Evaluation of plan quality in radiotherapy planning with an MR-linac.
Phys Imaging Radiat Oncol
; 10: 19-24, 2019 Apr.
Article
em En
| MEDLINE
| ID: mdl-33458263
ABSTRACT
BACKGROUND & PURPOSE:
Clinical introduction of magnetic resonance (MR)-guided radiotherapy involves treatment planning while taking into account machine-specific characteristics. Our aim was to investigate the feasibility of high-quality MR-linac treatment planning for an MR-linac and to benchmark MR-linac plan quality (IMRT) against current clinical practice (VMAT). MATERIALS &METHODS:
Data of eight rectal and eight prostate cancer patients, who received radiotherapy on a conventional CBCT-integrated linac, were selected. Clinically acquired CTs and associated delineations of target volumes and organs-at-risk (OARs) were used for MR-linac treatment planning in Monaco. To investigate treatment planning software bias 'quasi MR-linac plans' were generated in Pinnacle3 by mimicking MR-linac specific beam characteristics. MR-linac, quasi MR-linac, and clinical plans were compared and differences in target and OAR doses assessed. Differences in plan complexity were determined by the number of segments and monitor units.RESULTS:
Compared to clinical plans, MR-linac plans showed a statistically significant decrease in plan homogeneity, an increase in PTV Dmean (prostate 0.6â¯Gy; rectum 0.8â¯Gy) and D1% (prostate 1.9â¯Gy; rectum 2.0â¯Gy), and increases in OAR dose. Quasi MR-linac plans were comparable to MR-linac plans with respect to OAR dose and plan homogeneity. For rectal cancer an increase was seen in PTV Dmean (0.12â¯Gy) and D1% (0.5â¯Gy) compared to regular MR-linac plans. All created plans were clinically equivalent to current clinical practice.CONCLUSIONS:
This study demonstrates the feasibility of creating high-quality MR-linac treatment plans. The results supported the clinical introduction of an MR-linac.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Phys Imaging Radiat Oncol
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Holanda