d.b.a. 3D Dosimetry
  • QAbyMail™ Service for High-Definition 3D End-to-End QA in Radiation Therapy and Radiosurgery


    The CrystalBalls™ are radiochromic polymer gel dosimeters, sealed inside thin-wall glass spheres of standardized dimensions, approximating the size of a human head. ​ Self-developing.  Muscle-tissue equivalent.  Instant QA phantom setup.  No Cables.  No electronics. 

    Specifications:  isotropic voxel resolution down to (0.5mm)^3.  Dosimetric accuracy:  1% relative,  2% absolute. 

    For QA of:  SRS,  SBRT,  VMAT,  MR-Linac,  CyberKnife,  GammaKnife, Proton Therapy.  Good for both machine QA and patient-specific QA.  

    Ideal QA for single-isocenter VMAT of multiple brain metastases. 

    QAbyMail ™ Service:  Customers return exposed CrystalBalls and DICOM files to 3D Dosimetry Lab for laser CT scanning and QA analysis.  High-definition 3D QA reports are returned by email. They may be customized but normally include 3D gamma histograms & passing rates; volume histograms and voxel statistics for dose difference and distance-to-agreement; overlays of planned vs measured 3D and 2D isodoses, profiles and dose-volume histograms; detected shifts of the center of mass of the 3D dose cloud;  interactive 3D maps of dose difference, distance-to-agreement, and 3D gamma. 


    The CrystalBall™ mounted in a QA stand and ready for simulator CT


    The CrystalBall™ set up for Proton Therapy QA


    CrystalBall™ mounted in an SRS head frame

                                                                                                                                                                                                                                                                                                                                            EXAMPLE  RESULTS

    Coronal frontal view of overlaid 3D isodose surfaces (VMAT of six brain metastases, PTV#4)


    Overlay of 2D (sagittal left) isodose lines (VMAT of six brain metastases, PTV#4)


    Overlay of I-S profiles (VMAT of six brain metastases, PTV#4)

    3D gamma

    3D gamma volume histogram for PTV#4 (VMAT of six brain metastases)


    CrystalBall™ 3D QA report summary for one PTV in a six brain-metastases VMAT

    Proton Therapy QA

    Proton PBS IMPT. (a) 3D isodose surfaces at 50% dose level. Red - plan, blue - measurement; (b) Coronal isodoses. Solid - plan, dotted - measurement. (c) I-S profile overlay. Red - plan, blue - measurement, yellow - dose difference, magenta - DTA, cyan - 3D gamma.

The Crystal Ball™ End-to-End QA detects and measures any and all clinically significant cumulative errors that may originate anywhere during radiation therapy or radiosurgery planning and delivery process ​ and are located anywhere within the treated volume.