Clinical stage II (T-, N-) or stage III (any T, N+) based on magnetic resonance imaging (MRI) Multicentric cancer in the same breast as diagnosed by clinical examination, mammography, ultrasound; magnetic resonance imaging (MRI) or pathologic assessment, not amenable to excision with negative margins with a single lumpectomy Baseline imaging: At least one lesion that can be accurately measured in two dimensions utilizing mammogram, ultrasound, or magnetic resonance imaging (MRI) images to define specific size and validate complete clinical and pathologic response Patients must have T/ or N+ disease by magnetic resonance imaging (MRI) or endoscopic ultrasound Magnetic resonance imaging (MRI) scans of the brain and spine must be completed within days prior to patient registration; all MRI scans should be with and without gadolinium Ability to tolerate magnetic resonance imaging (MRI). Patients not able to have a magnetic resonance imaging (MRI) (due to pacemaker, claustrophobia, etc.) Patients must have measurable (defined by at least cm x cm) contrast-enhancing disease by magnetic resonance imaging (MRI) imaging within days of starting treatment Able to undergo a magnetic resonance imaging (MRI) scan and receive gadolinium-based contrast Contraindication to magnetic resonance imaging (MRI) For patients who have received prior cranial radiation, no increase in corticosteroid dose in the week prior to the baseline brain magnetic resonance imaging (MRI) Patients must have a baseline evaluation including history and physical examination with neurological evaluation and magnetic resonance imaging (MRI) of the brain (with and without gadolinium-based contrast), all completed within days prior to initiation of treatment Participants with known spinal or distant metastases; patients with ependymoma, medulloblastoma or germinoma must have metastatic workup including spine magnetic resonance imaging (MRI) to rule out metastases Evidence of disease activity as outlined (e.g. gadolinium enhancement on magnetic resonance imaging of the brain or clinical progression) - definitive intracranial lesions must be present on magnetic resonance imaging (MRI) of the brain Cytologically-confirmed LMD or radiologically detectable LMD defined as either/or:\r\n* A measurable lesion on contrast-enhanced magnetic resonance imaging (MRI) of either the brain or total-spine > mm that has not been radiated within the last months prior to commencement of study therapy\r\n* Positive CSF cytology Five-twenty intracranial lesions must be present on magnetic resonance imaging (MRI) of the brain Experienced first unequivocal progression of tumor by magnetic resonance imaging (MRI) [as assessed via Radiologic Assessment in Neuro-Oncology (RANO) criteria within months from the last dose of TMZ. Patient must have magnetic resonance imaging (MRI) confirming progressive disease Presence of T gadolinium (Gd)enhancing lesions (on magnetic resonance imaging [MRI]) suggestive of high-grade glioma Inability to undergo magnetic resonance imaging (MRI) evaluation for treatment planning and follow-up Multicentric breast cancer in the ipsiltateral breast as diagnosed by clinical exam, mammogram, ultrasound or magnetic resonance imaging (MRI) Patients must have measurable disease (in -dimensions) on magnetic resonance imaging (MRI) scan of brain and/or spine to assess preliminary evidence of response Patients must be able to have magnetic resonance imaging (MRI) scans Myometrial invasion > % or evidence of nodal or metastatic disease on baseline magnetic resonance imaging (MRI) (MRI only to be done for EC patients) or tumor size > cm on MRI or pelvic ultrasound Patients with newly diagnosed DIPG by magnetic resonance imaging (MRI); defined as patients with a pontine location and diffuse involvement of at least / of the pons are eligible without histologic diagnosis. For lesions with typical imaging features, biopsy is neither encouraged nor required for eligibility. Tumors that are biopsied will be eligible if proven to be supportive of the diagnosis of a DIPG. Consensus of diagnosis by the study team must be met. Histologically proven adenocarcinoma of the lower rectum (lower border =< cm from anal verge as assessed by pelvic magnetic resonance imaging [MRI]). Is able to have magnetic