TY - JOUR
T1 - Real-time prostate motion assessment
T2 - Image-guidance and the temporal dependence of intra-fraction motion
AU - Cramer, Avilash K.
AU - Haile, Amanu G.
AU - Ognjenovic, Sanja
AU - Doshi, Tulsee S.
AU - Reilly, William M.
AU - Rubinstein, Katherine E.
AU - Nabavizadeh, Nima
AU - Nguyen, Thuan
AU - Meng, Lu Z.
AU - Fuss, Martin
AU - Tanyi, James A.
AU - Hung, Arthur Y.
N1 - Funding Information:
This work was supported in part by funds from the Ted R. Lilly Cancer Continuing Umbrella of Research Education (CURE) Project (laureates: Mr. Alvaro Flores and Mr. Amanu G. Haile) and the Upward Bound Program at Portland State University, Portland, OR (laureates: Ms. Clarizza Catabay and Ms. Julia Nguyen). The authors are grateful to Ms. Clarizza Catabay, Ms. Julia Nguyen and Mr. Alvaro Flores for their independent contribution to study integrity validation. The authors are also grateful to Dr. Katelyn M. Atkins and Mr. Brandon Merz for providing careful review of the manuscript. Finally, the authors would like to acknowledge the professionalism, expertise and dedication of the radiation therapists at the Oregon Health & Science Knight Cancer Institute with special thanks to Dorothy J. Hargrove, M.S., R.T.(R)(T), Janet Garrett, R.T.(T), Robert Breckenridge, R.T.(T), Jennifer McLaughlin, R.T.(T), and Bonnie Luedloff, R.T.(T).
PY - 2013/9/23
Y1 - 2013/9/23
N2 - Background: The rapid adoption of image-guidance in prostate intensity-modulated radiotherapy (IMRT) results in longer treatment times, which may result in larger intrafraction motion, thereby negating the advantage of image-guidance. This study aims to qualify and quantify the contribution of image-guidance to the temporal dependence of intrafraction motion during prostate IMRT.Methods: One-hundred and forty-three patients who underwent conventional IMRT (n=67) or intensity-modulated arc therapy (IMAT/RapidArc, n=76) for localized prostate cancer were evaluated. Intrafraction motion assessment was based on continuous RL (lateral), SI (longitudinal), and AP (vertical) positional detection of electromagnetic transponders at 10 Hz. Daily motion amplitudes were reported as session mean, median, and root-mean-square (RMS) displacements. Temporal effect was evaluated by categorizing treatment sessions into 4 different classes: IMRTc (transponder only localization), IMRTcc (transponder + CBCT localization), IMATc (transponder only localization), or IMATcc (transponder + CBCT localization).Results: Mean/median session times were 4.15/3.99 min (IMATc), 12.74/12.19 min (IMATcc), 5.99/5.77 min (IMRTc), and 12.98/12.39 min (IMRTcc), with significant pair-wise difference (p<0.0001) between all category combinations except for IMRTcc vs. IMATcc (p>0.05). Median intrafraction motion difference between CBCT and non-CBCT categories strongly correlated with time for RMS (t-value=17.29; p<0.0001), SI (t-value=-4.25; p<0.0001), and AP (t-value=2.76; p<0.0066), with a weak correlation for RL (t-value=1.67; p=0.0971). Treatment time reduction with non-CBCT treatment categories showed reductions in the observed intrafraction motion: systematic error (Σ)<0.6 mm and random error (σ)<1.2 mm compared with ≤0.8 mm and <1.6 mm, respectively, for CBCT-involved treatment categories.Conclusions: For treatment durations >4-6 minutes, and without any intrafraction motion mitigation protocol in place, patient repositioning is recommended, with at least the acquisition of the lateral component of an orthogonal image pair in the absence of volumetric imaging.
AB - Background: The rapid adoption of image-guidance in prostate intensity-modulated radiotherapy (IMRT) results in longer treatment times, which may result in larger intrafraction motion, thereby negating the advantage of image-guidance. This study aims to qualify and quantify the contribution of image-guidance to the temporal dependence of intrafraction motion during prostate IMRT.Methods: One-hundred and forty-three patients who underwent conventional IMRT (n=67) or intensity-modulated arc therapy (IMAT/RapidArc, n=76) for localized prostate cancer were evaluated. Intrafraction motion assessment was based on continuous RL (lateral), SI (longitudinal), and AP (vertical) positional detection of electromagnetic transponders at 10 Hz. Daily motion amplitudes were reported as session mean, median, and root-mean-square (RMS) displacements. Temporal effect was evaluated by categorizing treatment sessions into 4 different classes: IMRTc (transponder only localization), IMRTcc (transponder + CBCT localization), IMATc (transponder only localization), or IMATcc (transponder + CBCT localization).Results: Mean/median session times were 4.15/3.99 min (IMATc), 12.74/12.19 min (IMATcc), 5.99/5.77 min (IMRTc), and 12.98/12.39 min (IMRTcc), with significant pair-wise difference (p<0.0001) between all category combinations except for IMRTcc vs. IMATcc (p>0.05). Median intrafraction motion difference between CBCT and non-CBCT categories strongly correlated with time for RMS (t-value=17.29; p<0.0001), SI (t-value=-4.25; p<0.0001), and AP (t-value=2.76; p<0.0066), with a weak correlation for RL (t-value=1.67; p=0.0971). Treatment time reduction with non-CBCT treatment categories showed reductions in the observed intrafraction motion: systematic error (Σ)<0.6 mm and random error (σ)<1.2 mm compared with ≤0.8 mm and <1.6 mm, respectively, for CBCT-involved treatment categories.Conclusions: For treatment durations >4-6 minutes, and without any intrafraction motion mitigation protocol in place, patient repositioning is recommended, with at least the acquisition of the lateral component of an orthogonal image pair in the absence of volumetric imaging.
KW - Intrafraction variation
KW - Prostate cancer
KW - Real-time motion tracking
KW - Treatment margin
KW - Treatment time
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U2 - 10.1186/1756-6649-13-4
DO - 10.1186/1756-6649-13-4
M3 - Article
C2 - 24059584
AN - SCOPUS:84884399657
SN - 1756-6649
VL - 13
JO - BMC Medical Physics
JF - BMC Medical Physics
IS - 1
M1 - 4
ER -