Presenter: A. Maity Presenter's Affiliation: Department of Radiation Oncology, Hospital of the University of Pennsylvania Type of Session: Poster
The most optimal therapy for intracranial germinomas remains controversial. While many oncologists have moved towards using focal radiation therapy, the policy at the University of Pennsylvania has still been to use craniospinal radiation because of the excellent results they have obtained. This study reports on their 25 year experience with this approach.
Materials and Methods
40 patients with intracranial germinomas were treated at CHOP/HUP from 9/76 to 5/01
Of the 40 patients, 39 received craniospinal radiation and were therefore further evaluated for this study.
All tumors were initially imaged by CT (n=15) or MRI (n=24). Dissemination of disease was assessed radiologically by myelogram and/or MRI (n=32) and cytologically by examination of CSF fluid (n=35).
In two patients the pathology was suspicious for mixed histology; but all other cases appeared to be pure germinomas.
The median whole brain dose was 36 Gy (range 18 - 44.2 Gy), the median total dose to intracranial disease 50.4 Gy (range 44-55.8 Gy), and the median spinal dose 30.6 Gy (range 18-40 Gy).
Sites of spinal disease were boosted to a total dose ranging from 39.6-50.2 Gy.
Two patients were treated with CMT because of the possibility of a mixed germinoma.
In addition, three other patients, all treated prior to 1992, also received combined modality therapy.
There were 9 females and 30 males in the study population
The median age of patients at diagnosis was 15 years (range 8-43)
Nine out of 32 (28%) patients had evidence of spinal leptomeningeal seeding by radiologic imaging.
Four out of 35 (11%) patients had positive CSF cytology. Of these four, only two had positive radiologic imaging.
A total of 11 out of 36 patients (31%) had some evidence of spinal dissemination. With a median follow-up of 6.8 years (range 0.5-20.2 years), there have been no relapses.
This includes 5 patients without spinal dissemination who received 18-19.8 Gy to the craniospinal axis in whom the median length of follow-up is 5.4 years (range 0.5-6.8 years).
Of the 39 patients in the study there has been a single death, a patient who was NED at 12.9 years but then died of unknown causes 4 months later.
The CHOP/HUP experience with craniospinal radiation in the treatment of biopsy-proven germinomas has yielded outstanding results with no relapses with long follow-up. This data suggest that 18-20 Gy to the craniospinal axis in patients without radiologically or cytologically detectable spinal dissemination may give the same excellent results as seen with higher doses. The results obtainable with craniospinal radiation must be considered when evaluating other approaches such as chemotherapy only or local field irradiation.
Radiation therapy (RT) has an established role in the treatment of pineal and suprasellar tumors of germ cell origin. There continues to be controversies in the optimal volume and dose of RT. The role of neoadjuvant chemotherapy is yet to be fully resolved. Treatment with neoadjuvant chemotherapy and low-dose (30 to 40 Gy) focal irradiation has resulted in increased failure rates in some centers thus; the use of low dose craniospinal RT would seem a reasonable alternative in selected patients. We look forward to the review of the neurocognitive functioning level in the CHOP/HUP population. If the neurocognitive functioning level in the CHOP/HUP group is acceptable and comparable to the functioning level in the focal RT with neoadjuvant study population, then craniospinal radiation should be considered when evaluating treatment.
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