Percutaneous radiofrequency ablation of osteoid osteoma

Current trends in treatment of osteoid osteoma with an emphasis on radiofrequency ablation

This article reviews current trends in the treatment of osteoid osteoma with an emphasis on the evolving use of radiofrequency thermoablation as a primary definitive treatment and for recurrent and residual lesions. In so doing, the article reviews merits and relative disadvantages of both surgical and non-surgical imaging-guided techniques in treatment. Radiofrequency ablation of osteoid osteoma is a highly effective, efficient, minimally invasive and safe method of treating osteoid osteoma. Clinical success range from 76 to 100%. Surgery remains the standard treatment in cases where histology of the lesion is in doubt, neurovascular structures are within 1.5 cm or in repeated failure of any other minimally invasive ablative technique or percutaneous resection. Clinical success of surgery ranges from 88 to 100%. Laser interstitial thermal therapy shares many of the advantages and much of the success of radiofrequency thermoablation but has not been as available. Clinical success ranges from 87 to 100%. Cryotherapy, ethanol therapy and imaging-guided excision remain second-line therapies. Clinical success ranges from 77 to 100% for imaging-guided resection and 100% for ethanol therapy.

Minimally invasive surgery for ablation of osteoid osteoma of the spine

STUDY DESIGN

Compare the effectiveness of two different techniques for the management of osteoid osteoma of the spine.

OBJECTIVE

To describe the technique, feasibility, and indications of two different minimally invasive surgical methods for the treatment of osteoid osteoma of the spine.

SUMMARY OF THE BACKGROUND DATA

Current treatment of osteoid osteoma of the spine is usually conventional surgical excision. The successful treatment of osteoid osteoma of the appendicular skeleton by percutaneous radiofrequency probe ablation is known; however, there have been only a few cases reported utilizing this method to treat osteoid osteoma of the spine. The high success rate of percutaneous transpedicle vertebral biopsy and diskectomy led us to believe this technique can also be applicable for the treatment of osteoid osteoma of the spine.

METHODS

Two patients with symptomatic osteoid osteoma of the spine underwent two different surgical managements with local anesthesia. In one patient, the osteoid osteoma was localized in the apex of the right L4 superior articular process joint. Under computed tomography guidance he underwent radiofrequency coagulation with the use of a radiofrequency generator at 90 degrees for 240 seconds. The lesion in the second patient was located in the right pedicle of the T9 vertebra close to the exiting nerve root and was cored out by means of a special percutaneous instrument designed for percutaneous biopsy under fluoroscopic guidance.

RESULTS

Both patients experienced immediate relief of pain, resumed their regular activities, and also remained free of symptoms after the 2.5- and 3-year follow-up.

CONCLUSION

Minimally invasive surgery can successfully be applied in the treatment of osteoid osteoma of the lumbar spine. When the nidus is not adjacent to the neural elements radiofrequency thermal ablation can be an effective and safe treatment of osteoid osteoma in the spine.

Osteoid osteoma: percutaneous treatment with radiofrequency energy

PURPOSE

To report our experience with technical success, complications, and long-term clinical success of radiofrequency (RF) ablation of osteoid osteoma.

MATERIALS AND METHODS

After needle biopsy, computed tomography (CT)-guided percutaneous RF ablation was performed with general or spinal anesthesia. With an RF electrode, the lesion was heated to 90 degrees C for 6 minutes. Patient age and sex, lesion size and location, biopsy results, and complications were recorded. Clinical success was assessed at a minimum of 2 years after the procedure. Significance of patient age and sex and lesion location and size as a predictor of biopsy result was tested by means of chi2 analysis. In addition, effects of patient age and sex, lesion location and size, and biopsy results on clinical success were tested with the Fisher exact test.

RESULTS

During an 11-year period, 263 patients who were suspected of having osteoid osteoma underwent 271 ablation procedures. All procedures were technically successful. There were two anesthesia-related complications (aspiration, cardiac arrest) and two minor procedure-related complications (cellulitis, sympathetic dystrophy). Results at biopsy were positive in 73% (197 of 271 biopsies). Two-year follow-up data were available for 126 procedures. The other procedures had been performed more recently or the patients could not be contacted. There was complete relief of symptoms after 112 of the 126 procedures (89%). For procedures performed as the initial treatment, the success rate was 91% (107 of 117 procedures). Procedures for recurrent lesions had a significantly lower success rate (six of 10 procedures [60%], P <.001). Clinical outcome was not dependent on biopsy result, patient age or sex, or lesion size or location.

CONCLUSION

CT-guided percutaneous RF ablation of osteoid osteoma is a safe and effective technique.

