QUANTUM
Research type
Research Study
Full title
Quantification of Abdominal Organ Motion using Magnetic Resonance Imaging (MRI)
IRAS ID
276790
Contact name
Cynthia Eccles
Contact email
Sponsor organisation
The Christie NHS Foundation Trust
Duration of Study in the UK
0 years, 6 months, 30 days
Research summary
Research Summary
The primary aim of the study is to quantify intra-abdominal inter and intra-fraction motion on MRI using three-motion management strategies a) free-breathing, b) using an abdominal compression belt and c) using MRI-compatible visually guided breath-holds. Non-patient and patient volunteers will be asked to undergo MRI to evaluate abdominal organ motion in free-breathing, in breath-hold or with an abdominal compression belt. We will ask volunteers to undergo 1-3 repeat sessions lasting not more than one hour to evaluate the sequences used to assess motion, and the usefulness of the breath-hold and compression devices within a radiotherapy setting.
Summary of Results
Twenty-three participants were recruited to this institutional observational imaging study, including six non-patient staff volunteers and seventeen patients undergoing radical radiotherapy to the abdomen. The study included recruitment to two cohorts based on respiratory motion management strategy: abdominal compression vs free-breathing, and breath-hold vs free-breathing. Three non-patient staff volunteers were recruited at the start of each cohort to allow for magnetic resonance imaging (MRI) protocol development on both the MR Sim and the MR Linac. Fifteen patient participants completed at least one imaging session, thirteen completed two sessions and five completed all three imaging sessions. Of the patient participants, 11 were male and 4 were female. Mean age of patient participants was 65 years (SD, 12.1). Four patients had hepatocellular carcinoma (HCC), five pancreatic cancer, and six had abdominal oligometastatic sites from pancreatic neuroendocrine, glomangiosarcoma, colorectal and renal cancer.
This study quantified motion of abdominal organs with three different motion management strategies commonly used for radiotherapy: free-breathing (FB), breath-hold (BH) and abdominal compression (AC) using MRI. Multiple MRI sequences for intra-abdominal motion evaluation for radiotherapy planning and delivery were optimised for clinical use, including three-dimensional (3D) VANE, single and three-plane dynamic cine MRI to evaluate respiratory motion, as well as a single-plane BH cine protocol for evaluation of peristaltic motion.
Abdominal fat, both under the skin and internally around the organs, was found to not directly impact the effectiveness of abdominal compression devices. The mean change in motion was a 7.8 mm (IQR, 5.0; p = 0.001) reduction with compression. No correlation between % motion change and %AT, nor BMI, were seen. Mean % change in motion was larger in the BMI < 27.2 group (51.24%) in comparison to BMI > 27.2 (29.44%).
Other patient factors, however, including body mass index (BMI), cirrhosis and sex were found to be independent factors leading to larger motion of upper abdominal organs in FB. Mean FB motion (mm) was higher for males than females in the craniocaudal (19.56mm and 12.55mm respectively, p=0.95) and medio-lateral (13.88mm and 2.55mm respectively, p=0.36) directions respectively. An increase in mean FB motion in the craniocaudal direction was observed for patients with normal, overweight, and obese BMIs (12.41mm, 19.44mm and 23.46mm respectively). There was a trend towards larger IQR with increasing BMI in craniocaudal and medio-lateral directions, although this was not statistically significant (r=0.11 and -0.33, respectively). Mean FB motion in the medio-lateral direction was largest in patients classified as overweight (18.77mm). For both craniocaudal and left-right directions, patients with cirrhosis had larger FB motion (Figure 1). Mean FB motion was higher in non-diabetic patients compared to diabetics. There was no correlation between BMI and craniocaudal (r=0.11) or medio-lateral (r=0.06) motion.
Visually-guided breath holds using a novel internal navigator system were compared with voluntary end exhale BH and was found to be feasible as well as having similar inter-breath hold stability but improved intra-breath hold stability. Mean diaphragm position and standard deviation during breath holds for patient 1 was -0.3 ± 0.8 mm with VG and -1.2 ± 1.1 mm without VG, for patient 2 was -2.8 ± 4.4 mm with VG and -4.8 ± 4.6 mm without VG and for patient 3 was 2.5 ± 3.3 mm with VG and -5.0 ± 11.4 mm without VG. Scan data showed similar displacements. Evaluation of whether visual guidance (VG) can improve reproducibility showed a pooled mean (SD) inter-breath hold stability measured by mean distance to agreement (mDTA) of the contoured liver of 0.18 cm (0.11) and 0.14 cm (0.02) with and without VG, therefore VG was successful with good reproducibility.REC name
Wales REC 6
REC reference
20/WA/0353
Date of REC Opinion
21 Dec 2020
REC opinion
Favourable Opinion