S269 ESTRO 33, 2014 The audit results showed a good agreement between planned and measured dose (see Table below) i.e. within ±2% w.r.t the treatment planning system. Conclusions: It is anticipated that this type of Intensity Modulated Radiotherapy Photon Audit will be fully implemented across the South West IPEM Audit Group in 2014. Further work: Set the tolerance and action levels e.g. 3% per an IMRT beam and 5% per IMRT /VMAT plan Include bone inhomogeneity next to the prostate volume to test the dose calculation algorithm e.g. Collapsed cone Add a measurement point in the OAR i.e. rectum Review the IMRT/VMAT Audit Working Instructions based on the feedback from the SWRAG centres EP-1751 UK audit of intraoperative radiotherapy dosimetry D.J. Eaton 1 , B. Earner 1 , P. Faulkner 1 , N. Dancer 1 1 Royal Free Hospital, Radiotherapy Physics, London, United Kingdom Purpose/Objective: Independent dosimetry audits form a fundamental part of radiotherapy quality assurance, especially for novel technologies, and give confidence in accurate, safe and consistent delivery of complex treatments. Intraoperative radiotherapy is becoming increasingly common as a treatment of the breast tumour bed immediately after surgical excision. The Carl Zeiss INTRABEAM system, a mobile compact 50kV x-ray unit, is the subject of the TARGIT international randomised controlled trial, and is in clinical use in a number of centres around the UK. Materials and Methods: Audit visits were made to all seven clinical systems in 2012, to measure radiation output, isotropy and depth dose, using previously established methods of independent quality assurance. Results: The average difference between measured and planned output dose across all centres was -3.2 ± 2.7%. Isotropy and depth doses also agreed within measurement uncertainties with manufacturer provided values, except for a mean enhancement of +11% in the forward direction, which is unlikely to be clinically significant. Conclusions: Measurement uncertainties are dominated by the sensitivity to positioning, owing to the steep dose gradients around the device, but these tests are practical for inter-departmental audit and local baseline comparison. The first UK inter-departmental audit of intraoperative radiotherapy gives confidence in the safe and accurate delivery of this technique. EP-1752 RT.net - interoperable data exchange in radiotherapy M. Memelink 1 , P. Steininger 1 , H. Deutschmann Heinz 1 , F. Sedlmayer 1 1 Paracelsus Medizinische Privatuniversität, radART, Salzburg, Austria Purpose/Objective: The exchange of medical patient-oriented data in intramural area is fully established since years. Information systems as well as department-specific PACS systems communicate with each other using proprietary protocols and openstandards such as DICOM and HL7. Nevertheless, the exchange of DICOM objects such as RT plan, RT Dose and RT Structure Set between radiotherapy centers still is a hurdle when importing them into local planning systems. Aim of this project (RT.net) is to provide a communication platform for the secure exchangeof health data in intra- as well as extramural area. Special focus is set on the exchange and automatic importing and processing of specific DICOM RT objects based on open standards and communication protocols. Materials and Methods: For implementation a decentralized communication platform design based onclient-server architecture was chosen. The transfer of data is performed via web services using the 'Simple Object Access Protocol' (SOAP) over HTTPS and TCP. For optimized transmission of binary data using SOAP, the W3C recommendation MTOM/XOP is used for streaming functionality. For providing transmission security HTTPS SSLv3 and TLSv1 is used. An integrated function for'end -to-end encryption' (E2EE) provides additional security in data transmission. For the acquisition of transmitted DICOM RT objects in therespective planning systems of individual radiotherapy centers, client- side specific translation and mapping functionalities (RT.net client) are provided to import DICOM RT objects from foreign linear accelerators. Results: The technical basis for the development of the RT.net communication platform for the exchange of radiotherapy specific data was successfully implemented. Participating clients are provided with 'Web Services Description Language'(WSDL) files for interconnecting with RT.net services. Stored data on RT.net servers are only provided for a configured time period. For consultation purpose without an existing RT.net client, an integrated web portal can be used with the ability to transfer data to participating healthcare facilities. Conclusions: The developed RT.net communication platform provides highest security demands on data transmission and data storage. However, the integration of different healthcare facilities and the performed data exchange usually fails not for lack of technical implementation, but on the acceptance of the users. The approach of distributed client-server architecture for the in-patient and out-patient data exchange has proven to be very effective. The exchange and import of DICOM RT objects into local oncology information system installation was used and successfully tested within a study. EP-1753 A unique PDF-form/e-form manager platform to improve data quantity and quality in IAEA randomized trials T. Menon 1 , Y. Pynda 2 , E. Rosenblatt 2 , E. Zubizarreta 2 , E. Fidarova 2 , G. Jones 1 1 Trillium Health Partners, Radiation Oncology, Mississauga Ontario, Canada 2 IAEA, Human Health, Vienna, Austria Purpose/Objective: Clinical trials need careful monitoring for data quantity and quality to meet regulations and to get a data-set that correctly answers research questions. Data management is being professionalized to more reliably and quickly convert protocol to product as assets for researchers, organizations and future patients. Adopting electronic methods may improve trial quality and expedite products. Materials and Methods: Our context is multi-centre, low-to-middle income country (LMIC), international randomized trials in radiation oncology. Specifications for a data-platform include low-cost, cross- platform compatibility, on-or-offline use, save-complete-later capacity, mobility, internal form validation, and simple submission via one-click e- mail. These facilitate trials where internet access is typically difficult or restricted and investigators are busy and get interrupted. We chose PDF (ADOBE) technology with Acrobat Reader as fully cross-platform compatible, with within-form data validation by Java script, and custom- built e-form manager to assemble accepted forms into data-sets. PDF forms for follow-up consolidated several prior forms (patient, disease and treatment status, and adverse event grading) and were implemented in cervix (2011) and breast (2013). A rectal trial was opened with a full suite of 14 forms (2011). With 4,099 processed PDF forms we compare quantity and quality of data in cervix and breast (before-after design) and the impact of an all-PDF approach in rectum. Results: In before-after studies (2058 forms), submission rates of forms did not change but adverse event grading (0-5) became far more systematic. For example, arm measurements for lymphedema were included in 57.1% (before) then 96.8% (after) of submissions, p<0.0005. In rectum(2041 forms), investigators who were submitting within days of patient assessments and using the validation mechanism had significantly fewer missing data fields and illogical data. The submit mechanism issues a standardized e-mail to the DMC based on validation status and with correct patient identification, and overall queries are significantly reduced. Working with the PDF-e-form platform means that DMC strategies for international trials shift to pre-trial planning (to directly link form structures to data-set assembly),automating progress reports, and conducting within-patient-across-form reviews to identify composite queries on patient trajectories. Data-sets are much cleaner and readier for analysis (e.g. within days of stopping data submissions). Efficiencies mean that DMC staff can do meta-trial activities like literature summaries and drafting non-result manuscript material to expedite final products. Conclusions: Our pilot experience with a unique, previously unpublished, electronic platform helps professionalize data management of international randomized trials in LMIC contexts. EP-1754