ESTRO 2024 - Abstract Book

S906

Clinical - CNS

ESTRO 2024

Figure 2: Mean lesion quotients for 3-dimensional volumetric calculation and simple linear measurement calculations. A ratio of greater than 0.2 appears to be an exclusion value for exclusive radiation necrosis in both 3D volumetric and simple calculation methods.

Conclusion:

A low lesion quotient appears to be a promising MRI parameter to diagnose presence of RN following SRS for brain metastasis(es) and to guide subsequent clinical management. Simple volume calculation using maximal linear measurements is a feasible and efficient method to determine this ratio in busy clinical practices compared to the more time-consuming 3D volumetric assessment. A lesion quotient of above 0.2 may be an exclusion criterion for presence of exclusive RN. Further large-scale data is required to validate this parameter.

Keywords: Radiation necrosis, Stereotactic radiosurgery

References:

1. Saghal A et al. Phase 3 Trials of Stereotactic Radiosurgery With or Without Whole-Brain Radiation Therapy for 1 to 4 Brain Metastases: Individual Patient Data Meta-Analysis. Int J Radiat Oncol Biol Phys. 2015;91(4):710 – 7.

2.

Lin X, DeAngelis L. Treatment of Brain Metastases. J Clin Oncol. 2015;33:3475 – 85.

3. Sperduto P et al. Survival in Patients With Brain Metastases: Summary Report on the Updated Diagnosis Specific Graded Prognostic Assessment and Definition of the Eligibility Quotient. J Clin Oncol. 2020;38:3773 – 84.