Computed Tomography Guided Radiofrequency Ablation Research Articles

Radio frequency ablation of an ilio-sacral schwannoma

We describe the successful treatment of an ilio-sacral schwannoma using Computed Tomography–Guided Radio Frequency Ablation (CT-RFA).

Computed tomography guided radiofrequency ablation of osteoid osteoma in children: a single center's experience.

To report a single center's experience evaluating the efficacy and safety of computed tomography-guided radiofrequency ablation for the treatment of osteoid osteoma in children. Institutional database research identified 33 symptomatic patients (≤ 18years of age; male/female ratio: 21/12, mean age 13.09 ± 3.66) with osteoid osteoma who were treated by CT-guided RFA. Technical and clinical success as well as complication rates were recorded. The duration of the procedure, the number of computed tomography scans and the results of the biopsy were assessed. Pain, prior, the following morning and 1week, 1/6/12months after the procedure were compared by means of a numeric visual scale (NVS) questionnaire. Mean lesion size was 8.28 ± 4.24mm. Mean follow-up was 23.33 ± 17.61months (range 12-62). Mean pain score prior to radiofrequency ablation was 9.06 ± 0.80 NVS units. On week 1 and 1/6/12months, all patients were pain-free reporting 0 NVS units (p < 0.05). The mean procedure time was 54min (range 51-59) and a mean of 7 CT scans were performed during the ablation session. RF electrode was successfully placed in the center of the nidus in all cases. In our study, none of our patient experienced recurrence of the pain, nor complications. The present study demonstrates that percutaneous CT-guided radiofrequency ablation constitutes a safe and effective technique for osteoid osteoma treatment in children.

Our experience with osteoid osteomas treated by percutaneous radiofrequency ablation

Aim: Evaluating the outcome of computed tomography (CT) guided percutaneous radiofrequency ablation in the treatment of osteoid osteoma in unattainable region. Material and Methods: 12 patients between 12 - 30 years of age with osteoid osteoma were selected and treated by percutaneous CT guided radio-frequency ablation. All the patients had complained of pain. Evaluation done with x-ray, CT, MRI and bone scintigraphy. The lesion is heated to 900 C for a minimum of 6 minutes by Radiofrequency ablation under general anaesthesia. Results: All patients had complete relief of pain after radiofrequency ablation and was fully weight bearing without any support. Local erythema was noted in 6 patients, paresthesia was observed in 2 patients, 1 patients had a small cortical chip fracture at entry site of needle which healed spontaneously and 3 cases of minor thermal injury of skin were noted which required dressing with 0.2% Silver Nitrate ointment. Patients were followed up for 2 years (24 months), and no recurrence was reported. Conclusion: CT guided percutaneous radiofrequency ablation is an effective, minimally invasive and economic treatment method for osteoid osteomas.

Computed tomography guided radiofrequency ablation of osteoid osteoma in technically challenging locations: Tracking through the opposite cortex

Computed tomography (CT)-guided percutaneous radiofrequency (RF) ablation is an established minimally invasive treatment option of osteoid osteoma. The standard technique involves the percutaneous advancement of an RF probe under CT-guidance through the cortex overlying the nidus of osteoid osteoma in a plane oriented perpendicular to the cortex. In certain specific scenarios, aiming the osteoid osteoma nidus through the overlying cortex is not feasible either due to technical limitations or due to the potential risk of complications. The nidus can be approached through the opposite unaffected cortex in these situations, obviating the need for surgical excision. Performing CT-guided RF ablation of osteoid osteoma through the opposite unaffected cortex is a technically demanding procedure; and, thus requires a high level of expertise. There is a paucity of literature highlighting the RF ablation procedure in technically challenging locations and thus forms the cornerstone of our current technical note.

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

PurposeTo 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 MethodsDatabase 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. ResultsOf 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. ConclusionsThe 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.

Feasibility and safety of percutaneous computed tomography guided radiofrequency ablation of lymph nodes in oligometastatic patients: a single center's experience.

