CONTACT: BECKY SOGLIN
Iowa City IA 52242
(319) 335-6660; fax (319) 384-4638
Release: Aug. 13, 2001
UI only U.S. center to study tumor treatment in children
IOWA CITY, Iowa -- University of Iowa Health Care physicians have received
a two-year, $500,000 National Cancer Institute grant for a Phase I clinical
trial to study a potential treatment for nervous system tumors in children.
Phase I trials are designed to determine the maximum drug dosage at which
children with relapsed cancer can safely be treated.
The UI will be the only institution in the United States where children can
participate in this treatment trial. The UI already is one of three hospitals
nationwide offering the treatment to adults with neuroendocrine tumors such
The approach involves adapting a radioactive imaging method used to diagnose
nervous tumors for use as a treatment that involves tumor-targeted radiation.
Both the diagnostic test and the new therapy have been approved by the Food
and Drug Administration.
Over the next two years, UI investigators expect to treat up to 20 children
who have brain tumors such as meduloblastoma or peripheral nervous system
tumors such as neuroblastoma.
The treatment may have several advantages, said lead investigator M. Sue
O'Dorisio, M.D., Ph.D., UI Foundation Professor of Pediatrics and director
of the UI Division of Pediatric Hematology/Oncology.
"Children whose tumors have become resistant to chemotherapy may respond
to this radiation therapy. Previous research on adults shows that the treatment
has fewer side effects than other treatments," O'Dorisio said. "However,
children whose tumors do not 'light up' in the diagnostic test will not be
given the therapy and therefore not exposed to radiation that will not work
Previous research has shown that a particular hormone, somatostatin, is used
by both the central and peripheral nervous systems to regulate nerve growth.
The cancerous tumors also use this hormone.
Based on this knowledge, European researchers in the mid-1990s developed
a diagnostic test of the brain, spine, chest and other organs where tumors
might be located. The test involves adding a radioactive compound to a synthetic
version of the hormone, which then is given internally to a person. The radioactive
hormone is taken up by tumors at a much higher rate than by other tissues.
As a result, if tumors are present, they will appear in images as much brighter
areas than normal tissue.
Because this method was so successful in providing images of tumors for diagnostic
purposes, researchers decided to put a different type of radioactive compound
on the hormone in an attempt to deliver radiation therapy to tumors, O'Dorisio
"We can give a patient who has a tumor one form of the radioactive hormone,
then take a picture," O'Dorisio said. "If their tumor takes up the
hormone, then they may be eligible for the study and actually be treated with
the other radioactive form of the hormone."
The diagnostic technique is known as OctreoScan, and the treatment method
is known as OctreoTher.
O'Dorisio emphasized, "In both cases, it's the same hormone. However,
in one case it has a radioactive compound that is good for taking pictures,
and in the second case it has a radioactive compound that gives highly focused
Based on earlier studies performed in the laboratory of Sue O'Dorisio and
Thomas M. O'Dorisio, M.D., UI professor of internal medicine, approximately
95 percent of all neuroblastomas and 100 percent of all meduloblastomas take
up the hormone because they have somatostatin receptors.
To date, 12 adults with metastatic neuroendocrine and carcinoid tumors have
been treated at UI Hospitals and Clinics and the Veterans Affairs Medical
Center (VAMC) in Iowa City by Thomas O'Dorisio, who also is a VAMC researcher
and staff physician, and David Bushnell, M.D., UI associate professor of radiology.
Sue O'Dorisio said there have been no serious side effects, and some improvement
in symptoms and tumor shrinkage has been seen in these patients to date. However,
the researchers caution that the study is in early stages, and no analysis
of either toxicity or efficacy can be made at this time.
The immediate goal in the new UI study involving children is to determine
the dosage at which side effects remain low; therefore, only children who
have failed other treatments will be eligible.
However, if side effects are low, researchers hope eventually to treat children
who are newly diagnosed with a neuroblastoma or a meduloblastoma, in conjunction
with other chemotherapy or radiation therapy, O'Dorisio said.
She added, "The hope is we'll be able to use lower doses of therapy
if we can treat the children immediately after diagnosis."
All patients in the study will be referred by physicians. Novartis, which
supports the Phase II adult study at the UI, will provide the radioactive
hormone drug for the study, and the National Cancer Institute will pay other
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