Unusually located osteoid osteomas

The files of 12 patients (aged 12–33 years) with an equal number of surgically proven osteoid osteomas (OOs) were reviewed in attempt to find a diagnostic algorithm in cases of unusually located OOs. Plain radiography (PR) and thin collimation computed tomography (CT) had been performed in all patients, while bone scintigraphy (BS) had been performed in eight and magnetic resonance imaging (MRI) in two. The OOs were located at juxta- or intra-articular sites, except for one located at the left neck of the L₄ vertebra. The diagnosis based on the MRI examinations was synovitis. BS showed increased accumulation of the radioisotope at the site of the lesions, without the ‘double density’ sign. PR showed the nidus of OO in only six patients, whereas CT located the nidus in all patients. In conclusion, we believe that when an OO is clinically suspected at an unusual location, CT should be performed in all cases, even when a lesion is depicted by PR and BS, because CT will not only locate the nidus but will also provide a precise anatomy of the area around the nidus and help in therapeutic decision making and surgical planning. MRI can be misleading and must not be used in the initial assessment of a possible osteoid osteoma.     

Computed tomography of axial skeletal osteoid osteomas

The CT features of a case of adult ileocolic intussusception and of experimentally induced ileocolic, cecocolic, and colocolic intussusceptions are presented. Both the clinical and experimental cases demonstrated (1) "target" masses with enveloped, eccentrically located areas of low density and (2) interspersed low- and high-density stripes within the intussusception producing a "layered" or "stratified" pattern. This layered pattern of abdominal masses may be characteristic of intussusceptions regardless of location.     

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.     

Percutaneous removal of osteoid osteomas using CT control

A method is described whereby an osteoid osteoma may be conveniently removed on an outpatient basis, using a bone biopsy drill and CT control.     

Didactic review of 175 radionuclide-guided excisions of osteoid osteomas

The complete removal of a lesion which resembles, or is covered by adjacent tissue may be difficult. Therefore, the capacity of certain lesions to specifically concentrate a radiopharmaceutical has been used to orient progress during surgery. Usually, the measurements of radioactivity in the operative field are carried out by means of small, handy radiation-detecting probes which can be sterilized. Intra-operative nuclear medicine or radionuclide-guided surgery has steadily gained in importance. However, this technique is not being taught. Our study, based on radionuclide-guided surgery of 175 orthopaedic patients suspected of having osteoid osteoma, is well suited to teach the particularities of intra-operative radiation detection, as well as the collaboration between the nuclear physician and the surgeon in the operating theatre.Part of this work was carried out when M.W. and A. S.-A. were at the Saint-Antoine (Paris) and Henri Mondor (Créteil) hospitals respectively.     

Computed tomography in suspected osteoid osteomas of tubular bones

Six cases of suspected osteoid osteoma of tubular bones were evaluated by computed tomography (CT). In all cases a radiolucent nidus was clearly demonstrated. In two cases a radiodense center of the nidus was visualized. It is suggested that CT may replace conventional tomography in the evaluation of these lesions. Due to its ability to locate the lesion in the transverse plane, CT is superior for the exact planning of surgery to avoid unnecessary large or misdirected resections. Adequate window settings are essential in the evaluation of these lesions.     

Percutaneous laser photocoagulation of osteoid osteomas under CT guidance

AIM: The aim was to evaluate laser photocoagulation and the use of the Bonopty needle system in the treatment of osteoid osteoma. MATERIALS AND METHODS: Five patients with osteoid osteomas were treated with computed tomography (CT)-guided, percutaneous laser photocoagulation using the Bonopty biopsy system. RESULTS: Complete pain relief was obtained in four patients. In one patient, pain persisted until the 6 weeks follow-up but resolved within 24 h of repeating the procedure. There were no complications, and patients remained symptom free at follow-up of 4-23 months (mean, 14 months). CONCLUSION: CT-guided laser photocoagulation of osteoid osteoma is a minimally invasive technique that represents a cost-effective alternative to surgical excision. The Bonopty needle system allows successful penetration of the sclerotic bone surrounding the nidus with manual pressure alone.     

