Gold seed fiducials in analysis of linear and rotational displacement of the prostate bed

Tutkimustuotos: ArtikkelijulkaisuArtikkeliTieteellinenvertaisarvioitu

Abstrakti

Background and purpose
This study aimed to investigate the magnitude of interfraction prostate bed motion during radiotherapy using both the implanted gold seed fiducials and the soft tissue registration and to define reasonable planning target volume (PTV) margins for different localization methods.

Material and methods
Thirteen prostatectomized prostate cancer patients, after implanting four gold seed fiducials into their prostate bed, were imaged daily using a pretreatment cone-beam computed tomography (CBCT). Linear and the rotational prostate bed motion (PBM) was measured for 466 CBCTs.

Results
The linear PBM mean and standard deviation values in millimeters are 0.0±0.5, 0.7±2.1 and 0.8±1.6 in the LR, SI and AP axes, respectively. In 20% of the fractions the rotation of the prostate bed in sagittal plane exceeds ±6° and in 5% it exceeds ±10° from the position on the planning CT. In the transversal and coronal planes 1% and 2% of it exceeds ±6°. The PTV margins are 2.4, 6.5 and 6.6mm in the LR, SI and AP axes, respectively, if imaging is performed for the first three treatment fractions.

Conclusion
The linear PBM is largest in the SI and AP axis, whereas the rotation is largest in the sagittal plane. Bone localization during the first three treatment fractions can reduce PTV margins by 52%, 18% and 10% in the LR, SI and AP axes, respectively, whereas in daily CBCT the use of the gold seed fiducials seems profitable.

Keywords: Prostate bed motion, Gold seed fiducials, Rotation of the prostate bed, Margin, Prostate cancer
Alkuperäiskielienglanti
LehtiRadiotherapy and Oncology
Vuosikerta110
Numero2
Sivut256-260
Sivumäärä5
ISSN0167-8140
DOI - pysyväislinkit
TilaJulkaistu - 2014
OKM-julkaisutyyppiA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä, vertaisarvioitu

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