Radiofrequency ablation for non-spinal osteoid osteomas in 557 patients

Image-guided Ablative Procedures

Various image-guided ablative procedures include chemical and thermal ablation techniques and irreversible electroporation. These have been used for curative intent for small tumours and palliative intent for debulking, immunogenicity and pain control. Understanding these techniques is critical to avoiding complications and achieving superior clinical outcomes. Additionally, combination with immunotherapy and chemotherapies is rapidly evolving. There are numerous opportunities in interventional radiology to advance ablation techniques and seamlessly integrate into current treatment regimens for both benign and malignant tumours.

Intraoperative cone-beam computed tomography-guided curettage for osteoid osteoma

Recently, cone-beam computed tomography (CBCT)-guided surgeries have been developed for bone and soft tissue tumors. The present study aimed to evaluate the efficacy of CBCT-guided curettage for osteoid osteoma. Our study population included 13 patients who underwent primary curettage for osteoid osteoma using intraoperative CBCT in a hybrid operating room between April 2019 and November 2022. We collected the following data: sex, age, follow-up period, symptom onset to time of surgery, tumor size and location, length of skin incision, operating time, radiation dose, recurrence, postoperative complications, and visual analog scale for pain during the last follow-up. There were 10 male and 3 female patients, and the mean age was 25.0 years (range, 9-49 years). The mean follow-up period was 10.6 months (range, 0.4-24.0 months). The locations of the tumors were the proximal femur in 6 patients, the acetabular region in 2 patients, and the ilium, tibial shaft, calcaneus, cuboid, and talus in 1 patient each. The mean time of symptoms onset to surgery was 18.7 months (range, 2.3-69.9 months). The mean maximum diameter of the tumor was 5.9 mm (range, 3.5-10.0 mm). The mean length of the skin incision was 2.2 cm (range, 1.5-3.5 cm). The mean operating time was 96.9 minutes (range, 64-157 minutes). The mean dose of radiation was 193.2 mGy (range, 16.3-484.0 mGy). No recurrences, postoperative complications, and reoperation were observed in this study. All the patients reported 0 mm on the visual analogue scale for pain on the last follow-up. CBCT-guided curettage for osteoid osteoma was minimally invasive and reliable. This procedure can be effective for the treatment of lesions found in deep locations such as the pelvic bone and proximal femur or an invisible lesion that cannot be detected by regular fluoroscopy.

Percutaneous Cryoablation under Conscious Sedation: A Safe, Effective and Painless Option for the Treatment of Pediatric Osteoid Osteoma

BACKGROUND

Percutaneous CT-guided cryoablation is an emerging technique for treating bone tumors. However, experience with using this procedure for osteoid osteomas in pediatric patients remains limited. Our study aims to assess its technical feasibility, clinical efficacy, and safety in children treated under conscious anesthesia.

METHODS

We conducted a retrospective study of consecutive pediatric patients who underwent CT-guided percutaneous cryoablation for osteoid osteomas at our institution between September 2017 and March 2021. All patients received conscious anesthesia. Data on peri-procedural VAS scores, post-procedural VAS scores, imaging findings, and nonsteroidal anti-inflammatory drug (NSAID) usage rates were collected for each patient. Technical success was defined as proper cryoprobe placement at the nidus center, while clinical success referred to pain relief without NSAID use. Intra- and post-operative complications were also evaluated.

RESULTS

Nine patients underwent CT-guided percutaneous cryoablation for osteoid osteomas under conscious sedation, with a 100% overall success rate with low peri-procedural and median VAS scores (p < 0.01). No complications were observed during or after the procedure.

CONCLUSIONS

CT-guided percutaneous cryoablation of pediatric osteoid osteomas is an effective and safe minimally invasive procedure feasible under conscious anesthesia, holding promise as a valuable treatment option.

The effect of radiofrequency ablation on pain score and non-steroidal painkiller use in osteoid osteoma patients

AIM

CT-guided radiofrequency ablation (RFA) is among the thermal ablative procedures and provides great benefits with a minimally invasive procedure. In this prospective study, we aimed to reveal the significance of a multidisciplinary method in reducing the recurrence and complications in osteoid osteoma patients with CT-guided RFA performed by a team of experts in the field.

MATERIALS AND METHODS

A total of consecutive 40 patients with osteoid osteoma were prospectively evaluated and treated with CT-guided RFA. Before and the post ablation the visual analog scale (VAS) and use of nonsteroidal anti-inflammatory drugs (NSAIDS) were compared.

RESULTS

Post-ablation VAS of the patients at the 1st week and 3rd month after the procedure decreased significantly (p < 0.01) compared to the pre-ablation. The frequency of NSAID use after the ablation decreased significantly (p < 0.01) compared to the pre-ablation time. The pre-procedure NSAID use of our patients included in the study was average 6.93 per week, the NSAID use in the 3rd month post-procedure controls was average 0.53 per week. Recurrence was detected in 4 of our patients, 36 patients had complete recovery.

CONCLUSION

Radiofrequency ablation is an effective treatment method in the management of osteoid osteomas. Radiofrequency ablation has low recurrence rates and provides rapid regression in patients' pain after treatment.

CT-Guided Radiofrequency Thermal Ablation for the Treatment of Atypical, Early-Onset Osteoid Osteoma in Children Younger than 4 Years Old: Single-Institution Experience and Literature Review

The aim of our study is to report our experience on CT-guided radiofrequency ablation (RFA) for osteoid osteoma (OO) in children under 4 years of age and to review the literature regarding this atypical, early onset of the disease. We retrospectively reviewed the clinical and radiological records of the patients treated with CT-guided RFA for OO at our institution (2006−2021), including those under 4 years of age. Data regarding technical success, clinical success, and biopsy diagnostic yield were collected. Moreover, we performed a literature review including previous articles on early-onset OO. We found only 12 patients that were under 4 years of age (12/842−1.4%) at the time of RFA treatment: 4 F and 8 M, mean age at the time of the treatment 35.3 months (range 22−46 months). The mean follow-up was 22.8 months (range 6−96 months). Technical success was achieved in all cases (12/12). In all patients (12/12), a complete remission of the pain symptoms was achieved at clinical follow-up controls. No recurrence of pain or complications were documented. The histopathological diagnosis was confirmed in 4 patients (4/12−33.3%). Moreover, we found another 9 articles in the literature with a main focus on early-onset OO (<4 years old), with a total of 12 patients included; 6 of those patients (6/12−50%) were treated with CT-guided RFA, with success reported 5 cases (5/6−83.3%). Our series of cases treated at a single institution, together with the existing data from the literature, confirms that CT-guided RFA is effective and safe for the treatment of osteoid osteoma, even in atypical, early onset in children under 4 years of age.

The surgical management of osteoid osteoma: A systematic review

Background

Osteoid osteoma (OO) comprises approximately 11%-14% of benign bone tumors. The main symptom of OO is localized pain accompanied by nighttime aggravation. Surgical treatment is frequently used in clinic, including open surgery and percutaneous ablation, the latter including radiofrequency ablation, cryoablation, and microwave ablation, but there is no consensus on when and how to choose the best treatment for OO.

Purpose

We did a systematic review of the literature on existing surgical treatments of OO to assess the safety and efficacy of surgical treatments of OO and to evaluate the surgical options for different locations of OO.

Methods

The inclusion criteria in the literature are 1. Patients diagnosed with osteoid osteoma and treated surgically; 2. Include at least five patients; 3. Perioperative visual analogue scale (VAS), postoperative complications, and recurrence were recorded; 4. Literature available in PubMed from January 2014 to December 2021.

Results

In the cohort, 1565 patients (mainly adolescents) with OO received 1615 treatments. And there are 70 patients with postoperative recurrence and 93 patients with postoperative complications (minor: major=84:9). The results of Kruskal-Wallis examination of each experimental index in this experiment were clinical success rate H=14.818, p=0.002, postoperative short-term VAS score H=212.858, p<0.001, postoperative long-term VAS score H=122.290, p<0.001, complication rate H=102.799, p<0.001, recurrence rate H=17.655, p<0.001, the technical success rate was H=45.708, p<0.001, according to the test criteria of α=0.05, H₀ was rejected. The overall means of the outcome index in each group were not completely equal.

