Multi‐institutional dosimetric and geometric commissioning of image‐guided small animal irradiators

Lindsay, Patricia; Granton, Patrick V.; Gasparini, Alessia; Jelveh, Salomeh; Clarkson, Richard W. E.; Hoof, S. Van; Hermans, J.; Kaas, J.; Wittkämper, F.W.; Sonke, Jan‐Jakob; Verhaegen, Frank; Jaffray, David A.

doi:10.1118/1.4866215

Cited by 42 publications

(51 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For machine commissioning or yearly QA assessments, however, it is recommended to use one of the more comprehensive protocols available in the literature, which include depth dose curves and lateral dose profiles. (Tryggestad et al 2009, Clarkson et al 2011, Pidikiti et al 2011, Lindsay et al 2014)…”

Section: Discussionmentioning

confidence: 99%

“…Some comprehensive protocols have been published to ensure accurate commissioning and dosimetric characterization as well as calibration of the beam alignment. (Matinfar et al 2009, Rodriguez et al 2009, Tryggestad et al 2009, Pidikiti et al 2011, Lindsay et al 2014) These procedures, although comprehensive, are quite time consuming and are more appropriate for machine commissioning and annual system checks, rather than ongoing monthly or weekly QA. A recent paper presented an elegant solution for everyday QA measures using a mouse-sized metal oxide semiconductor field effect transistor (MOSFET) phantom capable of measuring daily output consistency, beam energy, cone profiles and some simple image quality measures such as noise and uniformity, although no assessment for materials of varying x-ray density was included.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Proposal for a Simple and Efficient Monthly Quality Management Program Assessing the Consistency of Robotic Image-Guided Small Animal Radiation Systems

Brodin

Guha

2015

Health Physics

View full text Add to dashboard Cite

Modern pre-clinical radiation therapy (RT) research requires high precision and accurate dosimetry to facilitate the translation of research findings into clinical practice. Several systems are available that provide precise delivery and on-board imaging capabilities, highlighting the need for a quality management program (QMP) to ensure consistent and accurate radiation dose delivery. An ongoing, simple, and efficient QMP for image-guided robotic small animal irradiators used in pre-clinical RT research is described. Protocols were developed and implemented to assess the dose output constancy (based on the AAPM TG-61 protocol), cone-beam computed tomography (CBCT) image quality and object representation accuracy (using a custom-designed imaging phantom), CBCT-guided target localization accuracy and consistency of the CBCT-based dose calculation. To facilitate an efficient read-out and limit the user dependence of the QMP data analysis, a semi-automatic image analysis and data representation program was developed using the technical computing software MATLAB. The results of the first six months experience using the suggested QMP for a Small Animal Radiation Research Platform (SARRP) are presented, with data collected on a bi-monthly basis. The dosimetric output constancy was established to be within ±1 %, the consistency of the image resolution was within ±0.2 mm, the accuracy of CBCT-guided target localization was within ±0.5 mm, and dose calculation consistency was within ±2 s (± 3 %) per treatment beam. Based on these results, this simple quality assurance program allows for the detection of inconsistencies in dosimetric or imaging parameters that are beyond the acceptable variability for a reliable and accurate pre-clinical RT system, on a monthly or bi-monthly basis.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Proposal for a Simple and Efficient Monthly Quality Management Program Assessing the Consistency of Robotic Image-Guided Small Animal Radiation Systems

Brodin

Guha

2015

Health Physics

View full text Add to dashboard Cite

show abstract

“…Animal irradiators have less guidance for the frequency and type of QA performed, with the result that delivery of radiation may not be as accurate as reported. 37 With the advent of partial irradiation techniques for animal models, targeting also becomes a necessary part of QA but is not standardized, leaving each laboratory to determine what level of testing is sufficient for the experiment at hand.…”

Section: Contribution Of Radiation Technique To Model Responsementioning

confidence: 99%

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

Koontz¹,

Verhaegen²,

Ruysscher³

2017

BJR

View full text Add to dashboard Cite

Animal modelling is essential to the study of radiobiology and the advancement of clinical radiation oncology by providing preclinical data. Mouse models in particular have been highly utilized in the study of both tumour and normal tissue radiobiology because of their cost effectiveness and versatility. Technology has significantly advanced in preclinical radiation techniques to allow highly conformal image-guided irradiation of small animals in an effort to mimic human treatment capabilities. However, the biological and physical limitations of animal modelling should be recognized and considered when interpreting preclinical radiotherapy (RT) studies. Murine tumour and normal tissue radioresponse has been shown to vary from human cellular and molecular pathways. Small animal irradiation techniques utilize different anatomical boundaries and may have different physical properties than human RT. This review addresses the difference between the human condition and mouse models and discusses possible strategies for future refinement of murine models of cancer and radiation for the benefit of both basic radiobiology and clinical translation.

