Daisuke Kawai1, Ryo Takahashi2, Tatsuya Kamima2, Hiromi Baba3, Toshijiro Yamamoto4, Yoko Kubo4, Satoru Ishibashi5, Yoshihiro Higuchi5, Kensuke Tani6, Norifumi Mizuno6, Shunta Jinno7, Hidenobu Tachibana8. 1. Division of Radiological Technology, Kanagawa Cancer Center, Kanagawa 241-0815, Japan. 2. Department of Radiation Oncology, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan. 3. Particle Therapy Division, Research Center for Innovative Oncology, The National Cancer Center, Chiba 2778577, Japan. 4. Department of Radiological Technology, Otemae Hospital, Osaka 540-0008, Japan. 5. Department of Radiology, Sasebo City General Hospital, Sasebo, Nagasaki 857-8511, Japan. 6. Department of Radiation Oncology, St Luke's International Hospital, 104-8560, Japan. 7. Graduate Division of Health Sciences, Komazawa University, Tokyo 154-8525, Japan. 8. Particle Therapy Division, Research Center for Innovative Oncology, The National Cancer Center, Chiba 2778577, Japan. Electronic address: htachiba@east.ncc.go.jp.
Abstract
PURPOSE: The aim of the present investigation was to evaluate the dosimetric variation regarding the analytical anisotropic algorithm (AAA) relative to other algorithms in lung stereotactic body radiation therapy (SBRT). We conducted a multi-institutional study involving six institutions using a secondary check program and compared the AAA to the Acuros XB (AXB) in two institutions. METHODS: All lung SBRT plans (128 patients) were generated using the AAA, pencil beam convolution with the Batho (PBC-B) and adaptive convolve (AC). All institutions used the same secondary check program (simple MU analysis [SMU]) implemented by a Clarkson-based dose calculation algorithm. Measurement was performed in a heterogeneous phantom to compare doses using the three different algorithms and the SMU for the measurements. A retrospective analysis was performed to compute the confidence limit (CL; mean±2SD) for the dose deviation between the AAA, PBC, AC and SMU. The variations between the AAA and AXB were evaluated in two institutions, then the CL was acquired. RESULTS: In comparing the measurements, the AAA showed the largest systematic dose error (3%). In calculation comparisons, the CLs of the dose deviation were 8.7±9.9% (AAA), 4.2±3.9% (PBC-B) and 5.7±4.9% (AC). The CLs of the dose deviation between the AXB and the AAA were 1.8±1.5% and -0.1±4.4%, respectively, in the two institutions. CONCLUSIONS: The CL of the AAA showed much larger variation than the other algorithms. Relative to the AXB, larger systematic and random deviations still appeared. Thus, care should be taken in the use of AAA for lung SBRT.
PURPOSE: The aim of the present investigation was to evaluate the dosimetric variation regarding the analytical anisotropic algorithm (AAA) relative to other algorithms in lung stereotactic body radiation therapy (SBRT). We conducted a multi-institutional study involving six institutions using a secondary check program and compared the AAA to the Acuros XB (AXB) in two institutions. METHODS: All lung SBRT plans (128 patients) were generated using the AAA, pencil beam convolution with the Batho (PBC-B) and adaptive convolve (AC). All institutions used the same secondary check program (simple MU analysis [SMU]) implemented by a Clarkson-based dose calculation algorithm. Measurement was performed in a heterogeneous phantom to compare doses using the three different algorithms and the SMU for the measurements. A retrospective analysis was performed to compute the confidence limit (CL; mean±2SD) for the dose deviation between the AAA, PBC, AC and SMU. The variations between the AAA and AXB were evaluated in two institutions, then the CL was acquired. RESULTS: In comparing the measurements, the AAA showed the largest systematic dose error (3%). In calculation comparisons, the CLs of the dose deviation were 8.7±9.9% (AAA), 4.2±3.9% (PBC-B) and 5.7±4.9% (AC). The CLs of the dose deviation between the AXB and the AAA were 1.8±1.5% and -0.1±4.4%, respectively, in the two institutions. CONCLUSIONS: The CL of the AAA showed much larger variation than the other algorithms. Relative to the AXB, larger systematic and random deviations still appeared. Thus, care should be taken in the use of AAA for lung SBRT.
Authors: Carles Muñoz-Montplet; Rafael Fuentes-Raspall; Diego Jurado-Bruggeman; Sebastià Agramunt-Chaler; Albert Onsès-Segarra; Maria Buxó Journal: Adv Radiat Oncol Date: 2021-05-19