A: MRI scans of S-180 tumor mass around the sciatic nerve. After inoculation of S-180 tumor cells around the sciatic nerve, MRI scan was performed. (a) On inoculation day (b) 10 days after inoculation (c) 16 days after inoculation (d) 24 days after inoculation. B: S-180 implantation around sciatic nerve-induced neuropathic cancer pain according to cell number in a time course study. Withdrawal latency of left hind paws was measured every 2 days until 17 days after inoculation. Values are expressed means ± SE. Statistically significant differences were recorded after comparison to the control using the student's t test (* p < 0.05, ** p < 0.01).