Oligodendroglioma, Left Pariental

Contributor:

Dr. Chris Ekong

Consultants:

Dr. Michael Schwartz
Dr. James Perry

Case 2

Age: 36

Sex: Female

History: Sudden right arm focal seizures March '99. Ct of head was done and showed a mass lesion.

Treatment:

Stereotaxic biopsy done. Confirmed Oligodendroglioma. Treated with radiation.

Progress:

Another seizure June 2000. Examination normal.

Treatment:

We are considering Radiosurgery!

Comments:

To: Dr. Mike Schwartz, Neurosurgeon, Toronto - July 12, 2000

Dear Mike;

I would like your opinion on this 36 year old lady with recurrent left oligogdendroglioma. She presented with focal seizures in March 1999 and the CT showed deep left parietal oligogdendroglioma which we treated successfully with radiation. She now presents with a recurrence. Do you think she would be a good candidate for stereotaxic radiation?

Thank-you.

Chris

Dr. Mike Schwartz, Neurosurgeon, Toronto - July 13, 2000

Dear Chris,

I looked at the images and I am forwarding this e-mail to Mary Tsao, my radiation oncology colleague and to James Perry, the neuro-oncologist at Sunnybrook. It might be suitable to treat only the visible tumour with radiosurgery, but we both know that there will be tumour cells beyond the boundaries of the abnormality on the scan. It might therefore be preferable to treat a wider field with fractionated radiotherapy. Since it is an oligo, chemotherapy might be the best option overall. I expect that they will write you.

Best regards,

Mike

Dr. James Perry, Neuro-oncologist, Toronto - July 13, 2000

Thanks for passing this along Mike. Interesting webpage.

I agree that, in general, stereotactic radiosurgery is not an appropriate treatment for a non-localized diffuse disease like glioma, even if it seems relatively small and targetable on scans.

A key question in the reliability/certainty of the diagnosis of oligogdendroglioma. It would be useful to test for allelic loss of chromosome 1p on the tumour specimen as this is the "molecular signature" of oligogdendroglioma and virtually invariably associated with chemoresponsiveness. I would suggest that, even if LOH 1p is not available for testing, a trial of chemotherapy be undertaken to assess treatment sensitivity. If it is a true oligo it will shrink. We would usually use standard PCV or temozolamide.

Many thanks,

James

Dr. Mary Tsao, Radiation oncologist, Toronto - July 13, 2000

Dear Colleagues,

I agree with James and Mike. The standard is to treat with chemo after RT for relapsing oligo. So I would not offer repeat RT at this juncture.

Kind regards,

Mary Tsao

Dr. Angus Kirby, Pathologist, Regina, July 26, 2000

At Dr. Ekong's request for testing for deletions of chromosome 1p and 19q, this case has been referred to Dr. Arie Perry in St. Louis, Missouri, who has identified these deletions (in roughly 95% of all cells) by flourescence in situ hybridization (FISH) from the tissue block. This genetic phenotype has been associated with enhanced chemosensitivity and prolonged survival in oligodendrogliomas, however, the associations have not been absolute and the data should, for the time being, be considered preliminary and experimental. Dr. Perry also ststes that because of the small amount of tissue submitted for examination and the clinical behavior, the patient more likely harbours and anaplastic glioma which has been under-sampled.

FINAL DIAGNOSIS:

Brain tumour biopsies (on target), Left parietal lobe:

- Oligodendroglioma

- Chromosome 1p and 19q deletions positive (see text)

ADK

A Project of The Emmanuel Charitable Foundation