Download or read book Practical implementation of Portal Dosimetry into a Clinical Environment written by Christina Weik and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of modern treatment techniques like intensity modulated arc therapy and volumetric modulated arc therapy allows the creation of completely patient specific treatment plans. The ability to deliver highly conformal doses to treatment volumes as well as the improved sparing of organs at risk and the normal tissue are advantages of these treatment techniques. However, the uniqueness also leads to several drawbacks such as an increased complexity of the plans and difficulties in error detection. Therefore, the demand of patient specific verification procedures raises and pre-treatment quality assurance is nowadays considered as a necessary prerequisite for patient treatments. Thus, the use of electronic portal imaging devices for dosimetric purposes gains in importance. A potential improvement in patient specific verification is achieved by a portal imager based pre-treatment verification method, which is implemented and tested. Furthermore, the performance of transit measurements with the portal is evaluated in phantom and patient measurements. The results of patient specific pre-treatment verification show nearly equivalent results compared to the currently used method. Phantom transit measurements confirm the detection of small dose differences and changes in the positioning, though dependent on the direction of the movement. Additionally, the treatment plan and the location of the target volume influence the measurable deviation. The patient transit measurements in a total of 14 patients show mostly good agreements. Gamma pass rates (1 %/1 mm) higher than 95 % are achieved for 9 patients, 90% to 95% for three patients and lower than 90 % for two patients. *****The use of modern treatment techniques like intensity modulated arc therapy and volumetric modulated arc therapy allows the creation of completely patient specific treatment plans. The ability to deliver highly conformal doses to treatment volumes as well as the improved sparing of organs at risk and the normal tissue are advantages of these treatment techniques. However, the uniqueness also leads to several drawbacks such as an increased complexity of the plans and difficulties in error detection. Therefore, the demand of patient specific verification procedures raises and pre-treatment quality assurance is nowadays considered as a necessary prerequisite for patient treatments. Thus, the use of electronic portal imaging devices for dosimetric purposes gains in importance. A potential improvement in patient specific verification is achieved by a portal imager based pre-treatment verification method, which is implemented and tested. Furthermore, the performance of transit measurements with the portal is evaluated in phantom and patient measurements. The results of patient specific pre-treatment verification show nearly equivalent results compared to the currently used method. Phantom transit measurements confirm the detection of small dose differences and changes in the positioning, though dependent on the direction of the movement. Additionally, the treatment plan and the location of the target volume influence the measurable deviation. The patient transit measurements in a total of 14 patients show mostly good agreements. Gamma pass rates (1 %/1 mm) higher than 95 % are achieved for 9 patients, 90% to 95% for three patients and lower than 90 % for two patients.