Peripheral Blood Stem Cell Collection with G-CSF Alone within 2 Weeks after Surgery in Patients with Pediatric Brain Tumors Requiring Craniospinal Irradiation

Abstract

The radiation field of craniospinal irradiation (CSI) for malignant brain tumor includes the entire skull and vertebra. Therefore, aggressive chemotherapy after CSI causes severe myelosuppression and prolonged duration of treatment; eventually, the dose intensity decreases. To maintain the dose intensity, we performed peripheral blood stem cell (PBSC) collection with granulocyte colony-stimulating factor (G-CSF) alone and administered aggressive chemotherapy followed by autologous peripheral blood stem cell transplantation (aPBSCT) in eight patients with malignant brain tumors. We attempted to complete PBSC collection so as to start CSI within 2 weeks of surgery. In six patients with initial presentation of their tumors, the median CD34⁺ cell number harvested was 12.6×10⁶/kg (3.9–21.6×10⁶/kg). However, in two out of the six and in two additional patients with relapsed disease, the number of cells collected for several transplants was insufficient. Therefore, in these four patients, chemotherapy with aPBSCT was started and a second PBSC collection was attempted. A sufficient number of CD34⁺ cells (13.7–42.1×10⁶/kg) could be collected after one cycle of aPBSCT. Although WBC counts tended to be higher during the administration of G-CSF, possibly owing to the postoperative acute phase reaction, we did not observe any severe adverse events. In all the patients enrolled, chemotherapy followed by aPBSCT was accomplished at planned intervals without prolonged myelosuppression. Although our cohort is too small to yield a conclusion, PBSC collection with G-CSF alone within 2 weeks of surgery is feasible and appears to be safe. Further study is needed to assess the usefulness of our approach to treating malignant brain tumors requiring CSI during the early postoperative period.