Intrafraction pancreatic tumor motion patterns during ungated magnetic resonance guided radiotherapy with an abdominal corset

Grimbergen, Guus; Eijkelenkamp, H.; Heerkens, H.D.; Raaymakers, B W; Intven, Martijn; Meijer, G.J.

doi:10.1016/j.phro.2021.12.001

Cited by 12 publications

(10 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Abdominal organ motions including motions related to respiration, 1–3 cardiovascular function, 1,4 and gastrointestinal activity 5–7 result in imprecise delivery of radiation therapy (RT) for abdominal tumors. For example, the respiration‐induced motion can be up to 4 cm in the cranio‐caudal direction for a pancreatic or liver tumor, which presents a considerable challenge in the delivering conformal radiation dose, such as those in stereotactic body RT (SBRT) 8–11 .…”

Section: Introductionmentioning

confidence: 99%

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

View full text Add to dashboard Cite

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...

show abstract

Section: Introductionmentioning

confidence: 99%

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

View full text Add to dashboard Cite

show abstract

“…Pancreatic and intra-abdominal malignancies are challenging to treat with SBRT [16,26], and require high-quality imaging with appropriate motion management [27,28]. However, most studies of online adaptive MRI-guided SBRT on clinical MRI-Lianc(s) used the pre-set MRI sequences provided by the manufacturer [11][12][13][14][15], which limited the visualization of the target and OAR on MR image sets.…”

Section: Introductionmentioning

confidence: 99%

Online Adaptive MRI-Guided Stereotactic Body Radiotherapy for Pancreatic and Other Intra-Abdominal Cancers

Lee,

Renz,

et al. 2023

Cancers

View full text Add to dashboard Cite

A 1.5T MRI combined with a linear accelerator (Unity®, Elekta; Stockholm, Sweden) is a device that shows promise in MRI-guided stereotactic body radiation treatment (SBRT). Previous studies utilized the manufacturer’s pre-set MRI sequences (i.e., T2 Weighted (T2W)), which limited the visualization of pancreatic and intra-abdominal tumors and organs at risk (OAR). Here, a T1 Weighted (T1W) sequence was utilized to improve the visualization of tumors and OAR for online adapted-to-position (ATP) and adapted-to-shape (ATS) during MRI-guided SBRT. Twenty-six patients, 19 with pancreatic and 7 with intra-abdominal cancers, underwent CT and MRI simulations for SBRT planning before being treated with multi-fractionated MRI-guided SBRT. The boundary of tumors and OAR was more clearly seen on T1W image sets, resulting in fast and accurate contouring during online ATP/ATS planning. Plan quality in 26 patients was dependent on OAR proximity to the target tumor and achieved 96 ± 5% and 92 ± 9% in gross tumor volume D90% and planning target volume D90%. We utilized T1W imaging (about 120 s) to shorten imaging time by 67% compared to T2W imaging (about 360 s) and improve tumor visualization, minimizing target/OAR delineation uncertainty and the treatment margin for sparing OAR. The average time-consumption of MRI-guided SBRT for the first 21 patients was 55 ± 15 min for ATP and 79 ± 20 min for ATS.

show abstract

“…Currently, the commercially available MRI- and CBCT-guided online ART solutions have limited options for intra-fraction motion management including compensation for respiratory motion. One of the available MRlinac systems employs gating [6] , [13] , [14] , while a second MRlinac system and the current CBCT-guided systems require the use of a larger margin to compensate for respiratory motion of the target or the use of abdominal compression to try and minimize this motion [15] , [16] , [17] , [18] .…”

Section: Introductionmentioning

confidence: 99%

Technical feasibility of online adaptive stereotactic treatments in the abdomen on a robotic radiosurgery system

Milder

Magallon-Baro

Toom

et al. 2022

Physics and Imaging in Radiation Oncology

View full text Add to dashboard Cite

Intrafraction pancreatic tumor motion patterns during ungated magnetic resonance guided radiotherapy with an abdominal corset

Cited by 12 publications

References 20 publications

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

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

Online Adaptive MRI-Guided Stereotactic Body Radiotherapy for Pancreatic and Other Intra-Abdominal Cancers

Technical feasibility of online adaptive stereotactic treatments in the abdomen on a robotic radiosurgery system

Contact Info

Product

Resources

About