Abstract
PURPOSE: Respiratory motion poses a significant challenge in radiation therapy for thoracic and abdominal malignancies. For tomotherapy machines, it is even more challenging due to the 10-s warm-up time before initiating the treatment beams. A recent tomotherapy system upgrade has reduced this warm-up time to 0.5 s for the TomoDirect delivery mode, enabling the feasibility of performing breath-holding treatments. In this study, we investigated the feasibility of performing breath-holding treatments on a tomotherapy machine with spirometry technique. METHODS: A patient with gastric mucosa-assisted lymphoid tissue lymphoma was treated with deep inspiration breath holding (30 Gy in 20 fractions) on a tomotherapy machine with Active Breathing Coordinator™. An in-house visual system, featuring a compact 7″ LCD monitor, was implemented to provide visual feedback, allowing the patient to self-monitor their breathings and adhere to the prescribed pattern. RESULTS: The patient tolerated the breath-hold well for the entire treatment. The number of breath-holds for treatment was 9. The beam-on time for each field ranged from 12.4 to 19.7 s, average 15.2 s. CONCLUSIONS: We have shown that BH treatment is feasible using an upgraded tomotherapy machine (Radixact v3.5) with Active Breathing Coordinator. Our proposed workflow includes an in-house visual system that allows patients to visualize their breathing patterns on-screen. This technique provides a practical solution for patients with thoracic and abdominal malignancies, addressing respiratory motion while minimizing radiation exposure for certain diseases.