This study evaluates the feasibility of hypofractionated radiotherapy (RT) in the palliative treatment of recurrent diffuse intrinsic pontine glioma (DIPG). Participants will receive 15 Gy in 3 fractions as opposed to the standard 20 Gy in 10 fractions.

Inclusion Criteria:

1. Patients must be ≤30 years of age
2. Patients must have a diagnosis of progressive DIPG.
3. Received prior IMRT based definitive radiotherapy to a dose of ≥54 Gy.
4. The patient and or parent/legal guardian must be physically and mentally capable of signing the consent form of their own volition.
5. Steroids dosage must be unchanged for 5 days.
6. No Bevacizumab within 21 days (Half-life 11 days ~)

Exclusion Criteria:

1. Patients with incomplete medical records
2. Patients with prior history of reirradiation for DIPG
3. Life expectancy < or equal to 1 month
4. Pregnant women
5. Age >30
6. Prisoners
7. Concurrent systemic therapy at the time of reirradiation
8. Physically or mentally incapable of signing the consent form of their own volition
9. < 6 mos time interval between completion of initial RT to start of reRT.

Individual participant data will be kept confidential and will not be shared with other researchers