Is noncoplanar plan more robust to inter-fractional variations than coplanar plan in treating bilateral HN tumors with pencil-beam scanning proton beams?

Autor: Yi B; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA.; Maryland Proton Treatment Center, Baltimore, Maryland, USA., Jatczak J; Maryland Proton Treatment Center, Baltimore, Maryland, USA., Deng W; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA.; Maryland Proton Treatment Center, Baltimore, Maryland, USA., Poirier YP; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA.; Maryland Proton Treatment Center, Baltimore, Maryland, USA., Yao W; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA.; Maryland Proton Treatment Center, Baltimore, Maryland, USA., Witek ME; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA.; Maryland Proton Treatment Center, Baltimore, Maryland, USA., Molitoris JK; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA.; Maryland Proton Treatment Center, Baltimore, Maryland, USA., Zakhary MJ; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA.; Maryland Proton Treatment Center, Baltimore, Maryland, USA., Zhang B; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA.; Maryland Proton Treatment Center, Baltimore, Maryland, USA., Biswal NC; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA.; Maryland Proton Treatment Center, Baltimore, Maryland, USA., Ferris MJ; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA.; Maryland Proton Treatment Center, Baltimore, Maryland, USA., Mossahebi S; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA.; Maryland Proton Treatment Center, Baltimore, Maryland, USA.
Jazyk: angličtina
Zdroj: Journal of applied clinical medical physics [J Appl Clin Med Phys] 2024 Feb; Vol. 25 (2), pp. e14186. Date of Electronic Publication: 2023 Nov 16.
DOI: 10.1002/acm2.14186
Abstrakt: Purpose: Noncoplanar plans (NCPs) are commonly used for proton treatment of bilateral head and neck (HN) malignancies. NCP requires additional verification setup imaging between beams to correct residual errors of robotic couch motion, which increases imaging dose and total treatment time. This study compared the quality and robustness of NCPs with those of coplanar plans (CPs).
Methods and Materials: Under an IRB-approved study, CPs were created retrospectively for 10 bilateral HN patients previously treated with NCPs maintaining identical beam geometry of the original plan but excluding couch rotations. Plan robustness to the inter-fractional variation (IV) of both plans was evaluated through the Dose Volume Histograms (DVH) of weekly quality assurance CT (QACT) sets (39 total). In addition, delivery efficiency for both plans was compared using total treatment time (TTT) and beam-on time (BOT).
Results: No significant differences in plan quality were observed in terms of clinical target volume (CTV) coverage (D95) or organ-at-risk (OAR) doses (p > 0.4 for all CTVs and OARs). No significant advantage of NCPs in the robustness to IV was found over CP, either. Changes in D95 of QA plans showed a linear correlation (slope = 1.006, R 2  > 0.99) between NCP and CP for three CTV data points (CTV1, CTV2, and CTV3) in each QA plan (117 data points for 39 QA plans). NCPs showed significantly higher beam delivery time than CPs for TTT (539 ± 50 vs. 897 ± 142 s; p < 0.001); however, no significant differences were observed for BOT.
Conclusion: NCPs are not more robust to IV than CPs when treating bilateral HN tumors with pencil-beam scanning proton beams. CPs showed plan quality and robustness similar to NCPs while reduced treatment time (∼6 min). This suggests that CPs may be a more efficient planning technique for bilateral HN cancer proton therapy.
(© 2023 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine.)
Databáze: MEDLINE
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