Lung cancer remains a leading
cause of cancer death worldwide, with approximately
90% of cases related to smoking. In the United
States alone, approximately 173,000 new cases
of lung cancer were diagnosed in 2004. Advances
in technology and medical imaging are allowing
identification of more patients with early
stage lung cancer than ever before. Despite
these advances, approximately 160,000 Americans
will die of lung cancer this year, representing
approximately 28% of cancer deaths in the
United States. More Americans will die of
lung cancer than from breast, prostate and
colon cancers combined. Utilization of the
best current technology results in an overall
five year survival rate of lung cancer of
about 15%. Because of the low survival rate,
new chemotherapy agents and in particular,
newer technologies are being integrated into
treatment regimens.
Radiofrequency
Ablation
Radiofrequency ablation
(RFA) is one of the newest technologic concepts,
the clinical applications of which continue
to be developed. In some cases it has advantages
over traditional chemotherapy and radiation
therapy, but can also be used in conjunction
with these more traditional treatment options,
as is often done at the Upper Michigan Cancer
Center of Marquette General Health System,
to enhance patient survival and improve quality
of life.
Surgical removal of a lung tumor has been
and will continue to be the standard of care
in the treatment of lung cancer. Unfortunately,
not all patients are candidates for surgical
removal of tumor, possibly due to spread to
lymph nodes or because of illness such as
heart or kidney disease which would not allow
them to tolerate open surgery. While RFA has
many properties similar to surgery, it is
a relatively new technology.. However, while
long term studies of its effectiveness are
only now underway, early studies do show some
promise of outcomes very similar to surgical
removal of early stage lung cancers.
Image guided RFA may be able to be used in
these patients for two purposes. One would
be for definitive therapy and in a few cases,
possible cure of the tumor, where there has
been no spread of tumor to lymph nodes or
other organs. A second option would be “palliative”
treatment, where RFA is not intended for cure
but is utilized as an adjunct - for shrinkage
of tumor before chemotherapy or radiation
therapy, to reduce symptoms related to tumor
growth such as chest pain or shortness of
breath, to reduce pain in cases where tumor
has spread, or to slow regrowth of tumor in
patients who have had previous radiation therapy
or surgery and cannot be retreated.
Figure 1 –
Ablation probe
A
B
C
Figure 2 –
68 year-old gentleman with lung
tumor (arrow). CAT scan shows
probe in place (B). Follow-up
CAT scan 3 months later shows
a small residual scar. Close follow-up
is always needed after RFA to
monitor for tumor regrowth or
new tumor formation.
RFA is not suitable in all patients who have
lung cancer. Surgical removal remains a mainstay
of treatment when possible. If tumor spread
to lymph nodes and other organs is too extensive,
there may also be no role for RFA due to little
chance of increased survival or improvement
in symptoms. In some of these cases, chemotherapy
or radiation therapy, or some combination
of treatment options, may offer benefit to
patients.
Radiofrequency ablation if usually performed
as a short-stay procedure. Patients are usually
admitted the day of the procedure and are
discharged to return home the morning following
the procedure. Utilizing anesthesia, most
patients are placed asleep for the procedure.
During the procedure, a special ablation needle
(figure 1) is advanced through the skin in
to the lung, similar to a biopsy procedure.
Using CAT scan guidance, the needle is directed
toward and advanced into the tumor. An electric
current is then applied to the needle, resulting
in heating of the tumor cells around the needle
and eventual cell death. Depending on the
size and configuration of the tumor, several
needle placements may be required in a single
session, in an attempt to achieve maximal
desired tumor death.
At the conclusion of the procedure, the needle
is removed and a bandage placed. There are
no incisions or sutures. Risks of the procedure
are small. Rare complications include bleeding
and infection. The most common complication,
occurring in about 10-15% of cases, is some
degree of lung collapse (pneumothorax). In
the great majority of cases, collapse is minimal
and requires no treatment. A minority of cases
do require placement of a small catheter through
the chest wall to allow air to escape and
the lung to re-expand, the tube typically
being removed the following morning.
Patients are usually seen in the interventional
clinic 3-4 weeks after the procedure. Like
any cancer treatment, patients that undergo
RFA require close follow-up examination and
typically, CAT scan or MRI imaging is performed
at 3 month intervals for at least one year.
One advantage of RFA is the ability to perform
repeat ablations, if necessary, for tumor
recurrence. Previous ablation does not significantly
limit the ability to repeat the ablation procedure.
If necessary, ablation can often be repeated
on several separate occasions.
