The implementation of MR-sim and MR-linac in Radiation Oncology has been driven by the unique advantages of magnetic resonance imaging (MRI) such as excellent soft tissue contrast, biomarkers information, motion assessment and lack of ionising radiation during image acquisitions1. This study aims to assess the utility of MR images obtained from the MR-simulator and MR-linac workflow in patients with upper gastrointestinal carcinomas.

In this single observational cohort study, patients with oesophageal, gastroesophageal junction or gastric carcinomas who were eligible for surgical resection alone and neoadjuvant treatments were enrolled. Pre-operative imaging, including T1-weighted, T2-weighted, diffusion-weighted (DWI) and apparent diffusion coefficient (ADC) sequences, was performed within 2 weeks of surgery using the Philips Ingenia MR-simulator and Elekta Unity MR-linac. Baseline MRI scans were obtained for patients undergoing neoadjuvant treatment to assess morphological and functional changes. Pathological findings were compared to the MRI results.

Of the 16 patients who underwent surgical resection: Demographics: 13 males and 3 females with a median age of 73 years (range: 51 - 83). Diagnosis: Mid oesophageal adenosquamous carcinoma: 1 patient. Distal oesophageal/gastroesophageal: 8 patients (7 adenocarcinoma, 1 squamous cell carcinoma). Gastric adenocarcinoma: 7 patients. Clinical Stages: Stage 1: 7 patients Stage 2: 7 patients Stage 4a: 2 patients Treatment: Surgery alone: 8 patients (50%) Neoadjuvant treatment followed by surgery: 8 patients (50%) Pathological correlation was found in 10 patients, while 4 showed downstaging...

The combined workflow of MR-simulator and MR-linac presents potential application in upper gastrointestinal carcinomas. Notably, MR imaging showed higher sensitivity than CT in detecting residual disease and monitoring treatment responses to neoadjuvant therapy.

E. Lau: Nothing to disclose

1. Chandarana H, Wang H, Tijssen RHN, Das IJ. Emerging role of MRI in radiation therapy. J Magn Reson Imaging. 2018;48(6):1468-1478.