resonance imaging (MRI) with contrast of the brain INCLUSION - ENROLLMENT: cT-N on clinical staging (verified to have no suspicious axillary or internal mammary nodes on magnetic resonance imaging [MRI] or ultrasound) Documented first or second recurrence of glioblastoma (GBM) by diagnostic biopsy or contrast enhanced magnetic resonance imaging (MRI) performed within days of randomization per Response Assessment for NeuroOncology (RANO) criteria. Brain magnetic resonance imaging (MRI) (or CT if contraindication to MRI) within the last days showing no evidence of metastatic disease Is unable (due to existent medical condition) or unwilling to have a contrast enhanced magnetic resonance imaging (MRI) of brain Phase I patients must have measurable contrast-enhancing disease (defined as at least cm x cm) by magnetic resonance imaging (MRI) imaging within days prior to starting treatment (patients may have gross total resection, but should have measurable disease post-operatively); patients must be able to undergo MRI of the brain with gadolinium Patients must be able to undergo magnetic resonance imaging (MRI) scan with gadolinium contrast for treatment planning Meet eligibility requirements for SRS: able to get magnetic resonance imaging (MRI), lesion must not be abutting optic apparatus or brainstem, and must be able to be secured and positioned in a stereotactic U-frame mask Patients who cannot safely undergo magnetic resonance imaging (MRI) due to non-MRI compatible pacemaker, or other reason Patient cant have magnetic resonance imaging (MRI) scan Patients with absolute contraindication to magnetic resonance imaging (MRI) imaging are not eligible for the study Have an enhancing mass on magnetic resonance imaging (MRI) amenable to > % resection of contrast-enhancing tumor (as determined by the neurosurgeon pre-operatively) and histological diagnosis of glioblastoma from a prior stereotactic biopsy Patients with inability to complete brain magnetic resonance imaging (MRI) studies with contrast A magnetic resonance (MR) scan must be obtained within days of enrollment and must demonstrate an enhancing mass without significant mass effect; tumors must be less than approximately cc in total volume, as assessed by the principal investigator (PI) based on pre-enrollment magnetic resonance imaging (MRI); the lesion must be stereotactically accessible Participants must have locally advanced rectum cancer where primary resection without chemoradiotherapy (CRT) is unlikely to achieve clear margins as defined by magnetic resonance imaging (MRI), with no metastatic disease, as assessed by independent review. Unifocal tumor =< cm based on contrast-enhanced prone-breast magnetic resonance imaging (MRI) As defined on magnetic resonance imaging (MRI), target lesion must be at least mm distance from skin (defined as volume encompassing first mm from breast surface) Patients with newly diagnosed DIPG by magnetic resonance imaging (MRI); defined as patients with a pontine location and diffuse involvement of at least / of the pons are eligible without histologic diagnosis; for lesions with typical imaging features, biopsy is neither encouraged nor required for eligibility; tumors that are biopsied will be eligible if proven to be supportive for the diagnosis of a DIPG; consensus of diagnosis by the study team must be met Be able to undergo a brain magnetic resonance imaging scan Patients with untreated/active brain metastases as documented by magnetic resonance imaging (MRI) within months of study enrollment Able to undergo brain magnetic resonance imaging (MRI) with and without contrast without requiring general anesthesia Patients unable to undergo magnetic resonance imaging (MRI) of the spine Chest imaging (x-ray, CT or magnetic resonance imaging [MRI]) negative for metastasis no more than weeks prior to the date of RPLND Magnetic resonance imaging (MRI) findings consistent or with a histologically confirmed newly diagnosed GBM that has not been treated and would benefit from further surgical resection Subjects must have suspected high grade glioma by magnetic resonance imaging (MRI) A contrast-enhanced magnetic resonance imaging (MRI) scan showing >= treatable brain metastases Patient must be able have a magnetic resonance imaging (MRI) of the brain for