SU-E-J-148: Fabrication of an Anatomically Realistic Dynamic Respiratory Phantom

The purpose of this project was to design an anatomically correct respiratory phantom that allows for accurate dose measurement within thoracic structures that move in a realistic fashion allowing for a more accurate simulation of in vivo measurements.

The basis for this phantom is The Dynamic Breathing Phantom (TBP), an Alderson Phantom by Radiology Support Devices (RSD). The phantom was disassembled, removing the proprietary pneumatic lung apparatus as well as the motor driven tumor mount. A CT of the phantom at rest in the exhale position was acquired with 0.25 cm slice thickness. Every sixteenth slice was printed out to scale. The lung cavity was segmented on the images. These were used to cut out 4.0 cm thick slabs of foam rubber matching the contour of the lung. These were assembled along with other thoracic structures manually imbedded in the foam rubber. The organs were then placed within the chest cavity of the phantom. A purpose-built diaphragm chamber made of a rubber bladder was inserted under the lung material. The manufacturer-provided air compressor system was re-tasked to drive the diaphragm chamber.

The foam rubber used as lung material has comparable density to human lung (-800 HU). The phantom is capable of producing realistic respiratory motion. This phantom will easily accommodate a variety of dosimeters and can be adapted for a variety of tumor/critical structure shapes, sizes and locations.

The creation of this versatile humanoid phantom opens the door for a multitude of experiments to investigate dose to organs within the chest cavity for different planning techniques, under different respiratory condition, while using a more anatomically correct experimental setup.