MRI Overestimated Oral Cancer Invasion Depth Regardless of Biopsy Timing

Edited by Dentaltown staff

MRI consistently overestimated the depth of invasion of early oral squamous cell carcinoma compared with final pathology, and neither biopsy technique nor the interval between biopsy and imaging explained the gap, according to a retrospective cohort study published Aug. 10 in Clinical Oral Investigations.

Researchers reviewed 47 patients with early-stage oral squamous cell carcinoma who underwent incisional biopsy, MRI, and surgical resection. After excluding noninvasive tumors and cases where radiological depth of invasion could not be reliably assessed, 22 patients were analyzed. Two radiologists independently measured radiological depth of invasion and compared it against pathological depth from the surgical specimen.

MRI overestimated depth of invasion by a mean of 2.95 mm, with a standard deviation of 2.71 mm and limits of agreement running from negative 2.37 to 8.26 mm. Concordance was weak to moderate, with Lin’s concordance correlation coefficient at 0.494 and Spearman’s rho at 0.563.

Neither variable under investigation accounted for the discrepancy. Whether the biopsy was taken with a cold blade or forceps made no significant difference, at P = .61, and the biopsy-to-MRI interval showed no significant association either, at P = .79.

The authors concluded that MRI tends to overestimate depth of invasion in early-stage oral squamous cell carcinoma irrespective of biopsy technique or imaging timing, and that delaying MRI to allow presumed biopsy-related inflammation to resolve appears unjustified given the prognostic importance of prompt treatment.

Nicoletta Gardenal, Emilia Cancellieri, Giulia Ottaviani, Katia Rupel, and colleagues, including senior author Paolo Boscolo-Rizzo, conducted the study.

The analyzed sample was 22 patients, and the design was retrospective at a single institution. The authors noted that larger, adequately powered studies are needed, and framed their finding as evidence that does not support delaying MRI rather than as a definitive answer on imaging accuracy.

Sources:
Clinical Oral Investigations, “Impact of biopsy-related variables on MRI assessment of tumor invasion in early oral squamous cell carcinoma,” published online Aug. 10, 2026: link.springer.com/10.1007/s00784-026-07068-3