Specific issues in small animal dosimetry and irradiator calibration

Abstract

Purpose In response to the increased risk of radiological terrorist attack, a network of Centers for Medical Countermeasures against Radiation (CMCR) has been established in the United States, focusing on evaluating animal model responses to uniform, relatively homogenous whole- or partial-body radiation exposures at relatively high dose rates. The success of such studies is dependent not only on robust animal models but on accurate and reproducible dosimetry within and across CMCR. To address this issue, the Education and Training Core of the Duke University School of Medicine CMCR organised a one-day workshop on small animal dosimetry. Topics included accuracy in animal dosimetry accuracy, characteristics and differences of cesium-137 and X-ray irradiators, methods for dose measurement, and design of experimental irradiation geometries for uniform dose distributions. This paper summarises the information presented and discussed. Conclusions Without ensuring accurate and reproducible dosimetry the development and assessment of the efficacy of putative countermeasures will not prove successful. Radiation physics support is needed, but is often the weakest link in the small animal dosimetry chain. We recommend: (i) A user training program for new irradiator users, (ii) subsequent training updates, and (iii) the establishment of a national small animal dosimetry center for all CMCR members.

Radiation Biology Irradiator Dose Verification Survey

“…These systems have high-resolution imaging capabilities, technically precise robotic movements, and energies scaled to match the small animal geometries. Concurrent to the rise in popularity of these irradiation systems has been a call for accurate and standardized dosimetry within small animal models (5,6).…”

“…The widespread usage of small animal models has spurred development of physical phantoms of mice as well. Simple mouse phantoms, which are often no more than a tube with slots for the insertion of a detector, are prevalent for dosimetry (3,5,6,21). The rise in popularity and capability of rapid prototyping tools, such as 3D printers and computer controlled milling machines, has allowed for a new generation of physical mouse phantoms with intricate features that closely mimic the animals they represent.…”

Verification of a novel method for tube voltage constancy measurement of orthovoltage x‐ray irradiators

“…As Yoshizumi et al 8 have reported, "Physics support is needed, but is often the weakest link in the small animal dosimetry chain." The current status of irradiator physics, especially orthovoltage x-ray units, calls for more recognition of the importance of having a rigorous irradiator QA program and advancement in related technological and scientific research.…”

Radiation Enhancement of Head and Neck Squamous Cell Carcinoma by the Dual PI3K/mTOR Inhibitor PF-05212384

“…Cell Cycle Analysis, RT-PCR genomic expression analysis, immunohistochemistry, and irradiation technique followed standard experimental methodology (32, 33). A detailed breakdown can be found in the Supplementary Materials and Methods section.…”