@article{PolatKaiserWohllebenetal.2017,
  author    = {Polat, B{\"u}lent and Kaiser, Philipp and Wohlleben, Gisela and Gehrke, Thomas and Scherzad, Agmal and Scheich, Matthias and Malzahn, Uwe and Fischer, Thomas and Vordermark, Dirk and Flentje, Michael},
  title     = {Perioperative changes in osteopontin and TGFβ1 plasma levels and their prognostic impact for radiotherapy in head and neck cancer},
  series = {BMC Cancer},
  volume    = {17},
  journal   = {BMC Cancer},
  number    = {6},
  doi       = {10.1186/s12885-016-3024-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157529},
  year      = {2017},
  abstract  = {Background: In head and neck cancer little is known about the kinetics of osteopontin (OPN) expression after tumor resection. In this study we evaluated the time course of OPN plasma levels before and after surgery. Methods: Between 2011 and 2013 41 consecutive head and neck cancer patients were enrolled in a prospective study (group A). At different time points plasma samples were collected: T0) before, T1) 1 day, T2) 1 week and T3) 4 weeks after surgery. Osteopontin and TGFβ1 plasma concentrations were measured with a commercial ELISA system. Data were compared to 131 head and neck cancer patients treated with primary (n = 42) or postoperative radiotherapy (n = 89; group B1 and B2). Results: A significant OPN increase was seen as early as 1 day after surgery (T0 to T1, p < 0.01). OPN levels decreased to base line 3-4 weeks after surgery. OPN values were correlated with postoperative TGFβ1 expression suggesting a relation to wound healing. Survival analysis showed a significant benefit for patients with lower OPN levels both in the primary and postoperative radiotherapy group (B1: 33 vs 11.5 months, p = 0.017, B2: median not reached vs 33.4, p = 0.031). TGFβ1 was also of prognostic significance in group B1 (33.0 vs 10.7 months, p = 0.003). Conclusions: Patients with head and neck cancer showed an increase in osteopontin plasma levels directly after surgery. Four weeks later OPN concentration decreased to pre-surgery levels. This long lasting increase was presumably associated to wound healing. Both pretherapeutic osteopontin and TGFβ1 had prognostic impact.},
  language  = {en}
}
@article{RichterWeickKriegeretal.2017,
  author    = {Richter, Anne and Weick, Stefan and Krieger, Thomas and Exner, Florian and Kellner, Sonja and Polat, B{\"u}lent and Flentje, Michael},
  title     = {Evaluation of a software module for adaptive treatment planning and re-irradiation},
  series = {Radiation Oncology},
  volume    = {12},
  journal   = {Radiation Oncology},
  number    = {205},
  doi       = {10.1186/s13014-017-0943-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158711},
  year      = {2017},
  abstract  = {Background: The aim of this work is to validate the Dynamic Planning Module in terms of usability and acceptance in the treatment planning workflow. Methods: The Dynamic Planning Module was used for decision making whether a plan adaptation was necessary within one course of radiation therapy. The Module was also used for patients scheduled for re-irradiation to estimate the dose in the pretreated region and calculate the accumulated dose to critical organs at risk. During one year, 370 patients were scheduled for plan adaptation or re-irradiation. All patient cases were classified according to their treated body region. For a sub-group of 20 patients treated with RT for lung cancer, the dosimetric effect of plan adaptation during the main treatment course was evaluated in detail. Changes in tumor volume, frequency of re-planning and the time interval between treatment start and plan adaptation were assessed. Results: The Dynamic Planning Tool was used in 20\% of treated patients per year for both approaches nearly equally (42\% plan adaptation and 58\% re-irradiation). Most cases were assessed for the thoracic body region (51\%) followed by pelvis (21\%) and head and neck cases (10\%). The sub-group evaluation showed that unintended plan adaptation was performed in 38\% of the scheduled cases. A median time span between first day of treatment and necessity of adaptation of 17 days (range 4-35 days) was observed. PTV changed by 12 ± 12\% on average (maximum change 42\%). PTV decreased in 18 of 20 cases due to tumor shrinkage and increased in 2 of 20 cases. Re-planning resulted in a reduction of the mean lung dose of the ipsilateral side in 15 of 20 cases. Conclusion: The experience of one year showed high acceptance of the Dynamic Planning Module in our department for both physicians and medical physicists. The re-planning can potentially reduce the accumulated dose to the organs at risk and ensure a better target volume coverage. In the re-irradiation situation, the Dynamic Planning Tool was used to consider the pretreatment dose, to adapt the actual treatment schema more specifically and to review the accumulated dose.},
  language  = {en}
}