Commissioning and Quality Assurance of Catalyst+ HD Surface-guided Radiotherapy on TrueBeam HyperArc Linear Accelerator: An Indian Experience in Precision Radiotherapy

Objective: In this study, we describe and critically review our experience in the commissioning of the surface-guided radiation therapy (SGRT) system from C-RAD (Uppsala, Sweden), integrated with a Varian TrueBeam HyperArc linear accelerator (LINAC). Materials and Methods: The C-RAD SGRT system was commissioned according to the guidelines of the American Association of Physicists in Medicine Task Group 147 and the European Society for Radiotherapy and Oncology–Advisory Committee for Radiation Oncology Practice report. The commissioning tests included the isocenter, camera thermal drift, reproducibility, static localization accuracy with a 6-degree-of-freedom (DOF) couch, dynamic gating delivery, and an end-to-end test. The tools and phantoms employed for this verification included: (a) Sentinel 4DCT daily check device, (b) Catalyst⁺ HD daily check device, (c) Penta-guide, (d) gating phantom, (e) calibration board, (f) Winston-Lutz phantom, and (g) the Little John anthropomorphic phantom. Results/Discussion: The reproducibility of both the Sentinel 4DCT and Catalyst⁺ HD cameras demonstrated accuracy within ± 1 mm. The radiation isocenter measurements for both the Sentinel 4DCT and Catalyst⁺ HD cameras were found to be <1 mm, well within the recommended reports of the relevant international guidelines. The static localization accuracy of the Catalyst⁺ HD camera with a 6DOF couch was determined to be 0.15 ± 0.13 mm, 0.42 ± 0.23 mm, and 0.20 ± 0.15 mm for the vertical, longitudinal, and lateral directions, respectively. The rotational accuracy for roll, pitch, and yaw was found to be 0.05°±0.05°, 0.12°±0.18°, and 0.13°±0.10°, respectively. All results were within the tolerances recommended by the international recommendations and highlight the accuracy and precision of the C-RAD SGRT system in conjunction with the TrueBeam HyperArc LINAC. Conclusion: The newly installed advanced C-RAD SGRT systems have been successfully integrated with the Varian TrueBeam LINAC for clinical use, marking a significant milestone as the first deployment of SGRT technology of its kind in India.