PHOTODYNAMIC THERAPY FOR RECURRENT SUPRATENTORIAL GLIOMAS

We have used photodynamic therapy (PDT) in the treatment of 56 patient s with recurrent supratentorial gliomas who had failed radiation thera py and who were candidates for palliative reoperation, There were 34 m ales and 22 females; their mean age was 41 years and the mean Karnofsk y score was 79. Thirty-two patients had glioblastoma multiforme (GBM), 14 had malignant astrocytoma (MA), 6 had malignant mixed glioma (MM), and 4 had ependymoma (EP). Porphyrin photosensitizer was administered intravenously (i,v.) 12-36 hours prior to photoillumination. Ail pati ents had the recurrent tumor subtotally resected or cyst drained at su rgery followed by intraoperative cavitary photoillumination. In 15 cas es interstitial photoillumination using fibers with 2 cm diffusing tip s supplemented the cavitary illumination. The total light energy deliv ered ranged from 440 to 4,500 Joules (J) (median= 1,800 J), The energy administered ranged from 120 to 150 J per fiber and the linear energy density ranged from 65 to 450 J/cm, The energy density ranged from 8 to 110 J/cm(2) (median = 38 J/cm(2)), There were two postoperative dea ths and three patients were left with a persistent increase in their p ostoperative neurological deficit, The post-PDT median survival of pat ients with recurrent GEM was 30 weeks with a 1- and 2-year actuarial s urvival of 18% and 0%, respectively, The median survival of patients w ith recurrent GEM from first diagnosis was 118 weeks with a 1- and 2-y ear actuarial survival of 82% and 57%, respectively, The post-PDT medi an survival of patients with recurrent MA was 44 weeks with a 1- and 2 -year actuarial survival of 43% and 36%, respectively. The median surv ival of patients with recurrent MA from first diagnosis was 147 weeks with a 1- and 2-year actuarial survival of 86% and 71%, respectively. Patients with MA who received more than the median light dose had a lo nger survival than those who received less than the median light dose, Recurrent malignant gliomas have a very poor prognosis, PDT is a succ essful palliative treatment when they recur and are amenable to furthe r surgical treatment. With increasing light doses, better light delive ry systems, and more effective photosensitizers further considerable i mprovement in survival can be expected. (C) 1995 Wiley-Liss, Inc.