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FSRT
Coombs et al. used fractionated stereotactic radiother-
apy to treat intracranial ependymoma in young children.
Their success rate was comparable to conventional irradi-
ation using a total dose of 54 Gy that was administered in
two phases involving, first, the posterior fossa and, second,
the tumor bed. Progression-free survival at 5 years was
reported to be 64%. Murthy and others ] compared
dosimetry for posterior fossa ependymoma based on
treatment strategies. Target and normal structures contoured
included the normal brain, brainstem, cochleae, optic
chiasm, hypothalamic axis, supratentorial brain, and the
temporal lobes. They found that a six-field technique was
optimal irrespective of the size of the target volumes,
especially for tumors located anterior to the brainstem.
SRS
Stereotactic radiosurgery (SRS) has been used adjuvantly
after surgery alone or in combination with fractionated
external beam irradiation for residual disease .
Stereotactic radiosurgery has also been used as a salvage
treatment with or without addition resection for patients
who fail fractionated irradiation. In a series by Lo et al. ]
that included the aforementioned clinical scenarios, among
the five patients treated with surgery and fractionated
external beam who experienced treatment failure, three
were salvaged with stereotactic radiosurgery using approx-
imately 14 Gy with a median follow-up of 30 months.
Necrosis was observed and successfully managed. Both
patients treated with postoperative fractionated irradiation
and focal SRS boost for residual disease were controlled
during the same time frame. Jawahar et al. ] assessed the
role of stereotactic radiosurgery to treat locally progressive
ependymoma in adults and children. Their series included
22 patients. The mean tumor volume was 13.7 cm3 and the
mean maximal and median margin doses were 32.3 and
16.1 Gy. With a median follow-up of 21 months, 68%
responded to treatment and 41% developed distant metas-
tasis. Median survival was 2.2 years.
Craniospinal RT
The series by Timmermann et al. ] included 55 children
with anaplastic ependymoma with 28 treated with GTR and
various methods of irradiation. All received chemotherapy.
Median follow-up was 38 months; local disease progression
occurred in 20 of 53 irradiated patients. The overall
survival rate at 3 years after surgery was 75.6%. This value
is considered low but includes patients with metastatic
disease. The 3-year event-free survival was 66% for
localized tumors. Irradiation volume and other clinical
factors did not influence survival. McLaughlin et al. ]
is a classic series where patients with anaplastic tumors
received craniospinal irradiation and those with differenti-
ated tumors were treated focally. The differences in
outcome are difficult to measure based on the high rate of
local recurrence. Among 32 intracranial tumors, 21 suffered
recurrence at the primary site. Overall and relapse-free
survival rates were 51% and 46%, respectively, at 10 years.
Tumor site was prognostic for absolute survival (p =
Series Time period Patients 5-year EFS 10-year EFS 5-year OS 10-year OS
Akyuz 1972–1991 62 – 36% – 50%
Perilongo 1977–1993 92 – 35% – 56%
Shu 1980–2000 49 41% 31% 66% 56%
Oya 1961–1999 48 42% 42% 62% 47%
Pollack 1975–1993 40 46% 36% 57% 45%
Jaing 1985–2002 43 46% – 54% –
V. Veelan 1980–1999 83 48% 46% 73% 51%
Robertson 1986–1992 32 50% – 64% –
Mansur 1964–2000 60 58% 46% 71% 55%
Merchant 1997–2007 153 74% 69% 85% 75%
Table 2 Event-free and overall
survival estimates from selected
radiotherapy series reporting 5
and 10 year outcomes
EFS event-free survival, OS
overall survival
Series Time period GTR/patients 5-year OS (%) 5-year EFS (%)
Massimino 1993–2001 46/63 82 65
Shu 1980–2000 30/49 83 61
Mansur 1964–2000 14/60 84 69
Merchant 1997–2007 125/153 93 86
Table 3 Event-free survival
estimates for favorable patients
from selected radiotherapy se-
ries reporting 5-year outcomes
GTR gross-total resection, EFS
event-free survival, OS overall
survival
Childs Nerv Syst