To retrospectively evaluate feasibility and safety of CT-guided percutaneous radiofrequency ablation (RFA) of metastatic lymph nodes (LN) in terms of achieving local tumor control. Institutional database research identified 16 patients with 24 metastatic LNs who underwent percutaneous CT-guided radiofrequency ablation. Mean patient age was 66.6 ± 15.70 years (range 40-87) and male/female ratio was 8/8. Contrast-enhanced CT or MRI was used for post-ablation follow-up. Patient and tumor characteristics and RFA technique were evaluated. Technical and clinical success on per tumor and per patient basis as well as complication rates were recorded. Mean size of the treated nodes was 1.78 ± 0.83 cm. The mean number of tumors per patient was 1.5 ± 0.63. The mean procedure time was 56.29 ± 24.27 min including local anesthesia, electrode(s) placement, ablation and post-procedural CT evaluation. Median length of hospital stay was 1.13 ± 0.34 days. On a per lesion basis, the overall complete response post-ablation according to the mRECIST criteria applied was 75% (18/24) of evaluable tumors. Repeat treatment of an index tumor was performed on two patients (three lesions) with complete response achieved in 87.5% (21/24) of evaluable tumors following a second RFA. On a per patient basis, disease progression was noted in 10/16 patients at a mean of 13.9 ± 6.03 months post the ablation procedure. CT-guided percutaneous RFA for oligometastatic LNs is a safe and feasible therapy. With this percutaneous therapeutic option, metastatic LNs can be eradicated with a very low complication rate.

Computed tomography-guided radiofrequency ablation combined with transarterial embolization assisted by a three-dimensional visualization ablation planning system for hepatocellular carcinoma in challenging locations: a preliminary study

ObjectiveTo assess the clinical efficacy and safety of computed tomography-guided radiofrequency ablation(CT-RFA) combined with transarterial embolization(TAE) assisted by a three-dimensional visualization ablation planning system(3DVAPS) for hepatocellular carcinoma(HCC) in challenging locations.MethodsData from 62 treatment-naive patients with hepatocellular carcinoma(HCC), with 83 lesions in challenging locations, and who met the Milan criteria and underwent CT-RFA between June 2013 and June 2016 were reviewed. Patients were divided into one of two groups according to different treatment modalities: study group (TAE combined with RFA assisted by 3DVAPS [n = 32]); and control (RFA only [n = 30]). Oncological outcomes included ablation-related complications, local tumor progression (LTP), and overall survival (OS). Univariate and multivariate Cox proportional hazards regression analyses were performed to assess risk factors associated with LTP and OS.ResultsHCC lesions (mean size, 1.9 ± 1.0 mm in diameter) abutting the gastrointestinal tract (n = 25), heart and diaphragm (n = 21), major vessels (n = 13), and gallbladder (n = 3) were treated. A significant difference was detected in LTP between the two groups (P = 0.034), with no significant difference in OS between the two groups (P = 0.193). There were no severe complications related to ablation. Univariate analysis revealed that sex (P = 0.046) and child-turcotte-pugh (CTP) grade (P<0.001) were risk factors for OS, whereas CTP grade and treatment method (P<0.001) were risk factors for LTP. Multivariate analysis revealed that CTP grade B (P = 0.005) was independently associated with poor OS, and RFA alone (P<0.001) was independently associated with poor LTP.ConclusionCT-RFA combined with TAE assisted by a 3DVAPS provided ideal clinical efficiency for HCC in challenging locations and was a highly safe treatment modality.

Computed tomography guided radio-frequency ablation of osteoid osteomas in atypical locations.

Purpose:Percutaneous radio-frequency ablation is a minimally invasive treatment option for osteoid osteomas. The ablation process is straightforward in the more common locations like the femur/tibia. Surgery has historically been the gold standard, but is currently used in lesions, that may not be effectively and safely ablated, i.e. close to skin/nerve. Radio-frequency ablation can still be used in such cases along with additional techniques/strategies to protect the sensitive structures and hence improve the outcomes. The authors describe their experience with four challenging osteoid osteoma ablation cases.Methods:We retrospectively reviewed radio-frequency ablations of four osteoid osteomas in rather atypical locations, the protective techniques/strategies employed, the adequacy and safety of the radio-frequency ablation with the use of these techniques.Results:All patients had complete resolution of pain with no recurrence in the follow-up period. No complications were reported.Conclusion:RFA has been proven to be an effective and safe option for treatment of OOs in the common locations. It is generally recommended to have a 1 cm safety margin between the RF probe and any critical structures in the vicinity. However, with OOs in atypical locations this may not be always possible and hence additional techniques may be needed to ensure protection of the surrounding sensitive structures and also allow for effective ablation.

