Rectal cancer with complete endoscopic response after neoadjuvant therapy: what is the meaning of a positive MRI?

ConclusionsAlthough most +DWI exams discordant with endoscopy are false positive, 22% will reveal that DWI-MRI detects tumor recurrence before endoscopy.Key Points• Most often, in post-treatment assessment for rectal cancer when DWI-MRI shows restriction in the tumor bed and endoscopy shows no tumor,+DWI MRI will be proven false positive.• Conversely, our study demonstrated that, allowing for sequential follow-up at a 3-month maximum interval, DWI-MRI may detect tumor presence in the treated tumor bed before endoscopy in 22% of discordant findings between DWI-MRI and endoscopy.• Our results showed that a majority of DWI-MRI-positive scans in treated rectal cancer concur with the presence of tumor on endoscopy performed within 2 weeks.
Source: European Radiology - Category: Radiology Source Type: research