show abstract

“…1 Microirradiators enable exploration of the efficacy of novel radiation treatment approaches by providing the capability to reproduce realistic treatment delivery in small animal models. [2][3][4][5][6][7] Investigation of the efficacy and biological radio-response from new radiation treatments rely on the use of these small animal models before reaching the clinic. Preclinical studies aim to highlight the biological mechanisms governing radiotherapy response in many radiation applications.…”

Section: Introductionmentioning

confidence: 99%

Investigating the accuracy of microstereotactic‐body‐radiotherapy utilizing anatomically accurate 3D printed rodent‐morphic dosimeters

et al. 2015

View full text Add to dashboard Cite

Purpose: Sophisticated small animal irradiators, incorporating cone-beam-CT image-guidance, have recently been developed which enable exploration of the efficacy of advanced radiation treatments in the preclinical setting. Microstereotactic-body-radiation-therapy (microSBRT) is one technique of interest, utilizing field sizes in the range of 1-15 mm. Verification of the accuracy of microSBRT treatment delivery is challenging due to the lack of available methods to comprehensively measure dose distributions in representative phantoms with sufficiently high spatial resolution and in 3 dimensions (3D). This work introduces a potential solution in the form of anatomically accurate rodent-morphic 3D dosimeters compatible with ultrahigh resolution (0.3 mm 3 ) optical computed tomography (optical-CT) dose read-out. Methods: Rodent-morphic dosimeters were produced by 3D-printing molds of rodent anatomy directly from contours defined on x-ray CT data sets of rats and mice, and using these molds to create tissue-equivalent radiochromic 3D dosimeters from Presage. Anatomically accurate spines were incorporated into some dosimeters, by first 3D printing the spine mold, then forming a high-Z bone equivalent spine insert. This spine insert was then set inside the tissue equivalent body mold. The high-Z spinal insert enabled representative cone-beam CT IGRT targeting. On irradiation, a linear radiochromic change in optical-density occurs in the dosimeter, which is proportional to absorbed dose, and was read out using optical-CT in high-resolution (0.5 mm isotropic voxels). Optical-CT data were converted to absolute dose in two ways: (i) using a calibration curve derived from other Presage dosimeters from the same batch, and (ii) by independent measurement of calibrated dose at a point using a novel detector comprised of a yttrium oxide based nanocrystalline scintillator, with a submillimeter active length. A microSBRT spinal treatment was delivered consisting of a 180• continuous arc at 225 kVp with a 20 × 10 mm field size. Dose response was evaluated using both the Presage/optical-CT 3D dosimetry system described above, and independent verification in select planes using EBT2 radiochromic film placed inside rodent-morphic dosimeters that had been sectioned in half. Results: Rodent-morphic 3D dosimeters were successfully produced from Presage radiochromic material by utilizing 3D printed molds of rat CT contours. The dosimeters were found to be compatible with optical-CT dose readout in high-resolution 3D (0.5 mm isotropic voxels) with minimal artifacts or noise. Cone-beam CT image guidance was possible with these dosimeters due to sufficient contrast between high-Z spinal inserts and tissue equivalent Presage material (CNR ∼10 on CBCT images). Dose at isocenter measured with optical-CT was found to agree with nanoscintillator measurement to within 2.8%. Maximum dose in line profiles taken through Presage and film dose slices agreed within 3%, with FWHM measurements through each profile found to agree within 2%. Conclusions: T...

show abstract

Multi‐institutional dosimetric and geometric commissioning of image‐guided small animal irradiators

Cited by 42 publications

References 38 publications

Proposal for a Simple and Efficient Monthly Quality Management Program Assessing the Consistency of Robotic Image-Guided Small Animal Radiation Systems

Proposal for a Simple and Efficient Monthly Quality Management Program Assessing the Consistency of Robotic Image-Guided Small Animal Radiation Systems

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

Investigating the accuracy of microstereotactic‐body‐radiotherapy utilizing anatomically accurate 3D printed rodent‐morphic dosimeters

Contact Info

Product

Resources

About