Day-to-Day Reproducibility of Prostate Intrafraction Motion Assessed by Multiple kV and MV Imaging of Implanted Markers During Treatment

Observation of intrafraction prostate displacement through the course of conventionally fractionated radiotherapy for prostate cancer

“…There was a tendency for large IFPDs (≥3 mm) to increase with elapsed time. Our results were consistent with previous studies [1][2][3][4][5][6][7][8][9][10][11]. In our present study, an IFPD of ≥3 mm in each direction was detected in only ~2-3 % of all obtained TLS images (2,336 images).…”

“…They reported that IFPDs of >2 mm in the sagittal plane appeared in all fractions in 40 % of patients. They concluded that comparatively large systematic IFPDs are well predicted by measurements in the initial five fractions [5]. On the other hand, it is difficult to predict randomly appearing temporary or persistent IFPDs.…”

“…To determine the optimal planning target volume (PTV) margins in non-realtime IGRT for prostate cancer, knowledge of intrafraction prostate displacement (IFPD) is necessary. Many previous studies, including non-real-time tracking studies and realtime tracking studies have pointed out the characteristics of IFPD as follows: (1) IFPD is larger in cranio-caudal (CC) and antero-posterior (AP) directions compared to the left-right (LR) direction [1][2][3][4][5][6][7][8][9][10][11], (2) individual differences in IFPD are significant [3][4][5]10], (3) IFPD increases with elapsed time in each fraction [6][7][8][9][10][11], and (4) large IFPDs are observed in a small proportion of all treatment time [1,[9][10][11]. Although these characteristics of IFPD have been clarified, institutional IFPD data should be assessed because significant differences in clinical practice may exist (e.g.…”

Shortening Delivery Times of Intensity Modulated Proton Therapy by Reducing Proton Energy Layers During Treatment Plan Optimization

“…This can result in an increase in the number of treated patients and subsequently in a reduction of treatment costs. Regardless of the type of facility, delivery time reduction may also improve patient comfort and reduce treatment uncertainties, because intrafraction displacements of, for example, spine, prostate, and liver tumors tend to increase with delivery time (20)(21)(22)(23).…”

Automatic Prostate Tracking and Motion Assessment in Volumetric Modulated Arc Therapy With an Electronic Portal Imaging Device

“…Patient reproducibility between different fractions to control interfraction motion of the prostate, as well as movement in a single fraction (intrafraction motion) are issues to be addressed in any image-guided radiation therapy (IGRT) program. Prostate tracking and intrafraction motion assessment has been performed by means of Calypso electromagnetic transponders in real-time (1–4), kilovoltage (kV) and megavoltage (MV) imaging based on fiducial markers, employing daily portal images (5–7), pre- and post- treatment delivery kV and treatment beam MV images (8), cone-beam computed tomography (CBCT) (9), continuous kV imaging (10), x-ray stereoscopic imaging taken periodically during treatment with CyberKnife (11), and real-time tumor-tracking radiotherapy with a dedicated machine (RTRT) (12). Cine magnetic resonance imaging (MRI) images (13), and ultrasound (14) have also been employed.…”