Guidelines for using the ABC system on the Elekta for Respiratory Gating Treatment
Radiation Therapy Supervisor, MD Anderson Cancer Center, Colorado Technical University, USA
Submission: January 24, 2018; Published: February 07, 2018
*Corresponding author: Debra Moore, Radiation Therapy Supervisor at MD Anderson Cancer Center, Colorado Technical University, Albuquerque, New Mexico Area, USA, Email: email@example.com
How to cite this article: Debra M. Guidelines for using the ABC system on the Elekta for Respiratory Gating Treatment. Canc Therapy & Oncol Int J. 2018; 9(3): 555761. DOI: 10.19080/CTOIJ.2018.09.555761
The ABC or Active breathing coordinator system is the respiratory gating system used with the Elekta treatment machine. Unlike the Varian, this system uses a spirometer to track the patients actual lung volume. Consists of 3 main parts: ABC cart, laptop interface, mouthpiece w/ flow meter and valve.
i. ABC is used when there is a need to reduce the anatomical movement in the thorax and abdomen caused by breathing and cardiac motion.
ii. Intended use is for breath-hold treatments in simulation and XRT
iii. Specifically used for left breast treatments to spare dose to heart, lung and other thoracic cancers to reduce tumor target margins, SRS thorax treatments, and certain liver and pancreatic tumors.
iv. Patient can hold and maintain an accurate breath- hold to a specific lung volume that can be monitored in the treatment room by that patient. The therapist monitors the breathing on a laptop in the treatment area.
v. A patient controlled balloon valve lets the patient do breath-hold treatments at the same lung volume for each field (Figures 1 & 2).
Patient presses the button during treatment and only
releases it to stop the breathold. When the button is released the balloon valve is deflated. If the patient presses the button twice is one second it will send a distress signal that will show up on the laptop screen (Figure 3)
Modification to set up can be made by selecting Patient Settings and clicking and entering desired levels (Figures 20). Physics will provide instructions to the patient explaining the steps to the ABC procedure (Figure 21). Position mouth piece, nose clamp and patient control switch. Ask patient to take in a big breath and take note as to how many liters are inspired. Repeat 3 times and adjust threshold to approximately 80% of maximum volume. Activate System by pressing space bar once. Have patient depress green button and take in a big breath. System will cut up breath upon reaching the preselected volume. Have them let go of the button and breath normally. After patient tumor loc and marking, attach flexible arm to table top. Insert balloon device and lock in place.
Remove Laptop from cart and place on counter. Connect computer to Elekta Response Box and network cable. Turn on Response Box on (hold down until green light appears) (Figure 23). Turn on computer. Take ABC cart into Tx room and connect network cable into cart (Figure 24). Plug in cart unit to nearest outlet. Turn on control module power switch. Remove table clamp from cart and attach to superior/top of table. Insert flexible arm into table clamp. Attach patient respiratory device to flexible arm along with mouth piece (Figure 25). Login to ABC computer (Password: abc lowercase). Double click on ABC icon. ABC System Check should all be green (connected) (Figure 26). Trouble shooting (if needed). Load existing patient. Click on ABC patient data (Upper left corner). Select correct patient from existing list. Highlight patient for treatment. Select - open patient (Figure 27). ABC patient setting Box will appear (Figure 28). Under session record today's date. Click DONE (lower left). Load Patient information (plan) on linac. Highlight field and add pre-port film (must image daily).
Select port needed. Instruct patient to hold control switch (Figures 29-31). 2nd therapist should be providing patient
with breathing instructions over intercom. Patient instructed to release green button as needed with breathing crisis, (release of button will necessitate 2nd therapist to hit space bar to reactivate ABC control) Hit space bar to activate breath control with linac. ABC control is represented by green bar. Instruct patient to gently take in a deep breath. ABC control will prevent patient from normal breathing once dose delivery threshold is reached. Treatment delivery achieved within countdown window (Figure 32).
iv. Micro USB cable connected on the bottom left is often the culprit as it works loose with gravity (Figure 35).
v. This is also where the power switch for the control module is located (Figure 36).
vi. Green light on top indicates power to the module and control unit are on (Figure 37).
vii. Red light on top along with audible alarm indicates power switch to the module and control unit are off (Figure
viii. Power switch for the ABC control cart is located on the side of the unit along with the network connector (Figure
ix. Lastly check that the network cable is plugged securely into the correct jack (Figure 40).
If all connections are securely plugged try to re-launch the USB server from the control laptop (Figure 41). All green lights indicate ABC is in the correct state for treatment (Figure 42). While delivering treatment you find that the space bar will not activate the system. Make sure patient is holding the patient control button down (Figure 43). This will change the respiratory indicator line blue. If line is blue and space bar still does not work then press pause then record to re-activate system (Figure 44). This is the correct activated treatment state (Figure 45). If beam will not deliver check that the response box is active (Figure 46). Press and hold power switch till light turns green. If light is red, press and hold till light turns off then turn it back on. This is what the response box should look like when ready to deliver beam. If beam will not deliver check that the response box is active. Press and hold power switch till light turns green.
Therapy Staff - Supervisor - Debra Moore, Roshan Cherian Brandon Held, Leslie Robson Virginia Hernandez Bernal, Ameenah Roybal Janis Roybal Garcia, Dosimetry - Paul Chavez, Erik Frija and Rocio Bergamo, Nursing - Elfrida Bauer, Celina Trujillo and Jayme Runyan, Dr. Ramesh Gopal - Radiation Oncologist, Dr. Amit Garg - Radiation Oncologist, Dr. Kara Bucci - Radiation Oncologist, Special Thanks to Physics - Elder Calderon, Mark Garcia and Mark Marshall.