Purpose To develop and check the suitability and efficiency of a thorough quality assurance (QA) phantom for the tiny Animal Radiation Study System (SARRP). constancy measurement results showed daily variations within 3%. Using the Mosfet in phantom as target results showed that this difference between TPS L 006235 calculations and measurements was within 5%. Annual QA results for the Percentage depth dose (PDD) curves lateral beam profiles beam flatness and beam profile symmetry were found consistent with results obtained at commissioning. PDD curves obtained using film and OSLDs showed good agreement. Image QA was performed monthly with image-quality parameters assessed in terms of CBCT image geometric accuracy CT number accuracy image spatial resolution noise and image uniformity. Conclusions The results show that this developed QA phantom can be employed as a tool for comprehensive performance evaluation of the SARRP. The study provides a useful reference for development of a comprehensive quality assurance program for the SARRP and other similar small animal irradiators with proposed tolerances and frequency of required assessments. is the pixel intensity value of ROI from the material and is pixel intensity value of ROI from water. The pixel image intensity analysis was processed using ImageJ. Physique 2 Image QA phantom. (A) Tissue equivalent material slab (60 × 60 × 5 mm) with 3 inserts (B) slab phantom (25 × 25 × 10 mm) with holes for CBCT image resolution. Following recommendations from the manufacturer CBCT Image resolution QA was performed on an image reconstructed from 1440 image projections taken at 50 kVp and 0.8 mA. The QA slab (Fig. 2B) for this test contains Rabbit Polyclonal to TOP2A. a series or pattern of equi-distant holes with different sizes. Following American College of Radiology guidelines the smallest hole size distinctly resolved in the CBCT image is considered a measure of spatial resolution. In general qualitative QA can also be done by visual comparison of images of this slab with a reference image obtained e.g. during commissioning or acceptance testing. Results The output constancy QA results for different field sizes (Fig. 3) showed maximum distinctions of 2.5% 2.3% 2.01% and 1.89% respectively for open field (20 × 20 cm2) 3 × 3 mm 5 × 5 mm2 and 12 mm fields. The email address details are inside the tolerances (3% for daily QA) suggested by AAPM Job record 40 and 142 [14 15 Body 3 The SARRP result L 006235 check measurements gathered daily over weekly. Figure 4 displays the lateral profile for field size of 5 × 5 mm2 and 12 mm at two depths (0 mm and 10 mm). Analyzed outcomes (Desk 1) present the beam flatness outcomes between 1.78% and 3.1% as well as the beam profile symmetry between 1.07% and 2.12% for the investigated field sizes and depths. The results from the symmetry and flatness act like those from previous work for clinical systems . The penumbra L 006235 from the 5 × 5 mm2 and 12 mm collimators demonstrated a optimum difference of 0.8 mm between commissioning and QA measurements. This finding is leaner compared to the 2 mm recommended by clinical process . Body 4 The beam profile for 5 × 5 mm2 and 12 mm collimators at depth 0 mm and 10 mm. Table 1 Flatness symmetry and penumbra for collimator 5 × 5 mm2 and 12 mm at depth d1 = 0 mm and L 006235 d2 = 10 mm all measurements were performed at SSD = 31 cm. Meanwhile from Fig. 5A-B the PDD plot for commissioning and annual QA data shows maximum discrepancies of less than 2% for 5 × 5 mm2 and 12 mm collimators at depth 0 mm 5 mm 10 mm 55 mm and 75 mm. These results are within the recommendation of AAPM Task Report 40 . However for depth 15 25 35 and 45 mm the maximum differences were 5% for 5 × 5 mm2 and 7% for 12 mm. These larger discrepancies could be due to uncertainties arising from film handling air gap between slabs orientation dependence for EBT2 L 006235 film used for commissioning etc. To further verify and validate the QA data the PDD was also investigated using calibrated L 006235 OSLDs incorporated in the QA phantom and compared to the EBT3 film method. Figure 7A-B shows good agreement of results using both methods. The Bland Altman plot was used to further analyze both dosimetry methods. For the 5 × 5 mm2 collimator the results range between.