Safety and efficacy of concomitant chemotherapeutic wafers and iodine-125 seeds for recurrent glioblastoma

Abstract

Background:Patients with recurrent malignant gliomas have a uniformly poor prognosis. However, further treatment is often warranted at the time of recurrence. Low-activity implanted brachytherapeutic devices, such as iodine-125 seeds, and implantable chemotherapeutic devices such as 1, 3-bis (2-chloroethyl)-nitrosourea (BCNU) impregnated polymer wafers (Gliadel®) have been shown to be safe and modestly effective, but a comparison of combination therapy versus Gliadel® implantation alone has not been performed.Methods:We retrospectively examined 24 patients following re-resection of recurrent glioblastoma, with 17 patients undergoing implantation of both Gliadel® and iodine-125 seeds, and 7 patients undergoing implantation of Gliadel® only. Outcomes examined included adverse events, survival after re-resection (SAR), and time to tumor progression after re-resection (PAR).Results:Implantation of both Gliadel® and low activity iodine-125 seeds is safe with only two wound infections noted, a complication rate comparable to previous reports. The combination appears to confer a median SAR benefit if the activity per tumor resection volume exceeds 0.8 mCi/mL (60 versus 31 weeks, P = 0.02), and this benefit remained significant on multivariate analysis (HR =0.26 [CI:0.07-0.93], P = 0.03). Gross total resection of tumor was also significantly associated with longer time to PAR (HR =5.4 [CI: 1.13-26.0], P = 0.03).Conclusions:The concomitant use of Gliadel® and low activity iodine-125 seeds following re-resection of recurrent glioblastoma is safe. Our study demonstrated a significant benefit in SAR if the iodine-125 activity per tumor volume is greater than 0.8 mCi/mL. While our sample size is small, our results are in agreement with previous studies demonstrating the efficacy of combination treatment.

GammaTile ® : Surgically targeted radiation therapy for glioblastomas

“…While the rapid dose falloff of 131 Cs-based STaRT increases the safety profile in terms of wound healing and radiation induced neurological morbidities, there are limitations in terms of treatment for the microscopic tumor cells that extend beyond 2 cm of the resection cavity where STaRT is implanted. Ultimately, while STaRT affords an increased likelihood of local control, meaningful improvements in clinical outcomes requires synergy with other forms of adjuvant therapy [59,60].…”

Interstitial chemotherapy for malignant glioma: Future prospects in the era of multimodal therapy

“…[ 6 14 74 ] In the most recent study, conducted on a small subset of 17 patients with recurrent glioblastoma, the concomitant treatment of local iodine-125 and Gliadel ® yielded an overall survival rate higher than Gliadel ® alone (60 vs. 31 weeks). [ 28 ]…”