SARRP

 Small Animal Radiation Research Platform or SARRP 200 

(Model: SARRP200_ST_AB, Xstrahl Life Sciences, Suwanee, GA).

The SARRP 200 combines pre-treatment, cone beam micro-CT imaging with conformal small-beam radiation delivery. This irradiator enables the user to image small tumors and normal organs in order to precisely deliver radiation therapy to within 0.2 mm of the target.

  System Summary :

· Fully integrated imaging, registration, and radiation dose planning software

· 6 standard collimators

· 2 standard filters for beam hardening

· Radiosurgical dose delivery

· Fast CT reconstruction and dose calculation

· 225 kV dual focus X-ray tube

· Robotic Specimen Stage for position accuracy (15 µm) and true continuous arc treatments

· True non-coplanar treatments

Specific Features Included

225 kV dual focus X-ray tube: A 225 kV x-ray source is needed to generate X-rays for radiation treatment delivery. This photon energy is suitable to use radiation to treat small animals. 2 Standard filters: Filters are required to “harden” the X-ray in order to remove low energy photons and to create a relatively monoenergetic beam suitable for imaging or radiation therapy.

Motorized Variable Collimator – allows for selection of variable rectangular irradiation sizes.

On-board cone beam micro-CT imaging system: The capability to perform CT-quality imaging while the animal is in the irradiator in the treatment position is an essential feature of the proposed instrument. The capability to perform small-animal micro-CT will allow precise target localization and radiation treatment delivery. By integrating micro-CT with radiation delivery, this feature will allow true image-guided radiation delivery to small animals. Small animals will receive 60 kV X-rays, with standard voxel size of 0.275 mm. Transmitted photons that are captured with a flat panel detector generate the image.

Robotic Specimen Stage: The robotic specimen stage with 360-degree rotation capability is requested for imaging small animals by micro-CT and for positioning the animal with respect to the radiation-treatment isocenter. This robotic specimen stage simulates the treatment ‘couch’ that is clinically used for patients. It will provide position accuracy of 15 µm, which is necessary for irradiating tumors and specific organs to high doses while avoiding adjacent normal tissues. It is also fitted to allow delivery of gas anesthesia.

Electronic portal imaging device (EPID): Because some users study multi-fraction radiation treatment regimens, the EPID is required in order to verify treatment position for successive treatments. The EPID allows the user to take a PA (posterior–anterior) portal image of the specimen prior to irradiation. This image can then be captured and used as a reference for set-up confirmation of subsequent treatments. This feature is especially useful for high throughput experiments which require fractionated radiation therapy regimens for multiple rodents. For example, with daily target localization using EPID, cancer in a mouse can be treated using the same ‘gold standard’ radiation therapy regimen that most patients receive (i.e., daily treatments with EPID 5 days/week, with cone beam CT imaging performed 1-2x/week).

Real-time fluoroscopy: This feature allows for continuous “real-time” X-ray imaging of the mouse during the treatment. This allows the user to monitor and document any changes or shifts that may occur in the target during the treatment. This feature also allows for monitoring of physiologic motion changes during treatment, such as with respiration.

Muriplan Software: Comprehensive software is available for image acquisition and reconstruction, control of the robotic stage, multi-modality image fusion, segmentation, contouring, beam planning, dose computation including dose volume histograms, dose verification, dose delivery, and reporting.

CCTV camera: This feature allows the user to view the small animal during imaging and treatment. Changes in body position or other environmental factors (e.g., level of anesthesia) are monitored visually by the user.

External Lasers: Lasers are used to locate the isocenter on the small animal for visual alignment of the position prior to treatment. This feature allows for rapid setup and preparation of the animal for onboard imaging.

This instrument was obtained by NIH funding of an S10 grant. Any work published using this instrument should reference that the work was supported by grant S10OD028575 for the SARRP Image-Guided Radiation Therapy System, Duke Small Animal Irradiator Service Center facility.