27-41. Tumor volumes are normalized to the volume at the time of H5.010RSVT/< 
injection and expressed as the ratio of observed volume (Vo) an the specified day to 
initial volume (Vi). Each line represents an individual animal. The dark line illustrates 
the tumor course in the control animals 
Medulloblastoma response to GCV was dependent on tumor size at initial treatment. Figure 2 illustrates 
the response of D324 (DAOY) medulloblastoma to H5.010RSVTK' + GCV therapy in relatively small 
tumors at initial treatment. All tumors demonstrated complete volume regression. No late tumor 
recurrences were observed in this group. By contrast, relatively large tumors (i.e., median tumor 
volume > 0.8 cm 3 ) showed a significant growth delay but only 2 of 6 tumors demonstrated growth 
reduction (figure 3). 
DAOY MEDULLOBLASTOMA 
TUMOR < 0.4 cm 3 
Figure 2. Tumor volume reduction for small DAOY medulloblastoma glioma flank 
xenografts, carried out as described in figure 1 . 
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Recombinant DNA Research, Volume 20 
