Children must commence Induction chemotherapy within days of the most recent definitive surgical procedure and within days of the most recent neuro-imaging studies (magnetic resonance imaging [MRI] of brain, performed with and without gadolinium contrast, and MRI of total spine, performed with gadolinium contrast) and lumbar cerebrospinal fluid (CSF) cytological examination; the required eligibility observations must be done within days of the start date of treatment; the date protocol therapy is projected to start must be no later than calendar days after the date of study enrollment Contraindications to MRI and use of intravenous gadolinium-based contrast agents Allergy to iodine or gadolinium contrast that cannot be safely controlled with premedication Known contraindication to MRI with gadolinium contrast, such as cardiac pacemaker, shrapnel, or ocular foreign body Participants who cannot receive gadolinium Participants who cannot receive gadolinium Inability to undergo MRI secondary to: a) metal b) claustrophobia c) gadolinium contrast allergy Gadolinium allergy Contraindications to gadolinium contrast-enhanced MRI (e.g., non-compatible pacemaker, estimated glomerular filtration rate [eGFR] < , gadolinium allergy) Prior allergic reaction to gadolinium-based contrast agents (if receiving contrast for MRI) Medical contraindication to MR imaging (e.g. pacemakers, metallic implants, aneurysm clips, known contrast allergy to gadolinium contrast, pregnancy, nursing mothers, weight greater than pounds) Allergy to gadolinium MRI MONITORING SUB-STUDY: Previously had an allergic response to MR contrast agents (gadolinium) All patients must have a brain MRI with and without contrast (gadolinium) within days prior to study enrollment; all patients with history of spinal or leptomeningeal disease and those patients with symptoms suspicious of spinal disease, must have a spine MRI with contrast (gadolinium) performed within days prior to study enrollment; lumbar puncture is necessary if there is evidence of tumor dissemination on the MRI of spine Patients with a known allergy to gadolinium-DTPA Patients are excluded if there is any history of gadolinium allergy. Known intolerance or allergies to the MRI contrast agent (e.g. Gadolinium or Magnevist) including advanced kidney disease Contraindication to magnetic resonance imaging (MRI), including presence of a pacemaker or aneurysm clip, severe claustrophobia, a known reaction to gadolinium contrast, or body weight exceeding pounds (lbs) All patients must have a cranial MRI with and without gadolinium at diagnosis/prior to enrollment; if surgical resection is performed, patients must have pre-operative and post-operative cranial MRI with and without gadolinium; the post-operative brain MRI should be obtained within hours of surgery; if patient has a biopsy only, post-operative cranial MRI is recommended but not required; all patients must have a spine MRI with gadolinium obtained at diagnosis/prior to enrollment; Note: if the spine study is performed for the first time after surgical resection or biopsy, it is recommended to be obtained with and without gadolinium Cranial MRI (with and without gadolinium) must be done pre-operatively; post-operatively, cranial MRI (with and without gadolinium) must be done, preferably within hours of surgery; entire spinal MRI must be obtained either pre-operatively (with gadolinium) or post-operatively (at least days following surgery) prior to study enrollment (with and without gadolinium); patients with MRI evidence of spinal disease are eligible for this study Able to undergo MRI evaluation with gadolinium contrast Patients must have:\r\n* Pre-operative cranial magnetic resonance imaging (MRI) (recommended with gadolinium) or pre-operative computed tomography (CT) (recommended with contrast)\r\n* Post-operative cranial MRI with and without gadolinium within hours of surgery\r\n* Spinal MRI pre-op with and without gadolinium or post-op with and without gadolinium preferably within hours of surgery All patients must have a brain MRI with and without gadolinium and a spine MRI with gadolinium performed within weeks prior to study enrollment Contraindications to administration of gadolinium-based MRI contrast agent (e.g. Magnevist), such as chronic, severe kidney disease, acute kidney injury, history of Sickle Cell Disease, history of anemia, or intolerance/allergy to the contrast agent Known allergy to latex or gadolinium (Gd). Contraindications to MRI .. Claustrophobia .. Implanted ferromagnetic materials or foreign objects .. Known intolerance to the MRI contrast agent (e.g. Gadolinium or Magnevist) .. Known contraindication to utilization of MRI contrast agent Contraindication to use of gadolinium-based intravenous contrast, including life-threatening allergy or compromised renal function (creatinine > .) Known contraindication to MRI with gadolinium contrast, such as cardiac pacemaker, shrapnel, or ocular foreign body Inability to tolerate periodic MRI scans or gadolinium contrast To document the degree of residual tumor, the following must be obtained:\r\n* All patients must have a brain MRI with and without contrast (gadolinium) within week prior to study enrollment; for patients on steroids, baseline MRI scans must be performed after at least week at a stable or decreasing dose of steroids\r\n* All patients with a history of spinal or leptomeningeal disease, and those patients with symptoms suspicious of spinal disease, must have a spine MRI with and without contrast (gadolinium) performed within weeks prior to study enrollment Known allergy to gadolinium Contraindication to gadolinium-enhanced MRI imaging Measurable contrast-enhancing disease by MRI of brain and or spine (with gadolinium contrast). Known intolerance or allergy to MR contrast agent (gadolinium chelates) including advanced kidney disease Known contraindication to intravenous gadolinium contrast administration (e.g., renal impairment, known allergy); standard institutional policies on gadolinium and renal function will be followed At least one measurable lesion defined as lesion(s) that can be accurately measured in at least two dimensions and is ? mm in each dimension by Gadolinium (Gd)-MRI, irrespective of slice thickness/reconstruction interval, for CNS lesions and CT or MRI (with or without contrast) for non-CNS lesions. All patients with CNS lesions must have a brain MRI with and without gadolinium and a spine MRI with gadolinium within weeks prior to first dose of study treatment. Contra-indications to receiving gadolinium contrast History of immediate or delayed hypersensitivity reaction to gadolinium contrast agents, or other contraindication to gadolinium contrast and other known contraindication to MRI; Allergy to gadolinium Inability to undergo MRI with and without contrast (e.g. claustrophobia, non-MRI compatible implant or foreign body, gadolinium allergy or renal dysfunction preventing the patient from receiving gadolinium- institutional guidelines should be used to determine if patients are at risk for renal dysfunction); note that patients with severe claustrophobia are permitted on this study if they are willing and able to undergo MRI with adequate sedation or anesthesia Known intolerance or allergies to the MRI contrast agent (e.g. Gadolinium or Magnevist) including advanced kidney disease Confirmation of tumor recurrence or progression on contrast MRI (with and without gadolinium contrast) as determined by RANO criteria within days prior to registration for patients who did not have recent resection of their glioblastoma or only had a stereotactic biopsy. > cm diameter of blood seen on contrast MRI (with and without gadolinium contrast) Contraindication to gadolinium contrast administration during MR imaging, such as allergy or insufficient renal function Allergy or intolerance to gadolinium EXCLUSION - PATIENT: History of adverse or allergic-like reaction to gadolinium MRI intravenous contrast, rendering the participant unable to safely receive intravenous contrast based on institutional clinical protocol Contraindication to gadolinium (Gd) contrast agents Patients must be able to tolerate brain MRI scans with dynamic intravenous gadolinium-based contrast agent injections\r\n* Ability to withstand -gauge intravenous (IV) placement\r\n* No history of untreatable claustrophobia\r\n* No magnetic resonance (MR) incompatible implants/devices or metallic foreign bodies\r\n* No contraindication to intravenous contrast administration\r\n** Adequate organ function, including adequate renal function defined as estimated glomerular filtration rate (eGFR) >= mL/min/. m^ as calculated per institution standard of care, and meeting local site requirements for intravenous administration of gadolinium-based MRI contrast agents\r\n* No known allergy-like reaction to gadolinium or moderate or severe allergic reactions to one or more allergens as defined by the American College of Radiology (ACR); patient may be eligible if willing to undergo pre-treatment as defined by the institution's policy and/or ACR guidance\r\n* Weight compatible with limits imposed by the MRI scanner table Patients in which gadolinium contrast is contra-indicated Medical