Excluding lung tissue from the ptv during internal mammary irradiation. A safe technique for oar-sparing?
Borm KJ, Hofmann C, Duesberg M, Oechsner M, Dapper H, Devecka M, Combs SE (2021)
Publication Type: Journal article
Publication year: 2021
Journal
Book Volume: 13
Article Number: 1951
Journal Issue: 8
Abstract
The current study aims to determine whether exclusion of lung tissue from planning treatment volume (PTV) is a valid organ at risk (OAR)-sparing technique during internal mammary irradiation (IMNI). Twenty patients with left-sided breast cancer undergoing adjuvant radiotherapy including IMNI after mastectomy or lumpectomy with daily ConeBeam CT (CBCT; median n = 28) were enrolled in the current study. The daily dose distribution of the patients was estimated by recalculating treatment plans on CBCT-scans based on a standard PTV (PTV margin: 5mm-STD) and a modified PTV, which excluded overlapping lung tissue (ExLung). Using 3D-deformable dose accumulation, the dose coverage in the target volume was estimated in dependence of the PTV-margins. The estimated delivered dose in the IMN-CTV was significantly lower for the ExLung PTV compared to the STD PTV: ExLung: V95%: 76.6 ± 22.9%; V90%: 89.6 ± 13.2%, STD: V95%: 95.6 ± 7.4%; V90%: 99.1 ± 2.7%. Daily CBCT imaging cannot sufficiently compensate the anatomic changes and intrafraction movement throughout the treatment. Therefore, to ensure adequate delivery of the prescribed dose to the IMN-CTV, exclusion of lung tissue from the PTV to spare the OARs is not recommended.
Involved external institutions
Germany (DE)How to cite
APA:
Borm, K.J., Hofmann, C., Duesberg, M., Oechsner, M., Dapper, H., Devecka, M., & Combs, S.E. (2021). Excluding lung tissue from the ptv during internal mammary irradiation. A safe technique for oar-sparing? Cancers, 13(8). https://doi.org/10.3390/cancers13081951
MLA:
Borm, Kai J., et al. "Excluding lung tissue from the ptv during internal mammary irradiation. A safe technique for oar-sparing?" Cancers 13.8 (2021).
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