Preliminary Report of RTOG 9508: A Phase III Trial Comparing Whole Brain Irradiation Alone Versus Whole Brain Irradiation Plus Stereotactic Radiosurgery for Patients with Two or Three Unresected Brain Metastases
Presenter: P. W. Sperduto
Affiliation: Radiation Therapy Oncology Group
Brain metastases develop in approximately 25% of all cancer patients. Management with stereotactic radiotherapy for patients with 3 or less solitary lesions remains an area of controversy. This preliminary analysis is of a group of patients treated with whole brain radiation versus whole brain radiotherapy plus a radiosurgical boost.
- Patients with 2 or 3 solitary metastases were evaluated in this analysis
- Patients were randomized to either 3750 cGy/15 fractions whole brain RT or 3750 cGy/15 fractions whole brain RT + 1500 cGy to 2400 cGy radiosurgical boost (size dependent)
- The groups were well balanced for parameters such as KPS, numbers of lesions, and other factors
- Median survival in the 2 arms were 5.8 and 6.7 months, and were not significantly different.
- Local control was marginally better in the stereotactic boost arm vs. the whole brain alone arm
- There was a 20% improvement in Karnofsky status in the radiosurgery arm versus 0% in the whole brain alone arm, and a similar reduction in steroid dependence among patients receiving boost RT.
- There was no grade 4 or 5 toxicity in either arm, and 4% grade III toxicity in the boost arm versus 0% in the no-boost arm
- In patients with 2 or 3 brain metastases, stereotactic boost following whole brain RT has no impact on survival, improves local control, and may improve quality of life
- Patients with 2 or 3 brain metastases may benefit from such therapy in terms of local control and quality of life
- Further study will be required to identify subsets of patients who derive the most benefit from this therapy.