2495 - End-to-End Evaluation of Sub-Millimeter Isocenter Accuracy in a Frameless Intracranial SRS Workflow using a Hidden Target Test
Presenter(s)
S. Quirk1, T. K. Kosak2,3, D. Ribok4, J. S. Bredfeldt5, N. A. Saeed6, M. Kearney7, N. E. Martin2, and L. Warren8; 1Department of Radiation Oncology, Brigham and Women’s Hospital/Dana-Farber Cancer Institute, Boston, MA, 2Brigham and Women's Hospital, Boston, MA, 3Department of Radiation Oncology, Dana-Farber Brigham Cancer Center, Boston, MA, 4Brigham and Women's Hospital/Dana Farber Cancer Institute, Boston, MA, United States, 5Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 6Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 7Department of Radiation Oncology, Brigham and Women’s Hospital and Dana-Farber Cancer Institute, Boston, MA, 8Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA
Purpose/Objective(s): To evaluate the performance of a prospective, disease-site–specific peer review program and assess whether physician experience influenced the frequency of feedback received during peer review.
Materials/Methods: We conducted a retrospective analysis of all consecutive radiation therapy cases prospectively reviewed through a structured peer review program between June 2024 and January 2026. Peer review was performed in dedicated 30-minute, disease-site–specific meetings held 3 to 5 days per week and incorporated a two-stage review process, including contour review prior to treatment planning and plan review prior to treatment initiation. Peer review outcomes were categorized as no change, minor (optional or future consideration), or major (mandatory immediate evaluation). Thirty eligible attending physicians were grouped by clinical experience (0 to 2 years, 2 to 5 years, greater than 5 years). Rates of modification recommendations received by individual physicians were compared across experience groups using the Kruskal–Wallis test.
Results: The cohort included 1,638 cases: gastrointestinal (n = 170), genitourinary (n = 846), thoracic (n = 429), and head and neck (n = 193). Thirty eligible physicians were categorized by years of clinical experience: 0 to 2 years, 2 to 5 years, and greater than 5 years. Median peer review change recommendation rates were 21.6% among physicians with 0 to 2 years of experience (n = 4), 23.6% among those with 2 to 5 years (n = 7), and 26.2% among those with greater than 5 years (n = 19). No significant differences in change recommendation rates were observed across experience groups (Kruskal–Wallis H = 2.97, p = 0.23).
Conclusion: In a prospective, two-stage, disease-site–specific peer review framework, physician experience was not significantly associated with the receipt of peer review modification recommendations. These results suggest that structured, high-frequency peer review can promote consistent and equitable treatment quality by identifying potential changes early and reducing reliance on individual experience. Such system-based quality improvement approaches may enhance safety, standardization, and scalability in radiation oncology practice.
| Experience (years) | Number of physicians | Cases presented (median (IQR)) | Modification rate (%) |
|---|---|---|---|
| 0 to 2 | 4 | 35 (31-126) | 21.6 |
| 2 to 5 | 7 | 54 (50-75) | 23.6 |
| = 5 | 19 | 33 (20-70) | 26.2 |