The Future
that the new probes to be used in the operating
theatre environment will combine the present
probe merits of convenience and portability with
the features associated with imaging. Work is in
progress on imaging probes able to detect not just
gamma rays (as for the technology described in
this book) but also beta-emitting radionuclides,
and both endoscopic and surgical probes have
been developed. Another important area of pro-
gress is in the design of probes which minimise the
effect of background radiation, which can hamper
the successful identification of small volumes
of tumour. Dual-energy imaging may also help
in the detection of more superficial or deeper
lying abnormalities. Sub-millimetre resolution has
already been achieved, but the ultimate resolu-
tion will be imposed by the characteristics of the
collimators used.
Optical Biopsy Probes
Elastic scattering spectroscopy is also under devel-
opment as a means to obtain spectral imprints of
tissue. An optical biopsy probe is under develop-
ment – white light is passed through an optical
fibre placed on the tissue under examination and
the back-scattered elastic light is then analysed.
Different tissues do exhibit different spectra. It
would be possible to use this device in conjunction
with sentinel node detection devices and obtain
instant optical read-outs of the tissue character-
istics of a number of sentinel nodes (Fig. 1).
Radiopharmaceuticals
At present all tracers used in the detection of
the sentinel node demonstrate passive mecha-
Introduction
It is clear that significant developments will take
place, on a wide front, in the fascinating field of
sentinel node detection. At the very least this will
lead to renewed interest in the study of the lym-
phatics in health and in disease.With the improved
imaging techniques at our disposal and with better
and more stable radiopharmaceuticals, the detail-
ed study of patterns of lymph drainage and the
mapping of lymph node basins will gain renewed
focus. Much has been learned from the initial
efforts of many and we now understand better the
conditions which must be met in order to obtain
reproducible and physiologically meaningful data.
Further understanding the role of the lymphatic
system in man will help to clarify the mechanisms
and conditions which preside over the spread of
disease and will also help to stratify patients more
accurately into groups at high,low or intermediate
risk.Developments are expected in most if not
all of the areas covered in this text, and in this
summary it will not be feasible to detail all the
possible avenues of progress. Some are described
below.
Radiation Detector Technology
Since radiation detectors are used widely in medi-
cine, important groups within both academia and
industry are dedicated to the development of new
technology with improved imaging and detection
characteristics. New radiation detector materials
are being not just bench but also patient tested,
and the past few years have been particularly excit-
ing. New technology will develop on a broad basis,
but it is to be expected that imaging and external
detection will be combined and miniaturised such
chapter
14