Radiofrequency Ablation, Cryoablation, and Microwave Ablation for T1a Renal Cell Carcinoma: A Comparative Evaluation of Therapeutic and Renal Function Outcomes

PurposeTo compare the therapeutic and renal function outcomes of radiofrequency (RF) ablation, cryoablation, and microwave (MW) ablation for treatment of T1a renal cell carcinoma (RCC). Materials and MethodsA retrospective assessment of 297 patients (mean age 72 years range 24–90 years) with biopsy-proven RCC treated with image-guided percutaneous thermal ablation was performed between October 2006 and December 2016. Mean tumor size was 2.4 cm; mean radius, exophytic/endophytic properties, nearness of tumor to collecting system or sinus, anterior/posterior, hilar tumor touching the main renal artery or vein, and location relative to polar lines; Preoperative Aspects and Dimensions Used for an Anatomical; and c-centrality scores were 6.0, 7.0, and 2.8, respectively. Assessments of adverse events, treatment efficacy, and therapeutic outcomes were performed among RF ablation, cryoablation, and MW ablation. The 2-year disease-free, metastatic-free, and cancer-specific survival rates were tabulated. Estimated glomerular filtration rate was used to assess for treatment related changes in renal function. ResultsA total of 297 T1aN0M0 biopsy-proven RCCs measuring 1.2–3.9 cm were treated with computed tomography–guided RF ablation (n = 244, 82%), cryoablation (n = 26, 9%), and MW ablation (n = 27, 9%). There were no significant differences in patient demographics among the 3 groups (P = .09). Technical success rates were similar among the 3 treatments (P = .33). Primary efficacy at 1 month postablation was more likely to be achieved with RF ablation and MW ablation than with cryoablation. At 2 years’ follow-up, there was no local recurrence, metastatic progression, or RCC-related death observed in the 3 groups. There was no significant change in estimated glomerular filtration rate among the 3 ablation groups compared with baseline at 2-year follow-up (P = .71). ConclusionRF ablation, cryoablation, and MW ablation are equivalent at 2 years for treatment of T1a RCC for therapeutic outcome, stability of renal function, and low adverse event rate.

Comparison of General Anesthesia and Conscious Sedation During Computed Tomography–Guided Radiofrequency Ablation of T1a Renal Cell Carcinoma

PurposePercutaneous radiofrequency ablation is so painful that this treatment requires pain control such as conscious sedation or general anesthesia. It is still unclear which type of anesthesia is better for treatment outcomes of renal cell carcinoma. This study aimed to compare general anesthesia and conscious sedation in treating patients with renal cell carcinoma with radiofrequency ablation. MethodsBetween 2010 and 2015, 51 patients with biopsy-proven renal cell carcinomas (<4 cm) were treated with computed tomography–guided radiofrequency ablation. General anesthesia was performed in 41 and conscious sedation was performed in 10 patients. Tumour size, local tumour progression, metastasis, major complication, effective dose, glomerular filtration rate difference, and recurrence-free survival rate were compared between these groups. ResultsThe mean tumour size was 2.1 cm in both groups (P = .673). Local tumour progression occurred in 0% (0 of 41) of the general anesthesia group, but in 40% (4 of 10) of the conscious sedation group (P = .001). Metastases in these groups occurred in 2.4% (1 of 41) of the general anesthesia group and 20% (2 of 10) of the conscious sedation group (P = .094). No major complications developed in either group after the first radiofrequency ablation session. The mean effective doses in these groups were 21.7 mSv and 21.2 mSv, respectively (P = .868). The mean glomerular filtration rate differences in the general anesthesia and conscious sedation groups were -13.5 mL/min/1.73 m2 and -19.1 mL/min/1.73 m2, respectively (P = .575). Three-year recurrence-free survival rates in these groups were 97.6% and 60.0%, respectively (P = .001). ConclusionsGeneral anesthesia may provide better intermediate outcomes than conscious sedation in treating small renal cell carcinomas with radiofrequency ablation.

Clinical assessment of computed tomography guided radiofrequency ablation in the treatment of inoperable patients with pulmonary tumors.

