Inclusion Criteria:

- Newly diagnosed pathologically confirmed Glioblastoma Multiforme (GBM) (WHO grade IV
glioma) planned to receive brain RT with temozolomide(TMZ), or patients with
pathologically confirmed breast or Non Small Cell Lung Cancer (NSCLC) with >3 brain
metastases as identified on contrast-enhanced brain MRI or CT, planned to receive
whole-brain radiotherapy(WBRT) recursive partitioning analysis (RPA) class I or class
II.

- Karnofsky performance status (KPS) of >=70%

- Controlled systemic disease

Exclusion Criteria:

- Previous treatment with HBOT for any other reason during the last 3 months prior to
inclusion.

- Any new chemotherapy or RT intervention during the first 5 weeks after RT.

- Patients with chest pathology incompatible with pressure changes, inner ear disease
or claustrophobia.

- Active Smoker

- Pre- existing or active psychiatric or neurologic impairments, not caused by the
brain malignancy which, in the opinion of the investigators, will interfere with the
proper administration or completion of the protocol.

- Previous cranial irradiation treatment.

- Previous treatment with an investigational drug for the primary disease within 14
days of baseline neuropsychological testing.

- Patients who have had surgery for their current brain malignancy must wait at least
14 days before baseline neuropsychological testing.

- Lepto-meningeal spread.

- Pregnancy or breast-feeding.

- Medical conditions deemed by the investigator to make the patient ineligible for
protocol investigations.