Case Volume and Experience in Stereotactic Radiation: Analysis of a Prospective Peer Review Program

Stereotactic radiation therapy (SRT) is highly effective but carries the risk of significant toxicity. We identified factors associated with SRT plans that require revision in a comprehensive, prospective peer review program conducted across a network of affiliated radiation oncology centers.

Weekly peer review rounds were conducted to review SRT cases prior to the start of radiation. Revision recommendations were tracked. Univariate and multivariable logistic regression was performed to identify factors associated with case revision.

From 2019 to 2024, 1172 SRT cases were reviewed at weekly rounds, including 313 brain stereotactic radiosurgery (SRS), 190 brain multi-fractionated SRS, and 669 stereotactic body radiation therapy. The yearly revision rate ranged from 19% in 2020 to 31% in 2024. There were 16 individual treating physicians with a median of 6 years of experience (range, 1-19 years), measured at the time of each SRT case review. Factors assessed for significance included SRT case volume in the 3 months preceding review (dichotomized as low- or high-volume), physician experience (≤2, 3-9, or ≥10 years), SRT technique (SRS, multi-fractionated SRS, or stereotactic body radiation therapy, and disease site. On multivariable logistic regression, revisions were less likely for high-volume physicians (odds ratio [OR], 0.58; 95% CI, 0.43-0.77), those with 3-9 years of experience (OR, 0.65; 95% CI, 0.44-0.96), and SRS technique (OR, 0.59; 95% CI, 0.41-0.84).

These data imply high value to prospective peer review for physicians with low SRT case volume and in their early career. Adequate case volume may be a critical factor for high quality SRT, analogous to the surgical literature. Annual revision rates in the program remained substantial over time, demonstrating the ongoing importance of an effective prospective peer review program for SRT.