Apoptosis is a specific form of cell death that leads to clearance of dead cells without
causing inflammation or injury to normal adjacent tissues. Targeted cancer therapeutics that
target this pathway for tumor cell death induction are in development, but few specific
biomarkers of apoptosis are available to assess treatment response. Apoptosis also occurs in
response to standard combination therapies such as rituximab, cyclophosphamide, doxorubicin,
vincristine, and prednisolone (R-CHOP) used to treat diffuse large B-cell lymphoma (DLBCL).
Caspase-3 activation occurs as a result of apoptosis and may be a specific marker of
apoptosis. Therefore, this study will assess whether 18F-FluorApoTrace (18F-FAT), a caspase-3
targeted tracer, has a reasonable dosimetry profile and can be used to detect apoptosis in
patients with newly diagnosed DLBCL being treated with R-CHOP.