23 research outputs found
Robust dose planning objectives for mesorectal radiotherapy of early stage rectal cancer – A multicentre dose planning study
Background and purpose
Organ preservation strategies are increasingly being explored for early rectal cancer. This requires revision of target volumes according to disease stage, as well as new guidelines for treatment planning. We conducted an international, multicentre dose planning study to develop robust planning objectives for modern radiotherapy of a novel mesorectal-only target volume, as implemented in the STAR-TReC trial (NCT02945566).
Materials and methods
The published literature was used to establish relevant dose levels for organ at risk (OAR) plan optimisation. Ten representative patients with early rectal cancer were identified. Treatment scans had mesorectal target volumes as well as bowel cavity, bladder and femoral heads outlined, and were circulated amongst the three participating institutions. Each institution produced plans for short course (SCRT, 5 × 5 Gy) and long course (LCRT, 25 × 2 Gy) treatment, using volumetric modulated arc therapy on different dose planning systems. Optimisation objectives for OARs were established by determining dose metric objectives achievable for ≥90% of plans.
Results
Sixty plans, all fulfilling target coverage criteria, were produced. The planning results and literature review suggested optimisation objectives for SCRT: V10Gy < 180 cm3, V18Gy < 110 cm3, V23Gy < 85 cm3 for bowel cavity; V21Gy < 15% and V25Gy < 5% for bladder; and V12.5Gy < 11% for femoral heads. Corresponding objectives for LCRT: V20Gy < 180 cm3, V30Gy < 130 cm3, V45Gy < 90 cm3 for bowel cavity; V35Gy < 22% and V50Gy < 7% for bladder; and V25Gy < 15% for femoral heads. Constraints were validated across all three institutions.
Conclusion
We utilized a multicentre planning study approach to develop robust planning objectives for mesorectal radiotherapy for early rectal cancer
The effectiveness of a web-based self-help intervention to reduce suicidal thoughts: A randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Suicide, attempted suicide and suicidal thoughts are major public health problems worldwide. Effective face-to-face treatments are Cognitive Behavioural Therapy (CBT), Dialectical Behavioural Therapy (DBT) and Problem Solving Treatment (PST). However, about two-thirds of persons who die by suicide have not been in contact with mental health care services in the preceding year, and many have never been treated. Furthermore, many patients do not disclose their suicidal thoughts to their care provider. This may be out of shame, due to fear of stigma or due to lack of trust in (mental) health care. Since many suicidal individuals seek information online, the internet provides an opportunity to reach suicidal individuals who would not be contacted otherwise. By providing a self-help intervention online, persons can anonymously learn to gain control over their suicidal thoughts. There is convincing evidence that self-help is effective for a number of mental disorders. In this study the effectiveness for suicidal thoughts is examined.</p> <p>Methods/Design</p> <p>In this study, a recently developed self-help intervention will be evaluated in a Randomized Controlled Trial. The intervention is based on Cognitive Behavioural Therapy and is aimed at subjects who experience mild to moderate suicidal thoughts. This is defined as a score between 1 and 26 on the Beck Scale for Suicidal Ideation (BSS). Higher and lower scores are excluded. In addition, severely depressed subjects are excluded. In total, 260 subjects will be randomly allocated to the intervention-condition (N = 130) or to the information-control condition (N = 130). Self-report questionnaires will be filled out at baseline, 6 weeks after baseline and 18 weeks after baseline. Primary outcome measure is the reduction in frequency and intensity of suicidal thoughts. Secondary outcome measures are the reduction of hopelessness, anxiety and depression, sleeplessness, worry and quality of life measures.</p> <p>Discussion</p> <p>This study is the first to evaluate the effectiveness of a web-based self-help intervention for suicidal thoughts. Several limitations and strengths of the design are discussed.</p> <p>Trial Registration</p> <p>Netherlands Trial Register, NTR1689</p
Hand osteoarthritis: clinical phenotypes, molecular mechanisms and disease management
Osteoarthritis (OA) is a highly prevalent condition and the hand is the most commonly affected site. Patients with hand OA frequently report symptoms of pain, functional limitations, and frustration in undertaking everyday activities. The condition presents clinically with changes to the bone, ligaments, cartilage and synovial tissue, which can be observed using radiography, ultrasonography or MRI. Hand OA is a heterogeneous disorder and is considered to be multifactorial in aetiology. This review provides an overview of the epidemiology, presentation and burden of hand OA, including an update on hand OA imaging (including the development of novel techniques), disease mechanisms and management. In particular, areas for which new evidence has substantially changed the way we understand, consider and treat hand OA are highlighted. For example, genetic studies, clinical trials and careful prospective imaging studies from the past 5 years are beginning to provide insights into the pathogenesis of hand OA that might uncover new therapeutic targets in disease
A genome-wide association study identifies an osteoarthritis susceptibility locus on chromosome 7q22.
OBJECTIVE: To identify novel genes involved in osteoarthritis (OA), by means of a genome-wide association study. METHODS: We tested 500,510 single-nucleotide polymorphisms (SNPs) in 1,341 Dutch Caucasian OA cases and 3,496 Dutch Caucasian controls. SNPs associated with at least 2 OA phenotypes were analyzed in 14,938 OA cases and approximately 39,000 controls. Meta-analyses were performed using the program Comprehensive Meta-analysis, with P values <1 x 10(-7) considered genome-wide significant. RESULTS: The C allele of rs3815148 on chromosome 7q22 (minor allele frequency 23%; intron 12 of the COG5 gene) was associated with a 1.14-fold increased risk (95% confidence interval 1.09-1.19) of knee and/or hand OA (P = 8 x 10(-8)) and also with a 30% increased risk of knee OA progression (95% confidence interval 1.03-1.64) (P = 0.03). This SNP is in almost complete linkage disequilibrium with rs3757713 (68 kb upstream of GPR22), which is associated with GPR22 expression levels in lymphoblast cell lines (P = 4 x 10(-12)). Immunohistochemistry experiments revealed that G protein-coupled receptor protein 22 (GPR22) was absent in normal mouse articular cartilage or synovium. However, GPR22-positive chondrocytes were found in the upper layers of the articular cartilage of mouse knee joints that were challenged with in vivo papain treatment or methylated bovine serum albumin treatment. GPR22-positive chondrocyte-like cells were also found in osteophytes in instability-induced OA. CONCLUSION: Our findings identify a novel common variant on chromosome 7q22 that influences susceptibility to prevalence and progression of OA. Since the GPR22 gene encodes a G protein-coupled receptor, this is potentially an interesting therapeutic target
A genome-wide association study identifies an osteoarthritis susceptibility locus on chromosome 7q22
Implementation of Functional Genomics for Bench-to-Bedside Transition in Osteoarthritis
Molecular Epidemiolog