treatment planning Patients with evidence of metastatic spinal disease by magnetic resonance imaging (MRI) are NOT eligible for either Stratum Histologically confirmed systemic malignancy with gadolinium contrast-enhanced magnetic resonance imaging (MRI) scan demonstrating - newly diagnosed intraparenchymal brain metastases Patients must have measurable lesion in the brain or spine that is >= mm seen on magnetic resonance imaging (MRI) with contrast; NOTE: contrasted pre-treatment MRI scan must be obtained =< days prior to stereotactic radiosurgery treatment No evidence of extraprostatic disease on T multiparametric pelvic magnetic resonance imaging (MRI) Radiographic evidence by magnetic resonance imaging (MRI) of brain metastasis (if patient is unstable to tolerate contrast, an MRI without contrast is acceptable) Diagnosis of biopsy proven stage I-IIIB (cT-, N-, M) adenocarcinoma of the rectum; staging must also be based on multidisciplinary evaluation including magnetic resonance imaging (MRI) and/or endorectal ultrasound Presence of any contraindications to magnetic resonance imaging (MRI) scanning Patients must have disease that can be measured and followed by mammogram and/or breast ultrasound (in special cases a dedicated breast magnetic resonance imaging [MRI] may be clinically indicated); the target lesion must not have been previously irradiated Patient has no contraindications to magnetic resonance imaging (MRI) scanning with intravenous contrast Inability to undergo magnetic resonance imaging Eligible for contrasted magnetic resonance imaging (MRI) on initial evaluation with glomerular filtration rate (GFR) >= ml/min; a diagnostic MRI ordered within days of diagnosis will be considered an acceptable alternative and will not be repeated Surgery: at least weeks following surgery including brain and spine provided post-operative magnetic resonance imaging (MRI) shows no active bleeding Imaging by magnetic resonance imaging (MRI), ultrasound and/or mammogram and physical exam to document lesions size must be performed within days of study entry Able to undergo brain magnetic resonance imaging (MRI) with and without contrast Unable to undergo magnetic resonance imaging (MRI) imaging Prospective participant is unable to undergo a magnetic resonance imaging (MRI) with contrast agent Gross disease must be unifocal on mammogram (mammo)/magnetic resonance imaging (MRI) imaging If consenting to participate in the optional PET/MR imaging sub-study, the patient must be able to tolerate PET/magnetic resonance imaging (MRI) with intravenous contrast administration and must complete the applicable MRI screening evaluation form Residual lesion must be >= . cm in diameter as determined by magnetic resonance imaging (MRI) Measurable disease on magnetic resonance imaging (MRI) scan Patients must have had a bilateral diagnostic mammogram within months of registration, and may also have a targeted sonography of the breast and/or ipsilateral axilla and magnetic resonance imaging (MRI) if clinically indicated Patients must have bilateral mammogram and/or breast magnetic resonance imaging (MRI) within months of diagnosis of their breast cancer Any contraindication for undergoing magnetic resonance imaging (MRI) All patients must have greater than but less than or equal to metastatic lesions seen on a contrast enhancing magnetic resonance imaging (MRI) scan obtained not less than one month prior to study enrollment; patients who are found to have up to metastatic lesions at the time of treatment planning (on volumetric MRI once the head frame is in place) may still participate in the trial Consensus of diagnosis must be reached by a multidisciplinary pediatric neuro-oncology team by considering both clinical evidence and magnetic resonance imaging (MRI) presentation; tissue diagnosis is not required There must be measurable disease on magnetic resonance imaging (MRI) Imaging studies: brain magnetic resonance imaging (MRI) before start of protocol therapy; images must include T, T with gadolinium, T, and fluid attenuated inversion recovery (FLAIR) sequences Inability to tolerate periodic magnetic resonance imaging (MRI) scans or gadolinium contrast Magnetic resonance imaging (MRI) scans of the brain and spine must be completed within days of patient