A FULLER PICTURE:
The Transformative Potential of Total-body PET
BY THOMAS CROCKER
IMAGE
COURTESY
OF
MARTIN
JUDENHOFER,
UC
DAVIS
PE T Ÿ ONE OF THE MOST IMPORTANT TOOLS IN CLINICIANS' ARMAMENTARIUM FOR CANCER
DIAGNOSIS, STAGING AND THER APY E VALUATION Ÿ HA S A SIGNIFICANT LIMITATION: IT CAN SCAN
ONLY A PORTION OF THE BODY AT A TIME. THAT MAY CHANGE SOON, WITH WIDE IMPLICATIONS FOR
RESE ARCH AND CLINICAL PR ACTICE.
T Y P I C A L LY C O M B I N E D W I T H C T,
PET detect s t he photon sig na l f rom
a radioactive tracer a nd its i nterac-
tion with a ta rget orga n. The sca nner
uses the sig na l to create images of the
organ and related processes, such as its
cells' absorption of glucose. How these
cellula r processes unfold provides key
clues to a ca ncer's presence a nd ex tent,
a s wel l a s to its response to t herapy.
PET can disting uish between lesions in
ways CT a nd MR I ca nnot, according to
Paula Jacobs, PhD, Associate Director
of the Nationa l Ca ncer Institute (NCI)
D iv i sion of Ca nc er T r e a t ment a nd
Diag nosis Ca ncer Imag ing Prog ra m.
"Neither [CT nor MR I] ca n tell if a
lesion is metabolically active," Jacobs
says. "One specifi c example is lung lesions.
A lesion may look much the same on CT
if it's benign, infectious or cancer, but
it will appear quite di€ erent on ... PET."
In spite of its uti lit y a s a clinica l
tool, PET is plagued by a fundamental
problem, says Simon Cherry, PhD, a radi-
ologist and Distinguished Professor of
Biomedical Engineering at the University
of California, Davis.
" The way we cur rent ly col lect our
dat a [usi n g PET] i s ver y i nef f icient
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