Conclusion

Percutaneous ablation and open surgery are safe and reliable for OOs, and the technical success rate of percutaneous ablation is higher than that of open surgery. Open surgery and cryoablation can be selected for OOs close to the nerve and atypical sites, while radiofrequency ablation and microwave ablation can be selected for OOs in most other sites.

O-Arm-Navigated, Robot-Assisted Versus Conventional CT Guided Radiofrequency Ablation in Treatment of Osteoid Osteoma: A Retrospective Cohort Study

Background

Osteoid osteoma is a common benign bone tumor, and clinically there is severe local pain that typically worsens at night. The conventional CT-guided radiofrequency ablation (RFA) was widely used in the treatment of osteoid osteoma (OO), which could result in some radiation-related and imprecise complications due to the overdose of radiation exposure. This study aimed to compare the surgical effect of robot-assisted RFA with O-arm navigation and conventional CT-guided RFA in the treatment of OO.

Methods

Sixty-two patients who underwent robot-assisted RFA with O-arm navigation (Robot-RFA, n = 24) or CT-guided RFA (CT-RFA, n = 38) were included in this retrospective cohort study. The mean follow-up time was 23.3 months. The intra-operative data, primary technical success rate, visual analog scale (VAS), and post-operative complications were analyzed.

Results

Primary technical success was obtained in 23 patients who had robot-assisted RFA, and 35 patients who had conventional CT-guided RFA. One patient in Robot-RFA group and three patients in CT-RFA group with pain recurrence received repeat-RFA and had a secondary success. Mean operation time and dose of radiation exposure were lower in Robot-RFA group than that in CT-RFA group. The Robot-RFA group took fewer K-wire adjustment times for each patient than the CT-RFA group. There was a statistically significant difference in the mean operation time, dose of radiation exposure, and K-wire adjustment times between the groups (p &lt; 0.05). No complications associated with the procedure were reported in the two groups during the follow-up period.

Conclusion

Robot-assisted RFA with O-arm navigation is a safer and more precise strategy in the treatment of osteoid osteoma with less operation time and radiation exposure compared with the conventional CT-guided radiofrequency ablation.

Percutaneous CT-guided radiofrequency ablation of osteoid osteoma: Potential Pitfalls and complications and how to avoid them

Targeted cannulation of the nidus and subsequent thermal ablation is the basis of CT-guided radiofrequency ablation (RFA) of osteoid osteoma, which is considered nowadays as the treatment of choice. The majority of complications during this procedure are due to thermal injury of adjacent structures. Specific measures as per the anatomical location of osteoid osteoma can avoid the majority of complications. This article enlists the possible complications and their necessary precautions and remedies to avoid these complications during CT-guided radiofrequency ablation of osteoid osteoma.

Comparison of arthroscopy versus percutaneous radiofrequency thermal ablation for the management of intra- and juxta-articular elbow osteoid osteoma: case series and a literature review

BACKGROUND

Today, intra-articular and juxta-articular osteoid osteomas are treated with arthroscopy and radiofrequency thermal ablation. However, for the case of an elbow joint, arguments are made for the use of a minimally invasive technique to be the optimal choice. This study aims to analyse our experiences of arthroscopically treated elbow osteoid osteomas and to compare it with the published results of both techniques.

METHODS

The retrospective study analyses the patients who underwent elbow arthroscopy ablation of an elbow osteoid osteoma at a single institution from January 2014 until March 2020. Clinical and diagnostic features, success and treatment failure rates, complications and tumour recurrence rates were all compared to 13 studies of intra-articular elbow osteoid osteoma arthroscopic ablation and 15 studies involving radiofrequency thermal ablation of intra-articular osteoid osteoma within different joints.

RESULTS

Four males and two females, with a mean age of 19.3 years, were encompassed. All the patients had immediate postoperative pain relief and improved range of motion. No tumour recurrences were observed during a median of 21.7 months. The literature review yielded 86.4% success rate, 68.2% successful biopsies, one minor complication and no recurrences following the arthroscopic ablation of an elbow osteoid osteoma; while radiofrequency thermal ablation of an intra-articular elbow osteoid osteoma yielded 96.3% success rate, 33.3% successful biopsies, no complications and 3.7% recurrence rate.

CONCLUSIONS

Our results are consistent with the published literature proving that arthroscopic ablation is an efficient method with low treatment failure rates and no recurrences in treating intra- and juxta-articular elbow osteoid osteomas. Advantages of arthroscopic ablation stem from the ability to visualise and safely deal with the lesion and the joint's reactive changes resulting in high biopsy rates, no recurrences and better postoperative elbow's range of motion. Still, the technique selection should be personalised considering the medical expertise of every institution.

Interventional Radiology’s Osteoid Osteoma Management: Percutaneous Thermal Ablation

Osteoid osteoma (OO) is one of the most common benign bone tumors with specific clinical and radiological characteristics. Analgesic therapy and surgical treatment have been considered the only therapy for a long time. Recently, safe and effective new therapeutic options have been introduced, among which percutaneous thermal ablation techniques. This review aims to describe the recent updates in the field of percutaneous thermal ablation techniques in the treatment of OO, assessing the outcomes in terms of efficacy, complications, and recurrence rate.

Osteoid Osteoma: Percutaneous CT-guided Cryoablation Is a Safe, Effective, and Durable Treatment Option in Adults

Background Cryoablation is playing an increasing role in the percutaneous treatment of bone tumors. However, despite its potential advantages over heat-based ablation techniques, the clinical safety and efficacy of cryoablation have not been established for osteoid osteoma treatment. Purpose To evaluate percutaneous CT-guided cryoablation for the treatment of osteoid osteoma in young patients and adults. Materials and Methods This retrospective study reviewed data from 50 consecutive patients who underwent percutaneous CT-guided cryoablation for the treatment of osteoid osteoma between January 2013 and June 2019 in a single institution. In 30 of 50 patients (60%), the procedure was carried out with the patient under local anesthesia and conscious sedation, with the cryoprobe covering the lesion from an extraosseous position, avoiding direct penetration of the nidus. Clinical and radiologic features, procedure-related data, visual analog scale (VAS) pain scores, complications, and overall success rate were evaluated. Statistical analyses were performed by using the nonparametric Friedman test and Wilcoxon signed rank test for repeated measures. Results Fifty patients (median age, 24 years; interquartile range [IQR], 19-38 years; 31 men) underwent CT-guided cryoablation for the treatment of osteoid osteoma, with a 96% (48 of 50 patients) overall clinical success rate. Of the two patients without clinical success, one patient had incomplete pain relief and the other experienced a recurrence of osteoid osteoma at 11 months, which was successfully treated with a second cryoablation procedure. The median VAS pain score was 8 (IQR, 7-8) before the procedure and 0 (IQR, 0-1; P < .001) after the procedure at both primary (6 weeks) and secondary (18-90 months) follow-up. Three of the 50 patients had minor complications (6%); no major complications were reported. Conclusion Osteoid osteoma was safely, effectively, and durably treated with CT-guided percutaneous cryoablation. In the majority of patients, treatment could be performed without general anesthesia, with the cryosphere covering the nidus from an extraosseous position. © RSNA, 2021.

Effects of control temperature, ablation time, and background tissue in radiofrequency ablation of osteoid osteoma: A computer modeling study

To study the effects of the control temperature, ablation time, and the background tissue surrounding the tumor on the size of the ablation zone on radiofrequency ablation (RFA) of osteoid osteoma (OO). Finite element models of non-cooled temperature-controlled RFA of typical OOs were developed to determine the resulting ablation radius at control temperatures of 70, 80, and 90°C. Three different geometries were used, mimicking common cases of OO. The ablation radius was obtained by using the Arrhenius equation to determine cell viability. Ablation radii were larger for higher temperatures and also increased with time. All geometries and control temperatures tested had ablation radii larger than the tumor. The ablation radius developed rapidly in the first few minutes for all geometries and control temperatures tested, developing slowly towards the end of the ablation. Resistive heating and the temperature distribution showed differences depending on background tissue properties, resulting in differences in the ablation radius on each geometry. The ablation radius has a clear dependency not only on the properties of the tumor but also on the background tissue. Lower background tissue's electrical conductivity and blood perfusion rates seem to result in larger ablation zones. The differences observed between the different geometries suggest the need for patient-specific planning, as the anatomical variations could cause significantly different outcomes where models like the one here presented could help to guarantee safe and successful tumor ablations.

