358 research outputs found

    Postoperative IMRT in head and neck cancer

    Get PDF
    BACKGROUND: Aim of this work was to assess loco-regional disease control in head and neck cancer (HNC) patients treated with postoperative intensity modulated radiation therapy (pIMRT). For comparative purposes, risk features of our series have been analysed with respect to histopathologic adverse factors. Results were compared with an own historic conventional radiation (3DCRT) series, and with 3DCRT and pIMRT data from other centres. Between January 2002 and August 2006, 71 patients were consecutively treated with pIMRT for a squamous cell carcinoma (SCC) of the oropharynx (32), oral cavity (22), hypopharynx (7), larynx (6), paranasal sinus (3), and an unknown primary, respectively. Mean and median follow up was 19 months (2–48), and 17.6 months. 83% were treated with IMRT-chemotherapy. Mean prescribed dose was 66.3 Gy (60–70), delivered with doses per fraction of 2–2.3 Gy, respectively. RESULTS: 2-year local, nodal, and distant control rates were 95%, 91%, and 96%, disease free and overall survival 90% and 83%, respectively. The corresponding survival rates for the subgroup of patients with a follow up time >12 months (n = 43) were 98%, 95%, 98%, 93%, and 88%, respectively. Distribution according to histopathologic risk features revealed 15% and 85% patients with intermediate and high risk, respectively. All loco-regional events occurred in the high risk subgroup. CONCLUSION: Surgery followed by postoperative IMRT in patients with substantial risk for recurrence resulted in high loco-regional tumor control rates compared with large prospective 3DCRT trials

    IsoBED: a tool for automatic calculation of biologically equivalent fractionation schedules in radiotherapy using IMRT with a simultaneous integrated boost (SIB) technique

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>An advantage of the Intensity Modulated Radiotherapy (IMRT) technique is the feasibility to deliver different therapeutic dose levels to PTVs in a single treatment session using the Simultaneous Integrated Boost (SIB) technique. The paper aims to describe an automated tool to calculate the dose to be delivered with the SIB-IMRT technique in different anatomical regions that have the same Biological Equivalent Dose (BED), i.e. IsoBED, compared to the standard fractionation.</p> <p>Methods</p> <p>Based on the Linear Quadratic Model (LQM), we developed software that allows treatment schedules, biologically equivalent to standard fractionations, to be calculated. The main radiobiological parameters from literature are included in a database inside the software, which can be updated according to the clinical experience of each Institute. In particular, the BED to each target volume will be computed based on the alpha/beta ratio, total dose and the dose per fraction (generally 2 Gy for a standard fractionation). Then, after selecting the reference target, i.e. the PTV that controls the fractionation, a new total dose and dose per fraction providing the same isoBED will be calculated for each target volume.</p> <p>Results</p> <p>The IsoBED Software developed allows: 1) the calculation of new IsoBED treatment schedules derived from standard prescriptions and based on LQM, 2) the conversion of the dose-volume histograms (DVHs) for each Target and OAR to a nominal standard dose at 2Gy per fraction in order to be shown together with the DV-constraints from literature, based on the LQM and radiobiological parameters, and 3) the calculation of Tumor Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) curve versus the prescribed dose to the reference target.</p

    Image-guided intensity modulated radiotherapy with helical tomotherapy for postoperative treatment of high-risk oral cavity cancer

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to assess the treatment results and toxicity profiles of helical tomotherapy (HT) for postoperative high-risk oral cavity cancer.</p> <p>Methods</p> <p>From December 6, 2006 through October 9, 2009, 19 postoperative high-risk oral cavity cancer patients were enrolled. All of the patients received HT with (84%) or without (16%) chemotherapy.</p> <p>Results</p> <p>The median follow-up time was 17 months. The 2-year overall survival, disease-free survival, locoregional control, and distant metastasis-free rates were 94%, 84%, 92%, and 94%, respectively. The package of overall treatment time > 13 wk, the interval between surgery and radiation ≤ 6 wk, and the overall treatment time of radiation ≤ 7 wk was 21%, 84%, and 79%, respectively. The percentage of grade 3 mucositis, dermatitis, and leucopenia was 42%, 5% and 5%, respectively.</p> <p>Conclusions</p> <p>HT achieved encouraging clinical outcomes for postoperative high-risk oral cavity cancer patients with high compliance. A long-term follow-up study is needed to confirm these preliminary findings.</p

    Pharmaceutical electrochemistry: the electrochemical detection of aspirin utilising screen printed graphene electrodes as sensors platforms.

