paediatrics Brussels 17

Preliminary Results From a Phase II Trial of Conformal

Radiation Therapy and Evaluation of Radiation-Related

CNS Effects for Pediatric Patients With

Localized Ependymoma

Thomas E. Merchant, Raymond K. Mulhern, Matthew J. Krasin, Larry E. Kun, Tani Williams,

Chenghong Li, Xiaoping Xiong, Raja B. Khan, Robert H. Lustig, Frederick A. Boop,

and Robert A. Sanford

A B S T R A C T

Purpose

We conducted a phase II trial of conformal radiation therapy (CRT) for localized childhood ependymoma

to determine whether the irradiated volume could be reduced to decrease CNS-related side effects

without diminishing the rate of disease control.

Patients and Methods

Between July 1997 and January 2003, 88 pediatric patients (median age, 2.85 4.5 years) received CRT

in which doses (59.4 Gy to 73 patients or 54.0 Gy after gross-total resection to 15 patients younger than

18 months) were administered to the gross tumor volume and a margin of 10 mm. Patients were

categorized according to extent of resection (underwent gross total resection, n 74; near-total

resection, n 6; subtotal resection, n 8), prior chemotherapy (n 16), tumor grade (anaplastic,

n 35), and tumor location (infratentorial, n 68). An age-appropriate neurocognitive battery was

administered before and serially after CRT.

Results

The median length of follow-up was 38.2 months ( 16.4 months); the 3-year progression-free survival

estimate was 74.7% 5.7%. Local failure occurred in eight patients, distant failure in eight patients, and

both in four patients. The cumulative incidence of local failure as a component of failure at 3 years was

14.8% 4.0%. Mean scores on all neurocognitive outcomes were stable and within normal limits, with

more than half the cohort tested at or beyond 24 months.

Conclusion

Limited-volume irradiation achieves high rates of disease control in pediatric patients with ependymoma

and results in stable neurocognitive outcomes.

INTRODUCTION

Ependymoma is a rare brain tumor that oc-

curs in very young children: fewer than 150

cases per year occur in the United States

among persons younger than 14 years.

Sur-

gery and postoperative radiation therapy are

essential to the successful management of

ependymoma, but those who receive radia-

tion therapy are at risk of side effects that

negatively affect cognitive, endocrine, and

neurologic function.

The specter of

radiation-related side effects, which is most

ominous for those who are very young at the

time of treatment, has motivated investiga-

tors to test strategies to delay or avoid the use

of radiation in young children. However,

cooperative group trials testing the use of

chemotherapy to delay irradiation have met

with limited success, reporting results inferior

to those achieved for patients treated with im-

mediate postoperative radiation therapy.

3-5

Conformal radiation therapy (CRT) is a

spectrum of radiation treatment planning

and delivery techniques developed to focus

radiation and limit the highest doses to the

From the Division of Radiation Oncol-

ogy, Department of Biostatistics, Divi-

sion of Behavioral Medicine, St Jude

Children’s Research Hospital; Semmes-

Murphey Neurologic and Spine Insti-

tute; and Division of Pediatric

Neurosurgery, University of Tennessee,

College of Medicine, Memphis, TN; and

Division of Pediatric Endocrinology, Uni-

versity of California San Francisco,

San Francisco, CA.

Submitted November 24, 2003; accepted

May 8, 2004.

Supported in part by Cancer Center

Support grant No. CA21765 from the

National Cancer Institute, by Research

Project grant No. RPG-99-252-01-CCE

from the American Cancer Society, and

by the American Lebanese Syrian

Associated Charities.

Authors’ disclosures of potential con-

flicts of interest are found at the end of

this article.

Address reprint requests to Thomas E.

Merchant, DO, PhD, Division of Radia-

tion Oncology, St Jude Children’s Re-

search Hospital, 332 N Lauderdale St,

Memphis, TN 38105-2794; e-mail:

thomas.merchant@stjude.org

Oncology

0732-183X/04/2215-3156/$20.00

DOI: 10.1200/JCO.2004.11.142

OURNAL OF

LINICAL

NCOLOGY

O R I G I N A L R E P O R T

VOLUME 22 NUMBER 15 AUGUST 1 2004

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