Prospective intra/inter-observer evaluation of pre-brachytherapy cervical cancer tumor width measured in TRUS and MR imaging

Abstract

Background Ultrasound (US) imaging has been proved as an excellent diagnostic tool in gynecology and, due to its wide availability and limited cost, is under intense investigation as base for dose adaptation in cervical cancer brachytherapy. Purpose of this work is to test inter/intra-observer uncertainties between magnetic resonance (MR) and trans-rectal ultrasound (TRUS) imaging in defining maximum tumor width before first brachytherapy (BT) application in a prospective cohort of cervical cancer patients undergoing image-guided adaptive brachytherapy (IGABT). Methods One hundred ten consecutive cervical cancer patients treated between 2013 and 2016 were included. Before the first BT implant patients underwent MR and TRUS scan with no applicator in place. Images were independently analyzed by three examiners, blinded to the other’s results. With clinical information at hand, maximum tumor width was measured on preBT TRUS and MR. Quantitative agreement analysis was undertaken. Intra-class correlation coefficient (ICC), Passing-Bablok and Bland Altman plots were used to evaluate the intra/inter-observers measurement agreement. Results Average difference between tumor width measured on MR (HRCTVMR) and TRUS (HRCTVTRUS) was 1.3 ± 3.2 mm (p < 0.001); 1.1 ± 4.6 mm (p = 0.01) and 0.7 ± 3 mm (p = 0.01). The error was less than 3 mm in 79, 82 and 80% of the measurements for the three observers, respectively. Intra-observer ICC was 0.96 (CI95% 0.94–0.97), 0.93 (CI95% 0.9–0.95) and 0.96 (CI95% 0.95–0.98) respectively. Inter-observer ICC for HRCTVMR width measures was 0.92 (CI95% 0.89–0.94) with no difference among FIGO stages. Inter-observer ICC for HRCTVTRUS was 0.86 (CI95% 0.81–0.9). For FIGO stage I and II tumors, ICC HRCTVTRUS values were comparable to respective HRCTVMR ICC values. For larger tumors HRCTVTRUS inter-observer ICC values were lower than respective HRCTVMR although remaining acceptable. Conclusions Our results suggest that TRUS is equivalent to MR in assessing preBT tumor maximum width in cervical cancer FIGO stage I/II. In more advanced stages TRUS seems to be slightly inferior to MR although maintaining a good agreement to gold standard imaging.

Clinical Outcomes of MRI-Guided Adaptive Brachytherapy for Each Fraction in Locally Advanced Cervical Cancer: A Single Institution Experience

“…MRI has been recommended as gold standard imaging for cervical cancer contours, with some comparative studies previously published ( 14 , 23 , 24 ), and for MR-IGABT (repetitive MRI during complete brachytherapy treatment), several studies reported its clinical efficacy for LACC patients in Europe ( 7 , 25 ) and North America ( 26 ). This study aimed to report the treatment outcomes of MR-IGABT for 97 Chinese LACC patients.…”

An Adversarial Deep-Learning-Based Model for Cervical Cancer CTV Segmentation With Multicenter Blinded Randomized Controlled Validation

“…Therefore, a novel auto-segmentation model that indeed performs comparably well or even better to manual delineation for CTV delineation is desirable. Moreover, the current evaluating performance of segmentation, particularly CTV segmentation, can be challenging due to the large variations among different centers and observers ( 35 , 36 ). Therefore, a three-stage randomized controlled evaluation framework was proposed, combining the three elements of traditional performance metrics, oncologist evaluation, and the Turing imitation test, for a comprehensive assessment of the proposed model in cervical cancer CTV segmentation.…”

Ultrasound guidance for cervical implantation

“…Another prospective comparison study using MRI and transrectal ultrasound images obtained prior to brachytherapy also showed good correlation in maximum tumor width measurements. In this study, a brachytherapy stepper unit was used to acquire the three-dimensional transrectal ultrasound image 15. Although these prospective studies demonstrated ultrasound imaging’s potential in gynecology, it is important to be aware of the technical details under which the studies were conducted in order to properly adapt this technology for application in brachytherapy.…”