MR imaging-guided laser ablation of osteoid osteomas with use of optical instrument guidance at 0.23 T

The purpose of this study was to determine the feasibility and features of low-field MR imaging in performing interstitial laser ablation of osteoid osteomas. Between September 2001 and April 2002, five consecutive patients with clinical and imaging findings suggesting osteoid osteoma and referred for removal of osteoid osteoma were treated with interstitial laser treatment. A low-field open-configuration MRI scanner (0.23 T, Outlook Proview, Philips Medical Systems, Finland) with optical instrument guidance hardware and software was used. Laser device used was of ND-Yag type (Fibertom medilas, Dornier Medizin Technik, Germany). A bare laser fiber (Dornier Medizin Technik, Germany) with a diameter of 400 microm was used. Completely balanced steady-state (CBASS; true fast imaging with steady precession) imaging was used for lesion localization, instrument guidance, and thermal monitoring. A 14-G (Cook Medical, USA) bone biopsy drill was used for initial approach. Laser treatment was conducted through the biopsy canal. All the lesions were successfully localized, targeted, and treated under MRI guidance. All the patients were symptom free 3 weeks and 3 months after the treatment. There was one recurrence reported during follow-up (6 months). The MRI-guided percutaneous interstitial laser ablation of osteoid osteomas seems to be a feasible treatment mode.

Basic and clinical studies of percutaneous radiofrequency ablation of osteoid osteoma using a standard electrosurgical generator

For percutaneous radiofrequency ablation of osteoid osteoma for pain management, we used a standard electrosurgical generator instead of the radiofrequency generator system. First, we used the standard electrosurgical generator to determine the diameter of the coagulated area of normal femurs and humeruses of dogs under general anesthesia and to detect damage to normal tissue around the bone. We then used a standard electrosurgical generator to perform percutaneous radiofrequency ablation of the osteoid osteoma. All three patients were almost pain-free within the first 24 h after the procedure, and they were discharged the day after the operation, being hospitalized for only 2 days. We thus confirmed that percutaneous radiofrequency ablation using a standard electrosurgical generator produced results similar to those achieved with the radiofrequency generator system.

The diagnostic and therapeutic challenge of femoral head osteoid osteoma presenting as thigh pain: a case report

Osteoid osteoma, an infrequent but important cause of musculoskeletal pain, is often difficult to diagnose. We present a case of a 31-year-old man who, for 2 years, had left groin pain radiating to the thigh. Symptoms began 1 month after a motorcycle crash in which he sustained only shin abrasions. Initial spine and hip radiographs were negative. Treatment with naproxen provided significant relief, but the symptoms gradually worsened over 6 months. An electromyogram and lumbar magnetic resonance imaging (MRI) of the left lower leg were unremarkable. Hip MRI revealed edema without fracture. Prophylactic femoral pinning for impending stress fracture provided no relief. Rheumatologic evaluation revealed normal serologies and synovial fluid. Cyclobenzaprine and sulfasalazine were started and provided mild relief. At presentation to our institution, he was in significant discomfort, but could ride a bicycle for exercise and was completing a home exercise program. He had antalgic gait and globally restricted hip motion with end-range pain. A neurologic examination showed no abnormalities. Hip and pelvis computed tomography scan revealed increased sclerosis of the femoral head, with a central lucency suggestive of osteoid osteoma. This was confirmed by biopsy. Radiofrequency ablation provided significant symptom relief.

Heat distribution and heat transport in bone during radiofrequency catheter ablation

BACKGROUND

To assess the feasibility of percutaneous radiofrequency ablation in large bone tumours, the heat distribution in cortical bone and marrow around inserted electrodes was measured.

METHODS

Fresh bovine cadaver tibial bones were locally heated through drill holes for a maximum of half an hour using water-cooled single radiofrequency electrodes (Radionics Instruments Inc) by pulsed energy. Temperatures were measured in the marrow canal as well as in cortical bone by thermocouples at various distances from the inserted probes.

RESULTS

Perpendicular to the probe, hyperthermia of more than 50 degrees C could be created in bone marrow in a sphere of approximately 3 cm, and of approximately 1 cm in cortical bone.

CONCLUSION

As irreversible cellular damage can be expected when increasing the temperature to 50 degrees C for a duration of 6 min, this method may be effective for the minimal invasive ablation of neoplasms within human bone in cigar-shaped regions of approximately 3-cm diameter.

Image-guided percutaneous radiofrequency ablation for osteoid osteomas

The authors present a retrospective analysis of the technical and clinical successes, complications, and clinical follow-up of image-guided percutaneous radiofrequency (RF) ablation of osteoid osteomas. Nine patients with osteoid osteomas underwent image-guided localization of osteoid osteomas. Outpatient percutaneous therapy (13 procedures) was performed under general anesthesia after image-guided localization of the nidus. Initial technical success was achieved in seven of nine patients. Two initial technical and clinical failures occurred early in this experience because of failure to adequately enter the nidus with use of fluoroscopic imaging alone. Clinical success was achieved in eight of nine patients. No major immediate or delayed complications were observed.

