Image-guided ablation of painful metastatic bone tumors: a new and effective approach to a difficult problem

Safe and effective intraosseous basivertebral nerve radiofrequency neurotomy in a patient with a permanent pacemaker

Introduction

Intraosseous basivertebral nerve radiofrequency neurotomy is a fairly novel technique which is currently considered contraindicated in patients with an implanted pacemaker. Re-evaluation of this restriction is important given the comorbidity of chronic low back pain and cardiac disease.

Case

A 78-year-old male with chronic low back pain (CLBP) that had failed both conservative and operative management with work-up including MRI spine suggestive of vertebrogenic low back pain. Patient agreed to undergo this procedure using a magnet to convert the active pacemaker to asynchronous pacing, resulting in fixed ventricular rate, perioperatively. The procedure was accomplished successfully with sustained improvement of his CLBP at six months follow up.

Conclusion

This is the first published case demonstrating successful intraosseous basivertebral nerve radiofrequency neurotomy in a patient with a permanent pacemaker with appropriate precautions.

Mini-open periacetabular cementoplasty for periacetabular bone metastasis: a report of two cases

Bone metastasis in the periacetabular region usually causes severe pain and functional disability. Some surgical procedures, such as the Harrington surgery and percutaneous cementoplasty, have been reported as treatment options for periacetabular bone metastases with limited efficacy. The former is highly invasive, while the latter may not allow the injection of a sufficient amount of cement. Here we report two surgical cases using a new modified surgical method (mini-open periacetabular cementoplasty: MO-PAC) consisting of tumor curettage and cementoplasty through a small incision.

Evaluation of Conditions for the Development of Cryogenic Spinal Cord Injury Using a Canine Model: An Experimental Study on the Safety of Cryoablation for Metastatic Spinal Tumors

BACKGROUND AND PURPOSE

Although the application of cryoablation to metastatic spinal tumors has been attempted, spinal cryoablation has the unique complication of cryogenic spinal cord injury. This study aimed to elucidate the conditions for the development of cryogenic spinal cord injury.

MATERIALS AND METHODS

Fifteen canines were used in this study. A metal probe was inserted into the 13th thoracic vertebral body. Cryoablation was performed for 10 minutes by freezing the probe in liquid nitrogen. The control canine underwent probe insertion only. Spinal cord monitoring, epidural temperature measurement, motor function assessment, and pathologic examination of the spinal cord were performed.

RESULTS

During the 10 minutes of cryoablation, the epidural temperature decreased and reached the lowest epidural temperature (LET) at the end of cryoablation. The LETs (degrees celsius [°C]) of each canine were -37, -30, -27, -8, -3, -2, 0, 1, 4, 8, 16, 18, 20, and 25, respectively. As the epidural temperature decreased, waveform amplitudes also decreased. At the end of cryoablation (10 minutes after the start of cryoablation), abnormal waves were observed in 92.9% (13/14) of canines. With epidural rewarming, the amplitude of the waveforms tended to recover. After epidural rewarming (2 hours after the start of cryoablation), abnormal waves were observed in 28.6% (4/14) of canines. The LETs (°C) of the canines with abnormal waves after epidural rewarming were -37, -30, -27, and -8. None of the canines with normal waves after epidural rewarming had any motor impairment. In contrast, all canines with remaining abnormal waves after epidural rewarming had motor impairment. In the pathologic assessment, cryogenic changes were found in canines with LETs (°C) of -37 -30, -27, -8, 0, and 1.

CONCLUSIONS

This study showed that 10-minute spinal cryoablation with LETs (°C) of -37, -30, -27, -8, 0, and 1 caused cryogenic spinal cord injury. There was no evidence of cryogenic spinal cord injury in canines with LET of ≥4°C. The epidural temperature threshold for cryogenic spinal cord injury is between 1 and 4°C, suggesting that the epidural temperature should be maintained above at least 4°C to prevent cryogenic spinal cord injury.

Complications of cryoprobe cryoablation as a surgical adjuvant for the treatment of metastatic carcinoma to bone, benign bone tumors, and soft tissue tumors: A series of 148 patients

BACKGROUND AND OBJECTIVE

This study describes the complication profile of modern cryoablation utilizing probes as an adjuvant during open surgical treatment of orthopedic tumors.