    Get PDF
    A sensitive electrochemical sensor was designed for acetyl salicylic acid detection using graphene modified Screen Printed Electrodes. The electrochemical response of the sensor with graphene was improved compared to Screen Printed Electrodes without graphene and displayed an excellent analytical performance for the detection of acetyl salicylic acid. The high acetyl salicylic acid loading capacity on the electrode surface and the outstanding electric conductivity of graphene were also discussed in this manuscript. When a range of different concentrations of acetyl salicylic acid from 0.1 to 100 μM into a pH 4 buffer solution (N defined as the sample size N = 9) were plotted against the oxidation peak a linear response was observed. The detection limit was found to be 0.09 μM based on (3-σ/slope). Screen Printed Graphene electrodes sensors methodology is shown to be useful for quantifying low levels of acetyl salicylic acid in a buffer solution as well as in biological matrixes such as human oral fluid. A linear response was obtained over a range of concentrations from 10 to 150 μM into a human oral fluid solution (N = 10) giving a detection limit of 8.7 μM

    Long-term outcome and patterns of failure in patients with advanced head and neck cancer

    Get PDF
    <p>Abstract</p> <p>Purpose</p> <p>To access the long-time outcome and patterns of failure in patients with advanced head and neck squamous cell carcinoma (HNSCC).</p> <p>Methods and materials</p> <p>Between 1992 and 2005 127 patients (median age 55 years, UICC stage III n = 6, stage IV n = 121) with primarily inoperable, advanced HNSCC were treated with definite platinum-based radiochemotherapy (median dose 66.4 Gy). Analysed end-points were overall survival (OS), disease-free survival (DFS), loco-regional progression-free survival (LPFS), development of distant metastases (DM), prognostic factors and causes of death.</p> <p>Results</p> <p>The mean follow-up time was 34 months (range, 3-156 months), the 3-, 5- and 10-year OS rates were 39%, 28% and 14%, respectively. The median OS was 23 months. Forty-seven patients achieved a complete remission and 78 patients a partial remission. The median LPFS was 17 months, the 3-, 5- and 10-year LPFS rates were 41%, 33% and 30%, respectively. The LPFS was dependent on the nodal stage (p = 0.029). The median DFS was 11 months (range, 2-156 months), the 3-, 5- and 10-year DFS rates were 30%, 24% and 22%, respectively. Prognostic factors in univariate analyses were alcohol abuse (n = 102, p = 0.015), complete remission (n = 47, p < 0.001), local recurrence (n = 71, p < 0.001), development of DM (n = 45, p < 0.001; median OS 16 months) and borderline significance in nodal stage N2 versus N3 (p = 0.06). Median OS was 26 months with lung metastases (n = 17). Nodal stage was a predictive factor for the development of DM (p = 0.025). Cause of death was most commonly tumor progression.</p> <p>Conclusions</p> <p>In stage IV HNSCC long-term survival is rare and DM is a significant predictor for mortality. If patients developed DM, lung metastases had the most favourable prognosis, so intensified palliative treatment might be justified in DM limited to the lungs.</p

    Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

    Get PDF
    Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition

    Equity Ownership Strategy in Greenfield Investments : Influences of Host Country Infrastructure and MNE Resources in Emerging Markets

