Using either a percutaneous, thoracoscopic, or open (thoractomy)
route, an RF needle electrode is advanced into the unresectable
lung tumor. Placement is guided by radiologic guidance
(3D Fluoroscopy, CT , thoracoscopy, or endoscopic ultrasound.
The advantage of Fluoroscopy with navigation is “real
time” guidance allowing needle electrode advancement
to the target tumor, thereby minimizing having to redirect
the needle for optimal placement into the tumor. This would
lessen complications of air leak or bleeding. The individual
tines then are deployed into the tissue to surround the
tumor. Following deployment, the tines are attached to
an RF generator, and four dispersive electrodes (return
or grounding pads) are placed on the patient, two on each
thigh. An established treatment algorithm is followed to
apply the RF energy (only Boston Scientific LeVeen needle
electrode has an established algorhythm for RF ablation
of lung tumors). The needle electrode is used to produce
a thermal lesion that incorporates not only the tumor,
but also nonmalignant lung parenchyma to create 1-cm-wide
zone surrounding the tumor, which mimics a surgical margin.
The resulting cystic-density lesion, as shown on computerized
tomography (CT) scans, usually is larger than the original
tumor; however, the size of this cystic area generally
decreases slightly over time.
• Using high resolution Fluoroscopic, Ultrasonic
or CT guidance, a radiofrequency electrode is inserted
into the tumor and an umbrella-shaped array is deployed
in the target tumor.
• The electrode is connected to a radiofrequency
• Power is applied
until tissue impedance (resistance to electrical current)
• Generator detects impedance rise and signals completion
In liver RFA, Arata found that in lesions with roll-off,
the local recurrence rate at 6 months was 15%, whereas
those treatments not reaching roll-off had a local recurrence
rate of 43%. The recurrence rates obtained by Curley et
al and Arata were lower than those reported in other studies,
which suggests that monitoring tissue impedance and use
of roll-off as a therapeutic endpoint may result in lower
rates of recurrence.
RFA Techniques compared Boston Scientific
1. Tissue desiccates gradually and eventually
loses its ability to conduct current.
2. Target lesion becomes resistant to current
3. Post RF Ablation cystic-density lesion is
formed which is usually larger than the original
tumor; however, the size of the cystic area decreases
slightly over time.
Most patients with primary
lung cancers and metastases to the lung are not candidates
for surgical resection. For treatment of primary lung tumors,
surgical resection remains the gold standard; however, relatively
few patients are candidates for surgery. For patients with
metastases to the lung and patients with lung malignancies
who are not candidates for resection, RFA may provide a relatively
safe, effective treatment to achieve local disease control.
RFA of lung tumors can be used to debulk tumors, possibly
increasing the efficacy of chemotherapy on remaining tumor
Monitoring tissue impedance and use of roll-off as a therapeutic
endpoint possibly could lead to lower rates of recurrence.
New metastases may appear in time so continued surveillance
is important. Retreatment may be beneficial in extending
• Radiofrequency ablation fills a need for addressing
nonresectable lung malignancies
• While continued evaluation is necessary, clinical
results to date seem favorable