Real-Time Motion Monitoring Using Orthogonal Cine MRI during MR-Guided Radiation Therapy for Liver Cancer

Jassar, Hassan; Tai, A.; Chen, X.; Paulson, E.S.; Ahunbay, E.E.; Omari, E.; Lathuiliere, F.; Bériault, S.; Cooper, D.; Hebert, F.; Savard, L.; Cloake, S.; Straza, M.W.; Awan, M.; Hall, W.A.; Li, A.

doi:10.1016/j.ijrobp.2022.07.482

Cited by 1 publication

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“…MMRP algorithm can accurately monitor the motion of abdominal malignancies in the pancreas head, renal fossa, and SLV in real‐time for the 13 patients having average (range) monitored centroid motions of 7.69 (4.71–11.15), 1.74 (0.81–3.05), and 2.71 (1.45–3.93) mm with average (range) SDE values of 1.14 (0.31–1.9), 0.98 (0.33–1.72), and 0.87 (0.37–1.43) mm in the SI, LR, and AP directions, respectively. We were able to make a confident determination of the SDE for liver tumor motion based on motion monitoring of the sub‐volume of the liver where the tumor resides, reducing uncertainties from integrating the independent motion from each segment in the liver comparing to the motion monitoring of the whole liver 59 . Values from the calculated SDE, monitored centroid motion, and maximum of tumor motion measured on 4D‐MRI images are tabulated in Table 1.…”

Section: Resultsmentioning

confidence: 99%

“…We were able to make a confident determination of the SDE for liver tumor motion based on motion monitoring of the subvolume of the liver where the tumor resides, reducing uncertainties from integrating the independent motion from each segment in the liver comparing to the motion monitoring of the whole liver. 59 Values from the calculated SDE, monitored centroid motion, and maximum of tumor motion measured on 4D-MRI images are tabulated in Table 1. The mean (range) of the maximum tumor motion from the 4D-MRI was 7.38 (2-11) mm in SI direction, smaller than the monitored centroid motion for all cancer cases.…”

Section: Evaluations With Patient Datamentioning

confidence: 99%

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Real‐time motion monitoring using orthogonal cine MRI during MR‐guided adaptive radiation therapy for abdominal tumors on 1.5T MR‐Linac

et al. 2023

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Background Real‐time motion monitoring (RTMM) is necessary for accurate motion management of intrafraction motions during radiation therapy (RT). Purpose Building upon a previous study, this work develops and tests an improved RTMM technique based on real‐time orthogonal cine magnetic resonance imaging (MRI) acquired during magnetic resonance‐guided adaptive RT (MRgART) for abdominal tumors on MR‐Linac. Methods A motion monitoring research package (MMRP) was developed and tested for RTMM based on template rigid registration between beam‐on real‐time orthogonal cine MRI and pre‐beam daily reference 3D‐MRI (baseline). The MRI data acquired under free‐breathing during the routine MRgART on a 1.5T MR‐Linac for 18 patients with abdominal malignancies of 8 liver, 4 adrenal glands (renal fossa), and 6 pancreas cases were used to evaluate the MMRP package. For each patient, a 3D mid‐position image derived from an in‐house daily 4D‐MRI was used to define a target mask or a surrogate sub‐region encompassing the target. Additionally, an exploratory case reviewed for an MRI dataset of a healthy volunteer acquired under both free‐breathing and deep inspiration breath‐hold (DIBH) was used to test how effectively the RTMM using the MMRP can address through‐plane motion (TPM). For all cases, the 2D T2/T1‐weighted cine MRIs were captured with a temporal resolution of 200 ms interleaved between coronal and sagittal orientations. Manually delineated contours on the cine frames were used as the ground‐truth motion. Common visible vessels and segments of target boundaries in proximity to the target were used as anatomical landmarks for reproducible delineations on both the 3D and the cine MRI images. Standard deviation of the error (SDE) between the ground‐truth and the measured target motion from the MMRP package were analyzed to evaluate the RTMM accuracy. The maximum target motion (MTM) was measured on the 4D‐MRI for all cases during free‐breathing. Results The mean (range) centroid motions for the 13 abdominal tumor cases were 7.69 (4.71–11.15), 1.73 (0.81–3.05), and 2.71 (1.45–3.93) mm with an overall accuracy of <2 mm in the superior–inferior (SI), the left‐right (LR), and the anterior‐posterior (AP) directions, respectively. The mean (range) of the MTM from the 4D‐MRI was 7.38 (2–11) mm in the SI direction, smaller than the monitored motion of centroid, demonstrating the importance of the real‐time motion capture. For the remaining patient cases, the ground‐truth delineation was challenging under free‐breathing due to the target deformation and the large TPM in the AP direction, the implant‐induced image artifacts, and/or the suboptimal image plane selection. These cases were evaluated based on visual assessment. For the healthy volunteer, the TPM of the target was significant under free‐breathing which degraded the RTMM accuracy. RTMM accuracy of <2 mm was achieved under DIBH, indicating DIBH is an effective method to address large TPM. Conclusions We have successfully developed and tested the use of a template‐based...

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Section: Resultsmentioning

confidence: 99%

Section: Evaluations With Patient Datamentioning

confidence: 99%