Clinical response assessment on DW-MRI compared with FDG-PET/CT after neoadjuvant chemoradiotherapy in patients with oesophageal cancer

• Published in: European journal of nuclear medicine and molecular imaging Vol. 48; no. 1; pp. 176 - 185
• Main Authors: Vollenbrock, Sophie E., Voncken, Francine E. M., Lambregts, Doenja M. J., Maas, Monique, Donswijk, Maarten L., Vegt, Erik, ter Beek, Leon C., van Dieren, Jolanda M., van Sandick, Johanna W., Aleman, Berthe M. P., Beets-Tan, Regina G. H., Bartels-Rutten, Annemarieke
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2021; Springer Nature B.V
• Subjects: Cancer; Cardiology; Chemoradiotherapy; Chemotherapy; Computed tomography; Diagnostic systems; Esophageal cancer; Esophagus; Imaging; Magnetic resonance imaging; Medicine; Medicine & Public Health; Nuclear Medicine; Oncology; Oncology – Digestive tract; Original Article; Orthopedics; Patients; Physicians; Positron emission; Positron emission tomography; Radiation therapy; Radiology; Sensitivity; Surgery; Tomography; Tumors; FDG-PET/CT; Oesophageal cancer; nCRT; MRI
• ISSN: 1619-7070; 1619-7089
• DOI: 10.1007/s00259-020-04917-5

Purpose In about 30% of patients treated with neoadjuvant chemoradiotherapy (nCRT) followed by surgical resection for locally advanced oesophageal cancer no vital tumour is found in the resection specimen. Accurate clinical response assessment is critical if deferral from surgery is considered in complete responders. Our study aimed to compare the performance of MRI and of FDG-PET/CT for the detection of residual disease after nCRT. Methods Patients with oesophageal cancer eligible for nCRT and oesophagectomy were prospectively included. All patients underwent FDG-PET/CT and MRI before and between 6 and 8 weeks after nCRT. Two radiologists scored the MRI scans, and two nuclear medicine physicians scored the FDG-PET/CT scans using a 5-point score for residual disease. Histopathology after oesophagectomy represented the reference standard. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated for detection of residual tumour (ypT+), residual nodal disease (ypN+), and any residual disease (ypT+Nx/ypT0N+). Results Seven out of 33 (21%) patients had a pathological complete response. The AUCs for individual readers to detect ypT+ were 0.71/0.70 on diffusion-weighted (DW)-MRI and 0.54/0.57 on FDG-PET/CT, and to detect ypN+ were 0.89/0.81 on DW-MRI and 0.75/0.71 on FDG-PET/CT. The AUCs/sensitivities/specificities for the individual readers to detect any residual disease were 0.74/92%/57% and 0.70/96%/43% on MRI; these were 0.49/69%/29% and 0.60/69%/43% on FDG-PET/CT, respectively. Conclusion MRI reached higher diagnostic accuracies than FDG-PET/CT for the detection of residual tumour in oesophageal cancer patients at 6 to 8 weeks after nCRT.