To enhance our understanding of the feasibility, effectiveness, safety and quality of life (QoL) of radiofrequency ablation (RFA) for inoperable patients with pulmonary tumors. The data of 88 patients with pulmonary tumors undergoing RFA were collected. Proof of malignancy was obtained by biopsy in all patients. Diagnoses included non-small cell lung cancer (NSCLC) in 74 patients and pulmonary metastases in 14 patients. Patients underwent computed tomography (CT)-guided RFA according to standard protocol and had a 2-year follow-up. Results assessment included feasibility (correct placement of the ablation probe into all targeted tumors), effectiveness (overall survival rate and local control rate), safety (treatment-related complication and changes in pulmonary function) and QoL. One hundred and thirty-four RFAs were successfully conducted in 88 patients with 96 nodules. Correct placement of ablation probe into targeted tumors with completion of the planned treatment protocol was feasible in all 88 (100%) patients and no procedure-related deaths occurred. Major complication rate was 4.5% (4/88), which consisted of symptomatic pneumothorax (2/88) and high fever (2/88). No significant worsening of pulmonary function was observed. Tumors shrank obviously at 6 months after RFA with a statistically significance (P<0.001).The overall survival rate in 6 months, 1 year and 2 years were 100%, 95.5% and 70.5%, respectively while the local control rate in 6 months, 1 year and 2 years were 92.1%, 87.5% and 51.1% respectively. There was no significant difference of overall survival rate and local control rate between NSCLC and metastatic carcinoma. No significant worsening of QoL was observed. CT-guided RFA is a feasible, effective and safe therapy for inoperable patients with pulmonary tumors. However, RFA could not obviously improve the QoL in the patients with pulmonary tumors. More prospective studies comparing RFA with standard non-surgical treatment options were needed.

CT-guided versus laparoscopic radiofrequency ablation in recurrent small hepatocellular carcinoma against the diaphragmatic dome

Computed tomography-guided radiofrequency ablation (CT-RFA) and laparoscopic RFA (L-RFA) have been used to treat intrahepatic recurrent small hepatocellular carcinoma (HCC) against the diaphragmatic dome. However, the therapeutic safety, efficacy, and hospital fee have never been compared between the two techniques due to scarcity of cases. In this retrospective study, 116 patients were divided into two groups with a total of 151 local recurrent HCC lesions abutting the diaphragm. We compared overall survival (OS), local tumor progression (LTP), postoperative complications, and hospital stay and fee between the two groups. Our findings revealed no significant differences in 5-year OS (36.7% vs. 44.6%, p = 0.4289) or 5-year LTP (73.3% vs. 67.9%, p = 0.8897) between CT-RFA and L-RFA. The overall hospital stay (2.8 days vs. 4.1 days, p < 0.0001) and cost (¥ 19217.6 vs. ¥ 25553.6, p < 0.0001) were significantly lower in the CT-RFA in comparison to that of L-RFA. In addition, we elaborated on the choice of percutaneous puncture paths depending on the locations of the HCC nodules and 11-year experience with CT-RFA. In conclusion, CT-RFA is a relatively easy and economic technique for recurrent small HCC abutting the diaphragm, and both CT-RFA and L-RFA are effective techniques.

Evaluation of efficacy of transcatheter arterial chemoembolization combined with computed tomography-guided radiofrequency ablation for hepatocellular carcinoma using magnetic resonance diffusion weighted imaging and computed tomography perfusion imaging: A prospective study.

