Shortening fraction >= 27% by echocardiogram Shortening fraction of >= 27% by echocardiogram, or ejection fraction of >= 50% by radionuclide angiogram Cardiac function:* Normal ejection fraction (>= 55%) documented by either echocardiogram or radionuclide multi gated acquisition scan (MUGA) evaluation; OR * Normal fractional shortening (>= 27%) documented by echocardiogram Shortening fraction of >= 27% by echocardiogram (ECHO) OR Ejection fraction >= 50% by ECHO or gated radionuclide study Pediatric patients: normal left ventricular function with ejection fraction > 55% or shortening fraction >= 27% Shortening fraction of >= 27% by echocardiogram, or Ejection fraction of >= 50% by radionuclide angiogram Patient must have a normal cardiac ejection fraction by pretreatment multigated acquisition scan (MUGA) or echocardiogram within 4 weeks prior to registration (resting ejection fraction >= 40% or >= 5% increase with exercise), shortening fraction by echocardiogram >= 24%, or to within the normal range of values for the institution Shortening fraction of >= 27% by echocardiogram, or Ejection fraction of >= 50% by radionuclide angiogram Patients with a history of congestive heart failure (CHF) or are at risk because of underlying cardiovascular disease or exposure to cardiotoxic drugs must have adequate cardiac function as clinically indicated:* Corrected QT interval (QTC) =< 480 msec* Shortening fraction of >= 27% by echocardiogram or ejection fraction of >= 50% by gated radionuclide study Shortening fraction of >= 27% by echocardiogram, or ejection fraction of >= 50% by radionuclide angiogram Shortening fraction of >= 27% by echocardiogram OR ejection fraction of >= 50% by radionuclide angiogram Shortening fraction of >= 27% or Shortening fraction of >= 27% by echocardiogram, or ejection fraction of >= 50% by gated radionuclide study Shortening fraction of >= 27% by echocardiogram, or Ejection fraction of >= 50% by radionuclide angiogram or echocardiogram Shortening fraction of >= 27% by echocardiogram, or Ejection fraction of >= 50% by radionuclide angiogram or echocardiogram RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Cardiac function: * Left ventricular ejection fraction >= 50 by gated radionuclide study OR shortening fraction of >= 27% by echocardiogram* Patient has no ventricular arrhythmias except for benign premature ventricular contractions* Patient has a corrected QT (QTc) interval =< 450 ms NON-PROGRESSED DIPG (STRATUM 2): Left ventricular ejection fraction >= 50 by gated radionuclide study OR shortening fraction of >= 27% by echocardiogram Ejection fraction of < 50% (by radionuclide angiogram or echocardiogram) or shortening fraction of < 25% (by echocardiogram)* Note: for instances where both are reported, and one is below the threshold, the site will have the option to re-measure it centrally at the core lab Shortening fraction of >= 27% by echocardiogram, or ejection fraction of >= 50% by gated radionuclide study Shortening fraction of >= 27% by echocardiogram Ejection fraction of >= 50% by radionuclide angiogram or echocardiogram Shortening fraction of >= 27% by echocardiogram, or ejection fraction of >= 50% by gated radionuclide study within 7 days prior to enrollment