Non-coplanar VMAT combined with non-uniform dose prescription markedly reduces lung dose in breath-hold lung SBRT

Autor: Natallia Prakofyeva, Anna Simeonova-Chergou, Jens Fleckenstein, Kerstin Siebenlist, Frederik Wenz, Frank Lohr, Judit Boda-Heggemann, Tanya Gudzheva
Rok vydání: 2018
Předmět:
Adult
Intensity-modulated radiotherapy
Lung neoplasms
Non-small-cell lung carcinoma
Radiotherapy planning
Stereotactic radiotherapy
Radiology
Nuclear Medicine and Imaging
Oncology
Lung Neoplasms
medicine.medical_treatment
Planning target volume
Radiosurgery
030218 nuclear medicine & medical imaging
Breath Holding
03 medical and health sciences
0302 clinical medicine
Carcinoma
Non-Small-Cell Lung
medicine
Humans
Radiology
Nuclear Medicine and imaging
Lung volumes
Radiation treatment planning
Lung
Aged
business.industry
Radiotherapy Planning
Computer-Assisted
Radiotherapy Dosage
Middle Aged
Volumetric modulated arc therapy
Dose prescription
Tumor Burden
Radiation therapy
Survival Rate
medicine.anatomical_structure
030220 oncology & carcinogenesis
Female
Dose Fractionation
Radiation
Radiotherapy
Intensity-Modulated
Nuclear medicine
business
Non coplanar
Zdroj: Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al]. 194(9)
ISSN: 1439-099X
Popis: In this retrospective treatment planning study, the effect of a uniform and non-uniform planning target volume (PTV) dose coverage as well as a coplanar and non-coplanar volumetric modulated arc therapy (VMAT) delivery approach for lung stereotactic body radiation therapy (SBRT) in deep inspiration breath-hold (DIBH) were compared. For 46 patients with lesions in the peripheral lungs, three different treatment plans were generated: First, a coplanar 220° VMAT sequence with a uniform PTV dose prescription (UC). Second, a coplanar 220° VMAT treatment plan with a non-uniform dose distribution in the PTV (nUC). Third, a non-coplanar VMAT dose delivery with four couch angles (0°, ±35°, 90°) and a non-uniform prescription (nUnC) was used. All treatment plans were optimized for pareto-optimality with respect to PTV coverage and ipsilateral lung dose. Treatment sequences were delivered on a flattening-filter-free linear accelerator and beam-on times were recorded. Dosimetric comparison between the three techniques was performed. For the three scenarios (UC, nUC, nUnC), median gross tumor volume (GTV) doses were 63.4 ± 2.5, 74.4 ± 3.6, and 77.9 ± 3.8 Gy, and ipsilateral V10Gy lung volumes were 15.7 ± 6.1, 13.9 ± 4.7, and 12.0 ± 5.1%, respectively. Normal tissue complication probability of the ipsilateral lung was 3.9, 3.1, and 2.8%, respectively. The number of monitor units were 5141 ± 1174, 4104 ± 786, and 3657 ± 710 MU and the corresponding beam-on times were 177 ± 54, 143 ± 29, and 148 ± 26 s. For SBRT treatments in DIBH, a non-uniform dose prescription in the PTV, combined with a non-coplanar VMAT arc arrangement, significantly spares the ipsilateral lung while increasing dose to the GTV without major treatment time increase.
Databáze: OpenAIRE
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