TY - JOUR
T1 - Evaluation of Auto-Contouring and Dose Distributions for Online Adaptive Radiation Therapy of Patients With Locally Advanced Lung Cancers
AU - Mao, Weihua
AU - Riess, Jeff
AU - Kim, Joshua
AU - Vance, Sean
AU - Chetty, Indrin J.
AU - Movsas, Benjamin
AU - Kretzler, Annette
N1 - Funding Information:
Sources of support: This work was supported in part by a grant from Varian Medical Systems, Palo Alto, CA (Siemens Healthineers).
Funding Information:
Disclosures: Drs Chetty, Mao, Movsas, Vance, and Kretzler received sponsored research grants from Varian Medical Systems (Siemens Healthineers), payments made to the institution. Dr Mao provided one-time consultant to Varian Medical Systems in 2019. Dr Movsas reports a pending patent for MRsim phantom patent and CTsim patent (no revenue from either).
Publisher Copyright:
© 2022 The Author(s)
PY - 2022/7/1
Y1 - 2022/7/1
N2 - Purpose: Retrospective studies were performed to evaluate the accuracy of automatically mapped structures and dosimetric consequences of daily online adaptive radiation therapy (ART) for lung cancer treatments. Methods and Materials: Ten patients with locally advanced lung cancer (prescription = 2 Gy × 30) with 297 fractions of treatment were selected for this retrospective study on a research emulator (Ethos, Varian Medical Systems). All adaptive treatments were simulated twice: automatic-ART (A-ART), automatic contours were used without modification, and supervised-ART (S-ART), automatic contours were modified manually by physicians and physicists. Dosimetric results were analyzed by relating supervised scheduled (S-SCH) dose (initial baseline reference plan delivered on daily anatomy and supervised contour correction without any adaptation), A-ART and S-ART to the initial baseline reference dose. Results: Two hundred ninety (of 297) fractions were analyzed. Comparing target volumes between A-ART and S-ART, dice similarity coefficient was 0.93 ± 0.05, mean contour distance was 1.5 ± 1.2 mm, and Hausdorff distance was 4.0 ± 2.3 mm. Analysis of daily results over 290 fractions of treatment showed that average target coverage improved from 0.96 ± 0.04 (S-SCH) to 1.00 ± 0.02 (A-ART) and 1.02 ± 0.04 (S-ART); average upper dose constraint was reduced from 1.01 ± 0.11 (S-SCH) to 0.94 ± 0.10 (A-ART) and 0.93 ± 0.12 (S-ART). A-ART and S-ART improved planning target volume minimum doses by 4.85 ± 3.03 Gy (P = .049) and 4.46 ± 8.99 Gy (P = .058), respectively. Statistical analysis shows that A-ART and S-ART significantly improved cumulative target dose by 0.033 ± 0.087 (P = .002) and 0.032 ± 0.086 (P = .003) and reduced upper constraints by 0.033 ± 0.072 (P < .001) and 0.032 ± 0.072 (P < .001) relative to S-SCH dose results, respectively. Conclusions: Accuracy of Ethos automatic contouring for lung cancer is considered clinically acceptable. The online adaptive radiation therapy improves target coverage and spares organs-at-risk significantly.
AB - Purpose: Retrospective studies were performed to evaluate the accuracy of automatically mapped structures and dosimetric consequences of daily online adaptive radiation therapy (ART) for lung cancer treatments. Methods and Materials: Ten patients with locally advanced lung cancer (prescription = 2 Gy × 30) with 297 fractions of treatment were selected for this retrospective study on a research emulator (Ethos, Varian Medical Systems). All adaptive treatments were simulated twice: automatic-ART (A-ART), automatic contours were used without modification, and supervised-ART (S-ART), automatic contours were modified manually by physicians and physicists. Dosimetric results were analyzed by relating supervised scheduled (S-SCH) dose (initial baseline reference plan delivered on daily anatomy and supervised contour correction without any adaptation), A-ART and S-ART to the initial baseline reference dose. Results: Two hundred ninety (of 297) fractions were analyzed. Comparing target volumes between A-ART and S-ART, dice similarity coefficient was 0.93 ± 0.05, mean contour distance was 1.5 ± 1.2 mm, and Hausdorff distance was 4.0 ± 2.3 mm. Analysis of daily results over 290 fractions of treatment showed that average target coverage improved from 0.96 ± 0.04 (S-SCH) to 1.00 ± 0.02 (A-ART) and 1.02 ± 0.04 (S-ART); average upper dose constraint was reduced from 1.01 ± 0.11 (S-SCH) to 0.94 ± 0.10 (A-ART) and 0.93 ± 0.12 (S-ART). A-ART and S-ART improved planning target volume minimum doses by 4.85 ± 3.03 Gy (P = .049) and 4.46 ± 8.99 Gy (P = .058), respectively. Statistical analysis shows that A-ART and S-ART significantly improved cumulative target dose by 0.033 ± 0.087 (P = .002) and 0.032 ± 0.086 (P = .003) and reduced upper constraints by 0.033 ± 0.072 (P < .001) and 0.032 ± 0.072 (P < .001) relative to S-SCH dose results, respectively. Conclusions: Accuracy of Ethos automatic contouring for lung cancer is considered clinically acceptable. The online adaptive radiation therapy improves target coverage and spares organs-at-risk significantly.
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U2 - 10.1016/j.prro.2021.12.017
DO - 10.1016/j.prro.2021.12.017
M3 - Article
C2 - 35219879
AN - SCOPUS:85127330790
SN - 1879-8500
VL - 12
SP - e329-e338
JO - Practical Radiation Oncology
JF - Practical Radiation Oncology
IS - 4
ER -