Implementation of Linac-based VMAT total body irradiation technique on Elekta platform using surface-guided radiation therapy

• DOI: 10.1016/j.ejmp.2025.104940
• Publication Date: 2025-02-20T08:37:27Z
• Authors: Magali Sandt; Stéphanie Marcet; Nathalie Guesnel; Line Claude; Isabelle Martel; Marie-Claude Biston
• Keywords: Total body irradiation

To present an optimal workflow using a rotatable tabletop and surface guided radiation therapy (SGRT) system for volumetric modulated arc (VMAT) based total-body irradiation (TBI). Twenty patients having received either 2 Gy, 8 or 12 Gy in per fraction were included. They immobilized vacuum cushion three-points mask positioned on tabletop. VMAT treatment plans performed Monaco 6.1 (Elekta LTD, Stockholm) planning then perturbed by applying shifts of 5mm the isocenters coordinates to evaluate robustness. Patients treated Synergy VersaHD Linac. Pretreatment positioning was with cone-beam CT images combined SGRT only. During treatment, intra-fraction motion controlled SGRT. Dosimetric data, robustness results sessions duration collected. In terms PTV coverage lung-sparing, all met requirements most recent recommendations. The use 20-30 cm distances between isocenters, 90° collimator rotation, enabled obtain linear dose gradient two consecutive beams, which ensured sufficient against 5 mm isocenter directions. With average 1 h ± min first last comparable length extended source-to-skin distance technique. Thanks system, accurate secured VMAT-based TBI treatments within reasonable timeframe, while ensuring patient comfort.