Physicians
Precise tumor localization and fast and accurate patient positioning prior to each treatment fraction are crucial steps in the effective treatment of tumors. Resonant Medical's products have been developed to address the fundamental problem of organ motion and the issues associated with comparing ultrasound to CT image modalities for motion measurement and patient repositioning. By addressing this fundamental problem, it also provides a new and unique solution to the poor soft tissue visualization on CT.
Organ motion and cross-modality comparison of organ volumes
The well-documented problem of organ motion, particularly for the prostate, over a course of treatment jeopardizes the intended outcome. Accounting for changes in tumor size, shape, and position increases dose delivery accuracy. The increase in confidence with respect to organ position is a necessary condition for advances in the area of dose escalation and more conformal techniques such as IMRT. Some position verification solutions use crossmodality comparisons to measure displacement, i.e. they compare different volumes derived from CT and ultrasound – volumes which may vary by as much as 40%, with the ultrasound volume being closer to the true anatomical volumes. Not only does this step decrease throughput on the accelerator, it also requires the radiation therapist to make a subjective judgment about how best to align different volumes from two different modalities at every fraction. Other solutions require time-consuming analysis or data reconstruction, making pre-treatment verification impractical. This can result in longer treatment times – with a negative impact on throughput – or constant postponement of organ position correction by a day.
With the Clarity system and its patented Mutual Referencing™ technology, these compromises are unnecessary. Organ displacements are calculated using ultrasound to ultrasound volumes, eliminating errors potentially introduced by cross-modality comparison. In addition, pre-treatment imaging, segmentation and alignment can be performed very quickly, making efficient pre-treatment image-guided positional verification and patient realignment a reality.
See published papers relating to intramodality position verification.
Poor Soft-Tissue Visualization on CT
By generating a reference ultrasound volume for Mutual Referencing™ in the CT room, Clarity also addresses another important problem in the treatment planning room. The success of conformal therapy, including Intensity Modulated Radiation Therapy (IMRT), is predicated on accurate delineation of tumor volume. Although CT imaging is the cornerstone of radiotherapy treatment planning, its low soft tissue contrast makes it challenging to contour target anatomy and critical structures at the time of treatment planning. In the pursuit of better organ definition, the use of Magnetic Resonance Imaging (MRI) and contrast media have been explored. However, access to MRI for treatment planning purposes is somewhat limited and the use of contrast media can be problematic. Ultrasound, on the other hand, presents superior soft-tissue and organ boundary imaging characteristics. Finding a way to combine the best of CT and ultrasound imaging modalities holds the potential to improve the accuracy of target (i.e. cancerous organ) definition. By implementing Mutual Referencing™ to address the fundamental problem in organ motion measurement, Clarity achieved this breakthrough capability in soft-tissue visualization.
Report generation
Pre-defined reports are readily accessible from any web browser within the facility, allowing image review and approval of daily patient realignments. Reports may be viewed, stored as PDF, or automatically forwarded for printing.