METHODS

A retrospective, single-surgeon study was performed for patients receiving cryoprobe cryoablation. Demographic information, malignancy-related and operative details, and clinical courses were collected. Outcomes assessed included rates of complications, recurrence, and correlations between the number of probes or cryoablation cycles performed.

RESULTS

In this 148-patient study, 67.6% had metastatic carcinoma to bone, 27.7% had benign bone tumors, and 4.7% had soft tissue tumors. An average of 3.4 ± 1.7 cryoablation probes were utilized and 1.7 ± 0.6 freezing cycles were performed. The overall cohort aggregate complication rate was 16.9%. These complications included postoperative fracture (3.4%), nerve palsy (2.7%), wound complications (7.4%), and infection (3.4%). The number of cycles and probes was significantly correlated with the incidence of aggregate complications in the overall cohort (Pearson = 0.162, p = 0.049) and metastatic bone cohort (Pearson = 0.222, p = 0.027). There were 13 recurrences.

CONCLUSION

This study describes the complication rates involving cryoablation probes used as surgical adjuvants. Greater probe number usage was correlated with increased aggregate complications in patients with metastatic disease to bone; meanwhile, more treatment cycles were associated with increased aggregate complications in the overall cohort.

Safety and Feasibility of Steerable Radiofrequency Ablation in Combination with Cementoplasty for the Treatment of Large Extraspinal Bone Metastases

Background: Radiofrequency ablation (RFA) and cementoplasty, individually and in concert, has been adopted as palliative interventional strategies to reduce pain caused by bone metastases and prevent skeletal related events. We aim to evaluate the feasibility and safety of a steerable RFA device with an articulating bipolar extensible electrode for the treatment of extraspinal bone metastases. Methods: All data were retrospectively reviewed. All the ablation procedures were performed using a steerable RFA device (STAR, Merit Medical Systems, Inc., South Jordan, UT, USA). The pain was assessed with a VAS score before treatment and at 1-week and 3-, 6-, and 12-month follow-up. The Functional Mobility Scale (FMS) was recorded preoperatively and 1 month after the treatment through a four-point scale (4, bedridden; 3, use of wheelchair; 2, limited painful ambulation; 1, normal ambulation). Technical success was defined as successful intraoperative ablation and cementoplasty without major complications. Results: A statistically significant reduction of the median VAS score before treatment and 1 week after RFA and cementoplasty was observed (p < 0.001). A total of 6/7 patients who used a wheelchair reported normal ambulation 1 month after treatment. All patients with limited painful ambulation reported normal ambulation after the RFA and cementoplasty (p = 0.003). Technical success was achieved in all the combined procedures. Two cement leakages were reported. No local recurrences were observed after 1 year. Conclusions: The combined treatment of RFA with a steerable device and cementoplasty is a safe, feasible, and promising clinical option for the management of painful bone metastases, challenging for morphology and location, resulting in an improvement of the quality of life of patients.

Interventional Radiology in the Management of Metastases and Bone Tumors

Interventional Radiology (IR) has experienced an exponential growth in recent years. Technological advances of the last decades have made it possible to use new treatments on a larger scale, with good results in terms of safety and effectiveness. In musculoskeletal field, painful bone metastases are the most common target of IR palliative treatments; however, in selected cases of bone metastases, IR may play a curative role, also in combination with other techniques (surgery, radiation and oncology therapies, etc.). Primary malignant bone tumors are extremely rare compared with secondary bone lesions: osteosarcoma, Ewing sarcoma, and chondrosarcoma are the most common; however, the role of interventional radiology in this fiels is marginal. In this review, the main techniques used in interventional radiology were examined, and advantages and limitations illustrated. Techniques of ablation (Radiofrequency, Microwaves, Cryoablation as also magnetic resonance imaging-guided high-intensity focused ultrasound), embolization, and Cementoplasty will be described. The techniques of ablation work by destruction of pathological tissue by thermal energy (by an increase of temperature up to 90 °C with the exception of the Cryoablation that works by freezing the tissue up to -40 °C). Embolization creates an ischemic necrosis by the occlusion of the arterial vessels that feed the tumor. Finally, cementoplasty has the aim of strengthening bone segment weakened by the growth of pathological tissue through the injection of cement. The results of the treatments performed so far were also assessed and presented focused the attention on the management of bone metastasis.

