T2-weighted MR imaging early after chemoradiotherapy to evaluate treatment response in head and neck squamous cell carcinoma

• Published in: American journal of neuroradiology : AJNR 2013-06, Vol.34 (6), p.1237-1241
• Main Authors: King, A D, Keung, C K, Yu, K-H, Mo, F K F, Bhatia, K S, Yeung, D K W, Tse, G M K, Vlantis, A C, Ahuja, A T
• Format: Article
• Language: English
• Subjects: Aged; Carcinoma, Squamous Cell - pathology; Carcinoma, Squamous Cell - therapy; Chemoradiotherapy; Diffusion Magnetic Resonance Imaging - methods; Diffusion Magnetic Resonance Imaging - standards; Drug Monitoring - methods; Female; Head & Neck; Head and Neck Neoplasms - pathology; Head and Neck Neoplasms - therapy; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Neoplasm, Residual - pathology; Neoplasm, Residual - therapy; Nuclear polyhedrosis virus; Predictive Value of Tests; Reproducibility of Results; Retrospective Studies; Sensitivity and Specificity; Treatment Failure
• ISSN: 0195-6108; 1936-959X
• DOI: 10.3174/ajnr.A3378

T2-weighted MRI shows potential in early posttreatment assessment of the primary tumor. Residual masses composed entirely of low T2-signal scar tissue suggest local control and those ≥1 cm of similar signal to untreated tumor suggest local failure. The purpose of this study was to investigate the diagnostic accuracy of T2-weighted MR imaging early after chemoradiotherapy for identifying primary tumor treatment failure in squamous cell carcinoma of the head and neck. At 6 weeks after treatment, T2-weighted MR images of 37 primary tumors in 37 patients were assessed. Residual masses were divided into 3 patterns: pattern 1 = scar tissue only (flat-edged/retracted mass of low T2 signal intensity); pattern 2 = mass without features described in pattern 1 or 3; and pattern 3 = any pattern that included an expansile mass ≥1 cm of intermediate T2 signal intensity (similar grade of signal intensity to the untreated tumor). T2 patterns were analyzed for local outcome (Fisher exact test) and time to local failure (univariate and multivariate analysis of T2 pattern, age, T stage, and tumor size by use of the Cox regression model). Residual masses after treatment were present in 34 (92%) of 37 patients. Local failures occurred in residual masses with pattern 1 in 0 (0%) of 14 patients; pattern 2 in 6 (55%) of 11 patients; and pattern 3 in 9 (100%) of 9 patients. Significant associations were found between local control and pattern 1 (P =