Photodynamic Therapy (PDT) for Recurrent Pediatric Brain Tumors
Status:
Completed
Trial end date:
2018-06-29
Target enrollment:
Participant gender:
Summary
The goal of this proposal is to evaluate a new Photodynamic Therapy (PDT) modification which
could revolutionize the treatment of brain tumors in children and adults. There are currently
few cases published involving the use of PDT in infratentorial (in the posterior fossa) brain
tumors in general and specifically those occurring in children. The investigators propose to
test a technique, for the first time in the U.S., that demonstrated in Australian adult
glioblastoma patients dramatic long-term, survival rates of 57% (anaplastic astrocytoma) and
37% (glioblastoma multiforme). These results are unprecedented in any other treatment
protocol.
Photodynamic therapy (PDT) is a paradigm shift in the treatment of tumors from the
traditional resection and systemic chemotherapy methods. The principle behind photodynamic
therapy is light-mediated activation of a photosensitizer that is selectively accumulated in
the target tissue, causing tumor cell destruction through singlet oxygen production.
Therefore, the photosensitizer is considered to be the first critical element in PDT
procedures, and the activation procedure is the second step. The methodology used in this
proposal utilizes more intensive laser light and larger Photofrin photosensitizer doses than
prior PDT protocols in the U.S. for brain tumor patients. The PDT will consist of
photoillumination at 630 nm beginning at the center of the tumor resection cavity, and
delivering a total energy of 240 J cm-2. The investigators feel that the light should
penetrate far enough into the tissue to reach migrating tumor cells, and destroy these cells
without harming the healthy cells in which they are dispersed.
The investigators will be testing the hypothesis that pediatric subjects with
progressive/recurrent malignant brain tumors undergoing PDT with increased doses of
Photofrin® and light energy than were used in our previous clinical study will show better
progression free survival (PFS) and overall survival (OS) outcomes. PDT will also be
effective against infratentorial tumors. The specific aims include determining the maximum
tolerable dose (MTD) of Photofrin in children and looking for preliminary effectiveness
trends.