ANGI-07. A CASE OF HYPERBARIC OXYGEN USED AS A TREATMENT MODALITY FOR ANAPLASTIC ASTROCYTOMA

Abstract Although its precise mechanism is unclear, hyperbaric oxygen is thought to impede the growth of tumor cells by inhibiting tumor hypoxia, a known driver for angiogenesis. We present a case of a 32-year-old pilot who developed sudden onset aphasia and disorientation which led to hospitalization and imaging. He was diagnosed with anaplastic astrocytoma and underwent resection, radiation, and chemotherapy with temozolomide. Approximately one year later, MRI showed enlarging non-enhancing T2/FLAIR hyperintense mass in the right temporal lobe. He received 4 cycles of lomustine. Four months later, MRI showed slight increase in the size of ring enhancement around the treatment area. These findings were thought to be related to treatment-related changes. After 4 doses of bevacizumab every 2 weeks, there was improvement in surrounding vasogenic edema. However, after 7 doses, his MRI brain demonstrated increase in treatment-related changes with more vasogenic edema. He also had worsening left-sided weakness, unable to lift his left arm against gravity, dysarthria, and cognitive slowing. MRI perfusion supported treatment-related changes rather than tumor growth. He then started hyperbaric oxygen treatments and after 20 sessions of treatment, his vasogenic edema and his left-sided weakness improved. After 60 sessions of hyperbaric oxygen, he noticed further improvement in his strength and short-term memory. Four months after completion of his hyperbaric oxygen, he was found to have increasing size of ring-enhancing lesion and was restarted on hyperbaric oxygen treatments in addition to bevacizumab and low-dose temozolomide. He completed a total of 100 rounds of hyperbaric treatments. MRI showed improvement and stability. His left-sided weakness continued to improve. Hyperbaric oxygen alone or combined with other treatment modalities may be a promising therapy to improve quality of life. Further research will assist with mechanisms through which hyperbaric oxygen works and patient outcomes.