|
>
Information for patients:
Osteoid osteoma is a benign tumor of the bone. This tumor is most frequently
found in the legs but may occur also at other bones in nearly any part of the
body. Osteoid osteoma is a tumor of children and young adults, it is very rare
in older adults over the age of 50.
top
Diagnosing an osteoid osteoma:
Osteoid osteoma causes a lot of pain in almost all patients. This pain is
most frequently in the night, and patients sometimes wake up from the pain.
The pain may also occur during the day. Sometimes the pain gets worse over time.
It may only be dull, but sometimes also very sharp and gets worse with activity.
Typically patients have relief of their pain with aspirin, ibuprofen or other
anti-inflammatory agents.
There may be a lot of inflammation around the tumor and the soft tissue around
the tumor may be painful or swollen. Sometimes even a lump may be felt.
top
Imaging of osteoid osteoma:
Imaging usually is very typical: X-rays show new bone formation
and sometimes a small lucent spot (smaller than 1.5 cm), which is defined as
the nidus. Computed tomography (cat scan, CT) is even better
suited to show the new bone formation and the nidus. Because there may be a
lot of inflammatory swelling and edema in the bone and soft tissues around the
tumor magnetic resonance imaging (MRI) may sometimes be difficult
to interpret and CT may be required to further assess these tumors. Radionuclide
or bone scans show increased uptake of the radioactive tracer, this
may sometimes be very focal.
Fig. 1: X-ray of an osteoid osteoma of the thigh (femur) with
increased bone formation and subtle lucency (arrow).
Fig. 2: CT scan of an osteoid osteoma of the thigh (femur),
a small, round lytic focus (arrow) surrounded by dense bone is demonstrated.
Fig. 3: Magnetic resonance image of an osteoid osteoma of
the thigh (femur). Increased bone formation (dark) surrounding a brighter spot
representing the nidus (arrow) of the osteoid osteoma.
top
Treating an Osteoid osteoma:
Osteoid osteoma is a benign tumor, it is not cancer, it does not spread do
other regions of the body and does usually not increase in size. In rare instances
this tumor even heals spontaneously. Therefore the tumor does not necessarily
have to be removed.
- Treating the pain:
The most significant symptom of osteoid osteoma is pain, this can be treated
with aspirin, ibuprofen or other over-the-counter anti-inflammatory drugs.
Some patients have relief from certain medications for a while, but then these
medications stop working. A change to another anti-inflammatory medication
may then be required.
It should, however, be considered that stomach ulcers, heartburn and bleeding
problems may develop from the use of anti-inflammatory medications.
- Treating with operation:
Surgical treatment has been the standard for a long time. However, for successful
surgery the tumor must be completely removed. Sometimes these surgeries are
quite extensive, require resection of large areas of bone and implantation
of bone grafts. These have a higher risk of complications and a longer recovery
period.
The operation usually entails a longer hospital stay of at least several days.
Osteoid osteomas are frequently located in weight-bearing bones and during
the recovery period from surgery a longer period of limited weight bearing
is required, often with crutches for a number of weeks.
- Treating minimal invasively with Radiofrequency Ablation (RFA):
Today the method of choice in many cases is radiofrequency ablation. During
this procedure the tumor is heated up for a period of approximately 6 minutes
and thus abladed. This procedure is minimal invasive, is done on an outpatient
basis and has a short recovery time.
Since the nidus of an osteoid osteoma is usually very painful, the procedure
is performed under general anesthesia.
The procedure can only be performed if the patient has the typical clinical
and imaging findings. The location of the osteoid osteoma should permit a
safe access and a safe heating/radiofrequency procedure without risking to
damage nerves, major blood vessels and the skin. If the tumor nidus is more
than 1 cm away from these structures the procedure can usually be safely performed.
The procedure takes approximately 2-3 hours including induction of general
anesthesia. After the procedure the patient is taken to the recovery room
and supervised by the anesthesiology team for approximately 4 hours. Patients
then are able to leave the hospital with a prescription of pain medication.
The RF ablation is performed under sterile conditions in the CT suite to optimally
localize the lesion. A thin biopsy needle, canula and drill needle are used
to access the osteoid osteoma (Fig. 4).
Fig. 4: A thin drill is placed in the osteoid osteoma nidus
(arrow).
Then the drill is removed but the canula is left inside and the RF-probe
is advanced through the canula into the nidus. The RF-probe is a straight
rigid electrode with an outer diameter of 1 mm and it is insulated throughout
its extent except the terminal 10 mm. The electrode is positioned in the center
of the lesion to coagulate a sphere of tissue of 1cm diameter with the tip
of the electrode at the center (Fig. 5).
Fig. 5: The RF-probe was placed in the nidus of the lesion
(arrow).
The electrode is connected to a radiofrequency generator. The electrode tip
is heated up to 85-90 C0 for 6 minutes. Subsequently the probe and canula
are withdrawn. There is usually no significant bleeding at the skin incision
site and a bandage is sufficient to cover the puncture site.
On the day of the procedure patients will have pain and pain medication is
required. In the following 72 hours pain will get better and after at least
one week patients usually are free of pain. Within the first 48 hours patients
usually will also be able to tell whether the typical tumor pain is gone.
Patients may return to work, school and other normal activities usually within
the first week after the procedure. Please note, however, if the tumor is
at a weight-bearing location (leg) sports, such as skiing, snowboarding, skate
boarding, long distance running and jumping should be avoided for period of
3 months.
Two follow-up visits are recommended, one after one month, and a second after
one year. These can be done by the patient’s doctor or orthopedist at
home.
It should be considered that recurrence rates of 10-20% have been described
and a second procedure may sometimes be required.
top
Summary of the advantages of RF-ablation
compared to surgery:
- rapid pain relief usually apparent within the first 2-3 days after the procedure,
- no overnight hospital stay,
- return to work, school and other normal activities usually within the first
week after the procedure, but no vigorous sports for 3 months,
- minimal damage to bones and muscle with no significant structural weakness,
- lower cost.
top
If you suffer from osteoid osteoma and are interested in being treated
at UCSF Medical Center
We would be delighted to see you, please contact:
Thomas M. Link, MD
Associate Professor of Radiology
Musculoskeletal
Section
Department of Radiology
400 Parnassus Ave, 3rd floor, ACC-Building
Phone: 415-353-8940
Fax: 415-476-0616
Email: tmlink@radiology.ucsf.edu
In order to assess whether you qualify for this procedure we need to confirm
your diagnosis of osteoid osteoma by reviewing the symptoms and the imaging
studies. The CT scan is in particular important for this purpose, it will also
help us to determine whether there is a safe needle access to the tumor without
damage viable structures such as nerves, vessels and skin.
We work together with our orthopedic tumor surgeon:
Richard O’Donnell, MD
Department of Orthopedic Surgery
1600 Divisadero St, 4th Floor Cancer Center, San Francisco
Phone: 415-885-3803
Fax: 415-885-3802
Email: StevensonC@orthosurg.ucsf.edu
He will be happy to review your symptoms and talk to you about the nature of
treatment procedures including the availability of alternative treatments and
the probability of success.
Dr. O’Donnell also has a highly qualified staff that is experienced at
dealing with insurance issues. In addition you may need a referral from your
local doctor.
Prior to the intervention you will also need to be seen by our anesthesiologists
in order to prepare for the anesthesia performed during the procedure.
A requirement for the procedure are also blood tests: parameters of the coagulation
of the blood (PT, PTT, INR) as well as a complete blood count including thrombocytes.
These blood tests are important to detect any abnormalities of blood clotting,
which may be a risk for this procedure.
top
|
