10 research outputs found

    Impact of endorectal filling on interobserver variability of MRI based rectal primary tumor delineation

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    Background: Online adaptive MR-guided radiotherapy allows for the reduction of safety margins in dose escalated treatment of rectal tumors. With the use of smaller margins, precise tumor delineation becomes more critical. In the present study we investigated the impact of rectal ultrasound gel filling on interobserver variability in delineation of primary rectal tumor volumes. Methods: Six patients with locally advanced rectal cancer were scanned on a 1.5 T MRI-Linac without (MRI_e) and with application of 100 cc of ultrasound gel transanally (MRI_f). Eight international radiation oncologists expert in the treatment of gastrointestinal cancers delineated the gross tumor volume (GTV) on both MRI scans. MRI_f scans were provided to the participating centers after MRI_e scans had been returned. Interobserver variability was analyzed by either comparing the observers’ delineations with a reference delineation (approach 1) and by building all possible pairs between observers (approach 2). Dice Similarity Index (DICE) and 95 % Hausdorff-Distance (95 %HD) were calculated. Results: Rectal ultrasound gel filling was well tolerated by all patients. Overall, interobserver agreement was superior in MRI_f scans based on median DICE (0.81 vs 0.74, p < 0.005 for approach 1 and 0.76 vs 0.64, p < 0.0001 for approach 2) and 95 %HD (6.9 mm vs 4.2 mm for approach 1, p = 0.04 and 8.9 mm vs 6.1 mm, p = 0.04 for approach 2). Delineated median tumor volumes and inter-quartile ranges were 26.99 cc [18.01–50.34 cc] in MRI_e and 44.20 [19.72–61.59 cc] in MRI_f scans respectively, p = 0.012. Conclusions: Although limited by the small number of patients, in this study the application of rectal ultrasound gel resulted in higher interobserver agreement in rectal GTV delineation. The endorectal gel filling might be a useful tool for future dose escalation strategies

    A multi-centre survey reveals variations in the standard treatments and treatment modifications for head and neck cancer patients during Covid-19 pandemic

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    BACKGROUND: The onset of the COVID-19 pandemic necessitated rapid changes to the practice of head and neck oncology. This survey was conducted to assess the pre-Covid-19 pandemic standard of practice for head and neck oncology patients and the treatment modifications introduced during the Covid-19 pandemic in UK. METHODOLOGY: The UK National Cancer Research Institute (NCRI) Head and Neck Clinical Studies Group initiated a multi-centre survey using questionnaire to investigate the effect on feeding tube practice, radiotherapy (RT) fractionation and volumes, use of chemotherapy in the neo-adjuvant, adjuvant and palliative setting, the use of immunotherapy in the palliative setting, access to radiology and histopathology services, availability of surgical procedures. RESULTS: 30 centres were approached across UK; 23 (76.7%) centres responded and were included in the survey. There were differences in the standard practices in feeding tube policy, RT dose and fractionation as well as concurrent chemotherapy use. 21 (91%) participating centres had at least one treatment modification. 15 (65%) centres initiated a change in radical RT; changing to either a hypofractionation or acceleration schedule. For post-operative RT 10 centres (43.5%) changed to a hypofractionation schedule.12 (52.2%) centres stopped neo-adjuvant chemotherapy for all patients; 13 (56.5%) centres followed selective omission of chemotherapy in concurrent chemo-radiotherapy patients, 17 (73.9%) centres changed first-line chemotherapy treatment to pembrolizumab (following NHS England’s interim guidance) and 8 (34.8%) centres stopped the treatment early or offered delays for patients that have been already on systemic treatment. The majority of centres did not have significant changes associated with surgery, radiology, histopathology and dental screening. CONCLUSION: There are variations in the standard of practice and treatment modifications for head and neck cancer patients during Covid-19 pandemic. A timely initiative is required to form a consensus on head and neck cancer management in the UK and other countries

    Policy framework for autonomic data management

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    The popularity of e-Business has lead to an exponential and unstructured growth in the applications space coupled with an increase in the database size. This has led to an increase in the complexity of the database management task. Moreover, organizations are increasingly concerned about the privacy of data. Thus, managing such large ever growing and privacy-preserving database is complex and time-consuming task. In this paper we describe a policy-based framework for autonomic database management using Business Objects. Our system automatically manages data based on events. 1

    Geometric and dosimetric evaluation of the differences between rigid and deformable registration to assess interfraction motion during pelvic radiotherapy

