Company: QTIWW
Filing Date: 2025-01-16
Form Type: S-1
Source: 0001628280-25-001723
Chunk: 206

Company: QT IMAGING HOLDINGS, INC.
Filing Date: 2025-01-16
Form: S-1
Chunk 206
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 in a cross section of female subjects. In this multi-reader multi-case (MRMC) study, we examined retrospective data from two clinical trials conducted at five sites. All subjects received FFDM and QT scans within 90 days. Data were analyzed in a reader study with full factorial design involving 22 radiologists and 108 breast cases (42 normal, 39 pathology-confirmed benign, and 27 pathology-confirmed cancer cases). The main results used a random-reader random-case analysis adjusted for location bias performed after a primary predefined random-reader fixed-case analysis. The readers’ mean rate of detecting lesions of any type was 4% higher ( p -value > 0.05) 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.

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