Diagnostic Accuracy of Multidetector Computed Tomography (MDCT) for Mandibular Bone Invasion in Oral Squamous Cell Carcinoma (OSCC): A Histopathologic Validation Study.

BACKGROUND

Mandibular bone invasion is a critical determinant of staging and surgical planning in oral squamous cell carcinoma (OSCC). Although multidetector computed tomography (MDCT) is widely used, its diagnostic performance in gingival OSCC requires multi-institutional validation.

PURPOSE: To evaluate the diagnostic accuracy of preoperative MDCT in detecting mandibular bone invasion in gingival OSCC patients, using histopathologic findings as the reference standard.

STUDY DESIGN, SETTING, SAMPLE: A multicenter retrospective cohort study included patients with gingival OSCC who underwent surgical resection at 7 university hospitals between 2020 and 2024; those with prior head and neck radiotherapy or chemotherapy, previous mandibular surgery, or extensive dental artifacts on MDCT were excluded.

PREDICTOR VARIABLE: The predictor variable was the radiologic diagnosis of mandibular bone invasion (present/absent), determined via consensus review of preoperative MDCT images by 2 oral and maxillofacial radiologists.

MAIN OUTCOME VARIABLE: The primary outcome variable was histopathologic confirmation of mandibular bone invasion (present/absent) through microscopic examination of decalcified surgical specimens.

COVARIATES: Covariates included demographics (age, sex [male/female at birth]), surgery type (marginal or segmental resection), and MDCT bone invasion patterns (cortical destruction, medullary invasion, inferior alveolar canal involvement).

ANALYSES: Diagnostic performance parameters with 95% CIs were calculated, and multivariable logistic regression analysis was performed to identify independent predictors of mandibular invasion; statistical significance was defined as a two-sided P value < .05.

RESULTS

A total of 145 patients were screened, and 121 (83.4%) subjects met the inclusion criteria for the final analysis. The sample was composed of 121 subjects with a mean age of 64.2 (SD, 12.8) years, and 74 (61.2%) were male at birth. MDCT showed a sensitivity of 83.5% and a specificity of 61.9% for detecting mandibular bone invasion. The overall diagnostic accuracy was 76.0%. Statistical analysis revealed that cortical destruction and medullary invasion on MDCT were statistically significantly associated with histopathologic bone involvement (P < .001).

CONCLUSIONS AND RELEVANCE: MDCT is an accurate imaging modality for detecting mandibular bone invasion in gingival OSCC, exhibiting high sensitivity (83.5%) but lower specificity (61.9%) due to inflammatory mimics. These findings suggest that while MDCT is excellent for preoperative screening and surgical planning, positive radiologic findings should be interpreted with caution to avoid potential over-treatment.