Does it matter whether you use CyberKnife (CK) or a LINAC-based VMAT for lung SBRT? This retrospective retrospective study of an institutional database compared outcomes for 227 patients with T1-2N0 NSCLC treated with SBRT. The majority were treated with CK (63%) and the rest were treated with VMAT. Regardless of delivery technique, the PTV consisted of a 5-7mm expansion from the 4DCT generated GTV. The fractionation schemes delivered with CK were 18-20 Gy x 3 (23.9%), 12-12.5 Gy x 4 (30.3%), and 10-11Gy x 5 (45.8%). Four-to-five fraction regimens were more common with VMAT with only 4.7% receiving 18-20 Gy x 3 compared to 34.1% receiving 12-12.5 Gy x 4, and 61.2% receiving 10-11 Gy x 5. VMAT plans were more heterogeneous and had higher maximum and mean doses to the GTV and PTV relative to prescription. VMAT plans also had lower lung and heart V5 as well as lower mean lung dose. Despite the dosimetric differences, there were no differences in local tumor control, survival, or toxicity. | Deshpande, Pract Radiat Oncol 2022


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