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Custers J.A.E.,Radboud University Nijmegen | Gielissen M.F.M.,University of Amsterdam | de Wilt J.H.W.,Radboud University Nijmegen | Honkoop A.,Isala Klinieken | And 6 more authors.
Journal of Cancer Survivorship | Year: 2016

Purpose: In order to understand the multidimensional mechanism of fear of cancer recurrence (FCR) and to identify potential targets for interventions, it is important to empirically test the theoretical model of FCR. This study aims at assessing the validity of Lee-Jones et al.’s FCR model. Methods: A total of 1205 breast cancer survivors were invited to participate in this study. Participants received a questionnaire booklet including questionnaires on demographics and psychosocial variables including FCR. Data analysis consisted of the estimation of direct and indirect effects in mediator models. Results: A total of 460 women (38 %) participated in the study. Median age was 55.8 years (range 32–87). Indirect effects of external and internal cues via FCR were found for all mediation models with limited planning for the future (R2 = .28) and body checking (R2 = .11–.15) as behavioral response variables, with the largest effects for limited planning for the future. A direct relation was found between feeling sick and seeking professional advice, not mediated by FCR. Conclusions: In the first tested models of FCR, all internal and external cues were associated with higher FCR. In the models with limited planning for the future and body checking as behavioral response, an indirect effect of cues via FCR was found supporting the theoretical model of Lee-Jones et al. Implications for Cancer Survivors: An evidence-based model of FCR may facilitate the development of appropriate interventions to manage FCR in breast cancer survivors. © 2016 The Author(s) Source

Cisternas E.,German Cancer Research Center | Cisternas E.,University of Santiago de Chile | Mairani A.,Centro Nazionale Of Adroterapia Oncologica | Mairani A.,Heidelberg Ion Therapy Center | And 5 more authors.
IFMBE Proceedings | Year: 2015

We present matRad, an open source software for three-dimensional radiation treatment planning of intensity-modulated photon, proton, and carbon ion therapy. matRad is developed for educational and research purposes; it is entirely written in MATLAB. A first beta release is available for download1. The toolkit features a highly modular design with a set of individual functions modeling the entire treatment planning workflow based on a segmented patient CT. All algorithms, e.g. for ray tracing, photon/proton/carbon dose calculation, fluence optimization, and multileaf collimator sequencing, follow well-established approaches and operate on clinically adequate voxel and bixel resolution. Patient data as well as base data for all required computations is included in matRad. We achieve computation times of 60-100s (60-400s) for realistic patient cases including photon (particle) dose calculation and fluence optimization. Memory consumption ranges between 0.2GB and 2.2GB. Dose distributions of a treatment planning study for a phantom and prostate patient case considering multiple radiation modalities are shown. Both the computational and dosimetric results encourage a future use of matRad in an educational and scientific setting. © Springer International Publishing Switzerland 2015. Source

Westbury C.B.,University College London | Yarnold J.R.,The Institute of Cancer Research and the Royal Marsden NHS Foundation Trust
Clinical Oncology | Year: 2012

Cancer survivors previously treated with curative radiotherapy are at risk of developing long-term toxicities due to radiation-induced normal tissue injury. Radiation fibrosis is an important component of the spectrum of radiation injury and at the present time treatment for this condition is limited. Data from both studies of clinical intervention and from preclinical models support the idea that fibrosis is a dynamic process and may in part be reversible. Clinical therapeutic interventions for radiation fibrosis have included empirical treatments, such as antioxidant therapies using superoxide dismutase, or vitamin E and pentoxifylline, and although evidence for therapeutic efficacy exists, further randomised studies are required. Potential therapeutic strategies that have shown promise in preclinical models include targeting pro-fibrotic cytokines such as: (1) transforming growth factor beta 1, (2) platelet-derived growth factor and its receptor tyrosine kinase and (3) connective tissue growth factor and the Rho/ROCK intracellular signalling pathway. Progress in the understanding of stem cell biology and the involvement of stem cells in radiation injury has led to the investigation of their role as a therapeutic strategy for ameliorating this disease process by promoting organ regeneration and repair. In this review we discuss the clinical and pathological features of radiation fibrosis and present the available clinical data and laboratory data relevant to these approaches to therapeutic intervention. © 2012 The Royal College of Radiologists. Source

