Intraobserver Variability in Bladder Cancer Treatment Response Assessment With and Without Computerized Decision Support.

Lubomir M Hadjiiski,Prasad R Shankar,Kenny H Cha,Alon Z Weizer,Matthew S Davenport,Ajjai Alva,Elaine M Caoili,Nathaniel Meyer,Richard H Cohan,Isaac R Francis,Galina Kirova-Nedyalkova,Heang-Ping Chan,Kimberly Shampain,Phillip L Palmbos,Ravi K Samala,Sean A Woolen,Daniel Barkmeier

doi:10.18383/j.tom.2020.00013

Abstract

We evaluated the intraobserver variability of physicians aided by a computerized decision-support system for treatment response assessment (CDSS-T) to identify patients who show complete response to neoadjuvant chemotherapy for bladder cancer, and the effects of the intraobserver variability on physicians' assessment accuracy. A CDSS-T tool was developed that uses a combination of deep learning neural network and radiomic features from computed tomography (CT) scans to detect bladder cancers that have fully responded to neoadjuvant treatment. Pre- and postchemotherapy CT scans of 157 bladder cancers from 123 patients were collected. In a multireader, multicase observer study, physician-observers estimated the likelihood of pathologic T0 disease by viewing paired pre/posttreatment CT scans placed side by side on an in-house-developed graphical user interface. Five abdominal radiologists, 4 diagnostic radiology residents, 2 oncologists, and 1 urologist participated as observers. They first provided an estimate without CDSS-T and then with CDSS-T. A subset of cases was evaluated twice to study the intraobserver variability and its effects on observer consistency. The mean areas under the curves for assessment of pathologic T0 disease were 0.85 for CDSS-T alone, 0.76 for physicians without CDSS-T and improved to 0.80 for physicians with CDSS-T (P = .001) in the original evaluation, and 0.78 for physicians without CDSS-T and improved to 0.81 for physicians with CDSS-T (P = .010) in the repeated evaluation. The intraobserver variability was significantly reduced with CDSS-T (P < .0001). The CDSS-T can significantly reduce physicians' variability and improve their accuracy for identifying complete response of muscle-invasive bladder cancer to neoadjuvant chemotherapy.

Highlights

81,400 new cases of bladder cancer (62,100 in men, 19,300 in women) will be diagnosed in 2020, resulting in 17,980 deaths (13,050 male, 4,930 female) according to estimates by the American Cancer Society [1]
The study population consisted of 123 subjects with 157 muscleinvasive bladder cancers who had undergone computed tomography (CT) scanning of the pelvis before and after neoadjuvant chemotherapy treatment before radical cystectomy
Surgical histology revealed that 25% (40 / 157) of bladder cancers were determined to have a pathologic stage of T0 following neoadjuvant chemotherapy

Summary

Introduction

81,400 new cases of bladder cancer (62,100 in men, 19,300 in women) will be diagnosed in 2020, resulting in 17,980 deaths (13,050 male, 4,930 female) according to estimates by the American Cancer Society [1]. Assessing response to neoadjuvant chemotherapy is not reliable at present, which may cause some patients to suffer adverse reactions to treatment with chemotherapy while gaining minimal benefit [6, 7]. It is important to develop an accurate method for assessment of treatment response. Such a method could be very useful for personalizing therapy to patients in the neoadjuvant chemotherapy setting. It might facilitate optimal selection of patients for bladder-sparing therapy [8], in which trimodal therapy (ie, transurethral resection, chemotherapy, radiation) can be used as a curative option for patients who do not wish to undergo the morbidity of radical cystectomy

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Results

Discussion

Conclusion