Cortical lesions of the tibia: characteristic appearances at conventional radiography

Lesions that involve the cortex of the tibia are fairly common in radiology practice. However, the number of diseases that involve the tibial cortex is great, and it can be difficult to arrive at a limited differential diagnosis from radiographic findings. Categorization of lesions of the tibia into those that cause cortical destruction and those that cause cortical proliferation can help narrow the broad differential diagnosis. Lesions that cause cortical destruction include nonossifying fibroma, fibrous dysplasia, osteofibrous dysplasia, aneurysmal bone cyst, giant cell tumor, eosinophilic granuloma, Ewing sarcoma, neurofibromatosis, adamantinoma, osteoblastoma, chondromyxoid fibroma, hemangioendothelioma, renal cell metastatic disease, hemangioma, and hemangiopericytoma. Lesions that cause cortical proliferation include osteochondroma, stress fracture, osteoid osteoma, periosteal osteogenic sarcoma, diaphyseal dysplasia, venous stasis, cellulitis, chronic osteomyelitis, osteopathia striatum, and melorheostosis. Conventional radiography along with clinical and pathologic data can aid in diagnosis of the wide variety of disease processes that involve the tibial cortex.

Femur: MR imaging-guided radio-frequency ablation in a porcine model-feasibility study

PURPOSE

To determine the feasibility of magnetic resonance (MR) imaging-guided and -monitored radio-frequency (RF) ablation of bone.

MATERIALS AND METHODS

Seven femurs were treated in five pigs with use of a 0.2-T open MR imager. An 11-gauge bone marrow needle was percutaneously inserted into the distal femur metaphysis with MR fluoroscopy (fast imaging with steady-state precession, or FISP, sequences) to introduce an RF electrode into the bone with further image guidance. Thermal ablation was performed for 10 minutes (90 degrees C +/- 2 [mean +/- SD]). MR follow-up was performed immediately after ablation and again at 7 and 14 days after the procedure (with contrast material-enhanced T1-weighted, T2-weighted, and fast short inversion time inversion-recovery, or STIR, sequences). The animals were sacrificed at day 14. The femurs were sliced, decalcified, and stained. Image analysis was performed to measure lesion diameter and contrast-to-noise ratio (CNR) and to evaluate complications.

RESULTS

Technical success was obtained in all animals. The lesion diameter perpendicular to the electrode was 15.4 mm +/- 2.7. No significant complications were noted. The thermal lesions displayed low signal intensity with a sharp rim of high signal intensity. T2-weighted images demonstrated the highest CNR and the lowest error in predicting the lesion size immediately after ablation (2.7 mm +/- 1.3). Contrast-enhanced T1-weighted images demonstrated the highest accuracy at day 14 (1.0 mm +/- 1.0).

CONCLUSION

RF ablation of bone with MR imaging as the sole imaging modality is feasible and allows monitoring of the ablation.

Foot tumors: diagnosis and treatment

Several large clinical series have demonstrated that benign and malignant tumors occur in the foot and ankle at a much higher rate than previously thought. Vigilance is warranted in investigating any foot mass, including those with an apparently indolent course. Although tumors in the foot tend to produce symptoms relatively early because of the foot's compact structure, many tumors are initially misdiagnosed. Given the comparatively small size of the anatomic compartments in the foot, tumors often present outside the original compartment, making timely diagnosis essential. Major treatment errors can be avoided if physicians consider the potential for malignancy when evaluating all foot masses. A high index of suspicion, an organized approach to diagnosis, and evaluation of and adherence to the basic principles of treatment of musculoskeletal neoplasms increase the likelihood of acceptable results.

Osteoid osteoma: CT-guided percutaneous radiofrequency ablation and follow-up in 47 patients

PURPOSE

To evaluate computed tomography (CT)-guided radiofrequency (RF) ablation as a minimally invasive therapy for osteoid osteoma with regard to technical and clinical success and immediate and delayed complications.

MATERIALS AND METHODS

Forty-seven patients (age range, 8-41 y; mean age, 19.6 y) with osteoid osteomas (femur, n = 25; tibia, n = 15; pelvis, n = 2; humerus, n = 1; ulna, n = 1; talus, n = 1; calcaneus, n = 1; vertebral body, n = 1) were treated with CT-guided RF ablation in 15 cases after one (n = 10) or two (n = 5) unsuccessful attempts at open surgical resection. Percutaneous therapy was performed with use of general or spinal anesthesia. After localization of the nidus with 1-3-mm CT sections, osseous access was established with either a 2-mm coaxial drill system or an 11-gauge Jamshidi needle. RF ablation was performed at 90 degrees C for a period of 4-5 minutes with use of a rigid RF electrode with a diameter of 1 mm. The procedures were regarded as technically successful if the tip of the RF electrode could be placed within the center of the nidus and could be heated to the desired temperature. Clinical success of treatment was defined as permanent relief of pain and return to normal function without additional treatment. In case of persistence or recurrence of symptoms after RF ablation, treatment was regarded as secondarily successful if permanent relief of symptoms could be achieved in a second procedure.

RESULTS

All procedures were technically successful. Clinical success was achieved in 94% of patients (44 of 47). Three patients had recurrence of pain 3, 5, and 7 months after treatment, respectively (mean observation interval, 22 mo). All recurrences were treated successfully in a second procedure (secondary success rate, 100%). No immediate or delayed complications were observed.

CONCLUSION

CT-guided percutaneous RF ablation is a simple, minimally invasive, safe and highly effective technique for treatment of osteoid osteoma.