CHICAGOAmong patients with intractable and severe pain because of bony
metastases, radiofrequency ablation either relieved pain completely or
produced a significant reduction in patients’ assessment of pain, according
to a study presented at the 88th Scientific Assembly and Annual Meeting of
the Radiological Society of North America (RSNA abstract 228VI-p). In this
multicenter study of 62 patients with osteolytic metastases, 44% reported
they were completely free of pain at some point during the 6 months following
radiofrequency ablation, 81% had a 3-point drop in the Brief Pain Inventory
(BPI), and 95% had at least a 2-point drop in BPI.
"Many studies have shown that a drop in pain score of 2 points is
significant. We are seeing drops of 4 points, which is a very large decrease
in patients who really have no alternatives," said Matthew R. Callstrom, MD,
PhD, assistant professor of radiology, Mayo Clinic, Rochester, Minnesota.
One patient with rectal carcinoma that had spread to the sacrum was unable
to sit upright or lie down before radiofre-quency ablation. Immediately after
initial treatment, which involved seven separate needle placements in the
inferior portion of the lesion, his mean pain score dropped from 8 to 3.
After further ablation of the upper portion of the sacral lesion, the mean
pain score dropped to 0, and he experienced no other pain during 6 months of
"The critical thing here is that the patient went from high doses of
narcotics and no other optionshe had explored radiation and chemotherapy,
but nothing workedto a very effective treatment. This was able to take away
his pain," Dr. Callstrom said.
Radiofrequency ablation spared a 29-year-old woman with metastasis to the
shoulder four-quarter amputation. Among seven patients who died during the
follow-up period, the procedure produced such a significant reduction in pain
that four patients were able to spend their last months enjoying time with
their families without being totally obtunded by narcotics, Dr. Callstrom
In addition to pain relief, the study showed that radiofrequency ablation
is safe. There were four major complications followed radiofrequency ablation
of osteolytic lesions. One patient sustained a fracture of the hip 6 weeks
after treatment. The patient already had a large destructive lesion in the
area of the fracture, so it was not clear if the fracture was due to
radiofrequency ablation or would have occurred eventually anyway. Three other
patients had tumor extending through a fistula below the level of the
tailbone. An additional patient developed minor bowel and bladder
incontinence, which resolved over a number of weeks.
As Dr. Callstrom explained, radiofrequency ablation delivers
high-frequency energy via an electrode that is placed in a lesion to destroy
cancer cells and in the process alleviate pain. The radiofrequency device,
which is inserted through a small incision in the skin, deploys a series of
tines into a lesion under guidance by CT or ultrasound and directs current
into targeted areas around a metastatic lesion for 5 to 10 minutes.