A Bicentric Propensity Score Matched Study Comparing Percutaneous Computed Tomography-Guided Radiofrequency Ablation to Magnetic Resonance-Guided Focused Ultrasound for the Treatment of Osteoid Osteoma

PURPOSE

To assess the safety and efficacy of computed tomography-guided radiofrequency (RF) ablation and magnetic resonance-guided focused ultrasound (MRgFUS) in the treatment of osteoid osteoma with a long-term follow-up study.

MATERIALS AND METHODS

Database research was performed at 2 different centers with experience in musculoskeletal interventions. Both centers, one performing RF ablation and the other MRgFUS, identified 116 patients who underwent either RF ablation or MRgFUS procedures for the treatment of symptomatic osteoid osteoma and retrospectively evaluated data regarding pain scores using a visual analog scale (VAS). Complications were recorded according to the Cardiovascular and Interventional Radiological Society of Europe classification system. Propensity score matching for multiple variables was performed. Pain scores before and after therapy were compared.

RESULTS

Of 116 patients treated, 61 and 55 underwent RF ablation and MRgFUS, respectively. Before treatment, the mean reported pain in the 2 groups were 9.1 ± 0.88 (RF ablation) and 8.7 ± 0.73 (MRgFUS) VAS units. After treatment, a statistically significant (P < .00001) overall reduction in pain symptomatology was recorded. No statistically significant difference was observed between the mean values of pain after treatment in both groups (P = .256). Over a mean of >2 years of follow-up, 4 cases of relapse (RF ablation, 1; MRgFUS, 3) and 1 complication (RF ablation) were observed. The analysis from propensity score matching that identified a matched cohort of 48 patients showed similar results.

CONCLUSIONS

The 2 techniques for the treatment of osteoid osteoma resulted in profound and similar pain relief. The presence of thick cortical bone over the nidus can reduce the effectiveness of MRgFUS.

Combined with interventional therapy, immunotherapy can create a new outlook for tumor treatment

Recent progress in immunotherapy provides hope of a complete cure to cancer patients. However, recent studies have reported that only a limited number of cancer patients with a specific immune status, known as "cold tumor", can benefit from a single immune agent. Although the combination of immune agents with different mechanisms can partially increase the low response rate and improve efficacy, it can also result in more side effects. Therefore, discovering therapies that can improve tumors' response rate to immunotherapy without increasing toxicity for patients is urgently needed. Tumor interventional therapy is promising. It mainly includes transcatheter arterial chemoembolization, ablation, radioactive particle internal irradiation, and photodynamic interventional therapy based on a luminal stent. Interventional therapy can directly kill tumor cells by targeted drug delivery in situ, thus reducing drug dosage and systemic toxicity like cytokine release syndrome. More importantly, interventional therapy can regulate the immune system through numerous mechanisms, making it a suitable choice for immunotherapy to combine with. In this review, we provide a brief description of immunotherapies (and their side effects) on tumors of different immune types and preliminarily elaborate on interventional therapy mechanisms to improve immune efficacy. We also discuss the progress and challenges of the combination of interventional therapy and immunotherapy.

Osteoid osteoma: which is the best mininvasive treatment option?

Osteoid osteoma is the third most common benign bone tumor, with well-known clinical presentation and radiological features. Although surgical excision has been the only therapeutic option for a long time, to date it has been replaced by minimally invasive techniques, which proved satisfactory success rates and low complication occurrence. Therefore, the purpose of this literature review was to describe the main updates of these recent procedures in the field of interventional radiology, with particular attention paid to the results of the leading studies relating to the efficacy, complications, and recurrence rate. Nevertheless, this study aimed to analyze the peculiarities of each reported technique, with specific focus on the possible improvements and pitfalls. Results proved that all mininvasive procedures boast a high success rate with slight number of complications and a low recurrence rate. Radiofrequency ablation is still considered the gold standard procedure for percutaneous treatment of osteoid osteoma, and it has the possibility to combine treatment with a biopsy. Interstitial laser ablation's advantages are the simplicity of use and a lower cost of the electrodes, while cryoablation allows real-time visualization of the ablated zone, increasing the treatment safety. Magnetic resonance-guided focused ultrasound surgery is the most innovative non-invasive procedure, with the unquestionable advantage to be radiation free.

Imaging-guided radiofrequency ablation of osteoid osteoma in typical and atypical sites: Long term follow up

Purpose

To assess efficacy and safety of imaging-guided radiofrequency ablation (RFA) of Osteoid Osteoma (OO) in both typical and atypical sites.

Methods and materials

Between January 2014 and March 2019, 102 consecutive percutaneous RFA were performed and retrospectively reviewed. The procedures were performed using a RFA bipolar ablation system (Covidien, exposed tip of 0.7-1cm), under Computed Tomography (CT) guidance or using a navigation system (Masmec) under CT and Cone Beam CT (CBCT) guidance. Patients were followed up over 24 months. Clinical success and recurrences were considered on the base of established criteria. In patients with clinical failure and/or imaging evidence of relapse, retreatment was considered.

Results

Administered power per-procedure was ≤8 W (mean temperature, 90°C). The pre-procedure average value of visual analog scale (VAS) was 8.33+/-0.91. Primary and secondary success rate 96.08% (98/102) and100% (102/102), respectively. No major complication was described. Technical success was proved in every patient by CT scan acquisition after needle positioning. Relapse and tumour location were significantly correlated (p-value = 0.0165). The mean dose-length product was 751.55 mGycm2. Advanced bone healing was noted in 68 lesions after 1y-follow up and in 86 lesions after 2y-follow up.

Conclusion

Imaging-guided percutaneous RFA is a highly effective technique for OO, both in typical and atypical sites. CT or CBCT guidance, navigation systems and operator experience grant the technical success, which is the most crucial parameter affecting outcome.

Computed tomography-guided percutaneous radiofrequency and laser ablation for the treatment of osteoid osteoma - long-term follow-up from 5 to 10 years

Purpose

The impact of computed tomography (CT)-guided, percutaneous radiofrequency ablation and interstitial laser ablation (ILA) on the management of patients with osteoid osteoma was studied. This was carried out by assessing immediate and long-term clinical outcomes, the complication rate, and repeat therapy effectiveness in recurrent patients who have already experienced percutaneous ablation.

Material and methods

Consecutive patients with osteoid osteoma were assessed before the interventional treatment in a single centre from 2010 to 2015. Patient demographics, complications, and recurrence were recorded. The pain was evaluated with Visual Analogue Scale (VAS). Percutaneous procedures were performed by means of radiofrequency thermoablation or ILA. Epidural or regional anaesthesia in the CT suite was applied in all procedures. Success, whether primary or secondary, was measured as complete pain relief without evidence of recurrence after the first or second procedure, respectively. Osteoid osteoma characteristics, procedure overview, and technical success were looked for in pre-procedural and procedural scans.

Results

Eighty-three per cent of osteoid osteomas were located in lower extremities, 56% of tumours were intracortical, and 83% of osteoid osteomas were extra-articular. The mean pre-procedure VAS score was 8.5 ± 0.8, while the overall primary success rate of radiofrequency thermoablation and ILA was 87.5%. No major complications were noted. The mean follow-up period for patients in was 7.5 years (5.0-10.2 years).

Conclusions

Percutaneous, CT-guided thermoablation proved to be effective and should become the method of choice in osteoid osteoma treatment because of its minimal invasiveness. Our results show that there is no risk of very late recurrence after achieving primary and secondary treatment success.

Effectiveness and reliability of traditional open surgery in atypical localizations of osteoid osteoma

Objectives

This study aims to evaluate traditional open surgery results of osteoid osteomas (OOs) in atypical localizations and explore whether open surgery can be a safe alternative in localizations where radiofrequency ablation (RFA) may not be suitable.