Management of Unresectable Localized Pelvic Bone Sarcomas: Current Practice and Future Perspectives

Simple Summary

Some locally advanced pelvic bone tumors are deemed unresectable and, as such, not suitable for curative surgery. In this setting, treatment options are generally limited and not unanimous, with decisions being made on an individual basis after multidisciplinary discussion. Ultimately, and notwithstanding the bright prospects raised by novel therapeutic approaches, treatment should be patient-tailored, weighing a panoply of patient- and tumor-related factors.

Abstract

Bone sarcomas (BS) are rare mesenchymal tumors usually located in the extremities and pelvis. While surgical resection is the cornerstone of curative treatment, some locally advanced tumors are deemed unresectable and hence not suitable for curative intent. This is often true for pelvic sarcoma due to anatomic complexity and proximity to vital structures, making treatment options for these tumors generally limited and not unanimous, with decisions being made on an individual basis after multidisciplinary discussion. Several studies have been published in recent years focusing on innovative treatment options for patients with locally advanced sarcoma not amenable to local surgery. The present article reviews the evidence regarding the treatment of patients with locally advanced and unresectable pelvic BS, with the goal of providing an overview of treatment options for the main BS histologic subtypes involving this anatomic area and exploring future therapeutic perspectives. The management of unresectable localized pelvic BS represents a major challenge and is hampered by the lack of comprehensive and standardized guidelines. As such, the optimal treatment needs to be individually tailored, weighing a panoply of patient- and tumor-related factors. Despite the bright prospects raised by novel therapeutic approaches, the role of each treatment option in the therapeutic armamentarium of these patients requires solid clinical evidence before becoming fully established.

The Roles of Magnetic Resonance-Guided Focused Ultrasound in Pain Relief in Patients With Bone Metastases: A Systemic Review and Meta-Analysis

Objective

Cancer pain, the most common skeleton-related event of bone metastases, significantly disturbs patients' life. MRI-guided focused ultrasound (MRgFUS) is a therapeutic option to relieve pain; however, its efficacy and safety have not been fully explored. Therefore, we aim to conduct a meta-analysis on studies reporting MRgFUS for patients with bone metastases.

Methods

Randomized controlled trials (RCT) and non-RCTs on MRgFUS treatment for patients with bone metastases were collected using PubMed, MEDLINE In-Process (US National Library of Medicine), National Institutes of Health (US National Library of Medicine), Embase (Elsevier), Web of Science, CINAHL, and the Cochrane Library between August 2007 and September 2019. Data on quantitative pain assessment before/after MRgFUS, response rate, and complication were extracted and analyzed.

Results

Fifteen eligible studies with 362 patients were selected in this meta-analysis. The average pain score was 6.74 (95% CI: 6.30-7.18) at baseline, 4.15 (95% CI: 3.31-4.99) at 0-1 week, 3.09 (95% CI: 2.46-3.72) at 1-5 weeks, and 2.28 (95% CI: 1.37-3.19) at 5-14 weeks. Compared with baseline, the pain improvement at 0-1 week was 2.54 (95% CI: 1.92-3.16, p < 0.01), at 1-5 weeks was 3.56 (95% CI: 3.11-4.02, p < 0.01), and at 5-14 weeks was 4.22 (95% CI: 3.68-4.76, p < 0.01). Change from baseline in OMEDD at 2 weeks after treatment was -15.11 (95% CI: -34.73, 4.50), at 1 month after treatment was -10.87 (95% CI: -26.32, 4.58), and at 3 months after treatment was -5.53 (95% CI: -20.44, 9.38). The overall CR rate was 0.36 (95% CI: 0.24-0.48), PR rate was 0.47 (95% CI: 0.36-0.58), and NR rate was 0.23 (95% CI: 0.13-0.34). Among 14 studies including 352 patients, 93 (26.4%) patients with minor complications and 5 (1.42%) patients with major complications were recorded.

Conclusion

This meta-analysis identifies MRgFUS as a reliable therapeutic option to relieve cancer pain for patients with metastatic bone tumors with controllable related complications.

Recent Advances in the Treatment of Bone Metastases and Primary Bone Tumors: An Up-to-Date Review

In the last decades, the treatment of primary and secondary bone tumors has faced a slow-down in its development, being mainly based on chemotherapy, radiotherapy, and surgical interventions. However, these conventional therapeutic strategies present a series of disadvantages (e.g., multidrug resistance, tumor recurrence, severe side effects, formation of large bone defects), which limit their application and efficacy. In recent years, these procedures were combined with several adjuvant therapies, with different degrees of success. To overcome the drawbacks of current therapies and improve treatment outcomes, other strategies started being investigated, like carrier-mediated drug delivery, bone substitutes for repairing bone defects, and multifunctional scaffolds with bone tissue regeneration and antitumor properties. Thus, this paper aims to present the types of bone tumors and their current treatment approaches, further focusing on the recent advances in new therapeutic alternatives.

