A Prospective Trial Demonstrating the Benefit of Personalized Selection Of Breath-Hold Technique for Upper-Abdominal Radiation Therapy Using the Active Breathing Coordinator.

PURPOSE: For upper abdominal tumors, our institutional-standard motion reduction method is the expiration breath-hold (EBH) technique, using Active Breathing Coordinator (ABC). However, an individual patient's breath-hold (BH) reproducibility (RBH) may be improved in deep inspiration or inspiration breath-hold (DIBH or IBH). This trial compared the tumor position RBH, stability (SBH), and breath-hold time (TBH) of 3 BH methods, using ABC, to personalize the selection of technique, by using a preplanning screening assessment. METHODS AND MATERIALS: We invited patients planned for upper abdominal radiation therapy (kidney, pancreas, liver, or adrenal gland) to participate in this prospective trial. We conducted ABC education with the study participants, who then attempted EBH, DIBH, and IBH in randomized order. During 5 consecutive BH's for each method, we acquire kV fluoroscopy images of the diaphragm. We personalized the BH technique selection according to a decision matrix. We analyzed the EBH and the personalized technique cohort mean RBH and SBH. RESULTS: Between May 2019 and March 2020, we recruited 19 participants. Median age of participants was 68 years (range 32-81). Tumor sites included kidney (n = 1), adrenal gland (n = 5) and liver (n = 14). We excluded 1 participant due to poor BH compliance, leaving 270 images from 18 participants for analysis. Mean TBH was 22.1, 23.9, and 24.2 seconds for EBH, DIBH, and IBH respectively. Screening selected EBH for 44% (n = 8), IBH for 39% (n = 7), and DIBH for 17% (n = 3) of participants. The mean RBH was superior at 0.92 mm (0.79 mm SD) for the personalized technique, compared with EBH of 1.79 mm (1.49 mm SD) (P = .016). Preplanned subset analysis of participants whose personalized technique was not EBH showed improved mean RBH of 0.63 mm (0.29 mm SD) compared with their EBH RBH of 2.2 mm (1.7 mm SD) (P = .011). CONCLUSIONS: In 56% of participants, DIBH or IBH demonstrated superior RBH compared with EBH. Personalised BH screening can inform selection of an ABC BH method which provides optimal RBH with improved TBH for an individual's planning and treatment course.