Patients and methods

A total of 26 patients (20 males, 6 females; mean age 23.3±14.2 years; range, 4 to 65 years) having OO in atypical localizations between January 2008 and January 2017 were retrospectively evaluated. All patients underwent traditional open surgery under anesthesia. All patients were followed-up, and their clinical success and complications were evaluated. The pain intensity was assessed using the visual analog scale (VAS).

Results

The postoperative first year VAS score was 0.2±0.5 (range, 0-2) (p<0.005). None of the patients showed any complications. No recurrences were reported at the end of the first year. All patients were relieved from pain due to OO in atypical localizations.

Conclusion

Although RFA has been accepted as the preferred treatment for OO, traditional open surgery may still be used for OO in atypical localizations yielding perfect clinical results with fewer complications. It is a safe alternative for localizations such as carpal bones, distal ulna, hand and foot where RFA complications can be seen more frequently. In these localizations, traditional open surgery can be recommended as the first treatment choice.

Computed Tomography-Guided Radiofrequency Ablation of Osteoid Osteoma in Atypical Sites: Efficacy and Safety in a Large Case Series

RATIONALE AND OBJECTIVES

Although computed tomography (CT) guided radiofrequency ablation (RFA) is accepted as the gold standard treatment for osteoid osteoma (OO) in extremities, most researchers have omitted OO in critical sites. We aimed to evaluate the efficacy and safety of CT-guided RFA in the management of OO in atypical sites.

MATERIALS AND METHODS

A prospective interventional study conducted on 34 patients (12 women and 22 men; mean age, 22.3 ± 3.5 years; range, 12-48 years) with OO in atypical sites. All patients were treated with CT-guided RFA. All procedures were performed under general anesthesia using a single straight, rigid RF electrode for 6 minutes at 90°C. All patients were followed up; technical and clinical successes of treatment were evaluated. The severity of pain was assessed on a visual analogue scale (VAS).

RESULTS

CT-guided RFA was performed in all patients with 100% technical success and 100% primary clinical success. All patients had complete pain relief and returned to their quality of life without further analgesics within 1 month after the procedure. All procedures were successfully completed without any major complications. The mean preprocedure VAS score dropped to zero by the end of the first week with a highly statistically significant difference (p < 0.001).

CONCLUSION

CT-guided RFA is a safe and effective procedure in the management of OO in atypical sites with 100% primary success rate, 0% long-term recurrence rate, and very low complication rate.

Percutaneous thermal ablation for treatment of osteoid osteoma: a systematic review and analysis

OBJECTIVE

Although radiofrequency ablation is well validated for treatment of osteoid osteoma, newer technologies, namely cryoablation, have been less thoroughly studied. The purpose is to perform a systematic review and pooled analysis of percutaneous ablation technologies for treatment of osteoid osteoma with subset analysis of intra-articular and spinal tumors.

MATERIAL AND METHODS

A total of 36 of 79 identified manuscripts met inclusion criteria, comprising 1863 ablations in 1798 patients. Inclusion criteria were (1) retrospective or prospective analysis of thermal ablation of osteoid osteomas in any location, (2) at least 6 months of clinical follow-up, (3) 10 or more patients, (4) patients not included in a second study included in this review, and (5) English language or English translation available. Success rate was defined as all ablations minus technical failures, clinical failures, and recurrences. Subset analysis of intra-articular and spinal tumors was performed.

RESULTS

Overall success rate was 91.9% (95% CI 91-93%). Technical failure, clinical failure, and recurrence rates were 0.3%, 2.1%, and 5.6% respectively. Complications were seen in 2.5% (95% CI 1.9-3.3%) patients. There was no significant difference when comparing radiofrequency ablation and cryoablation (p = 0.92). Success rates for intra-articular (radiofrequency ablation) and spinal tumors (radiofrequency and cryoablation) were 97% and 91.6% respectively.

CONCLUSION

Percutaneous ablation of osteoid osteomas was highly successful with low complication rates. Efficacy of radiofrequency ablation and cryoablation is similar, which is consequential because cryoablation is associated with decreased pain, predictable nerve regeneration, and theoretical immunotherapy benefits. Treatment of more challenging intra-articular and spinal lesions demonstrated similarly high success and low complication rates.

Cartilage-Preserving Arthroscopic-Assisted Radiofrequency Ablation of Periacetabular Osteoid Osteoma in a Young Adult Hip

Osteoid osteomas are benign bone lesions that commonly occur in the lower extremities and spine, with the radiographic evidence of a central nidus surrounded by circumferential reactive bone. Although nonsteroidal anti-inflammatory drugs can provide symptomatic relief and are used as an important diagnostic tool, surgical intervention is the definitive treatment. Arthroscopic-assisted radiofrequency ablation has been shown to be an effective technique to directly visualize and treat the lesion while minimizing damage to the articular cartilage.

CT-guided radiofrequency ablation of osteoid osteoma: established concepts and new ideas

Osteoid osteoma is a painful benign bone tumour of children and young adults with characteristic clinico-radiological features depending upon the location of the lesion. Intraoperative visualisation of the nidus is difficult and therefore curative surgery is often associated with excessive bone removal, significant perioperative morbidity and potential need of bone grafting procedures. With advancement in cross-sectional imaging and radiofrequency ablation (RFA) technology, CT-guided RFA has emerged as the treatment of choice for the osteoid osteoma. This procedure involves accurate cannulation of the nidus and subsequent thermocoagulation-induced necrosis.Multidisciplinary management approach is the standard of care for patients with osteoid osteoma. Appropriate patient selection, identification of imaging pitfalls, pre-anaesthetic evaluation and a protocol-based interventional approach are the cornerstone for a favourable outcome. Comprehensive patient preparation with proper patient position and insulation is important to prevent complications. Use of spinal needle-guided placement of introducer needle, namely, "rail-road technique" is associated with fewer needle trajectory modifications, reduced radiation dose and patient morbidity and less intervention time. Certain other procedural modifications are employed in special situations, for example, intra-articular osteoid osteoma and osteoid osteoma of the subcutaneous bone in order to reduce complications. Treatment follow-up generally includes radiographic assessment and evaluation of pain score. Dynamic contrast-enhanced MRI has been recently found useful for demonstrating post-RFA healing.

Multidisciplinary approach in the treatment of osteoid osteoma with radiofrequency ablation

OBJECTIVES

This study aims to present the importance of a multidisciplinary approach to radiofrequency ablation (RFA) treatment in osteoid osteoma (OO) patients by a team of experts in their field in preventing recurrence and complications.

PATIENTS AND METHODS

For this retrospective study, a team of two orthopedists, two interventional radiologists, and one anesthesiologist was established in January 2013 to manage the diagnosis, follow-up, and treatment process of patients with OO at Bakırköy Dr. Sadi Konuk Training and Research Hospital. A total of 27 patients (15 males, 12 females; mean age 22.9 years; range, 9 to 54 years) were treated by this team between February 2013 and September 2016. The anatomic localization included iliac crest in four patients, the femur in 12 patients, fibula in two patients, humerus in three patients, radius in one patient, tibia in three patients, talus in one patient, and metacarpal in one patient. The procedures were carried out by the same interventional radiologists, same orthopedic surgeons, and same anesthesiologist in the computed tomography (CT) unit under aseptic conditions. After appropriate anesthesia for the localization of OO, the patient was positioned on the CT bed and the localization of the lesion was confirmed with a CT scan mapping. Then, a bone penetration cannula was advanced and bone cortex was penetrated with a charged motor and Kirschner (K)-wire. When the cannula reached the nidus, it was replaced with RFA probe. Ablation of the nidus was performed for five minutes at 90°C.

RESULTS

The mean follow-up period was 46 months (range, 25 to 66 months). Patients were evaluated with visual analog scale (VAS) scores preoperatively and at postoperative 15th day, sixth month, and first year. In the last evaluation of the study data, the patients were called by telephone and questioned whether there were any changes in their final status. The mean preoperative VAS score was 7.2. The mean postoperative VAS scores of the 15th day, sixth month, and first year were 1.3, 0.6, and 0, respectively. In the last follow-up, the OO-related pain completely disappeared and none of the patients had any recurrence. There was a significant difference between preoperative and postoperative 15th day and sixth month VAS score measurements.

