Effect of intra-fraction motion on the accumulated dose for free-breathing MR-guided stereotactic body radiation therapy of renal-cell carcinoma

Autor: Fieke M. Prins, Sjoerd P M Crijns, Linda G W Kerkmeijer, Rob H N Tijssen, B. Stemkens, Cornelis A. T. van den Berg, Baudouin Denis de Senneville, Jan J W Lagendijk, M Glitzner, C Kontaxis
Rok vydání: 2017
Předmět:
medicine.medical_specialty
Stereotactic body radiation therapy
Movement
medicine.medical_treatment
dose reconstruction
Radiosurgery
stereotactic body radiation therapy
030218 nuclear medicine & medical imaging
03 medical and health sciences
0302 clinical medicine
Renal cell carcinoma
intra-fraction motion
medicine
Humans
Radiology
Nuclear Medicine and imaging
Fraction (mathematics)
Radiometry
Lead (electronics)
Carcinoma
Renal Cell
radiotherapy
Radiological and Ultrasound Technology
motion models
business.industry
Radiotherapy Planning
Computer-Assisted
Respiration
Dose fractionation
medicine.disease
Magnetic Resonance Imaging
Kidney Neoplasms
Radiation therapy
Surgery
Computer-Assisted
Radiology Nuclear Medicine and imaging
030220 oncology & carcinogenesis
MRI-guided radiotherapy
4D-MRI
Dose Fractionation
Radiation
Radiology
business
Nuclear medicine
Free breathing
Mri guided
Zdroj: Physics in Medicine and Biology, 62(18), 7407. IOP Publishing Ltd.
ISSN: 1361-6560
0031-9155
DOI: 10.1088/1361-6560/aa83f7
Popis: Stereotactic body radiation therapy (SBRT) has shown great promise in increasing local control rates for renal-cell carcinoma (RCC). Characterized by steep dose gradients and high fraction doses, these hypo-fractionated treatments are, however, prone to dosimetric errors as a result of variations in intra-fraction respiratory-induced motion, such as drifts and amplitude alterations. This may lead to significant variations in the deposited dose. This study aims to develop a method for calculating the accumulated dose for MRI-guided SBRT of RCC in the presence of intra-fraction respiratory variations and determine the effect of such variations on the deposited dose. For this, RCC SBRT treatments were simulated while the underlying anatomy was moving, based on motion information from three motion models with increasing complexity: (1) STATIC, in which static anatomy was assumed, (2) AVG-RESP, in which 4D-MRI phase-volumes were time-weighted, and (3) PCA, a method that generates 3D volumes with sufficient spatio-temporal resolution to capture respiration and intra-fraction variations. Five RCC patients and two volunteers were included and treatments delivery was simulated, using motion derived from subject-specific MR imaging. Motion was most accurately estimated using the PCA method with root-mean-squared errors of 2.7, 2.4, 1.0 mm for STATIC, AVG-RESP and PCA, respectively. The heterogeneous patient group demonstrated relatively large dosimetric differences between the STATIC and AVG-RESP, and the PCA reconstructed dose maps, with hotspots up to [Formula: see text] of the D99 and an underdosed GTV in three out of the five patients. This shows the potential importance of including intra-fraction motion variations in dose calculations.
Databáze: OpenAIRE
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