Background:The purpose of this study is to evaluate the efficacy of transcatheter arterial chemoembolization (TACE) combined with computed tomography-guided radiofrequency ablation (CT-RFA) in the treatment of hepatocellular carcinoma (HCC) using magnetic resonance diffusion weighted imaging (MR-DWI) and CT perfusion imaging (CT-PI).Methods:From January 2008 to January 2014, a total of 522 HCC patients receiving TACE combined with CT-RFA were included in this study. All patients underwent TACE followed by CT-RFA, and 1 day before treatment and 1 month after treatment they received MR-DWI and CT-PI. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the concentration of alpha-fetoprotein (AFP). Tumor response was evaluated using the revised RECIST criteria. One-year follow-up was conducted on all patients. Receiver-operating characteristic (ROC) curve was drawn to evaluate the efficacy of TACE combined with CT-RFA for HCC using MR-DWI and CT-PI.Results:Total effective rate (complete remission [CR] + partial remission [PR]) of TACE combined with CT-RFA for HCC was 82.95%. HCC patients of CR + PR had lower hepatic blood flow (HBF), hepatic blood volume (HBV), permeability surface (PS), hepatic arterial perfusion (HAP), and hepatic perfusion index (HPI) levels than those of SD + PD, but HCC patients of CR + PR had higher mean transit time (MTT) level than those of SD + PD. The patients of PR + CR had higher apparent diffusion coefficient (ADC) values than those of SD + PD. The patients of PR + CR showed lower AFP concentration than those of SD + PD. ROC curve analysis indicated that the area under the curve (AUC) of AFP, HBV, PS, HAP, HPI, and ADC was more than 0.7, but the AUC of HBF, MTT, and PVP were less than 0.7. After treatment, the AFP, HBF, HBV, PS, HAP, and HPI in the HCC patients with recurrence were higher than those in the HCC patients without, but MTT and ADC in the HCC patients with recurrence were lower than those in the HCC patients without.Conclusion:These findings indicate that MR-DWI and CT-PI can effectively evaluate the efficacy of TACE combined with CT-RFA and postoperative recurrence of HCC.

Unrecognized osteoid osteoma of the proximal femur with associated cam impingement.

Femoro-acetabular impingement is a common cause of hip pain in young athletes. Evaluation typically includes radiographs and magnetic resonance imaging. It is important to appreciate uncommon diagnoses and the role of complimentary imaging. This clinical vignette emphasizes the need complete imaging with CT in select case of atypical hip pain.We present a 19-year old soccer player who underwent seemingly successful arthroscopic FAI surgery but returned with pain. Computed tomography (CT) revealed osteoid osteoma of the lesser trochanter. The lesion was successfully treated with percutaneous CT guided radiofrequency ablation.

CT Guided Radiofrequency Ablation Followed Intratumoral Chemotherapy in the Treatment of Early Stage Non-small Cell Lung Cancer

背景与目的射频消融（radiofrequency ablation, RFA）已经成为无法手术的早期非小细胞肺癌（non-small cell lung cancer, NSCLC）的局部治疗方法之一。本研究观察计算机断层扫描（computed tomography, CT）引导下RFA与瘤内化疗（intratumoral chemotherapy, ITC）（RFA-ITC）的有效性和安全性。方法自2005年1月至2015年12月研究组前瞻性入组经病理学证实为早期NSCLC，因心肺功能较差或伴发其他疾病而无法耐受手术或拒绝手术的患者，接受RFA-ITC治疗。RFA采用导向器辅助CT引导穿刺准实时步进法，适形伞状电极、单点或多点消融，完成治疗计划并当CT显示肿瘤周围正常肺组织呈现磨玻璃样后结束消融治疗，经电极针将卡铂200 mg缓慢注射到肿瘤内。随访评估安全性和有效性。结果110例患者125次RFA-ITC治疗，技术成功率为100%。中位生存期为48.0个月，总生存率为55.4个月，无进展生存期为55.1个月；1年、2年、3年、5年总生存率分别为100%、90.7%、62.7%、21.9%。消融后有和无磨玻璃样改变的生存期分别是68.3个月、40.1个月，有统计学差异（P=0.001）。肿瘤的大小及有无N1分期的生存率无差异。无围手术期死亡发生，气胸、肺内出血、胸腔积液、发热、术中胸痛、皮下气肿、术中咳嗽等并发症轻微可耐受。结论CT引导RFA-ITC治疗不能手术的早期NSCLC，疗效好、并发症少，对患者损伤小，为不能手术治疗的早期NSCLC的治疗提供了一个良好方法。

Efficacy of Computed Tomography Guided Radiofrequency Ablation for Osteoid Osteomas in 31 Patients

Efficacy of Computed Tomography Guided Radiofrequency Ablation for Osteoid Osteomas in 31 Patients

Retroperitoneal schwannoma treated with percutaneous computed tomography–guided radiofrequency ablation

Retroperitoneal schwannomas (RSs) are particularly rare tumors, and resection is the first choice for symptomatic patients. However, some RSs with anatomical complexities pose great challenges for surgeons attempting radical resection without sacrificing the nearby critical structures, and subtotal resection leads to local recurrence, especially in refractory malignant RSs. The authors have successfully applied percutaneous CT-guided radiofrequency ablation in 2 cases of RSs, with favorable long-term progression-free survival.