CONCLUSION

Radiofrequency ablation treatment of OOs is a minimally invasive, safe, low-cost, and efficient method. We believe that with experienced teams and appropriate planning, RFA will take part in practice as the standard treatment of OO.

CT-guided radiofrequency ablation for osteoid osteomas: a systematic review

OBJECTIVES

CT-guided radiofrequency ablation (CT-RFA) is considered to be the gold standard for treatment of osteoid osteoma (OO) yet treatment failures (TFs) continue to be reported. This systematic review was conducted to evaluate factors associated with TF, such as ablation time, lesion location, and patient age as well as evaluating how TF has trended over time.

METHODS

Original studies reporting on patients undergoing CT-RFA of OO published between 2002 and 2019 were identified. TF was defined as patients with (1) recurrent or persistent pain +/- (2) imaging evidence of persistent OO. TFs were subdivided into those occurring after the index procedure (primary TF) or those occurring after repeat RFA (secondary TF). Subgroup analysis was performed for TF based on the study date (2002-2010 or 2010-2019), time duration of ablation at 90 °C (6 min or > 6 min), patient age, and tumor location (spinal vs. appendicular).

RESULTS

Sixty-nine studies were included for a total of 3023 patients. The global primary TF rate was 8.3% whereas the secondary TF rate was 3.1%. The TF rate reported in studies published after 2011(7%) was about half that during the earlier time period 2002-2010 (14%). There was no statistical difference in TF corrected for age, OO location, or duration of ablation (respectively p = 0.39, 0.13, and 0.23). The global complication rate was 3%, the most frequent being skin burns (n = 24; 0.7%).

CONCLUSIONS

A decrease in TF observed between 2011-2019 compared to 2002-2010 may reflect improvements in operator technique or advancements in equipment. Duration of ablation, patient age, or location of OO failed to significantly correlate with TF.

KEY POINTS

• CT-guided radiofrequency ablation of osteoid osteomas is a safe technique with a low rate of treatment failure (8.3% failure rate after the primary radiofrequency reducing to 3.1% following a secondary treatment). • The treatment failure rate has decreased over time, possibly due to an improved understanding of the disease process, better technique, and advances in equipment. • Duration of ablation, patient age, or lesion location did not significantly correlate with treatment failure.

Radiofrequency ablation of atypical cartilaginous tumors in long bones: a retrospective study

Purpose: To determine the size of the ablation zone after radiofrequency ablation (RFA) of atypical cartilaginous bone tumors (ACT) using temperature-controlled 20 and 30 mm RFA straight non-cooled electrodes.Materials and methods: Sixteen patients with ACT in their long bones, who had undergone a single-session single-application CT-guided temperature-controlled RFA, were included retrospectively in the study. Tumors with a diameter of 10-25 mm were treated with 20 mm electrodes (n = 10), and tumors of 25-35 mm, with 30 mm electrodes (n = 6). The ablated zone was measured after three months on MRI images.Results: All the tumors were within the ablated zone on the 3-month follow-up MRI scan. The mean ablation time with the electrode, at a target temperature of 90 °C, was 7.6 minutes (range 6-10). The median of the largest ablation diameters, on applying the 20 and 30 mm electrodes, were 42 mm (IQR 8.5, range 30-51 mm) and 44.5 mm (IQR 4.5, range 42-63 mm), respectively.Conclusions: All the retrospectively viewed tumors in the long bones of ACT patients treated with RFA were completely ablated. The ablation zone diameters in the bones were larger than expected, when compared to other tissues, such as the liver.

Osteoid osteoma of the base of the coracoid process – A case report

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Osteoid osteomas are benign bone tumors commonly found in long bones.

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Presence of osteoid osteomas elsewhere makes early diagnosis difficult.

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MRI and CT scans help detect osteoid osteomas early.

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Juxta-articular osteoid osteomas are best excised arthroscopically.

Introduction

Osteoid osteomas (OO) are small, well-defined, benign bone tumors of the young that are commonly found in long bones. In rare circumstances, when present elsewhere, they can mimic the symptoms of other pathologies pertaining to that area.

Presentation of case

We present such case in which an "OO" of the coracoid process led to a 2-year delay in diagnosis and management of a young male due to the presenting symptoms resembling those of other shoulder pathologies. Ultimately, the use of advanced imaging modalities proved to be useful in detecting the "OO", which was consequently arthroscopically excised.

Discussion

Appropriate imaging modalities such as CT or MRI often visualize the characteristic nidus more clearly as opposed to an X-ray and should therefore be used early when conservative management of shoulder pain has not been proven to be useful.

Conclusion

A long history of shoulder pain that is not responsive to conservative management in young patients should raise the suspicion of an "OO", and physicians should be encouraged to use early advanced imaging modalities in order to confirm it.

Treatment-related alterations of imaging findings in osteoid osteoma after percutaneous radiofrequency ablation

OBJECTIVES

We aimed to report the long-term outcomes of osteoid osteoma patients and to determine CT and dynamic contrast-enhanced MR imaging characteristics of radiofrequency ablation (RFA) treatment related changes of osteoid osteoma between follow-up periods.

MATERIALS AND METHODS

Thirty patients (seven female, 23 male) who underwent CT-guided RFA of osteoid osteoma were included. Follow-up imaging examinations were divided into two subgroups; first (1-3 months) and second (> 6 months) periods. Nidus size, calcification, cortical thickening, maximum signal intensity (SImax), time of SImax (Tmax), slope of signal intensity-time (SIT) curves were noted. CT and dynamic MR imaging findings were compared between follow-up periods.

RESULTS

Clinical success rate was 100%. The mean of OO nidi size was 5.85 ± 1.98 mm before treatment. There was a significant difference for OO nidi sizes between pretreatment and second follow-up period examinations (p = 0.002). SImax and slope of SIT curves of all patients (100%) showed decrease on follow-up MRIs. There was a significant decrease for SImax values between pretreatment and second follow-up period. There was a significant decrease for slope of SIT curves between pretreatment and both follow-up periods.

CONCLUSIONS

RFA is an effective and safe treatment choice for osteoid osteomas. On follow-up imaging, slope of SIT curve and Tmax have the most important positive predictive value for long-term outcomes and single dynamic contrast-enhanced MRI within first 3 months after treatment may be sufficient for symptom-free patients.

Image-guided Percutaneous Radiofrequency Ablation for Osteoid Osteoma: Experience from a Developing Nation

Objective

The purpose of this study is to report our experience in using image-guided percutaneous radiofrequency ablation (RFA) for the treatment of osteoid osteoma (OO) and the subsequent duration of pain relief over a period of about six years (May 2013-March 2019; 70 months) at a tertiary-care hospital in a developing nation.

Methods

A retrospective study was performed at the radiology department of Aga Khan University, Karachi, Pakistan. All patients who had undergone image-guided percutaneous RFA for OO between May 2013-March 2019 were included. All cases had been performed with CT-guidance under general anesthesia, with an additional local anesthesia injection also administered to the patients. A soloist needle had been used for RFA. The primary success rates, complications, symptom-free intervals, and follow-ups were evaluated.

Results

In total, 15 patients (11 males, 4 females) of a mean age of 13.93 years (range: 5-25 years; median age: 14.5 years) with OO underwent image-guided percutaneous RFA during a period of 70 months. Eleven lesions were located in the femur, three in the tibia, and one in the humerus. The mean nidus size was 8.1 x 5.73 mm [range: (4.9-11.5) x (3.8-9.1) mm]. All patients were successfully treated and experienced resolution of pain in 2.36 months (range: 1-4 months). During the follow-up period (range: 3-40 months; mean: 13.85 months; median: nine months), none of the patients experienced any relapse or persistent symptoms. No major complications were reported.

Conclusion

Image-guided percutaneous RFA is a minimally invasive and safe treatment option with high efficiency and a high rate of technical success for the treatment of OO. The risk of recurrence is remote with all patients achieving independent recovery.

C-arm cone-beam computed tomography-guided minimally invasive open excision of an osteoid osteoma undetectable on fluoroscopy: A case report

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A robotic C-arm cone-beam computed tomography (CBCT) system provides a clear intraoperative visualization of the osteoid osteoma.

