Clinical trials for glioma patients at the Finnish BNCT facility

Boron neutron capture therapy (BNCT) is an experimental radiotherapy used in clinical trials in Europe, Japan and USA to treat malignant glioma and melanoma. In BNCT the highly lethal radiation (a, 7Li*) released in thermal neutron capture of boron-1 atoms is used. The dose is targeted to the tumour using a boron carrier substance that is selectively taken up by the cancerous tissue. Clinical trials using borono-phenylalanine fructose complex (BPA-F) for the highly malignant brain tumour glioblast ma started at FiR 1 BNCT facility at VTT in May 1999. The neutron beam as well as the treatment environment, equipment and methods are of world top quality [1,2,3,4]. Patients are currently recruited to two clinical research protocols. By December 200118 newly diag-nosed, operated, but otherwise previously untreated patients have been treated in the first protocol using 290 mg/kg - 400 mg/kg BPA-F. BPA-F escalation p to 500 mg/ kg is planned for. The two hour BPA-F infusion has proofed safe and well tolerated. No severe late radiation therapy effects have been found. The acute and sub-acute toxicity has been acceptable. Since February 2001 three patients with recurrent glioblastoma have been treated using 290 mg/kg BPA-F. The radiation dose for these patients has been lower as compared to the first protocol due to the prior conventional RT given a minimum of six months before BNCT as part of conventional treatment for glioma. Also for these patients the BNCT treatment has been well tolerated and the adverse effects have been acceptable. First results suggest a prolonged survival. With the given BPA-F and RT doses stable diseases and partial responses to the treatment have been seen but the tumours tend to recur. The preliminary results support continuation of the BNCT research. Future plans involve fractionating BNCT irradiation and combining BNCT with stereotactically guided photon radiotherapy. [1] T. Seppälä et al., in these proceedings. [2] M. Kortesniemi et al., in these proceedings. [3] P. Ryynänen et al., in these proceedings. [4] J. Laakso, M. Kulvik, I. Ruokonen, J. Vähätalo, R. Zilliacus, M. Färkkilä, M. Kallio, Clin Chem., vol. 47 (2001) 10, p. 179