MRI surveillance of vestibular schwannomas without contrast enhancement: Clinical and economic evaluation

Abstract

Objectives: To determine if high-resolution T2-weighted (HRT2) magnetic resonance imaging (MRI) is a comparably accurate and economical alternative to the gold standard of contrast-enhanced T1-weighted (T1C) MRI for surveillance of know vestibular schwannomas (VSs).Study Design: Retrospective case-control analysis, systematic review, and economic evaluation. Methods: Vestibular schwannoma size in anteroposterior, mediolateral, and superoinferior axes were measured by two neuroradiologists, both blinded to previous measurements, for 50 randomized patients with T1C and HRT2 on two separate occasions. Measurements were assessed by Pearson product-moment correlation coefficients, and differences were analyzed by Student t test. Once the data were analyzed, appropriate economic evaluation was performed utilizing institutional-, federal-, and literature-based estimates of cost and incidence/prevalence.Results: Pearson correlations (r) between T1C and HRT2 were 0.991 and 0.973 for radiologists 1 and 2, respectively, with no statistically significant differences (P 0.05) between imaging techniques. Intraobserver and interobserver reliability estimates (j) were 0.88 to 1 for both T1C and HRT2, indicating very high reliability. Cost-minimization analysis demonstrated cost and charge differences of $148.02 and $1,284 per patient per scan, respectively. This represents an overall cost and charge savings for this 50-patient cohort of $7,401 and $64,200, respectively.Conclusion: HRT2 imaging is a highly reliable and lower-cost alternative to T1C for follow-up surveillance scans in patients with VS.

Diagnosis of small vestibular schwannomas using constructive interference steady state sequence

“…Interestingly, radiologists were also more likely to be confident when both CISS and contrast exams were read as negative compared to both being read as positive. This result is somewhat surprising, because other processes such as inflammation and clusters of nerves and blood vessels can cause false positive readings . Lastly, radiologists were less confident when they read the CISS examination as no tumor was present and the GdT1 exam as yes a tumor was present, compared to when both were read as no tumor.…”

“…Vestibular schwannomas (VSs) are benign tumors that arise from the Schwann cells of the vestibulocochlear nerve sheaths . VSs are typically slow‐growing tumors with an average growth rate of 1.2 mm per year and estimates of growth ranging from 30% to 90% .…”

“…Previous studies have shown comparable sensitivity and specificity of CISS in comparison to GdT1 MRI without the risks of side effects due to contrast infusion . It has also been shown to be significantly lower in overall healthcare cost, which may be of paramount concern in patients who require multiple follow‐up contrast‐enhanced scans.…”

“…1,2 VSs are typically slow-growing tumors with an average growth rate of 1.2 mm per year and estimates of growth ranging from 30% to 90%. [2][3][4] With advancements in imaging modalities, tumors are being found incidentally at increasing rates, and at smaller sizes, therefore symptomatology is not always present. 2 Standard of care screening for VS has been gadolinium contrast-enhanced T1-weighted (GdT1) magnetic resonance imaging (MRI).…”

“…[2][3][4] With advancements in imaging modalities, tumors are being found incidentally at increasing rates, and at smaller sizes, therefore symptomatology is not always present. 2 Standard of care screening for VS has been gadolinium contrast-enhanced T1-weighted (GdT1) magnetic resonance imaging (MRI). Depending on tumor size, location, growth, and symptomatology, management options vary from surgery, radiation, or expectant management with serial imaging.…”