ASCO 2012 Educational Session Presentation
One of the most controversial subjects in pediatric DIPGs over the last decade has been the biopsy issue. This has been the topic of discussion in private, editorials and even an FDA open hearing. At the 2012 ASCO meeting in Chicago there was an educational meeting chaired by Mark Kieran MD PhD entitled "Pontine Gliomas in Children:To Biopsy or Not to Biopsy". To me the greatest thing about this session is that it was taped and made available on the internet. This allows for those who were not in Chicago last year for ASCO to have a better understanding directly from some of the key international figures regarding this extremely important matter.
Stephanie Puget MD PhD, a French neurosurgeon, started the session with a 20 minutes presentation on "Is Biopsy Safe in Children with Newly Diagnosed Diffuse Intrinsic Pontine Glioma?" Dr Puget is a central figure in the landmark French DIPG clinical trial with upfront biopsy. Since the 2007 publication it seems that Dr Puget has had speaking engagements on both sides of the Atlantic to discuss DIPG biopsy. This was the first time though that I was able to actually hear her speak.
Dr. Puget started her talk with five questions.
1) Is biopsy needed for a DIPG diagnosis?
2) If not, why do biopsy for DIPG?
3) Can DIPG biopsy be safely preformed?
4) Can DIPG biopsy be preformed by everyone?
5) What can be done with the biopsy specimens?
The short answers-
1) No, it is made by MRI in conjunction with clinical symptoms.
2) Analysis of the tumors may lead to relevant biomakers and hopefully better treatment.
5) Allows for molecular studies (including whole genome sequencing and mutational analysis) and cell lines (of which they had 5 stem cell lines a the time).
During the presentation she reviewed the results of the French Biopsy experience. From 2002 to 2012, 92 biopsies were preformed with no mortality and only 5 patients experience morbidity. Four of these patients had transient problems including cranial nerve palsies or weakness. One child had a permanent hemiparesis but also was found to have disease progression. She said "it could be considered as safe as a stereotactic biopsy in the supra-tentorial space in a well-trained neurosurgical team".
She also addressed a few technical considerations: frame versus frameless surgery, choosing a route and choosing a biopsy site. Please note at approximately 14:30 minutes there are real videos of biopsy in children. At 18:30 minutes the size of the biopsy samples is shown as well as pre and post procedure MRIs.
For those interested in the pediatric DIPG biopsy issue, this is a very informative 20 minute presentation from someone who as been on the frontline.
Is Biopsy Safe in Children with Newly Diagnosed Diffuse Intrinsic Pontine Glioma?
Stephanie Puget MD PhD