Evolving role of minimally invasive techniques in the management of symptomatic bone metastases

PURPOSE OF REVIEW

Bone metastases are responsible for considerable morbidity, which can significantly limit a patient's quality of life. This article aims to review minimally invasive, image-guided locoregional treatments for symptomatic bone metastases as an adjunct to conventional treatment modalities.

RECENT FINDINGS

Conservative therapy and radiation therapy (RT) can be effective at addressing pain, however, they require time to achieve optimal efficacy and do not address the instability and progressive collapse of pathological fractures. Vertebral and pelvic augmentation with cement enhances structural stability and can prevent progressive collapse and deformity. Ablative therapies, including radiofrequency ablation (RFA), cryoablation, and photodynamic therapy (PDT), induce cellular destruction of tumor tissue. RFA and PDT can be combined with cement augmentation in a single sitting.

SUMMARY

Minimally invasive image-guided treatments can provide rapid pain relief, enhance mechanical stability, and improve quality of life. These treatments are associated with low complication rates and are suitable for frail patients. They can be used as companion procedures to conventional treatments, or function as an alternative for patients with radioresistant biologies or those with dose limitations from prior RT sessions.

Radiofrequency Ablation for the Palliative Treatment of Bone Metastases: Outcomes from the Multicenter OsteoCool Tumor Ablation Post-Market Study (OPuS One Study) in 100 Patients

PURPOSE

To evaluate the effectiveness of radiofrequency (RF) ablation as measured by change in worst pain score from baseline to 3 mo after RF ablation for the palliative treatment of painful bone metastases.

MATERIALS AND METHODS

One hundred patients (mean age, 64.6 y) underwent RF ablation for metastatic bone disease and were followed up to 6 mo. Subjects' pain and quality of life were measured before RF ablation and postoperatively by using the Brief Pain Index and European Quality of Life questionnaires. Opioid agent use and device-, procedure-, and/or therapy-related adverse events (AEs) were collected.

RESULTS

Eighty-seven patients were treated for tumors involving the thoracolumbar spine and 13 for tumors located in the pelvis and/or sacrum. All ablations were technically successful, and 97% were followed by cementoplasty. Mean worst pain score decreased from 8.2 ± 1.7 at baseline to 3.5 ± 3.2 at 6 mo (n = 22; P < 0.0001 for all visits). Subjects experienced significant improvement for all visits in average pain (P < .0001), pain interference (P < .0001), and quality of life (P < .003). Four AEs were reported, of which 2 resulted in hospitalization for pneumonia and respiratory failure. All 30 deaths reported during the study were attributed to the underlying malignancy and not related to the study procedure.

CONCLUSIONS

Results from this study show rapid (within 3 d) and statistically significant pain improvement with sustained long-term relief through 6 mo in patients treated with RF ablation for metastatic bone disease.

Role of laser ablation in multimodal treatment of radioiodine- refractory bone metastases of thyroid cancer: a retrospective study

PURPOSE

To assess the efficacy, safety, and pain benefits of imaging-guided laser ablation (IGLA) in patients with radioiodine-refractory (RR) bone metastases from differentiated thyroid carcinoma (DTC).

PATIENTS AND METHODS

The institutional medical records of patients with bone metastases from DTC treated with laser ablation (LA) were reviewed retrospectively. Local response, complications, and effects on pain relief were investigated.

RESULTS

Six osteolytic lesions in five patients (one male, four females; mean age 65.4 ± 5.1 years, range 58-72) were treated with IGLA. All lesions were osteolytic and all have had previous treatments with high-dose radioiodine therapy followed by external radiotherapy (EBRT). All patients assumed opioid analgesics for severe pain. Overall, the lesions (mean size 5.8 ± 3.2 cm; median 5.0 cm, range 3.0-12.0 cm) underwent nine IGLA sessions (mean 1.8 ± 0.4 sessions; median 2.0 sessions, range 1-2). In four (80%) out five lesions, cross-sectional imaging showed a nearly complete response (CR) while the largest lesion was ablated by 80%. Pain changes were assessed with the Brief Pain Inventory-Short Form, that was administered before IGLA and during a 6-month follow-up. Patients experienced significant reduction in worst pain, average pain, and pain interference. Following IGLA, the average daily opioid requirement rapidly and progressively decreased. Treatments were well-tolerated and no major complications occurred.

