Table 1

Comparison of total [11C] tracer and [11C] CO2-corrected [11C] temozolomide exposure (AUC0–90 min) after injection of [3-N-11C-methyl] temozolomide and [4-11C-carbonyl] temozolomide

Comparison between tissues demonstrated total [11C]tracer exposure in tumors was higher in tumor compared with normal tissue (P < 0.05). Similarly, [11C]temozolomide exposure was higher in tumors compared with normal tissue, reaching significance (P < 0.05) with [4-11C-carbonyl]temozolomide studies (n = 6), but not with [3-N-11C-methyl]temozolomide (n = 4). Comparison within tissues showed no differences in exposure to total tracer when temozolomide was injected labeled in either of the positions. In contrast, exposure to [11C]temozolomide was higher within tissues after [3-N-11C-methyl]-temozolomide injections tending towards significant levels (P = 0.07 for all tissues).

Total [11C]tracer AUC0–90 min Mean (SE) m2/ml[11C]temozolomide AUC0–90 min Mean (SE) m2/ml
[3-N-11C-methyl] temozolomide[4-11C-carbonyl] temozolomide[3-N-11C-methyl] temozolomide[4-11C-carbonyl] temozolomide
Tumor0.134 (0.03)0.136 (0.01)0.128 (0.03)0.101 (0.01)
Grey matter0.107 (0.005)0.110 (0.001)0.102 (0.008)0.077 (0.002)
White matter0.074 (0.007)0.081 (0.004)0.070 (0.005)0.056 (0.004)