high rates of burnout and post-traumatic stress amongst themselves. Whilst the prevailing literature has offered glimpses into their professional war, no review thus far has collated the deeply personal reflections of physicians and ascertained how their self-concept, self-esteem and perceived self-worth has altered during this crisis. Without adequate intervention, this may have profound effects on their mental and physical health, personal relationships and professional efficacy.MethodsWith mentions of the coronavirus pervading social media by the millions, this paper set out to collate and thematically analyse social media posts containing first-person physician reflections on how COVID-19 affected their lives and their coping mechanisms. A consistent search strategy was employed and a PRISMA flowchart was used to map out the inclusion/exclusion criteria.ResultsA total of 590 social media posts were screened, 511 evaluated, and 108 included for analysis. Salient themes identified include Disruptions to Personal Psycho-Emotional State, Disruptions to Professional Care Delivery, Concern for Family, Response from Institution, Response from Society and Coping Mechanisms.ConclusionIt is evident that the distress experienced by physicians during this time has been manifold, multi-faceted and dominantly negative. Self-concepts were distorted with weakened self-esteem and perceived self-worth observed. The Ring Theory of Personhood (RToP) was adopted to explain COVID-19's impact on physician personhood as it considers existential, individual, relational and social concepts of the self. These entwined self-concepts serve as 'compensatory' to one another, with coping mechanisms buffering and fortifying the physician's overall personhood. With healthcare institutions playing a vital role in providing timely and targeted support, it was further proposed that a comprehensive assessment tool based on the RToP could be developed to detect at-risk physicians and evaluate the presence and effectiveness of established support structures
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