CONCLUSIONS

IGLA is an effective and safe debulking procedure and provides significant pain relief in patients suffering from DTC bone metastases that are not responsive to standard treatments. So, IGLA could be considered as part of a multimodality management of advanced thyroid cancer with RR metastatic skeletal involvement.

Radiofrequency Ablation, Where It Stands in Interventional Radiology Today

Radiofrequency ablation (RFA) is one of the first developed minimally invasive definitive cancer therapies. The safety and efficacy of RFA is well documented and has led to its incorporation into multiple international societal guidelines. By expanding on the body of knowledge acquired during the clinical use of RFA, alternative ablative technologies have emerged and are successfully competing for locoregional therapy market share. The adaption of newer ablative technologies is leading to a rapid decline in the utilization of RFA by interventional radiologists despite the lack of proven superiority. In their 2010 article, Hong and Georgiades stated "… RFA is likely to remain the mainstay of ablations for small tumors until sufficient experience emerges for the widespread acceptance for alternative ablative modalities." Within a decade of this publication, has this time arrived?

Thermal ablation to relieve pain from metastatic bone disease: a systematic review

OBJECTIVE

To review the efficacy of percutaneous thermal ablation (TA) of bone metastases (radiofrequency ablation [RFA], microwave ablation [MWA], cryoablation [CA], and MR-guided focused ultrasound [MRgFUS]) in reducing pain in patients with advanced stage cancer.

MATERIALS AND METHODS

We searched MEDLINE/PubMed, MEDLINE In-Process, BIDS ISI, Embase, CINAHL, and the Cochrane database using the keywords "ablation," "painful," "bone," and "metastases" combined in multiple algorithms. Inclusion criteria were: original clinical studies published between 2001 and 2018; performance of RFA, MWA, CA or MRgFUS; and quantitative pain assessment before/after TA of bone metastasis.

RESULTS

Eleven papers (3 on RFA, 1 on MWA, 2 on CA, and 5 on MRgFUS) involving 364 patients were reviewed. A technical success rate of 96-100% was reported, with follow-up for up to 6 months. At baseline, pain scores ranged from 5.4 to 8, at 1-4 weeks from 0.5 to 5, and at 12 weeks from 0.3 to 4.5. Mean pain reduction compared with baseline ranged from 26 to 91% at 4 weeks and from 16% to 95% at 12 weeks. MWA treatments caused no complications, whereas MRgFUS showed the highest complication rate. The number of minor complications observed ranged from 0 to 59 (complication ratio 0-1.17), whereas the number of significant adverse effects ranged from 0 to 4 (complication ratio 0-0.04).

CONCLUSION

All techniques achieved pain relief after 1 and 3 months, in up to 91% and 95% of patients respectively. MWA showed a negligible complication rate, whereas MRgFUS is associated with a noteworthy rate of adverse events. Future studies should adopt a standardized pain reporting scale to allow for meta-analysis.

Strategies for interventional therapies in cancer-related pain-a crossroad in cancer pain management

PURPOSE

Interventional therapies are important to consider when facing cancer pain refractory to conventional therapies. The objective of the current review is to introduce these effective strategies into dynamic interdisciplinary pain management, leading to an exhaustive approach to supportive oncology.

METHODS

Critical reflection based on literature analysis and clinical practice.

RESULTS

Interventional therapies act on the nervous system via neuromodulation or surgical approaches, or on primitive or metastatic lesions via interventional radiotherapy, percutaneous ablation, or surgery. Interventional therapies such as neuromodulations are constantly evolving with new technical works still in development. Nowadays, their usage is better defined, depending on clinical situations, and their impact on quality of life is proven. Nevertheless their availability and acceptability still need to be improved. To start with, a patient's interdisciplinary evaluation should cover a wide range of items such as patient's performance and psychological status, ethical considerations, and physiochemical and pharmacological properties of the cerebrospinal fluid for intrathecal neuromodulation. This will help to define the most appropriate strategy. In addition to determining the pros and cons of highly specialized interventional therapies, their relevance should be debated within interdisciplinary teams in order to select the best strategy for the right patient, at the right time.

