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ESS - RADT - Livro, parte de livro ou capítulo de livro

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http://hdl.handle.net/10400.22/1091

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Browsing ESS - RADT - Livro, parte de livro ou capítulo de livro by Author "Gomes, Adriana"

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  • Comparison of different radiotherapy techniques for locally advanced pancreatic tumors
    Publication . Gomes, Adriana; Rodrigues, Darlene; Costa Ferreira, Brígida
    Radiotherapy (RT) associated with systemic therapy is the standard treatment for Locally Advanced Pancreatic Cancer (LAPC). The aim of this study was to compare the efficacy of different RT techniques using the clinical data reported in the literature. Clinical data was collected from scientific papers searched in the databases PubMed and ScienceDirect. Thirty-four documents published between 1997 and 2015 were found and met the inclusion criteria: locally advanced adenocarcinoma, unresectable and no metastasis. Values of Complete Response (CR), Partial Response (PR), Stable Disease (SD), Pro gression Disease, Progression Free Survival (PFS), and Overall Survival (OS) for Three-Dimensional Conformal Radiation Therapy (3DCRT), Intensity Modulated Radiation Therapy (IMRT) and Stereotactic Body Radiotherapy (SBRT) in the treatment of LAPC were collected. For all RT techniques, Response Rate (RR), defined as the sum of CR and PR, was for 3DCRT 25.2% ± 9.5 [range: 5.0%–49.0%], for IMRT 33.5% ± 10.5 [range: 10.6%–55.6%] and for SBRT 52.2% ± 17.7 [range: 13.3%–69.5%]. For all studied techniques, Local Control (LC), defined as the sum of RR and SD, ranged from 47% to 100%; PFS ranged from 4 to 12 months and OS ranged from 6 to 20 months. A significant improvement in overall response rate was obtained with SBRT compared to 3DRCT and IMRT. However, LC, PFS and OS were similar among the three RT techniques.
    2019-09Book part Restricted access Show more
  • Dose-response to different radiochemotherapy regimens in locally advanced pancreatic cancer
    Publication . Costa Ferreira, Brígida; Dias, Joana; Gomes, Adriana; Mavroidis, Panayiotis; Rocha, Humberto
    Conformal radiation therapy (RT) delivered concomitantly with chemotherapy including 5-fluorouracil (5-FU) or Gemcitabine (GEM) is a common treatment for patients with unresectable locally advanced pancreatic tumors. In this study, the Poisson model describing tumor response to these two treatment options was derived. Clinical data was retrieved from reports pub lished from 1990 to 2015. Dosimetric and clinical data from 1196 patients treated with RT with concurrent 5-FU or GEM were gathered. RT doses ranging from 3.6–64.8 Gy, delivered in fractions of 1.2–8 Gy, were converted to a 2 Gy fractionation scheme using the Biological Effective Dose concept. The param eters of the Poisson-Linear-Quadratic-Time model were derived using genetic algorithm optimization to minimize the least-square fitting error and a local search was then made using the maximum likelihood method. The goodness of the fit was assessed using the Pearson v2 -test. For RT+5-FU, D50 was 59.8 Gy, c was 1.3, a/b was 3.2, Tpot was 18.6 days and Tk was 25.0 days. For RT+GEM, D50 was 54.5 Gy, c was 1.4, a/b was 4.6, Tpot was 34.2 days and Tk was 37.2 days. As expected, RT+GEM showed higher efficacy than RT+5-FU. A RT dose-response effect was obtained showing that treatment strategies allowing a dose-escalation in pancreas tumors should be investigated
    2019-09Book part Restricted access Show more