Glioblastoma (GBM) is the most common primary brain tumor. Its incidence is estimated at 5 to 7 new cases
each year for 100 000 inhabitants. Despite reference treatment, including surgery, radiation oncology and
chemotherapy, GBM still has a very poor prognosis (median survival of 15 months). Because of a systematic
relapse of the tumor, the main challenge is to improve local control. In this context, PhotoDynamic Therapy
(PDT) may offer a new treatment modality.
GBM recurrence mainly occurs inside the surgical cavity borders. Thus, a new light applicator was designed for
delivering light during a PDT procedure on surgical cavity borders after Fluorescence Guided Resection. This
device combines an inflatable balloon and a light source.
Several experimentations (temperature and impermeability tests, homogeneity of the light distribution and ex-vivo
studies) were conducted to characterize the device. An abacus was created to determine illumination time
from the balloon volume in order to reach a therapeutic fluence value inside the borders of the surgical cavity.
According to our experience, cavity volumes usually observed in the neurosurgery department lead to an
acceptable average lighting duration, from 20 to 40 minutes. Thus, extra-time needed for PDT remains suitable
with anesthesia constraints. A pilot clinical trial is planned to start in 2017 in our institution. In view of the
encouraging results observed in preclinical or clinical, this intraoperative PDT treatment can be easily included
in the current standard of care.