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C-arm CBCT allowed precise access to the tumor, accurate tumor resection, and minimal sacrifice of the normal bone in osteoid osteoma surgery.

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Repurpose use of the dilator, retractor, and wider trephine tips achieved more conservative results with a smaller skin incision.

Introduction

The small size of a nidus and the extensive sclerosis around it often make it difficult to identify tumors from the surrounding normal bone by fluoroscopy, and a large amount of bone resection might be required to secure complete removal during osteoid osteoma surgery. In this report, we present the first case of radiographically invisible osteoid osteoma that was successfully resected under a robotic C-arm cone-beam computed tomography (CBCT) imaging system.

Presentation of case

A 14-year-old boy presented with persistent pain around the left knee joint was diagnosed with osteoid osteoma of the left distal femur. Since the tumor was not detectable by intraoperative fluoroscopy, a CBCT system was used for guidance during an open tumor resection. For a less invasive surgery, we repurposed the dilator and retractor of the microendoscopic discectomy (MED) system and resected the tumor using the wider trephine tips for bone biopsy. At the final follow-up one year later, the function of the afflicted limb was normal with no complaint of any symptoms. Plain radiograph at the final follow-up showed new bone formation completely filling the bone defect, without local recurrence.

Discussion

CBCT allowed for clear intraoperative visualization of the osteoid osteoma, thereby promising a secure resection and less invasive osteoid osteoma treatment. Furthermore, the repurposed use of the dilator and retractor of the MED system as well as the wider trephine tips for bone biopsy made the procedure less invasive.

Conclusion

CBCT-guided minimally invasive open excision surgery could be a useful option for the management of radiographically invisible osteoid osteoma.

Complications of Computer Tomography Assisted Radiofrequency Ablation in the Treatment of Osteoid Osteoma

Background

Osteoid osteoma (OO) is one of the most commonly occurring benign bone tumors. It constitutes 10-12% of benign bone tumors and 2-3% of primary bone tumors. In radiofrequency ablation (RFA) treatment, the cells of the tumor are thermally inactivated by the help of electrodes shaped like needles. In our study, we aimed to show the major and minor complications in patients undergoing RFA and to show what should be done to prevent these complications.

Methods

The study was carried out as a prospective study on the follow-up of 87 osteoid osteoma patients treated between 2015 and 2017. The youngest of the patients was 1 year old and the oldest was 42 years old. The RFA procedure lasted 10 min on average, excluding anesthesia and preparation. All lesions were ablated at 90 degrees for 7 minutes with the heat increased gradually. All patients were followed up for 1 day in the orthopedics clinic.

Results

Complications were observed in 7 patients. The lesions with the most complications were observed to be in the tibia, second-degree burns were seen in 2 patients, and superficial skin infection was observed in 2 patients. In 1 patient, the probe tip was broken and remained within the bone. Intramuscular hematoma was detected in 1 lesion located in the proximal femur. A complaint of numbness in the fingers developed in a lesion located in the metacarpus.

Conclusion

Preventive measures should be taken before the procedure in order to prevent minor complications, and, for major complications, close follow-up should be done after the procedure and patients should be kept away from heavy physical activities for the first 3 months.

COMPARISON OF RADIOFREQUENCY ABLATION AND CURETTAGE IN OSTEOID OSTEOMA IN CHILDREN

Objective:

Osteoid osteoma, which is observed in the adolescent and young adult population as benign bone tumors, appears as a single nidus with a diameter < 2 cm and is treated with open surgery. However, technological advances in medicine have made it possible to apply less invasive procedures in surgery.

Methods:

Between 2006–2014, 24 patients < 18 years of age were treated for osteoid osteoma. Patient demographic data, surgical data, complications, and recurrences were noted.

Results:

Twenty-four patients (mean age, 11 [2–18] years) were treated and followed up for a mean 3.58 (range, 1–9) years. Mean patient age in the curettage group was 12.1 (range, 3–18) years. Mean operation length was 69.5 (range, 60–120) minutes. Mean hospital stay was 1.3 (range, 0–2) days. Mean patient age in the radiofrequency ablation (RFA) group was 10.7 (range, 2–17) years. Five patients were female and 8 were male. Mean operation length was 49.6 (range, 20–90) minutes. Mean hospital stay was 0.3 (range, 0–1) days. Mean follow-up time was 1.76 (range, 1–4) years. Mean operation length, hospital stay, and follow-up were significantly shorter in the RFA group.

Conclusions:

Considering reduced costs due to shorter hospitalization periods and the ability to reach anatomically difficult locations, percutaneous procedures are likely to replace the conventional open approach. Level of evidence: II, retrospective study.

Percutaneous Treatments of Benign Bone Tumors

Benign bone tumors consist of a wide variety of neoplasms that do not metastasize but can still cause local complications. Historical management of these tumors has included surgical treatment for lesion resection and possible mechanical stabilization. Initial percutaneous ablation techniques were described for osteoid osteoma management. The successful experience from these resulted in further percutaneous image-guided techniques being attempted, and in other benign bone tumor types. In this article, we present the most common benign bone tumors and describe the available results for the percutaneous treatment of these lesions.

Present role and future perspectives of interventional radiology in the treatment of painful bone lesions

Interventional radiology has experienced an exponential growth in the last years. Nowadays it is possible to treat painful benign lesions or metastases with optimal results in terms of pain management and disease control. Among the benign lesions, osteoid osteoma is the most frequently treated with minimal invasive techniques and the results are excellent. Another lesion, traditionally treated with surgery (osteoblastoma) represent today another field of application. In the oncological field, metastases are, numerically, the most diffuse indications for treatment. Research carried out during the last decades has provided the interventional radiologist with a great variety of techniques of ablation and devices for monitoring the sensitive structures close to the target lesion. New ablation techniques and monitoring devices contribute to the achievement of significantly increasing rates of effectiveness and safety of interventional radiology procedures.

Percutaneous Radiofrequency Ablation for the Treatment of Osteoid Osteoma in Children and Adults: A Comparative Analysis in 92 Patients

PURPOSE

To compare technical success, complications, and long-term clinical success following radiofrequency ablation of osteoid osteomas in pediatric and adult patients.

MATERIALS AND METHODS

Ninety-two patients underwent percutaneous computed tomography-guided radiofrequency ablation for osteoid osteomas including 54 pediatric (mean age 12.9 years) and 38 adult (mean age 24.1 years) patients. Presenting indication, osteoma location, ablation method, technical success, complications, visual analog score, radiographic follow-up, clinical success, reintervention rate, and total follow-up were reported. Technical success was defined as placement of the probe in the radiolucent nidus with ablation. Clinical success was defined as resolution of symptoms.

RESULTS

Ablation indications included: pain localized to the lesion, night pain, and an osteoma on imaging in all patients. Majority of osteoid osteomas were localized to the femur (pediatric [n = 22, 40.7%]; adult [n = 12, 34.2%]) and tibia (pediatric [n = 21, 38.9%]; adult [n = 10, 26.3%]). Mean lesion size was 9.6 mm in pediatric patients and 9.0 mm in adults. Technical success was achieved in all pediatric patients (100%) and 97.4% of adults. Two complications occurred. Primary clinical success was achieved in 49 (90.7%) pediatric and 35 (92.1%) adult patients. Five (9.3%) pediatric and 3 (7.9%) adult patients sought reintervention for residual symptoms, and all had secondary clinical success. Mean total follow-up was 95.2 ± 58.7 months in pediatric and 90.0 ± 61.6 months in adult patients. No differences in outcomes were identified between pediatric and adult patients.

CONCLUSION

Radiofrequency ablation of osteoid osteomas is safe with excellent technical and clinical success rates in pediatric and adult patients.

