LOS ANGELESPET has arrived! Edward Coleman, MD,
said at a press conference held during the 46th annual meeting of the
Society of Nuclear Medicine. Dr. Coleman, professor of radiology and
director of the Nuclear Medicine Division, Duke University Medical
Center, noted that PET has expanded tremendously into the
clinical environment. He attributes this to the development of
fluorodeoxyglucose (FDG) PET imaging and PETs growing
applications in oncology.
According to Dr. Coleman, there were about 50 US centers offering PET
2 to 3 years ago, whereas today there are more than 300. Furthermore,
the number of patients having PET scans has doubled in the last 2
years, from 25,000 to almost 50,000 in 1998, and this number is
PET has proved to be accurate and cost effective in
diagnosing the most common and deadly cancers, and is now available
to more patients because the Health Care Financing Administration
(HCFA) and other third-party payers are paying for additional
indications, he said. On July 1, 1999, HCFA added three new
indications for FDG-PET imaging: evaluation of recurrent colorectal
cancer, staging of lymphoma, and detection of recurrent melanoma.
Dr. Coleman believes that PET is becoming the gold
standard for diagnosing cancer and other illnesses. He said
that PET is more accurate not only diagnostically but also in
determining the distribution of the disease. Clinical PET finds
cancers missed by other diagnostic tools, Dr. Coleman said.
If you more accurately diagnose a patient, you can better treat
that patient, and you would certainly expect better survival.
Finding the Sentinel Node
Lymphoscintigraphy is another imaging procedure not exactly
brand new to nuclear medicine that is receiving increased
attention as physicians learn to use it to refine and direct cancer
therapy, Robert Henkin MD, professor of radiology, Loyola University
Medical Center, Chicago, said at the press conference.
Lymphoscintigraphy is growing tremendously right now. Two
to 3 years ago at our institution, we were doing approximately one a
month, and now we do up to two or three a day, Dr. Henkin said.
The best treatment for involved lymph nodes is surgical
removal. But youve got to be able to know which patients need
to have the nodes removed, and thats the goal of this
Lymphoscintigraphy maps the drainage of the lymph nodes from the
region of the tumor, he said. A small amount of radiotracer is
injected around the tumor; the first lymph node that can be detected
with a gamma camera and a hand-held probe is most often the sentinel node.
Traditionally, the surgeon has not known which lymph node is
the correct node to be removed for biopsy, Dr. Henkin said.
As a result, the surgeon removes all the lymph nodes, the
complications of which are not trivial.
He cited a Dutch study in which predicting the location of the first
draining node based on anatomy alone produced an error rate of about
20%. That means that 20% of patients who do not undergo
lymphoscintigraphy may be under- or overtreated, he said.