Radiofrequency ablation for non-spinal osteoid osteomas in 557 patients

Objectives  

To present the results of biopsy and computed tomography (CT) guided radiofrequency ablation (RFA) for non-spinal osteoid osteomas, and compare the results before and after procedural modifications.     

557例非脊柱骨样骨瘤病人的射频消融治疗

目的描述非脊柱骨样骨瘤活检和CT引导下射频消融的结果,并比较程序修改之前和之后的结果。方法回顾性分析557例行活检和CT引导下射频消融治疗的非脊柱骨样骨瘤病人。68例病人行CT扫描,层厚3mm,间距2mm,     

Percutaneous radiofrequency thermocoagulation of osteoid osteomas: factors affecting therapeutic outcome

Objective To examine factors which affect local recurrence of osteoid osteomas treated with percutaneous CT-guided radiofrequency thermocoagulation.Design and patients A prospective study was carried out on 45 patients with osteoid osteoma who underwent percutaneous radiofrequency thermocoagulation with a minimum follow-up of 12 monthsResults There were seven local recurrences (16%); all occurred within the first year. Local recurrence was significantly related to a non-diaphyseal location (P<0.01). There was no significant relationship (P=0.05) between local recurrence and age of the patient, duration of symptoms, previous treatment, size of the lesion, positive biopsy, radiofrequency generator used or the number of needle positions. There were no complications.Conclusions Osteoid osteomas in a non-diaphyseal location are statistically more likely to recur than those in a diaphyseal location when treated with CT-guided percutaneous radiofrequency thermocoagulation. This relationship between local recurrence and location has not been previously reported.     

CT-guided percutaneous laser photocoagulation of osteoid osteomas of the hands and feet

Percutaneous local ablation of osteoid osteoma has largely replaced surgery, except in the small bones of the hands and feet. The objective of this study was to describe the technical specificities and results of computed tomography (CT)-guided percutaneous laser photocoagulation in 15 patients with osteoid osteomas of the hands and feet. We retrospectively examined the medical charts of the 15 patients who were treated with CT-guided percutaneous laser photocoagulation therapy at our institution between 1994 and 2004. The 15 patients had a mean age of 24.33 years. None of them had received any prior surgical or percutaneous treatment for the osteoid osteoma. The follow-up period was 24 to 96 months (mean, 49.93). The pain resolved completely within 1 week. Fourteen patients remained symptom-free throughout the follow-up period; the remaining patient experienced a recurrence of pain after 24 months, underwent a second laser photocoagulation procedure, and was symptom-free at last follow-up 45 months later. No adverse events related to the procedure or to the location of the tumor in the hand or the foot were recorded. CT-guided percutaneous laser photocoagulation is an alternative to surgery for the treatment of osteoid osteomas of the hands and feet.     

Role of radionuclide imaging in osteoid osteoma.

Radiophosphate bone scans readily disclosed osteoid osteomas in 20 symptomatic patients, including nine patients whose radiographic findings had been negative. In five of the nine patients adjuvant radiogallium imaging was performed, and four showed a disproportionately low uptake relative to radiophosphate. When this occurs, osteoid osteoma can be distinguished from subacute osteomyelitis, which is particularly helpful if the radiograph is equivocal. Radiophosphate bone imaging's generally accepted excellent sensitivity in disclosing obscure symptom-producing focal bone disorders makes it the screening procedure of choice, especially if osteoid osteoma is considered in the differential diagnosis. Only abnormal areas need to be radiographed to add specificity and more precise delineation.     

Ablation of osteoid osteomas with a percutaneously placed electrode: a new procedure.

Osteoid osteoma is a benign, self-limited tumor of bone that usually requires surgical excision for relief of pain and to prevent long-term consequences. Radio-frequency electrodes have been successfully and safely used to ablate small areas of the central nervous system and to perform ablation elsewhere in the body. The authors have used this technique in four patients with proved or presumptive osteoid osteoma, completely relieving the symptoms in three.     