Minimal invasive intralesional excision of extremity-located osteoid osteomas in children

In this retrospective study, we evaluated the efficiency of minimal invasive intralesional extended curettage in the treatment of osteoid osteomas of the extremities in children. Forty-seven children (29 males, 18 females; mean age 10.5 years; range 4-19 years) with osteoid osteoma of the extremities underwent minimal invasive intralesional extended curettage. The exact localization of the nidus was determined preoperatively by thin-section (1-1.5 mm) computed tomography scans, and complete excision of the nidus was performed using a modified burr-down technique. None of the procedures required bone grafting or internal fixation. The median follow-up duration was 59 months (range, 12-136 months). Histopathological confirmation of osteoid osteoma was achieved in all procedures. All patients experienced immediate and complete relief of lesional pain after surgery. Preoperative (a day before surgery) and postoperative (at the time of discharge) mean visual analogue scale scores, questioning the pain derived from osteoid osteoma, were 7.7±1.2 and 0.3±0.6, respectively, confirming complete removal of the nidus. Early motion of the involved extremities and mobilization of the patients were achieved within 2 days. The children resumed normal function within 3 weeks. Postoperative complication or recurrence was not encountered in any of the patients. Even though percutaneous radiofrequency thermoablation is accepted as the treatment of choice for extraspinal osteoid osteomas, this technique requires a regional reference institution. Minimal invasive intralesional extended curettage can be performed in conventional institutions, even those not specialized in bone tumor surgery, by orthopedic surgeons with high success and low morbidity rates, in addition to rapid functional recovery.

CT-guided radiofrequency ablation of osteoid osteoma using a multi-tined expandable electrode system

BACKGROUND AND AIM OF THE WORK

Radiofrequency ablation (RFA) is the gold standard for the treatment of symptomatic osteoid osteoma (OO) as RFA yields both a high success and low complication rate. It has been widely utilized over the years, but recurrences of OO after this treatment have been documented. These recurrences may be the result of various factors, including incomplete tumor ablation, and are significantly higher in lesions greater than 10 mm. Thus, the need to induce thermal ablation in a wider area led us to use a Multi-Tined Expandable Electrode System (MTEES). In this study we examined the efficacy and safety of RFA using a MTEES in symptomatic OO.

METHODS

Between January 2005 and June 2007, 16 patients with symptomatic OO were treated by CT-guided percutaneous RFA using a MTEES. The diameter of OO ranged from 6 to 15 mm (mean 10±2.6 mm). Patients were evaluated for clinical outcomes, complications and recurrence. Pain evaluation was assessed preoperatively, 2 weeks postoperatively and at last follow-up.

RESULTS

Clinical follow-up was available for all patients at a mean of 84.3 months (range 73-96 months). Mean preoperative VAS score was 7.4 (range 5-9), two weeks after the procedure mean VAS score was 0.3 (range 0-1) with a mean change of -7.06 points (p<0.0001). At the last follow-up a complete relief from pain has been observed in all patients. No major and minor complications were observed nor recurrences.

CONCLUSIONS

RFA using a MTEES has been effective, safe and reliable for the treatment of OOs. This system, by increasing the size of the necrosis, could be a viable alternative to the single needle electrode in lesions larger than 10 mm, reducing the risk of recurrence.

Radiofrequency ablation for osteoid osteoma - Recurrence rates and predictive factors

BACKGROUND AND PURPOSE

Osteoid osteoma is an infrequent but debilitating benign bone lesion which can be successfully managed by percutaneous radiofrequency ablation (RFA). There are few studies investigating the efficacy and follow-up of this treatment. An arbitrary upper limit of 15 mm has been used to differentiate between osteoid osteoma and osteoblastoma with surgery used for lesions above this limit. We aimed to analyse the cases identified from our prospectively maintained database over a ten year period since adoption of this technique in our unit. The primary objectives were to investigate factors which influenced recurrence and the time period at which patients are at risk of this.

BASIC PROCEDURES

Consecutive patients with confirmed osteoid osteoma were included. Patient demographics, complications, and recurrence were recorded and multiple regression analysis was performed to investigate causation.

MAIN FINDINGS

Within a minimum follow up of 21 months (mean 72), a recurrence rate of 16.3% was noted, higher than the published literature. Cox regression analysis to predict chance of recurrence revealed a relationship between larger lucent diameter and recurrence (p = 0.049, CI 95%, hazard ratio 1.33).

CONCLUSIONS

The traditional cut off between osteoid osteoma and osteoblastoma appears less rigidly defined than previously thought and probably represents a progressive scale with larger lesions responding less well to RFA. This study indicates that each millimetre increase represents a ×1.33 chance of recurrence. Clinicians should counsel patients accordingly with lesions approaching the larger limits of this diagnosis.

Therapeutic outcome of CT-guided radiofrequency ablation in patients with osteoid osteoma

OBJECTIVE

To assess the long-term outcome of computed tomography-guided radiofrequency ablation (CT-guided RFA) in patients with suspected osteoid osteoma (OO).

MATERIALS AND METHODS

Single-center retrospective study. Patients with clinical suspicion and imaging diagnosis of osteoid osteoma were treated by CT-guided RFA using the same device with either a 7- or 10-mm active tip electrode. Specific precautions were applied in case of articular or spinal OO. Patients were contacted by phone to evaluate the long-term outcome in terms of pain, ability to perform daily activities (including sports), and long-term complications. Success was defined as the absence of residual pain and ability to perform daily activities normally.

RESULTS

From 2008 to 2015, 126 patients were treated by CT-guided RFA for OO in our institution. Mean patient age was 26.1 years (SD = 11, range 1-53); mean delay to diagnosis was 16.9 months (SD = 15.2, range 1-120). Among patients who answered the follow-up call (n = 88), the overall success rate was 94.3%: 79/88 (89.8%) had primary success of the procedure, and 4/88 (4.5%) had a secondary success (repeat-RFA after pain recurrence). Mean follow-up time was 34.6 months (SD = 24.7, range 3-90). Few complications occurred: two mild reversible peripheral nerve injuries, one brachial plexus neuropathy, one broken electrode tip fragment, and one muscular hematoma.

CONCLUSION

Osteoid osteoma can be effectively and safely treated by CT-guided RFA using the presented ablation protocol. Beneficial effects of the treatment persist at long-term follow-up.

Noninvasive Therapy for Osteoid Osteoma: A Prospective Developmental Study with MR Imaging-guided High-Intensity Focused Ultrasound

Purpose To demonstrate that magnetic resonance (MR) imaging-guided high-intensity focused ultrasound (HIFU) is a safe, effective, and durable treatment option for the management of osteoid osteoma in children and young adults. Materials and Methods This prospective study was institutional review board approved and is registered with clinicaltrials.gov (identification number NCT02302651). Written informed consent was obtained from patients or their parents. Patients who had both clinical and radiologic findings that were diagnostic for nonvertebral osteoid osteoma and no contraindications to MR imaging-guided HIFU were enrolled between June 2010 and June 2013. The feasibility, safety, and clinical effectiveness of MR imaging-guided HIFU were considered primary outcomes; tumor control at imaging was considered a secondary outcome. Analyses were conducted on a per-protocol basis. Results Forty-five of the 50 recruited patients underwent MR imaging-guided HIFU. All patients were discharged without treatment-related complications. The median visual analog scale (VAS) pain score (scale, 0-10) decreased from 8 before treatment to 0 at 1-week and 1- , 6- , 12- , 24- , and 36-month follow-up. Similarly, median VAS scores for the degree to which pain interfered with sleep and physical and daily activities decreased to 0 within the 1st month after treatment and remained stable at subsequent follow-up. Overall, 39 (87%) of the 45 patients achieved and maintained a VAS score of 0 during the 3-year observation period. Quality of life, as assessed by using Functional Assessment of Cancer Therapy-Bone Pain (FACT-BP) scores (scale, 0-60 points), improved, with the median FACT-BP score of 28 (points) before treatment increasing to a median score of 55 at 1-week follow-up and 60 at 6-month and subsequent follow-ups. At (final) 36-month follow-up, MR imaging depicted an absence of residual nidus vascularity in 32 (76%) of the 42 patients who were treated with MR imaging-guided HIFU only. Conclusion The durable clinical efficacy and safety of MR imaging-guided HIFU were demonstrated. These features are evidence of the potential of MR imaging-guided HIFU to be part of a routine strategy for the treatment of osteoid osteoma. ^© RSNA, 2017.

Minimally invasive treatments of painful bone lesions: state of the art

The role of the interventional radiology (IR) in the musculoskeletal system, and in particular in the bone, is a field of knowledge that is growing significantly in the last years with indications for treatment of both benign and malign lesions. In this paper, we review the state of the art of this application of the IR in the bone (bone metastasis and benign bone lesions) with discussion about all the techniques today used.

