Validation of an integrated patient positioning system: Exactrac and iViewGT on Synergy Platform

Purpose: Evaluation of the newly integrated system for its validation and designing a quality assurance frame work to assess its geometrical, radiological and mechanical accuracy.Methods: Isocentric accuracy of two independent imaging modalities, kV based ExacTrac and MV based iViewGT was evaluated using Winston-Lutz test. A pelvic humanoid phantom was used for the radiological end-to-end test for its clinical utilization. Image quality for the systems was evaluated using Las Vegas Phantom and ETR-1 plate. The kV system was also assessed for kVp accuracy, kVp - dose linearity, mAs-dose linearity and timer linearity and its accuracy. The system was tested for total filtration and output consistency. Tests for uniformity and noise measurement of kVp accuracy and its reproducibility, linearity test between applied kVp and the x-ray dose, linearity Test between applied mAs and the x-ray dose were also done. Results: Winston-Lutz test gave the isocentric deviation of 0.058 ± 0.015 mm with the average lateral deviation as 0.028 ± 0.021 mm, average longitudinal deviation as 0.032 ± 0.015 mm and average vertical deviation as 0.030 ± 0.016 mm. With the phantom test, the minimum measured displacement of Exactrac positioning was 0.2 ± 0.3 mm, 0.0 ± 0.2 mm and 0.1 ± 0.3 mm in longitudinal, lateral and vertical directions respectively. In image quality test, visible smallest visible hole size seen by both Exactrac and EPID imaging system was 5 mm and can resolve 1.5 lp/mm or better. The image uniformity was found to be 132.9 ± 3.06 pixels for MV images and 139 ± 4.41 pixels for kV images with the associated noise of ≤1% both for 120 kV-20 mAs and 4 MV beam energy of ExacTrac and iViewGT respectively. The uniformity and noise test, measured pixel intensity values for various points on MV and kV images separately were found to agree within ± 1% with respect to the central axis pixel value. The kVp accuracy and its reproducibility were tested for kV imager only. The deviation of kVp was found to be than ± 1% and its precision was seen to be even lesser than ± 0.1%. Linearity test between applied kVp and the x-ray dose and applied mAs and x-ray dose were tested only for the ExacTrac. Both the coefficient of linearity for kVp as well as mAs was found to be < 0.1. Conclusion: It is feasible to install ExacTrac imaging system with an Elekta linear accelerator. Both the imaging systems were found to be compatible in terms of image quality test and isocentric accuracy and can be used for the patient imaging in the same Linear accelerator.-----------------------------Cite this article as: Jassal K, Munshi A, Sarkar B, Paul S, Sharma A, Mohanti BK, Ganesh T, Chougule A, Sachdev K. Validation of an integrated patient positioning system: Exactrac and iViewGT on Synergy Platform. Int J Cancer Ther Oncol 2014; 2(2):020212. DOI: 10.14319/ijcto.0202.1

Validation of an integrated patient positioning system: Exactrac and iViewGT on Synergy Platform