contraindication to MR imaging (e.g. pacemakers, metallic implants, aneurysm clips, known contrast allergy to gadolinium contrast, pregnancy, nursing mothers, weight greater than pounds, GFR < ) Known allergic reaction to gadolinium; patient may be eligible if the referring physician determines that the MRI is medically necessary and if the patient is willing to undergo pre-medication for contrast allergy History of allergic reactions to gadolinium-based MRI contrast agent Subjects who have a contraindication for Tesla (T) MRI, or have an allergy to gadolinium containing contrast material Patients with a contraindication to gadolinium based contrast agents, including allergy or impaired renal function (per UW health guidelines) Women with gadolinium contrast allergy Allergy to gadolinium containing contrast media Known allergy to FDG or gadolinium based contrast agents Patients with a known allergy or hypersensitivity to MRI contrast agents including gadolinium Have had allergic response to contrast agents (such as iodine or gadolinium) previously Known allergy to gadolinium or the sedative, propofol, used during MRI Patients with contra-indications to injection of gadolinium contrast; for example patients with prior documented allergy or those with inadequate renal function Participants with any contraindications to gadolinium-based contrast agents Allergy to gadolinium or other severe drug allergies Patients who are allergic to gadolinium based contrast agent Any contraindication to gadolinium intravenous contrast as per standard Department of Radiology contrast guidelines Any contraindication to gadolinium intravenous contrast as per standard Department of Radiology contrast guidelines Known allergy to gadolinium. No allergy to gadolinium Subjects with a contraindication to receiving gadolinium containing contrast for the MRI Contraindication to MRI or history of adverse reaction to gadolinium If agreeing to MRI contrast, participant must not have had a prior allergic reaction to gadolinium-based contrast agents Patients must be judged to be suitable to undergo MRI and receive the contrast agent gadolinium (exclusions follow):\r\n* No history of untreatable claustrophobia\r\n* No presence of metallic implants that, in the opinion of the radiologist, would make MRI a contraindication\r\n* No history of sickle cell disease\r\n* No contraindication to intravenous contrast administration;\r\n* No known allergy-like reaction to gadolinium or moderate or severe allergic reactions to one or more allergens as defined by the American College of Radiology (ACR); patient may be eligible if willing to undergo pre-treatment as defined by the institution's policy and/or ACR guidance\r\n* No findings consistent with renal failure, as determined by glomerular filtration rate (GFR) < mL/min/. m^ based on a serum creatinine level obtained within days prior to registration\r\n* Weight lower than that allowable by the MRI table Patients who have presence of a known contraindication to DCE-MRI may not participate in that portion of the study:\r\n* Known reaction to gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA), contrast agent \r\n* Chronic kidney disease\r\n* Nursing women Patients with a history of allergic reaction to latex or gadolinium containing intravenous contrast agents Individuals with renal disease or other contraindications to gadolinium will be excluded; the Brigham and Womens Hospital (BWH) standard MRI contrast screening criteria will be used to establish renal status Contraindication to use of gadolinium based intravenous contrast, including life threatening allergy or compromised renal function (creatinine > .) PART B: Contra-indication to gadolinium contrast (e.g. chronic renal disease, prior allergic reaction) for patient studies Known allergy to gadolinium containing contrast agents Subjects who have had past allergic or other adverse reactions to intravenous injection of Magnevist (gadopentetate dimeglumine) or other gadolinium-containing contrast agents Subjects who have exhibited past allergic or other adverse reactions in response to intravenous injection of Magnevist (gadopentetate dimeglumine) or other gadolinium-containing contrast agents Patient with known severe adverse drug reaction or contraindication to Gadolinium-Based Contrast Agent Subjects with known hypersensitivity and allergy to gadolinium contrast agents Known prior allergic reaction to gadolinium-based magnetic resonance (MR) contrast agents Women who have had a moderate or severe contrast reaction to intravenous gadolinium-diethylenetriamine pentaacetic acid (DTPA)