Brain SPECT by intraarterial infusion of 99mTc-HMPAO for assessing the cerebral distribution of carotid artery infusions in patient with brain tumor

In order to assess the cerebral distribution of intracarotid chemotherapy, 17 postoperative patients with brain tumor underwent brain SPECT obtrained by intraarterial infusion of 18.5 MBq of 99mTc-d,l,-hexamethylpropyleneamine oxime (99mTc-HMPAO). Injection methods were continuous (5.0 ml/min) or pulsatile infusion with supra- or infraophthalmic catheterization. The findings obtained by brain SPECT were frequently different from those of angiography and/or DSA. In supraophthalmic catheterization with continuous infusion, only 2 of 10 studies (20%) had homogeneous distribution and 5 of them (50%) had maldistribution of 99mTc-HMPAO which appears in association with laminar flow effect. The remaining 3 studies showed localized distribution (two: tumor localization, one: healthy brain localization). On the other hand, all of 5 studies with pulsatile infusion had homogeneous distribution of 99mTc-HMPAO. In infraophthalmic catheterization, all but one of 5 studies had homogeneous distribution with continuous infusion. These results suggest that pulsatile infusion may be effective in eliminating maldistribution of 99mTc-HMPAO in supraophthalmic catheterization. In conclusion, we are convinced that 99mTc-HMPAO is a useful intraarterial agent for assessing cerebral distribution of intracarotid chemotherpay. (author)