Cost comparison of nephron-sparing treatments for cT1a renal masses

ObjectivesTreatment options for small renal tumors have evolved from radical nephrectomy (RN) to partial nephrectomy (PN), thermal ablation, or active surveillance. With the advancement of techniques, costs differences are unclear. The objective of this study is to compare the 6-month costs associated with nephron-sparing procedures for cT1a renal tumors. Materials and methodsWe performed a review of patients diagnosed with a solitary cT1a renal mass who underwent surgical treatment from June 2008 to May 2011. Open partial nephrectomy (OPN), robot-assisted partial nephrectomy (RLPN), laparoscopic radio-frequency ablation (LRFA), or computed tomography guided radio frequency ablation (CTRFA) was performed on 173 patients. Cost data were collected for surgical costs, associated hospital stay, and the 6-month postoperative period. ResultsPatients underwent surgery, including 52 OPN, 48 RLPN, 44 LRFA, and 29 CTRFA. Median total costs associated were $17,018, $20,314, $13,965, and $6,475, for OPN, RLPN, LRFA, and CTRFA, respectively. When stratified by approach differences were noted for total cost (P < 0.001), operating room (OR) time (P < 0.001), surgical supply (P < 0.001), and room and board (P < 0.001) in univariable analysis. Multivariable linear regression (R2 = 0.966) showed surgical approach (P = 0.007), length of stay (P < 0.001), and OR time (P < 0.001) to be significant predictors of total cost. However, tumor size (P = 0.175), and Charlson comorbidity index (P = 0.078) were not statistically significant. ConclusionsSix-month cost of nephron-sparing surgery is lowest with radio frequency ablation (RFA) by either laparoscopic or computed tomography (CT)-guided approach compared to RLPN and OPN. As oncologic and safety outcomes improve and become comparable in all nephron-sparing surgery (NSS) approaches, cost of each procedure will start to play a stronger role in the clinical and healthcare policy setting.

CT-guided radiofrequency ablation of osteoid osteoma in the long bones of the lower extremity

To present our initial experience with computed tomography guided radiofrequency ablation (RFA) of osteoid osteoma (OO) in our institution. RFA was performed on eight patients (5 males and 3 females) with clinically and radiologically diagnosed OO (femoral neck, n = 4; femoral diaphysis, n = 2; tibial diaphysis, n = 1; fibular diaphysis, n = 1). Ablation was performed using an electrode with a 10-mm exposed tip for a total of 4-6 min at a targeted temperature of 90 degrees Celsius. No cooling system was used. The intervention was accepted as technically successful if the tip of the electrode could be placed within the center of the nidus. We defined clinical success as a disappearance within 2 wk after treatment of symptoms that had manifested at presentation. All procedures were technically successful. No major or immediate complications were observed. Clinical success was achieved in six of eight patients in the first procedure. A second procedure was performed for two patients who had recurrent or continued pain, and one of these cases was successfully treated. The overall rate of success was 87.5% (7/8). No complication was observed. Our preliminary results indicate a favorable success rate and no complications and are compatible with the previous reports of RFA of OO.

Magnetic Resonance Imaging–Guided Laser Ablation of Bone Tumors

Image-guided thermal ablation of bone tumors is gaining acceptance in the oncology community. Computed tomography-guided radiofrequency ablation and cryoablation are widely available and are used in clinical practice. However, a potentially devastating complication of these techniques is thermal injury to the spinal cord and nerve roots in patients with tumors involving the vertebra, paraspinal tissues, or pelvis. Magnetic resonance imaging-guided laser ablation with quantitative magnetic resonance temperature imaging is a novel technique that allows for accurate imaging of the tumor, real-time placement of laser fibers, and real-time monitoring of the ablation zone. With this technique, target temperature thresholds are placed on critical neural elements to provide real-time feedback that allows for automatic deactivation of the laser when the threshold temperature is reached. The ablation zone is generated quickly, with sharp and well-demarcated boundaries. As such, magnetic resonance imaging-guided laser ablation may be a safer technique for ablating bone tumors in the vicinity of the spinal cord, nerve roots, and peripheral nerves.