 Indexed Patient Positioning™ in its simplest form is a system in which any patient positioning devices indexes – or “docks” – into precisely the same table location – treatment after treatment, throughout the treatment cycle.
How does it work?
An indexing bar, or “lockbar” – designed for a particular couchtop width – indexes and locks down to any of the multiple indexing points running longitudinally along the edges of the couchtop. (Because table widths vary, this indexing bar will remain with a specific CT, simulator, or treatment table/couch in your department.) Any patient positioning/fixation device with the indexing bar interface can be docked to any indexing bar within your department – allowing the positioning device to go from simulation to treatment – indexed and locked quickly and precisely, and positioning the target relative to isocenter.
There are several obvious advantages to implementing an indexing system in your radiation oncology department. Patient setup times and associated errors are minimized through standardized, indexed locations. In addition, the patient positioning device is always “square” and straight with the table X,Y axes, and locked down to prevent movement.
Simulation to treatment. By installing an indexing system on a simulator and/or CT table – with the same distance between the indexing points on the longitudinal axis as the treatment table – a patient’s positioning device can be moved from the sim table to the treatment couch and locked down in the same location relative to the isocenter.
MED-TEC has developed a multiple level system approach to Indexed Patient Positioning that allows a facility to “stair step” from a basic entry Level I for the treatment table only, to a complete, high-end Level II system that features carbon fiber indexing couchtops for simulator, CT, and treatment tables. Both Level I and Level II systems feature identical center-to-center distance between indexing points (long axis) to provide economical and versatile system upgrades.
Level I
 A cost-effective, entry level system featuring our Table Indexer that adjusts for any couchtop width,and indexes to the table with your choice of three methods:
- Accessory rail standoffs. The Indexer’s vertical grip plates are contour-cut to the profile of the couchtop’s accessory rail “standoffs,” allowing the Indexer to be positioned quickly at each of these locations along the couch. Note: The longitudinal indexing points are limited to the standoffs.
- Accessory rail locking blocks. The Indexer is fitted with vertical posts (replacing the grip plates) that fit into locking blocks, allowing the Indexer to be positioned at any location along the longitudinal axis of the couch.
- Longitudinal table indexing strips. By installing a pair of indexing strips along the outside edges of the couchtop, the Indexer can “dock” at multiple pre-set points. These indexing points have the same center-to-center spacing found on our Level II systems, offering a cost-effective way to expand your Indexed Patient Positioning system and devices.
Level II
Carbon fiber couchtops, exclusively from MED-TEC, are designed for CT, simulator, and treatment tables, and feature indexing points along the longitudinal axis. Radiotranslucent carbon fiber grid treatment panels (which replace the factory-installed “tennis racket” inserts) on our simulator and treatment couch upgrades minimize deflection and provide expanded treatment angles while providing all the advantages of indexed patient positioning. CT flat-panel table inserts securely lock into the CT cradle, and also feature indexing points consistent with the treatment couchtop. Each indexed patient positioning couchtop within your department then provides a consistent frame of reference for all your patient positioning devices – from sim through treatment – for accurate, reproducible patient setup.
Note: Indexed patient positioning was originally co-developed with Varian Oncology as the Exact™ line of Indexed Immobilization™ systems to work in conjunction with the Varian Exact™ couchtop. For complete information on this conformal couchtop with indexing features, contact your MED-TEC or Varian account representative. |