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    Background and purpose: Appropriate internal margins are essential to avoid a geographical miss in intensity-modulated radiation therapy (IMRT) for endometrial cancer (EC). This study evaluated interfraction target motion using rigid and non-rigid approximation strategies and calculated internal margins based on random and systematic errors using traditional rigid margin recipes. Dosimetric impact of target motion was also investigated. Materials and methods: Cone beam CTs (CBCTs) were acquired days 1–4 and then weekly in 17 patients receiving adjuvant IMRT for EC; a total of 169 CBCTs were analysed. Interfraction motion for the clinical target volume vaginal vault and upper vagina (CTVv) was measured using bony landmarks and deformation vector field displacement (DVFD) within a 1 mm internal wall of CTVv. Patient and population systematic and random errors were estimated and margins calculated. Delivered dose to the CTVv and organs at risk was estimated. Results: There was a significant difference in target motion assessment using the different registration strategies (p < 0.05). DVFD up to 30 mm occurred in the anterior/posterior direction, which was not accounted for in PTV margins using rigid margin recipes. Underdosing of CTVv D95% occurred in three patients who had substantial reductions in rectal volume (RV) during treatment. RV relative to the planning CT was moderately correlated with anterior/posterior displacement (r = 0.6) and mean relative RV during treatment was strongly correlated with mean relative RV at CBCT acquired days 1–3 (r = 0.8). Conclusion: Complex and extensive geometric changes occur to the CTVv, which are not accounted for in margin recipes using rigid approximation. Contemporary margin recipes and adaptive treatment planning based on non-rigid approximation are recommended

    Imaging predictors of treatment outcomes in rectal cancer : An overview

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    The treatment protocols for rectal cancer continue to evolve, with increasing acceptance of a watch-and-wait policy for clinical complete responders to neoadjuvant chemoradiation therapy. It still, however, remains unclear who is likely to achieve a pathological complete response, which unequivocally portends a very favorable overall prognosis. Evolution of modern imaging techniques has paved the way for potential prediction of treatment response based on baseline, on-treatment, early post-treatment and subsequent follow-up imaging alone. Independent of tumor grade and stage, tumor marker levels, tumor size, radiation dose and fractionation, chemotherapy regimen, and extent/type of surgery, imaging biomarkers like circumferential resection margin (CRM), extramural venous space invasion (EMVI), imaging-based tumor regression grade, perfusion/diffusion-based functional imaging parameters, and imaging-based metabolic response have the ability to predict the likelihood of local recurrence and/or distant metastases. Textural features of images can add a further dimension to the predictive power of imaging. Finally, integration of genomic data with imaging biomarkers can potentially discern molecular mechanisms associated with distinct radiographic attributes of tumors. In this review, we evaluate and summarize the evidence to date of each imaging modality as a biomarker and its contribution to personalized decision making in rectal cancer

    Imaging predictors of treatment outcomes in rectal cancer : An overview

    No full text
    The treatment protocols for rectal cancer continue to evolve, with increasing acceptance of a watch-and-wait policy for clinical complete responders to neoadjuvant chemoradiation therapy. It still, however, remains unclear who is likely to achieve a pathological complete response, which unequivocally portends a very favorable overall prognosis. Evolution of modern imaging techniques has paved the way for potential prediction of treatment response based on baseline, on-treatment, early post-treatment and subsequent follow-up imaging alone. Independent of tumor grade and stage, tumor marker levels, tumor size, radiation dose and fractionation, chemotherapy regimen, and extent/type of surgery, imaging biomarkers like circumferential resection margin (CRM), extramural venous space invasion (EMVI), imaging-based tumor regression grade, perfusion/diffusion-based functional imaging parameters, and imaging-based metabolic response have the ability to predict the likelihood of local recurrence and/or distant metastases. Textural features of images can add a further dimension to the predictive power of imaging. Finally, integration of genomic data with imaging biomarkers can potentially discern molecular mechanisms associated with distinct radiographic attributes of tumors. In this review, we evaluate and summarize the evidence to date of each imaging modality as a biomarker and its contribution to personalized decision making in rectal cancer

    Safety and Treatment Outcomes of Nivolumab for the Treatment of Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma: Retrospective Multicenter Cohort Study.

