gms | German Medical Science

Objective: Although in recent years, several approaches for local therapies in the treatment of glioblastoma multiforme have been tested in clinical trials, carmustin polymeres (Gliadel^® Wafer) is the only evaluated local therapy to date. Because of the predominance of temozolomide, Gliadel^® is frequently used in recurrent gliomas only. However, data about effectivity and the pattern of re-recurrences are rare. Therefore, we initiated the present MRI-based retrospective study.

Methods: 37 patients had surgery for first recurrence of glioblastoma, where Gliadel^® Wafers (n=1–8) were implanted. Early post-op MRI was performed documenting the extent of resection, tumor remnants and wafer placements. Follow-up MRI was performed every two months looking particularly for tumor growth in relation to the wafer placements. Progression-free and overall survivals were recorded.

Results: 27 patients were available for evaluation, while 10 patients had incomplete data. In 24 (88%) patients an early tumor growth was recorded in the first MRI follow-up, 2 months post-op in areas where the wafers were not implanted. If the wafers had been placed in areas with suspicious tumor according to the early post-op MRI, tumor progression was recorded in the follow-up in 10 (67%) of 15 patients. If the wafers were placed in areas without suspicious tumor remnants (12 patients), regrowth in those areas was recorded only in 4 (33%) patients, meaning 67% of the patients had no early tumor progression when Gliadel^® was placed in tumor-free areas. However, tumor pseudo-progression has to be taken into account for all cases. Survival data will be determined.

Conclusions: The use of Gliadel^® Wafer in recurrent glioblastoma is most effective in areas with no tumor remnants, underlining the importance of surgical resection also of recurrent tumors.