CONCLUSIONS

Ultimately, the use of the interventional therapies can be limited by the requirement of specific trained healthcare teams and technical support, or the lack of health policies. However, these interventional strategies need to be proposed as soon as possible to each patient requiring them, as they can greatly improve quality of life.

Sequential Interventional Management of Osseous Neoplasms via Embolization, Cryoablation, and Osteoplasty

The purpose of this study is to determine if sequential interventional therapy can become a mainstay option in providing palliation from fastidious osseous neoplasms in patients with pain refractory to oral analgesia and radiotherapy. This retrospective monocentric study was approved by our institutional review board. Between July 2012 and August 2014, we reviewed 15 patients (6 women, 9 men; age range of 36-81 years) who underwent embolization followed by cryoablation, with or without osteoplasty. Patient demographics and tumor characteristics, including primary histology and the location of metastasis, were included in our review. Pain intensity at baseline, after radiotherapy, and after sequential interventional therapy was reviewed using the hospital electronic medical record. The use of oral analgesia and procedural complications was also noted. Data was then assessed for normality and a two-tailed Student's t-test was performed on mean pain scores for difference phases of treatment. While radiotherapy offers pain relief with a mean pain score of 7.25 ±1.5 (p =<.0001), sequential interventional therapy results in better comfort as demonstrated by a mean pain score of 3.9 ± 2.6 (p=.0015). Moreover, all patients who reported oral analgesic use at presentation reported a decrease in their requirement after sequential interventional therapy. Embolization and cryoablation were performed in all patients, while osteoplasty was indicated in 6 cases. There was no difference in postprocedural pain intensity between patients who required osteoplasty and patients who did not (p = 0.7514). There were no complications observed during treatment. This retrospective study shows that sequential intervention with transarterial embolization, cryoablation, and osteoplasty is both safe and efficacious for bone pain refractory to the current standard of care. We demonstrated that this combination therapy has the potential to become an effective mainstay treatment paradigm in the palliative care of osseous neoplasm to improve quality of life.

Percutaneous image-guided cryoablation of painful bone metastases: A single institution experience

BACKGROUND

Bone metastases are frequently painful and may lead to various complications that can affect quality of life. While external beam radiation therapy is the standard first-line treatment, 20-30% of patients do not experience sufficient pain relief. Cryoablation is increasingly being used for the treatment of musculoskeletal metastases. The purpose of our retrospective study was to analyze pain relief and local disease control after percutaneous image-guided cryoablation (PCA) therapy of painful bone metastases.

MATERIALS AND METHODS

Sixteen patients treated with PCA for painful bone metastases (n=18) over a 5-year period (from June 2011 to June 2016) were retrospectively reviewed. Five patients also benefited from long bone fixation because of an impending fracture. We analyzed the impact of treatment on pain relief, using a numerical rating scale (NRS), and local disease control.

RESULTS

The mean follow-up period was 12 months (range, 1.5-39 months). At last oncological outpatient consultation, 75% (12/16) of patients had good pain relief, while 63% (10/16) had locally stable disease or no local recurrence of the treated bone metastases. The mean NRS score decreased significantly from 3.3 to 1.2 after PCA (p=0.0024). The five patients with concomitant long bone fixation all had satisfactory pain relief at the last follow-up visit.

CONCLUSION

PCA is a safe and valid treatment option for pain and local disease control in cases of painful bone metastases after failed standard first-line therapy. This technique can also be effectively associated to prophylactic long bone fixation and may allow for easier rehabilitation protocols when treating weight-bearing bones.

LEVEL OF EVIDENCE

IV, Retrospective case series.

Preliminary results: use of multi-hole injection nails for intramedullary nailing with simultaneous bone cement injection in long-bone metastasis

OBJECTIVE

For symptomatic metastasis of the long bones, intramedullary nailing has been the most accepted fixation method. Intramedullary nailing has effective control of pain, perioperative bleeding, and local tumor progression by augmentation with bone cement around the nail. Here, we report the preliminary results of a new surgical implant that allows for simultaneous injection of bone cement while inserting a percutaneous, flexible intramedullary nail.

MATERIALS AND METHODS

We performed palliative surgeries for long-bone metastasis using a multi-hole injection nail (MIN) with multiple side holes in the distal one third. When the nail tip entered the metastatic cancer lesion, the bone cement injection was started, and continued until the nail was completely seated. Ten patients with advanced cancer underwent palliative surgery using the new implant with simultaneous bone cement injection for humeral (n = 4), femoral (n = 4), and tibial (n = 2) metastases.