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    Nivolumab is an anti-PD-1 monoclonal antibody currently used as immunotherapy for patients with recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) with evidence of disease progression after platinum-based chemotherapy. This study evaluates real-world safety and treatment outcomes of non-trial nivolumab use. A retrospective multicenter cohort study of patients with recurrent/metastatic HNSCC treated with nivolumab between January 2017 and March 2020 was performed. Overall, 123 patients were included. The median age was 64 years, the majority of patients were male (80.5%) and had a smoking history (69.9%). Primary outcomes included overall response rate (ORR) of 19.3%, median progression-free survival (PFS) of 3.9 months, 1-year PFS rate of 16.8%, a median overall survival (OS) of 6.5 months and 1-year OS rate of 28.6%. These results are comparable to the CHECKMATE-141 study. Of 27 patients who had PD-L1 status tested, positive PD-L1 status did not significantly affect PFS ( = 0.86) or OS ( = 0.84). Nivolumab was well tolerated with only 15.1% experiencing immune-related toxicities (IRT) and only 6.7% of patients stopping due to toxicity. The occurrence of IRT appeared to significantly affect PFS ( = 0.01) but not OS ( = 0.07). Nivolumab in recurrent/metastatic HNSCC is well tolerated and may be more efficacious in patients who develop IRT

    Dysphagia-optimised intensity-modulated radiotherapy versus standard intensity-modulated radiotherapy in patients with head and neck cancer (DARS): a phase 3, multicentre, randomised, controlled trial.

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    BACKGROUND: Most newly diagnosed oropharyngeal and hypopharyngeal cancers are treated with chemoradiotherapy with curative intent but at the consequence of adverse effects on quality of life. We aimed to investigate if dysphagia-optimised intensity-modulated radiotherapy (DO-IMRT) reduced radiation dose to the dysphagia and aspiration related structures and improved swallowing function compared with standard IMRT. METHODS: DARS was a parallel-group, phase 3, multicentre, randomised, controlled trial done in 22 radiotherapy centres in Ireland and the UK. Participants were aged 18 years and older, had T1-4, N0-3, M0 oropharyngeal or hypopharyngeal cancer, a WHO performance status of 0 or 1, and no pre-existing swallowing dysfunction. Participants were centrally randomly assigned (1:1) using a minimisation algorithm (balancing factors: centre, chemotherapy use, tumour type, American Joint Committee on Cancer tumour stage) to receive DO-IMRT or standard IMRT. Participants and speech language therapists were masked to treatment allocation. Radiotherapy was given in 30 fractions over 6 weeks. Dose was 65 Gy to primary and nodal tumour and 54 Gy to remaining pharyngeal subsite and nodal areas at risk of microscopic disease. For DO-IMRT, the volume of the superior and middle pharyngeal constrictor muscle or inferior pharyngeal constrictor muscle lying outside the high-dose target volume had a mandatory 50 Gy mean dose constraint. The primary endpoint was MD Anderson Dysphagia Inventory (MDADI) composite score 12 months after radiotherapy, analysed in the modified intention-to-treat population that included only patients who completed a 12-month assessment; safety was assessed in all randomly assigned patients who received at least one fraction of radiotherapy. The study is registered with the ISRCTN registry, ISRCTN25458988, and is complete. FINDINGS: From June 24, 2016, to April 27, 2018, 118 patients were registered, 112 of whom were randomly assigned (56 to each treatment group). 22 (20%) participants were female and 90 (80%) were male; median age was 57 years (IQR 52-62). Median follow-up was 39·5 months (IQR 37·8-50·0). Patients in the DO-IMRT group had significantly higher MDADI composite scores at 12 months than patients in the standard IMRT group (mean score 77·7 [SD 16·1] vs 70·6 [17·3]; mean difference 7·2 [95% CI 0·4-13·9]; p=0·037). 25 serious adverse events (16 serious adverse events assessed as unrelated to study treatment [nine in the DO-IMRT group and seven in the standard IMRT group] and nine serious adverse reactions [two vs seven]) were reported in 23 patients. The most common grade 3-4 late adverse events were hearing impairment (nine [16%] of 55 in the DO-IMRT group vs seven [13%] of 55 in the standard IMRT group), dry mouth (three [5%] vs eight [15%]), and dysphagia (three [5%] vs eight [15%]). There were no treatment-related deaths. INTERPRETATION: Our findings suggest that DO-IMRT improves patient-reported swallowing function compared with standard IMRT. DO-IMRT should be considered a new standard of care for patients receiving radiotherapy for pharyngeal cancers. FUNDING: Cancer Research UK
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