In vivo effects of radiofrequency ablation on long bones and the repair process in swine models

PURPOSE

To investigate in vivo effect of radiofrequency ablation (RFA) on swine long bones and the repair process.

MATERIALS AND METHODS

RFA was performed in six swine at the end and middle part of the tibia or femur. After RFA, radiological examinations were performed, and the swine were killed immediately and at different time points post-RFA for histopathological examination.

RESULTS

All swine had successful RFA. The RFA-induced elliptical necrotic area ranged from 3.81-5.24 cm² (mean 4.08 ± 0.73 cm²) at the bone end but 5.60-8.98 cm² (mean 7.58 ± 1.41) at the middle part immediately after RFA until 10 days, with the necrosis area significantly smaller (P = 0.000) at the end than at the middle. RFA only damaged the cortical bone slightly (0.01 cm thick) with no damage to the soft tissues outside the compact bone at both the end and middle. Surrounding the elliptic pale zone of coagulative necrosis was a narrow brown band of hemorrhage and inflammatory exudate. From day 10 until week 12, tissue proliferation and repair became increasingly apparent, with proliferated granulation, fibrous tissue, and fresh and mature bone trabecula.

CONCLUSION

RFA can quickly and effectively destroy the cancellous bone tissue without affecting the cortical bone and activate bone remodeling.

Intra-articular osteoid osteoma as a differential diagnosis of diffuse mono-articular joint pain

Background

The aim of this retrospective study was to investigate the frequency of intra-articular osteoid osteoma (iaOO) in a large study cohort and to demonstrate its clinical relevance as an important differential diagnosis of non-specific mono-articular joint pain.

Methods

We searched the registry for bone tumours of the University Medical Centre Hamburg-Eppendorf for osteoid osteomas in the last 42 years. Herein, we present three selected iaOO which were detected in the three major weight-bearing joints. Computed tomography (CT) or magnetic resonance imaging (MRI) scans were performed for initial diagnosis.

Results

Out of a total of 367 osteoid osteomas, 19 (5.2 %) tumours were localized intra-articularly. In all three presented tumours, a history of severe mono-articular pain was reported; however, the mean time to correct diagnosis was delayed to 20.7 months. Clearly, the nidus seen in CT and MRI images in combination with inconsistent salicylate-responsive nocturnal pain led to the diagnosis of iaOO.

Conclusions

Rarely, osteoid osteoma can occur in an intra-articular location. In cases of diffuse mono-articular pain, iaOO should be considered both in large and smaller joints to avoid delays in diagnosis and therapy of this benign bone tumour.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1313-3) contains supplementary material, which is available to authorized users.

Radiofrequency ablation of osteoid osteoma using a three-dimensional navigation system

OBJECTIVE

This study aimed to report the clinical outcomes for patients with osteoid osteoma (OO) treated by radiofrequency ablation (RFA) using a three-dimensional (3D) navigation system.

METHODS

We performed RFA using a 3D navigation system on 32 patients with clinically and radiologically diagnosed OO. This study included 25 males and 7 females with a median age of 20 years (range, 10-39 years). The median duration of follow-up was 18 months (range, 1-65 months). We investigated technical specifications, tumor localization, technical success, clinical success, biopsy success, complications, incomplete treatment, and recurrences.

RESULTS

Eighteen tumors were located in the femur, seven in the tibia, two in the humerus, and one each in the fibula, scapula, patella, lumbar vertebra, and acetabula. All procedures were technically successful, and pain relief was achieved in all patients. However, local recurrence developed in one patient, needing additional RFA. The clinical success rate was 96.8%. Biopsy showed OO in 12 patients (37%). Complications occurred in three patients (9%), two cases of fractures and one of osteomyelitis.

CONCLUSIONS

A 3D navigation provides real-time imaging and enables us to set the RFA needle in the correct position, particularly in case of OO-aroused complex anatomical structures. Our initial results indicated that radiofrequency ablation using a 3D navigation system is feasible and safe for patients with OO.

Long-term clinical outcomes of dual-cycle radiofrequency ablation technique for treatment of osteoid osteoma

PURPOSE

Radiofrequency ablation technique for treatment of OO including ablation time and temperature vary greatly between and within reported studies. This study evaluates the immediate and long-term efficacy and complication rate of a two sequential RFA technique for OO.

MATERIALS AND METHODS

We retrospectively reviewed medical records and attempted interview follow-up for 25 patients treated with RFA for OO. Each treatment included 2 consecutive RFAs at 90 °C for 6 min with inter-ablation cooling to 40 °C and occasional inter-ablation probe adjustment. Additionally, we statistically compared the proportion of successful ablations using the DCRFA technique with published studies that utilized alternative OO ablation procedures.

RESULTS

Long-term follow-up was obtained for 24 patients (96 %). Mean patient age at DCRFA was 17.2 years (range, 2.2-50.0 years). Mean time to follow-up was 60 ± 42 months (range 12-152 months). No acute DCRFA-related complications nor long-term recurrences were reported. All 24 interviewed patients reported partial relief of pre-procedural pain within 1 day of DCRFA and total relief within 1 week of DCRFA. One patient ultimately developed a major late complication (complex regional pain syndrome of the left ankle) after DCRFA of a cuboid lesion. Additionally, the DCRFA success rate was significantly higher when compared to two other published OO RFA treatment results.

CONCLUSION

DCRFA employing two sequential 6-min cycles is an effective treatment of OO. The 100 % primary success rate, 0 % long-term recurrence rate, and low complication rate compare favorably and may be superior to results of prior reports.

[Osteoidosteoma. From diagnosis to treatment]

An osteoid osteoma is a benign bone-forming tumor which usually presents in childhood and adolescence and is characterized by extensive nocturnal pain. Computed tomography (CT) is used to reveal the typical radiolucent nidus surrounded by a sclerotic reaction and in magnetic resonance imaging (MRI) a nidal enhancement and perifocal edema can confirm the diagnosis. Having shown excellent success rates radiofrequency ablation has become the treatment of choice which allows minimally invasive and precise destruction of nidal tumor tissue. By using thermal protection techniques and multiple ablation positions successful therapy of perineural tumors and niduses with diameters of more than 2 cm are possible.

Percutaneous Image-guided Laser Photocoagulation of Spinal Osteoid Osteoma: A Single-Institution Series

PURPOSE

To retrospectively evaluate the safety and efficacy of percutaneous image-guided laser photocoagulation for the treatment of spinal osteoid osteoma (OO) in proximity to neural structures.

MATERIALS AND METHODS

This study was institutional review board-approved with waivers of informed consent. From January 1994 until October 2014, 58 patients with spinal OO (mean age, 25 years; 40 men, 17 women) were treated in one institution by using laser photocoagulation with combined computed tomographic (CT) and fluoroscopic guidance. One patient was excluded because of less than 3 months of follow-up. All patients had typical clinical and imaging findings. Clinical features, radiologic data, and procedure-related data were reviewed, and limitations, complications, and failure rate were evaluated. All data were expressed as means ± standard deviation. P values of less than .05 were indicative of statistical significance.

RESULTS

OO was in the vertebral body for 18 of 57 patients, the neural arch for 21 of 57 patients, and the articular process for 18 of 57 patients. Mean nidal diameter was 8 mm, and the mean distance from the closest neural structure was 6.6 mm (minimum distance, ≤5 mm in 35 of 57 patients). In 35 of 57 patients, no cortical coverage was present between the nidus and neural structure in danger. Mean total energy delivered was 1271 J (2-watt continuous power mode). Thermal insulation (carbon dioxide and/or hydrodissection), temperature monitoring, and electrostimulation were used in 42, 24, and one patient, respectively. Primary clinical success at 1 month was 98.2%. Total recurrence rate was 5.3%. All recurrences were addressed percutaneously. Secondary success rate was 100%. One-year follow-up is available in 54 of 57 patients. No major complications were noted.

CONCLUSION

Spinal OO can be safely and effectively treated with percutaneous laser photocoagulation. In cases that are less than 8 mm to 10 mm distance and in the absence of cortical coverage, thermal protection techniques of the neural structures should be used.