registration; all MRI scans should be with and without gadolinium Newly diagnosed brain metastases (four or fewer by postcontrast magnetic resonance imaging [MRI] obtained within six weeks of study entry) Contraindication to magnetic resonance imaging (MRI) contrast agents There must be measurable contrast-enhancing progressive or recurrent GBM (single or multiple lesions) by magnetic resonance imaging (MRI) imaging with an interval of greater than or equal to months between recurrence and completion of prior radiotherapy; while there is no defined maximum tumor volume for eligibility in this study, patients with diffuse, multifocal recurrences may be excluded at the discretion of the study principle investigator (PI); there must be an MRI performed within weeks prior to any therapy Patients are excluded if they are unable to obtain a Magnetic resonance imaging (MRI) scan for any other reason. Contraindication for undergoing magnetic resonance imaging (MRIs) Inability or unwillingness to have magnetic resonance imaging (MRI) scans performed (e.g. cardiac pacemaker-dependent) Patients must have magnetic resonance imaging (MRI) within days of starting treatment; patients must be able to tolerate MRI Patients must be able to undergo magnetic resonance imaging (MRI) of the brain with gadolinium Patients must meet both of the first two conditions, OR the third:\r\n* Clinical findings consistent with a presumed new diagnosis of diffuse midline glioma (DMG) in the opinion of the treating neuro-oncologist, AND\r\n* Brain magnetic resonance imaging (MRI) findings consistent with a new diagnosis of DMG based on multidisciplinary consensus after review of imaging \r\n* OR, recurrent DMG requiring tumor resection or biopsy Documented recurrence by diagnostic biopsy or contrast enhanced magnetic resonance imaging (MRI) performed within days of entry in to the trial as per Response Assessment Criteria for High-Grade Gliomas (RANO) criteria Magnetic resonance imaging (MRI) performed within weeks of trial enrollment Arm patients must have measurable (defined by at least cm x cm) contrast-enhancing disease by magnetic resonance imaging (MRI) imaging within days of starting treatment Patients who cannot undergo brain magnetic resonance imaging (MRIs) If applicable, patients must be off bevacizumab therapy for days before the baseline magnetic resonance imaging (MRI) is obtained Radiologically confirmed metastatic brain lesion by magnetic resonance imaging (MRI) Patient is unable to undergo a magnetic resonance imaging (MRI) Contraindication for magnetic resonance imaging (MRI) Spinal compression or structurally unstable bone lesions suggesting impending pathologic fractures based on clinical findings and/or magnetic resonance imaging (MRI) > focal lesions detected by functional imaging including PET/CT and/or whole body magnetic resonance imaging (MRI) AND have measurable disease by protein electrophoresis analyses as defined by the following: A histologically proven, clinically significant lesion visible on mpMRI (magnetic resonance imaging) that is accessible to PRX transperineal injection. Cohort A: Histologically confirmed metastatic non-small cell lung cancer (all histologic subtypes allowed) with radiographic evidence by magnetic resonance imaging (MRI) of at least one measurable brain lesion as defined by Response Assessment in Neuro-Oncology (RANO) criteria that does not require corticosteroids for symptomatic control Documented recurrence by diagnostic biopsy or contrast enhanced magnetic resonance imaging (MRI) performed within days of entry in to the trial as per Response Assessment in Neuro-Oncology (RANO) criteria Patients must have undergone an evaluation by magnetic resonance imaging (MRI) within days of completing radiation and must also be within days prior to registration; MRI must NOT demonstrate tumor progression, but patients with imaging changes consistent with pseudo-progression, stable neurologic function and not needing corticosteroid treatment are eligible Histologically confirmed primary invasive adenocarcinoma of the breast with the size of the primary tumor being at least cm on imaging by either mammography, ultrasound or breast magnetic resonance imaging (MRI) Documentation of mammogram, ultrasound and magnetic resonance imaging (MRI) of the ipsilateral breast all performed within days prior to registration Participants must be willing and able to undergo regular magnetic resonance imaging (MRI) scans of the brain Absence > focal lesions on magnetic resonance imaging (MRI) studies Patients unable to obtain magnetic resonance imaging (MRI) for any reason (e.g., due to pacemaker, ferromagnetic implants, claustrophobia, extreme obesity) At least one recurrent or progressive brain metastasis(es) from any solid primary tumor that is visible on magnetic resonance imaging (MRI) as assessed by the patients treating physician Inability to undergo magnetic resonance imaging Patients with newly diagnosed DIPG, who undergo a biopsy are eligible; patients with disseminated disease are not eligible, and magnetic resonance imaging (MRI) of the spine must be performed if disseminated disease is suspected by the treating physician Clinical stage II-IIIC (T- N- M) by mammogram, ultrasound or magnetic resonance imaging (MRI) There must be documented progression or recurrence of disease by magnetic resonance imaging (MRI) imaging or cerebrospinal fluid (CSF) studies since completion of last tumor-directed medical therapy; patients may have had surgical resection or radiation of tumor, and need not have measurable or evaluable disease at study entry Inability or unwillingness to have magnetic resonance imaging (MRI) scans performed (e.g. cardiac pacemaker-dependent) Patient who is unable to undergo magnetic resonance imaging (MRI) brain and spine with gadolinium contrast. No increase in corticosteroid dose in the week prior to the baseline brain magnetic resonance imaging (MRI) Patients must have measurable disease, defined as at least one vestibular schwannoma (VS) > . ml (on volumetric analysis) that can be accurately measured by contrast-enhanced cranial magnetic resonance imaging (MRI) scan with fine cuts through the internal auditory canal ( mm slices, no skip) Patients must have unequivocal evidence of tumor progression by magnetic resonance imaging (MRI) performed no longer than days prior to study registration Able to undergo brain magnetic resonance imaging (MRI) with and without contrast Patients must have a baseline evaluation including history and physical examination with neurological evaluation and magnetic resonance imaging (MRI) of the brain (with and without gadolinium-based contrast), all completed within days prior to initiation of treatment Patients with greater than discrete metastases on magnetic resonance imaging (MRI) Patients must be able to undergo an magnetic resonance imaging (MRI) scan Patients must have MS using McDonald criteria supported by characteristic magnetic resonance imaging (MRI) changes Patients must agree to undergo repeat clinical neurological examinations and brain magnetic resonance imaging (MRI) with appropriate contrast after every other cycle of chemotherapy Patients must be able to undergo a pre-surgical magnetic resonance imaging (MRI) brain Patients meeting the following exclusion criteria will be excluded from the magnetic resonance imaging (MRI) portion only: \r\n* Metallic implant, e.g. pacemaker, defibrillator \r\n* Unmanageable claustrophobia \r\n* High risk for nephrogenic systemic fibrosis Patients with >= measurable brain metastases on a diagnostic-quality contrast-enhanced magnetic resonance imaging (MRI) obtained within days prior to registration No brain metastases detected by magnetic resonance imaging (MRI). Patients must have measurable disease on magnetic resonance imaging (MRI) that has progressed after prior therapy; progressive disease (PD) will be defined as a >= % increase in the sum of the products of greatest perpendicular diameters of all measurable disease over the smallest sum observed (since treatment started) on gadolinium magnetic resonance imaging (Gd-MRI), the appearance of new lesions on scan, or clinical or neurologic worsening despite stable disease on the last scans Contraindication to magnetic resonance imaging Patients must have measurable contrast-enhancing disease by magnetic resonance imaging (MRI) imaging within days of starting treatment; patient must be able to undergo MRI of the brain with gadolinium Brain magnetic resonance imaging (MRI) documenting CR must be obtained within days of study