TITLE:
The Quantification of Intra-Fractional Tumour Motion Errors in Lung Stereotactic Ablative Radiotherapy Patients
AUTHORS:
Ibrahem H. Kanbayti, Qamar Ghafoor, Gareth Webster, Saddig Jastaniah
KEYWORDS:
SABR, Geometric Errors, Lung Cancer
JOURNAL NAME:
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology,
Vol.6 No.2,
May
10,
2017
ABSTRACT: This work aims at quantifying intra-fractional motion errors and evaluating
the appropriateness of a Planning Target Volume (PTV) margin for Queen
Elizabeth (QE) Hospital’s patients. Intra-fractional motion errors were
quantified for 29 patients who underwent lung Stereotactic Ablative
Radiotherapy (SABR) treatment at the cancer centre of QE Hospital. One hundred
thirty post-Cone Beam Computed Tomography (CBCT) scans were collected to
calculate these errors. In terms of the adequacy of a PTV margin, the
intra-fractional motion errors that were calculated are combined with other
geometric errors which were taken from historical audit studies. Then, the
combined outcome was compared with the common PTV margin that is delineated by
most United Kingdom (UK) oncology centres. The findings of this study showed
that the systematic component of intra-fractional motion error is equal to
0.08, 0.08 and 0.08 cm in right/left, superior/anterior and anterior/posterior
directions, respectively, While the random component of this error is equal to
0.11, 0.13 and 0.14 cm. In addition to that, a PTV margin of 0.5 cm is the
appropriate margin for QE Hospital’s patients and this volume is compatible
with the common PTV margin that is delineated by the most UK oncology centres.
This work concluded that A PTV margin of 0.5 cm is the suitable volume for lung
SABR patients at QE Hospital.