Comprehensive quality assurance phantom for the small animal radiation research platform (SARRP)

Abstract

Purpose To develop and test the suitability and performance of a comprehensive quality assurance (QA) phantom for the Small Animal Radiation Research Platform (SARRP). Methods and materials A QA phantom was developed for carrying out daily, monthly and annual QA tasks including: imaging, dosimetry and treatment planning system (TPS) performance evaluation of the SARRP. The QA phantom consists of 15 (60 × 60 × 5 mm3) kV-energy tissue equivalent solid water slabs. The phantom can incorporate optically stimulated luminescence dosimeters (OSLD), Mosfet or film. One slab, with inserts and another slab with hole patterns are particularly designed for image QA. Results Output constancy measurement results showed daily variations within 3%. Using the Mosfet in phantom as target, results showed that the difference between TPS 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 the 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 tests.

Development and implementation of EPID‐based quality assurance tests for the small animal radiation research platform (SARRP)

“…We were able to measure values of flatness and symmetry (Table ), which agreed between imager and Gafchromic EBT3 film measurements. Despite different scattering conditions, our values for flatness and symmetry are consistent with those reported by Jermoumi et al., who measured profiles on the surface of a water phantom. The smallest collimator (5 × 5 mm 2 ) exhibited the best flatness and symmetry among the cones.…”

Tumour and normal tissue radiobiology in mouse models: how close are mice to mini-humans?

“…Multiple examples exist in the literature of QA regimens for initial commissioning and routine maintenance. [45][46][47] Key elements are QA testing for dose rate constancy, imaging quality and targeting localizations that are performed on a regular basis. More advanced dosimetry techniques for small animal research may be based on using an imaging panel, in analogy with portal dosimetry in RT.…”

Design of a modulated orthovoltage stereotactic radiosurgery system

“…Rodriguez et al . evaluated beam flatness for circular field sizes with diameters of 5, 10, and 20 mm with a small animal orthovoltage prototype irradiator, and Jermoumi et al . reported beam flatness for the small animal radiation research platform (SARRP) for a square (5 × 5) mm field and a 12 mm diameter circular field.…”

“…Most similar to this work, there are examples in the literature of evaluating beam flatness, as defined by the AAPM, for orthovoltage irradiators with radiosurgical fields. Rodriguez et al 72 evaluated beam flatness for circular field sizes with diameters of 5, 10, and 20 mm with a small animal orthovoltage prototype irradiator, and Jermoumi et al 73 reported beam flatness for the small animal radiation research platform (SARRP) for a square (5 9 5) mm 2 field and a 12 mm diameter circular field.…”