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Updated: Oct 25, 2026
Stereotactic Radiosurgery for Gynecologic Cancer
Published on: April 17, 2012
Trends in multi-lesion stereotactic radiosurgery: an IROC survey on the state of the practice
Austin M Faught1, Yevgeniy Vinogradskiy2, Nzhde Agazaryan3
1The Ohio State University Wexner Medical Center.
Purpose:
The last decade has seen an increase in the treatment of multiple lesions within a single course of stereotactic radiosurgery (SRS). Hardware, software, and processes have evolved to support the clinical adoption of multi-lesion SRS. An understanding of the current state of the practice is needed to provide proper guidance.
Methods:
The Imaging and Radiation Oncology Core (IROC) distributed an addendum on SRS practices along with its annual facility questionnaire. Participants were asked 13 questions regarding their SRS program, including: whether single-isocenter multiple target deliveries are performed, delivery equipment used, the maximum number of lesions treated with a single isocenter, quality assurance practices, and the margins used for treatment.
Results:
The survey generated 879 responses from institutions with an SRS program. Among those programs, 91% (n=789) reported treating multiple lesions within a single course of treatment. Among institutions with equipment capable of treating multiple lesions with a single isocenter, 83% (n=504) reported doing so. Practices varied across clinical programs; for example, expansion margins from gross tumor volume (GTV) to planning target volume (PTV) ranged from 0mm to 2+mm. This variation was partially associated with the use of a six degree-of-freedom (6DOF) couch and the maximum number of lesions treated in a single isocenter. Among programs that treated multiple lesions per isocenter, 84.1% used a 6DOF couch compared to only 50.8% that treated one lesion per isocenter (p<0.01, χ2=64.8). Similarly, among institutions that reported no GTV to PTV margin (n=79), 100% used a 6DOF couch while only 55.3% of institutions that used a 2 mm margin reported the use of a 6DOF couch (p<0.01, χ2=73.0).
Conclusion:
Treatment of multiple lesions in a single course of SRS has become standard practice. However, when treating with a single isocenter, variability exists in clinical practice, highlighting the need for guidance on best practices.