Bert C.,Friedrich - Alexander - University, Erlangen - Nuremberg | Bert C.,Helmholtz Center for Heavy Ion Research | Graeff C.,Helmholtz Center for Heavy Ion Research | Riboldi M.,Polytechnic of Milan | And 6 more authors.
Technology in Cancer Research and Treatment | Year: 2014

We report on recent progress in the field of mobile tumor treatment with scanned particle beams, as discussed in the latest editions of the 4D treatment planning workshop. The workshop series started in 2009, with about 20 people from 4 research institutes involved, all actively working on particle therapy delivery and development. The first workshop resulted in a summary of recommendations for the treatment of mobile targets, along with a list of requirements to apply these guidelines clinically. The increased interest in the treatment of mobile tumors led to a continuously growing number of attendees: the 2012 edition counted more than 60 participants from 20 institutions and commercial vendors. The focus of research discussions among workshop participants progressively moved from 4D treatment planning to complete 4D treatments, aiming at effective and safe treatment delivery. Current research perspectives on 4D treatments include all critical aspects of time resolved delivery, such as in-room imaging, motion detection, beam application, and quality assurance techniques. This was motivated by the start of first clinical treatments of hepato cellular tumors with a scanned particle beam, relying on gating or abdominal compression for motion mitigation. Up to date research activities emphasize significant efforts in investigating advanced motion mitigation techniques, with a specific interest in the development of dedicated tools for experimental validation. Potential improvements will be made possible in the near future through 4D optimized treatment plans that require upgrades of the currently established therapy control systems for time resolved delivery. But since also these novel optimization techniques rely on the validity of the 4DCT, research focusing on alternative 4D imaging technique, such as MRI based 4DCT generation will continue. © Adenine Press (2014). Source

Habermehl D.,TU Munich | Naumann P.,University of Heidelberg | Bendl R.,German Cancer Research Center | Bendl R.,Heilbronn University of Applied Sciences | And 4 more authors.
Radiation Oncology | Year: 2015

Background: With the development of more conformal and precise radiation techniques such as Intensity-Modulated Radiotherapy (IMRT), Stereotactic Body Radiotherapy (SBRT) and Image-Guided Radiotherapy (IGRT), patients with hepatic tumors could be treated with high local doses by sparing normal liver tissue. However, frequently occurring large HCC tumors are still a dosimetric challenge in spite of modern high sophisticated RT modalities. This interventional clinical study has been set up to evaluate the value of different fiducial markers, and to use the modern imaging methods for further treatment optimization using physical and informatics approaches. Methods and design: Surgically implanted radioopaque or electromagnetic markers are used to detect tumor local-ization during radiotherapy. The required markers for targeting and observation during RT can be implanted in a previously defined optimal position during the oncologically indicated operation. If there is no indication for a surgical resection or open biopsy, markers may be inserted into the liver or tumor tissue by using ultrasound-guidance. Primary study aim is the detection of the patients anatomy at the time of RT by observation of the marker position during the indicated irradiation (IGRT). Secondary study aims comprise detection and recording of 3D liver and tumor motion during RT. Furthermore, the study will help to develop technical strategies and mechanisms based on the recorded information on organ motion to avoid inaccurate dose application resulting from fast organ motion and deformation. Discussion: This is an open monocentric non-randomized, prospective study for the evaluation of organ motion using interstitial markers or implantable radiotransmitter. The trial will evaluate the full potential of different fiducial markers to further optimize treatment of moving targets, with a special focus on liver lesions. © 2015 Habermehl et al. Source

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