CT-guided radiofrequency ablation of spinal osteoid osteomas with concomitant perineural and epidural irrigation for neuroprotection

Here we report our experience of a neuroprotective adaptation of the technique of CT-guided radiofrequency (RF) ablation of spinal osteoid osteomas. Over 9 years seven patients underwent eight CT-guided RF treatments for osteoid osteoma. CT-guided RF ablation was performed with general anaesthesia. The lesion was heated to 90°C for 2 min for two cycles by using a Cosman SMK TC-10 RF electrode. This was preceded by a bolus of room temperature sterile water (10 ml) injected through a 26G curved spinal needle into the exit foramen and adjacent epidural space for neuroprotection. The age of the patient, sex, lesion location, biopsy results and complications were recorded. All the biopsies (n = 7) demonstrated histological features of osteoid osteoma. All the procedures were technically successful. Clinical success was assessed up to 3 years post procedure. There was an 85% clinical success rate (6 of the 7 patients), with recurrence of a lesion at 6 months, necessitating a repeat procedure (successful). CT-guided percutaneous RF ablation of spinal osteoid osteoma preceded by bolus of sterile water, injected through a spinal needle into the exit foramen and adjacent epidural space for neuroprotection, is a safe and effective procedure.     

The healing pattern of osteoid osteomas on computed tomography and magnetic resonance imaging after thermocoagulation

Objective To compare the healing pattern of osteoid osteomas on computed tomography (CT) and magnetic resonance imaging (MRI) after successful and unsuccessful thermocoagulation. Materials and methods Eighty-six patients were examined by CT and 18 patients by dynamic gadolinium-enhanced MRI before and after thermocoagulation for osteoid osteoma. Thermocoagulation was successful in 73% (63/86) and unsuccessful in 27% (23/86) of patients followed by CT. Thermocoagulation was successful in 72% (13/18) of patients followed by MRI. After treatment, the healing of the nidus on CT was evaluated using different healing patterns (complete ossification, minimal nidus rest, decreased size, unchanged size or thermonecrosis). On MRI the presence of reactive changes (joint effusion, “oedema-like” changes of bone marrow and soft tissue oedema) and the delay time (between arterial and nidus enhancement) were assessed and compared before and after thermocoagulation. Results Complete ossification or a minimal nidus rest was observed on CT in 58% (16/28) of treatment successes (with > 12 months follow-up), but not in treatment failures. “Oedema-like” changes of bone marrow and/or soft tissue oedema were seen on MR in all patients before thermocoagulation and in all treatment failures. However, residual “oedema-like” changes of bone marrow were also found in 69% (9/13) of treatment successes. An increased delay time was observed in 62% (8/13) of treatment successes and in 1/5 of treatment failures. Conclusion Complete, or almost complete, ossification of the treated nidus on CT correlated with successful treatment. Absence of this ossification pattern, however, did not correlate with treatment failure. CT could not be used to identify the activity of the nidus following treatment. The value of MR parameters to assess residual activity of the nidus was limited in this study.     

Combined dynamic contrast-enhancement and serial 3D-subtraction analysis in magnetic resonance imaging of osteoid osteomas

The purpose of this study was to retrospectively correlate the results of dynamic contrast-enhanced magnetic resonance imaging (MRI) with histological and clinical diagnoses in patients with osteoid osteomas. Fifty-four patients with the MR diagnosis of osteoid osteoma were studied. MRI (1.5 Tesla) consisted of thin-section STIR sequences, dynamic 3D T1 gradient echo sequences during application of contrast material, and high-resolution postcontrast T1 spin echo sequences with fat saturation (maximum voxel size 0.6?×?0.6?×?3.0 mm). Evaluation was focused on serial image subtraction during the early phase after contrast injection and on time-intensity curves. The surrounding edema was helpful in finding the nidus in each lesion. In 49 of 54 patients (90.7%), the diagnosis of osteoid osteoma was certain or highly probable (sensitivity 1.0, positive predictive value 0.91). A total of 38 of 54 osteoid osteomas were histologically proven. Five MRI diagnoses were regarded as false positives. A similar proportion has been reported for computed tomography. Tailored high-resolution MR examinations with dynamic contrast enhancement can reliably diagnose osteoid osteomas and exactly localize the nidus without radiation exposure. We propose a stepwise approach with STIR sequences, dynamic contrast-enhanced scanning, and high-resolution postcontrast T1 spin echo sequences with fat saturation.