Research Article: Quantitative MRI in the assessment of clival invasion in locally advanced nasopharyngeal carcinoma
Abstract:
This study assesses the value of quantitative magnetic resonance imaging (qMRI) in evaluating clival invasion (CI) and monitoring therapeutic response in locally advanced nasopharyngeal carcinoma (LA-NPC). It also investigates the relationship between qMRI parameter changes in CI and regression of nasopharyngeal soft-tissue invasion.
In this prospective study, fifty-five LA-NPC patients with CI from a single-center underwent qMRI at baseline (t0), pre-radiotherapy (t1), mid-radiotherapy (t2), and post-radiotherapy (t3). T1, T2, and T2* mappings were measured in manually delineated volumes of interest. Patients were categorized into complete response (CR) and non-CR groups based on nasopharyngeal soft tissue tumor regression per RECIST 1.1. The cervical vertebrae served as self-controls.
At baseline, T1, T2, and T2* mapping values were significantly higher in clival invasion than in normal cervical vertebrae ( p < 0.001). During treatment, the CR group (87.3%) exhibited marked decreases in T1 values (from 841.30 [IQR:521.31] ms at baseline to 587.61 [IQR: 187.54] ms at post-RT; p<0.001) and T2* values (from 7.27 [IQR: 5.28] ms to 4.86 [IQR: 3.48] ms; p<0.001), accompanied by a significant increase in T2 values (from 89.83 [IQR: 18.25] ms to 99.79 [IQR: 12.10] ms; p<0.001), whereas the non-CR group showed no significant alterations in T1 and T2 mapping values ( p > 0.05). Notably, there were no significant differences in T1, T2, and T2* mapping values between t2 and t3 in the CR group ( p > 0.05). Furthermore, differences between CI and cervical vertebrae measurements (?T1, ?T2, ?T2*) diminished in the CR group during treatment ( p < 0.05). Conversely, the non-CR group showed no significant changes in ?T1 ( p = 0.738) mapping values but did exhibit changes in ?T2 and ?T2* mapping values ( p < 0.001).
The qMRI-derived T1, T2, and T2* mapping demonstrates potential utility in monitoring CI response in LA-NPC, serving as an inherently quantitative tool that warrants further investigation in larger cohorts.
Introduction:
Nasopharyngeal carcinoma (NPC) is an epithelial malignancy with a pronounced geographical distribution, exemplified by China constituting 42.4% of the global 120,416 new cases reported in 2022 ( 1 , 2 ). Due to its concealed anatomical location, over 70% of NPC cases are initially diagnosed at a locally advanced stage, frequently complicated by skull base invasion—a key prognostic factor strongly associated with higher local recurrence rates and poorer survival outcomes ( 1 – 4 ). The clivus is the primary site of…
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