KEY POINTS
- The BRIDGE initiative evaluated how consistently clinicians apply CTCAE v6.0 to the same gynecologic radiotherapy toxicity scenarios during an ESTRO Gyn-SMART webinar. Of 183 registered users, 71 attended live, 30 completed the poll, and 23 consented to research analysis.
- The analyzed respondents were predominantly radiation oncologists (17/23, 73.9%). Most had prior CTCAE scoring experience (82.6%), and 60.9% had more than 10 years of professional experience, showing that disagreement was not confined to inexperienced users.
- Participants graded two clinical scenarios containing nine and eight adverse events, respectively, with the corresponding CTCAE severity definitions displayed during voting. Case 1 produced no complete agreement across any of the tested events.
- Agreement was particularly poor for subjective or lower-grade toxicities. For abdominal pain, ileus, insomnia, and depression, agreement fell below 70% in some assessments, with responses distributed across several CTCAE grades.
- Agreement improved when case descriptions explicitly used wording closely aligned with CTCAE criteria. In Case 2 there was complete agreement for urinary tract obstruction, while vaginal stricture still split 36% versus 64% between grades 2 and 3.
- Terminology itself created additional inconsistency. A rectovaginal fistula meets both the rectal and vaginal fistula definitions, which use the same severity criteria, yet respondents sometimes assigned different grades depending on which adverse-event term was selected.
- The authors argue that structured case-based training, clearer presentation of symptoms and interventions, and targeted questioning using CTCAE terminology could improve reproducibility. They also emphasize that patient-reported outcomes complement rather than replace clinician CTCAE assessment, particularly for symptomatic toxicities.
- Interpretation is limited by the very small, self-selected educational sample, narrative case presentation, and approximately 40% poll participation among live attendees. The exercise was not designed as a formal inter-rater reliability validation study.
CLINICAL TAKEAWAY
CTCAE grading is less objective than it can appear, particularly for symptomatic and lower-grade toxicities where interpretation of daily-function impact matters. This small BRIDGE exercise highlights why toxicity data across trials and institutions should be interpreted with attention to grading methods, training, terminology, and patient-reported symptom information.
SOURCE
Technical Innovations & Patient Support in Radiation Oncology