    Get PDF
    This chapter addresses equity ownership strategy in greenfield investments by multinational enterprises (MNEs) in the emerging markets (EMs). It is one of the few studies to hypothesize and analyze influences of host EM physical infrastructure in relation to investment decisions of MNEs. We use resource dependence theory (RDT) as a theoretical basis and test the moderating effects of firm resources like size and host country investment experience. Moreover, the current study assumes a more nuanced approach to studying equity ownership by analyzing wholly owned subsidiaries versus joint ventures (JVs) and including majority versus minority JVs in the analysis as well. The empirical results based on greenfield investments undertaken by Nordic (Danish, Finnish, Norwegian, and Swedish) MNEs in EMs during 1990–2015 reveals the importance of host country physical infrastructure for high equity ownership strategy. Moreover, host country investment experience moderates the effect of physical infrastructure on equity ownership strategy. Finally, the analysis of a sub-sample of greenfield JVs reveals that determinants of equity ownership strategy differ somewhat between greenfield JV or greenfield wholly owned subsidiaries (WOS).© The Author(s) 2019.fi=vertaisarvioitu|en=peerReviewed

    Cyclic AMP signalling pathways in the regulation of uterine relaxation

    Get PDF
    Studying the mechanism(s) of uterine relaxation is important and will be helpful in the prevention of obstetric difficulties such as preterm labour, which remains a major cause of perinatal mortality and morbidity. Multiple signalling pathways regulate the balance between maintaining relative uterine quiescence during gestation, and the transition to the contractile state at the onset of parturition. Elevation of intracellular cyclic AMP promotes myometrial relaxation, and thus quiescence, via effects on multiple intracellular targets including calcium channels, potassium channels and myosin light chain kinase. A complete understanding of cAMP regulatory pathways (synthesis and hydrolysis) would assist in the development of better tocolytics to delay or inhibit preterm labour. Here we review the enzymes involved in cAMP homoeostasis (adenylyl cyclases and phosphodiesterases) and possible myometrial substrates for the cAMP dependent protein kinase. We must emphasise the need to identify novel pharmacological targets in human pregnant myometrium to achieve safe and selective uterine relaxation when this is indicated in preterm labour or other obstetric complications

    Phase II study of induction chemotherapy with TPF followed by radioimmunotherapy with Cetuximab and intensity-modulated radiotherapy (IMRT) in combination with a carbon ion boost for locally advanced tumours of the oro-, hypopharynx and larynx - TPF-C-HIT

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Long-term locoregional control in locally advanced squamous cell carcinoma of the head and neck (SCCHN) remains challenging. While recent years have seen various approaches to improve outcome by intensification of treatment schedules through introduction of novel induction and combination chemotherapy regimen and altered fractionation regimen, patient tolerance to higher treatment intensities is limited by accompanying side-effects. Combined radioimmunotherapy with cetuximab as well as modern radiotherapy techniques such as intensity-modulated radiotherapy (IMRT) and carbon ion therapy (C12) are able to limit toxicity while maintaining treatment effects. In order to achieve maximum efficacy with yet acceptable toxicity, this sequential phase II trial combines induction chemotherapy with docetaxel, cisplatin, and 5-FU (TPF) followed by radioimmunotherapy with cetuximab as IMRT plus carbon ion boost. We expect this approach to result in increased cure rates with yet manageable accompanying toxicity.</p> <p>Methods/design</p> <p>The TPF-C-HIT trial is a prospective, mono-centric, open-label, non-randomized phase II trial evaluating efficacy and toxicity of the combined treatment with IMRT/carbon ion boost and weekly cetuximab in 50 patients with histologically proven locally advanced SCCHN following TPF induction chemotherapy. Patients receive 24 GyE carbon ions (8 fractions) and 50 Gy IMRT (2.0 Gy/fraction) in combination with weekly cetuximab throughout radiotherapy. Primary endpoint is locoregional control at 12 months, secondary endpoints are disease-free survival, progression-free survival, overall survival, acute and late radiation effects as well as any adverse events of the treatment as well as quality of life (QoL) analyses.</p> <p>Discussion</p> <p>The primary objective of TPF-C-HIT is to evaluate efficacy and toxicity of cetuximab in combination with combined IMRT/carbon ion therapy following TPF induction in locally advanced SCCHN.</p> <p>Trial Registration</p> <p>Clinical Trial Identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01245985">NCT01245985</a> (clinicaltrials.gov)</p> <p>EudraCT number: 2009 - 016489- 10</p
    corecore