Purpose: Evaluation of the newly integrated system for its validation and designing a quality assurance frame work to assess its geometrical, radiological and mechanical accuracy.Methods: Isocentric accuracy of two independent imaging modalities, kV based ExacTrac and MV based iViewGT was evaluated using Winston-Lutz test. A pelvic humanoid phantom was used for the radiological end-to-end test for its clinical utilization. Image quality for the systems was evaluated using Las Vegas Phantom and ETR-1 plate. The kV system was also assessed for kVp accuracy, kVp - dose linearity, mAs-dose linearity and timer linearity and its accuracy. The system was tested for total filtration and output consistency. Tests for uniformity and noise measurement of kVp accuracy and its reproducibility, linearity test between applied kVp and the x-ray dose, linearity Test between applied mAs and the x-ray dose were also done. Results: Winston-Lutz test gave the isocentric deviation of 0.058 ± 0.015 mm with the average lateral deviation as 0.028 ± 0.021 mm, average longitudinal deviation as 0.032 ± 0.015 mm and average vertical deviation as 0.030 ± 0.016 mm. With the phantom test, the minimum measured displacement of Exactrac positioning was 0.2 ± 0.3 mm, 0.0 ± 0.2 mm and 0.1 ± 0.3 mm in longitudinal, lateral and vertical directions respectively. In image quality test, visible smallest visible hole size seen by both Exactrac and EPID imaging system was 5 mm and can resolve 1.5 lp/mm or better. The image uniformity was found to be 132.9 ± 3.06 pixels for MV images and 139 ± 4.41 pixels for kV images with the associated noise of ≤1% both for 120 kV-20 mAs and 4 MV beam energy of ExacTrac and iViewGT respectively. The uniformity and noise test, measured pixel intensity values for various points on MV and kV images separately were found to agree within ± 1% with respect to the central axis pixel value. The kVp accuracy and its reproducibility were tested for kV imager only. The deviation of kVp was found to be than ± 1% and its precision was seen to be even lesser than ± 0.1%. Linearity test between applied kVp and the x-ray dose and applied mAs and x-ray dose were tested only for the ExacTrac. Both the coefficient of linearity for kVp as well as mAs was found to be &lt; 0.1. Conclusion: It is feasible to install ExacTrac imaging system with an Elekta linear accelerator. Both the imaging systems were found to be compatible in terms of image quality test and isocentric accuracy and can be used for the patient imaging in the same Linear accelerator.-----------------------------Cite this article as: Jassal K, Munshi A, Sarkar B, Paul S, Sharma A, Mohanti BK, Ganesh T, Chougule A, Sachdev K. Validation of an integrated patient positioning system: Exactrac and iViewGT on Synergy Platform. Int J Cancer Ther Oncol 2014; 2(2):020212. DOI: 10.14319/ijcto.0202.12</p

TEMOS - Telemedical support for travellers and expatriates

Introduction: Each year 45 million German tourists travel to foreign countries, 33,000 expatriates are working abroad. Additionally, millions of short term business trips are performed. 8% of this collective need medical support during their stay, one of 250 travellers is hospitalised and about 26.000 patients have to be repatriated annually. Travelers visiting countries with special health risks usually visit their physician, pharmacist or the internet to get advice regarding health precaution in the run-up to the journey. But people do not know: • where to go in case of an emergency abroad • whether the diagnosis of the foreign doctors is reliable • whether the quality of treatment is all right or whether repatriation is necessary Objective: The TEMOS project has been established within the ARTES-III program of the European Space Agency (ESA) to support travellers and expatriates with medical expertise during their stay abroad, to improve knowledge in travel medicine of the patient’s general practitioner and to provide information on medical institutions abroad. Methods: To fulfil these aims the TEMOS telemedical platform has been established combining a satellite based communication and education platform and an Internet based hospital data base containing information on so called certified TEMOS- and non-TEMOS hospitals and medical institutions. The satellite platform on one hand connects the TEMOS Telemedical Reference Center (TTRC) to the TEMOS hospitals. It offers the possibility for the hospitals to perform case discussions within video conferences with medical experts. The MedSky platform integrates an electronic patient record, a communication tool for the TEMOS members and a booking module for guaranteed satellite bandwidth. Live lectures for Continuous Medical Education (CME) can be held on the satellite platform e.g. for participants of the courses of the Center for Travel Medicine (CRM), for the physicians of the TEMOS hospitals abroad and vice versa. The TEMOS hospital database has been created to collect data on hospitals abroad, providing medical care following TEMOS standards (TEMOS certification). and on non-TEMOS-hospitals as well. Conclusion: TEMOS aims on an improvement of medical care for travellers worldwide by improving the medical preparation for a trip, by supporting travellers and assistance companies to select suitable medical institutions in case of illness and by offering medical expertise to hospitals abroad. Beyond enhanced quality of care a reduction of costs of medical assistance cases is expected by a reduction of unnecessary repatriations