enrollment Patients with extraocular disease evident on magnetic resonance imaging (MRI) (extension into the optic nerve), massive choroidal/uveal invasion (grade IIC or IID per ARET) or disease outside the globe evident on MRI or physical examination would also be excluded Known allergies against contrast agents required for magnetic resonance imaging (MRI) of intracranial lesions, or other contraindications for MRI, i.e., pacemaker A cardiac T* < ms by magnetic resonance imaging (MRI). Patients must have magnetic resonance imaging (MRI) within days of starting treatment Patients must be able to undergo brain or spine magnetic resonance imaging (MRI) scans with intravenous gadolinium, based on tumor location(s) within days prior to registration Patient is able to be assessed by periodic dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) scan Patients must have measurable progressive or recurrent disease by magnetic resonance imaging (MRI) within weeks of starting treatment Unable to undergo brain magnetic resonance imaging (MRI) Patients must have a magnetic resonance imaging (MRI) scan performed within days prior to initial protocol treatment A diagnostic contrast-enhanced magnetic resonance imaging (MRI) of the brain must be performed within days prior to registration Patients at institutions that elect to utilize central imaging review to confirm eligibility must be pre-registered prior to submission of these images; images should be submitted as soon as possible after the pre-registration magnetic resonance imaging (MRI) is obtained; turnaround time for this review will be =< business hours after receipt of images by the Imaging and Radiation Oncology Core (IROC) Patients must be receiving magnetic resonance imaging (MRI) scans at University of California San Francisco (UCSF) Stable dose of corticosteroids for >= days prior to baseline magnetic resonance imaging (MRI) Confirmed primary brain tumor diagnosis via magnetic resonance imaging (MRI) and their neuro-oncologist Magnetic resonance imaging (MRI)-incompatible head or neck tattoos Additional exclusion criteria include participation in a scheduled resistance exercise program within month of study entry; metal implants or other contraindications for the magnetic resonance imaging (MRI); history of diabetes, chronic renal disease characterized by a creatinine clearance of less than , uncontrolled hypertension; and a vitamin D status ((OH)D) of > ng/mL Patients unable to undergo magnetic resonance imaging (MRI) of the spine For the subset of participants who will undergo magnetic resonance imaging (MRI), ability to withstand lying down in small area (MRI scanner) for minutes Subjects should have breast and axillary imaging with breast magnetic resonance imaging (MRI) (preferred) or breast and axillary ultrasound (US) within weeks prior to treatment initiation Acute ischemic stroke within the prior four weeks, defined as a new neurologic deficit(s) with magnetic resonance imaging (MRI) evidence of acute ischemia in a referable location, and no clinical or radiologic indication of a non-cerebrovascular mimic, such as a brain metastasis, as the etiology of the deficit(s) Immediate need for magnetic resonance imaging (MRI) Participant had a breast magnetic resonance imaging (MRI) that was performed after the diagnosis of ADH but before surgical excision. Screening contrast-enhanced magnetic resonance imaging (MRI) or mTc-sestamibi based imaging of the breast(s) within the prior months or planned within the next two years Patients who are thought to have a breast magnetic resonance imaging (MRI) within year prior to the study Arm patients must have lymph node, soft tissue, or visceral metastatic disease measuring >= cm, or bone metastases, documented by prior CT or magnetic resonance imaging (MRI) imaging; Arm patients may have hormone-sensitive or castrate-resistant disease and may be receiving treatment with hormonal or other therapies Previous CT scan, magnetic resonance imaging/magnetic resonance cholangiopancreatography (MRI/MRCP) or EUS of the abdomen in the past three years Patients with breast implants are usually permitted to have an magnetic resonance imaging (MRI); check with the MRI technician to confirm Patients must have measurable, supratentorial contrast-enhancing