Purpose: Monitoring of androgen independent prostate cancer (AIPC) therapy involves monitoring prostate specific antigen (PSA) blood serum concentrations; however, the reliability of small changes in PSA values has been questioned. We performed a small pilot study to determine whether PET might be a useful monitor of changes during anti-angiogenic therapy in AIPC.
Procedures: Changes in tumor blood flow ([15O] water), blood volume ([11C]CO), 2-deoxy-2-[18F]fluoro-D-glucose (FDG) uptake and metabolic volume were measured before and during thalidomide treatment and compared with changes in PSA in six patients with AIPC.
Results: The percent change in PSA correlated with the FDG Delta%SUV(mean) (r=0.94, P<0.01) and Delta%metabolic tumor volume (r=0.91, P<0.01) but less well with Delta%blood volume (r=0.65, P=0.14). Percent change blood flow values showed an inverse correlation with percent changes in PSA (r=-0.83, P=0.032).
Conclusions: PET measures of tumor blood flow and metabolism may have use in monitoring the physiologic changes occurring during anti-angiogenic therapy in AIPC.