A novel technique for measuring human tissue pO2 at the cellular level

Area of Science:

• Oncology
• Radiochemistry
• Medical Imaging

Background:

• Hypoxic cells in tumors are resistant to radiation therapy.
• Electron-affinic drugs can selectively bind to hypoxic cells via metabolism.
• Identifying hypoxic zones is crucial for effective cancer treatment.

Purpose of the Study:

• To evaluate the use of a tritiated electron-affinic drug, misonidazole, for identifying chronically hypoxic cells in human melanoma.
• To assess the potential of 'sensitizer-adduct' techniques for measuring tumor hypoxia.

Main Methods:

• Administration of tritiated-misonidazole to a patient with advanced melanoma.
• Surgical resection of a metastatic lesion.
• Autoradiographic analysis of histological sections to detect drug localization.

Main Results:

• Autoradiography revealed intense labeling in specific zones of the tumor.
• These labeled zones correspond to chronically hypoxic tumor cells.
• The technique provides an indirect measure of tissue partial pressure of oxygen (pO2).

Conclusions:

• The 'sensitizer-adduct' technique can identify chronically hypoxic tumor cells.
• This method offers a way to estimate the tumor hypoxic fraction.
• The findings support the development of invasive and non-invasive methods for measuring tissue hypoxia.