progressive or recurrent glioblastoma or gliosarcoma by magnetic resonance imaging (MRI) imaging within days of starting treatment; patient must be able to tolerate MRIs More than focal lesion >= millimeter (mm) in diameter by magnetic resonance imaging (MRI) Patients must have a biopsy marker placed within the tumor bed with imaging confirmation (preferably mammogram but ultrasound or magnetic resonance imaging [MRI] is acceptable) of marker placement prior to neoadjuvant chemotherapy Clinical stage I grade - endometrial cancer also eligible with deep myoinvasion >= % shown on preoperative (preop) magnetic resonance imaging (MRI) and/or elevated preop cancer antigen (CA)- > U/ml Diagnostic CT or magnetic resonance imaging (MRI) scan within months of study entry Patients who have presence of a known contradiction to MRI\r\n* Pacemaker\r\n* Aneurysm clips\r\n* Patients with implants that are contradicted for magnetic resonance (MR) imaging will be excluded\r\n* Pregnant\r\n* Age and mental status wherein he/she is unable to cooperate for MRI study Patient agrees to undergo, prior to the procedure, magnetic resonance imaging (MRI, within days and preferably with days of the planned procedure) with perfusion, diffusion and spectroscopic imaging. Contraindication for magnetic resonance imaging Patient must have a solid tumor with a short-axis greater than or equal to cm (by CT, magnetic resonance imaging (MRI), ultrasonography or mammography) to allow reliable PET imaging. Implanted devices, metallic hazards or other conditions presenting a contraindication to Tesla cardiac magnetic resonance imaging (MRI) Diagnostic CT or magnetic resonance imaging (MRI) performed within days prior to the Ga-RM PET Contraindication to magnetic resonance imaging (MRI). Contraindication to magnetic resonance (MRI) imaging, as determined through review of the University of California, San Francisco (UCSF) MRI screening form by study investigator Scheduled for magnetic resonance imaging (MRI) fusion/transrectal ultrasound (TRUS) biopsy, followed by histology Standard gadolinium-enhanced magnetic resonance imaging (MRI) changes that are considered indeterminate for tumor progression versus (vs.) treatment-related changes by the neuroradiologist or clinician within weeks of completion of radiation Patients with non-magnetic resonance imaging (MRI) compatible implanted metallic foreign bodies are excluded from this study Diagnosis of HCC with one or more of the following:\r\n* Liver mass (>= cm) with arterial phase contrast enhancement and early washout on subsequent phases by CT or magnetic resonance imaging (MRI)\r\n* Suggestive imaging findings plus alpha-feto protein (AFP) > mg/dL; or\r\n* Tumor confirmed by arteriography Allergy or relative contraindications to magnetic resonance imaging (MRI) contrast agents No contraindications to magnetic resonance imaging (MRI) Suspected first recurrence of a glioblastoma tumor by clinical measures and/or magnetic resonance imaging (MRI) Magnetic resonance imaging (MRI) or transrectal doppler ultrasound demonstrating at least one target lesion CT/magnetic resonance imaging (MRI) scan must be obtained within weeks prior to study entry Inability to undergo a magnetic resonance imaging (MRI) or PET scan (e.g., claustrophobia or metal implant) Participants must be willing and able to undergo regular magnetic resonance imaging (MRI) scans of the brain The subject has concordant magnetic resonance imaging (MRI)/H MRSI findings from a magnetic resonance (MR) staging exam at UCSF performed prior to the C MRSI exam performed in this study with investigational medicinal product (IMP), or is willing to undergo MRI/H MRSI in connection with the study exam Diagnostic quality abdominal imaging (CT or magnetic resonance imaging [MRI]) within the past days Unable to receive or tolerate magnetic resonance imaging (MRI) scan after evaluation of MRI screening form Inability to undergo magnetic resonance imaging (i.e. those patients with automated implantable cardioverter defibrillators [AICD]/pacemakers) Expected to undergo magnetic resonance imaging (MRI) within two weeks following the study procedure DCIS must be >= cm based on extent of calcifications, presence of a mass on ultrasound OR enhancement on magnetic resonance imaging (MRI) OR