Radiation Oncology

SRS Dose Selection (RTOG)

Treatment Protocol: SRS Dose Selection

Tumor Morphometry

Max Tumor Diameter (mm)

Diameter-Dose Mapping

Enter the maximum tumor diameter to determine the appropriate single-fraction SRS dose based on prospective trial safety data.

Guidelines & Evidence

Verified

Last Review: 2026

RTOG 90-05 Guidelines

Standard Dose Selection

The RTOG 90-05 protocol established the maximum tolerated dose (MTD) for single-fraction Stereotactic Radiosurgery (SRS) in patients who had previously received whole-brain radiation. These doses are now widely used as the standard for both recurrent and newly diagnosed brain metastases treated with SRS.

Dose based on Tumor Diameter

Maximum Tumor Diameter	Prescription Dose (Gy)	MTD Threshold
≤ 20 mm	24 Gy	Safe and effective.
21 – 30 mm	18 Gy	Balanced control/toxicity.
31 – 40 mm	15 Gy	Increased risk of necrosis.
> 40 mm	N/A	Single fraction usually contraindicated.

Last Comprehensive Review: 2026