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the recurrence was local. The nature and timing of the local
failure may provide helpful clues about the risk of neuraxis
dissemination and move caregivers to recommend focal or
craniospinal treatment. The specter of metastatic disease
may be decreased in a patient who experiences disease pro-
gression where residual tumor was known to remain after ini-
tial surgery or in a patient who develops obvious local failure
relatively late, longer than 3 years after RT. Clinical condi-
tion and age of a patient also require consideration; very
young or debilitated patients may not fare well with CSI.
We do not propose a lower age cutoff for CSI, but consider
it to be an option in children older than 3 years because pa-
tients of a similar age with medulloblastoma continue to un-
dergo high-dose CSI as a front-line treatment option.
The role of radiosurgery is difficult to define from our
series because of the small number of patients and prepon-
derance of treatment sites that involve the brainstem. Al-
though it might be considered a better option for patients
with supratentorial local or metastatic disease, these patients
tend to have operable disease that may be removed and sim-
plify follow-up, which, after radiosurgery, is often com-
plicated by changes in the treated volume and normal
tissues. Even with radiosurgery, some normal brain is irra-
diated. High-dose single-fraction treatment can be harmful,
especially when such a critical structure as the brainstem is
involved.
Reirradiation for recurrent primary brain tumors has been
a long-standing treatment option, with investigators cogni-
zant of the attendant risks of necrosis or neurologic compli-
cation . One published series reported a 9% risk of
necrosis and overall complication rate of 29% in 34 patients
with primary brain tumors, including children, undergoing
fractionated reirradiation to a median combined dose of
79.7 Gy (range, 43.2–111 Gy) This series showed only
a modest palliative and survival benefit in a diverse group
of patients. A more specific evaluation of combined reirradia-
tion and lomustine therapy was conducted in a small cohort
of patients with high-grade glioma, showing a median overall
survival of 13.7 months. The reirradiation dose was limited to
34.5 Gy in 23 fractions, with a median interval between first
and second courses of irradiation of 14 months With the
advent of conformal RT, investigators attempted to minimize
the dose to normal tissues when reirradiation was attempted.
One series included 20 patients with primary brain tumors
unsuitable for brachytherapy or radiosurgery, predominantly
high-grade glioma. With a median reirradiation dose of 36
Gy (range, 30.6–59.4 Gy) and combined dose range of
80.6–119.4 Gy, neurologic improvement and stabilization
of disease was observed in more than 67% of patients
Different dose and fractionated schemes were attempted for
similar patients. For example, low-dose (36 Gy) fractionated
reirradiation was applied successfully to predominantly adult
patients with low- and high-grade astrocytoma. The lack of
observed toxicity might be attributable to the long interval
between courses (median, 50 months) for patients with low
grade and relatively short time to progression for patients
with high grade Similar low hypofractionated doses
were applied in patients with high-grade glioma and EP
with modest results. The FFRT and radiosurgery for
medulloblastoma appears to be safe, provided doses are rela-
tively low, and locally effective. However, overall results are
poor in a tumor system prone to metastatic failure, not unlike
EP
The patients in this report continue to be followed up for
treatment-related side effects involving neurologic, endo-
crine, and cognitive function. None was lost to follow-up.
Of the 23 patients for whom salvage therapy did not fail, 4
have notable disabilities, including the 2 patients alive and
without disease progression after necrosis (1 radiosurgery pa-
tient and 1 patient treated with CSI), 1 patient who was func-
tionally disabled by surgery before reirradiation, and the
patient who is the longest survivor in our series (>20 years)
who lives with parents and is simply employed. The rest of
the children continue to be followed up, and the magnitude
of side effects has been greatest in children treated with
CSI. Given the very small volume targeted for FFRT, barring
structure damage to the brainstem, the risks of endocrinop-
athy, ototoxicity, and cognitive decline for these patients
do not appear to be significantly greater than those observed
after their initial treatment course.
In summary, reirradiation with curative intent should be
considered for patients with recurrent EP after previous adju-
vant focal irradiation. Aggressive attempts to resect local and
metastatic disease are favored in this approach. Patients
treated in this manner require careful surveillance for side
effects of this combined salvage treatment approach.
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96 I. J. Radiation Oncology d Biology d Physics Volume 71, Number 1, 2008