Company: QTIWW
Filing Date: 2025-03-31
Form Type: 10-K
Source: 0001844505-25-000038
Chunk: 23

Company: QT IMAGING HOLDINGS, INC.
Filing Date: 2025-03-31
Form: 10-K
Item: Item 1
Chunk 23
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.05) with the Company. The mean non-cancer recall rate improved significantly, showing a decrease of 16% with QT (p-value > 0.03), at the expense of a 2% decrease in the mean cancer recall rate (p-value > 0.05) in comparison to FFDM. Combining performance on cancer and noncancer recall rates, the mean area under the receiver operator curve of confidence scores improved significantly by 10% with QT (p-value = 0.01). This MRMC study indicated that QTscan improves non-cancer recall rates without substantially affecting cancer recall rates. 

15

STATISTICAL ANALYSIS—The data were analyzed for the entire cohort of 108 breast cases (42 normal, 39 pathology-confirmed benign, and 27 pathology-confirmed cancer cases) using two general approaches: a random-reader fixed-cases (“RRFC”) analysis and a random-readers random cases (“RRRC”) analysis. RRFC analysis generalizes to the population of readers, but is specific to the particular case set and is termed random-reader fixed-cases analysis. In comparison, RRRC analysis generalizes both the case set and the population of readers. The RRRC analysis was expected to provide results more generalizable to new readers reading new cases, but with wider confidence levels compared to the RRFC analysis. 

For both approaches, performance comparisons between QT and FFDM were summarized in terms of mean differences between readers and 95% confidence intervals (“CI”) for these differences with p-values determining the degree of statistical significance. The performance metrics included non-cancer and cancer recall rates and detection rates for all lesions. In addition, the study analyzed the mean area under the receiver operator curve (“ROC-AUC”) based on the readers’ confidence scores as a statistically efficient approach to evaluating the cancer and noncancer performance metrics combined into a single measurement. These analyses were performed according to the method of Obuchowski & Rockette with Hillis adjustment to the degrees of freedom. The RRRC analysis of ROC-AUC was performed with the software package ORDBM MRMC 2.5, written by Stephen L, Kevin M. Schwartz, and Kevin S. Berbaum. The trapezoidal/Wilcoxon method for curve fitting and jackknifing for the covariance estimation were used in the analysis. All other statistical analyses were performed in the statistical computing environment R version 3.4.0 or higher. No statistical adjustments were made for multiple analyses. The ground truth was