PHOTODYNAMIC THERAPY OF MALIGNANT BRAIN TUMORS: CLINICAL and NEUROPATHOLOGICAL RESULTS

Fourteen patients with malignant brain tumors were treated 17 times with photodynamic treatment following either intravenous, selective intraarterial or direct intratumoral injection of Photofrin II. In eight patients the photodynamic treatment was followed immediately by single dose radiation of 4 Gy of ionizing radiation. The three injection modalities resulted in 2.5 μ.g. 3.2 μ.g and 9.8 μ,g g−1 tumor tissue respectively after 3 days. The histological examination immediately after light irradiation after intravenous and intra-arterial injection demonstrated a predominantly vascular and cellular effect whereas the direct injection resulted in a direct cellular effect with little effect on vascular structures. The median survival time for the three patients with multiple recurrences of the glioblastoma was 5 months, five patients with the first recurrence have a survival time of 2 to 7 months following PDT and six patients with the primary manifestation are surviving now up to 12 months. The intraarterial and direct intratumoral injection was tolerated well by the patients without increased skin phototoxicity. These results indicate that the direct intratumoral and selective intraarterial injection of HPD are a feasible route for PDT however they are too preliminary to allow a final conclusion of the value of this modified PDT in the treatment of malignant brain tumors.