RESULTS

The mean operative time was 42 min (range, 36-52 min). The mean length of the injection nail was 23.0 cm (range, 18.0-33.0 cm), and the mean volume of cement was 28.0 ml (range, 14.0-40.0 ml). Marked pain palliation (p < 0.001) and functional recovery (p = 0.01) were verified. The mean Musculoskeletal Tumor Society (MSTS) functional score improved significantly from 12.5 at 6 weeks preoperatively, to 24.9 postoperatively. No acute postoperative complications, including cement embolism, occurred.

CONCLUSION

This minimally invasive surgical method with MIN could be useful for stabilization of long-bone metastases in patients with advanced cancer.

Improved MR thermometry for laser interstitial thermotherapy

OBJECTIVES

To develop, test and evaluate improved 2D and 3D protocols for proton resonance frequency shift magnetic resonance temperature imaging (MRTI) of laser interstitial thermal therapy (LITT). The objective was to develop improved MRTI protocols in terms of temperature measurement precision and volume coverage compared to the 2D MRTI protocol currently used with a commercially available LITT system.

METHODS

Four different 2D protocols and four different 3D protocols were investigated. The 2D protocols used multi-echo readouts to prolong the total MR sampling time and hence the MRTI precision, without prolonging the total acquisition time. The 3D protocols provided volumetric thermometry by acquiring a slab of 12 contiguous slices in the same acquisition time as the 2D protocols. The study only considered readily available pulse sequences (Cartesian 2D and 3D gradient recalled echo and echo planar imaging [EPI]) and methods (partial Fourier and parallel imaging) to ensure wide availability and rapid clinical implementation across vendors and field strengths. In vivo volunteer studies were performed to investigate and compare MRTI precision and image quality. Phantom experiments with LITT heating were performed to investigate and compare MRTI precision and accuracy. Different coil setups were used in the in vivo studies to assess precision differences between using local (such as flex and head coils) and non-local (i.e., body coil) receive coils. Studies were performed at both 1.5 T and 3 T.

RESULTS

The improved 2D protocols provide up to a factor of two improvement in the MRTI precision in the same acquisition time, compared to the currently used clinical protocol. The 3D echo planar imaging protocols provide comparable precision as the currently used 2D clinical protocol, but over a substantially larger field of view, without increasing the acquisition time. As expected, local receive coils perform substantially better than the body coil, and 3 T provides better MRTI accuracy and precision than 1.5 T. 3D data can be zero-filled interpolated in all three dimensions (as opposed to just two dimensions for 2D data), reducing partial volume effects and measuring higher maximum temperature rises.

CONCLUSIONS

With the presented protocols substantially improved MRTI precision (for 2D imaging) or greatly improved field of view coverage (for 3D imaging) can be achieved in the same acquisition time as the currently used protocol. Only widely available pulse sequences and acquisition methods were investigated, which should ensure quick translation to the clinic. Lasers Surg. Med. 51:286-300, 2019. © 2019 Wiley Periodicals, Inc.

Palliative Percutaneous Cryoablation and Cementoplasty of Acetabular Metastases: Factors Affecting Pain Control and Fracture Risk

PURPOSE

To characterize the response of patients with acetabular metastases following combined cryoablation and cementoplasty (CCC) for pain palliation and fracture risk reduction, based on completeness of ablation and the presence of pre-existing pathologic fracture.

MATERIALS AND METHODS

Thirty-nine consecutive acetabular CCC procedures were performed in 37 patients (24 M:13F, age 66 ± 8 years). Pain was assessed using a 0-10 numeric rating scale. Development of new or progression of pre-existing fractures and local tumor progression (LTP) were determined on follow-up imaging. Pain score reduction and fracture development rates were compared by ablation completeness and the presence of pre-existing fractures.

RESULTS

Twenty-three of 27 (85%) patients with evaluable pain scores had reduced pain, decreasing from 7.5 ± 2.1 to 3.6 ± 2.6 (p < 0.0001). Of 39 tumors, 28 (72%) were completely ablated with no significant difference in pain reduction after complete versus incomplete ablations (p = 0.9387). Six of 30 (20%) patients with follow-up imaging demonstrated new/progressive acetabular fractures. Four of 5 (80%) patients with LTP developed new/progressive fractures compared to 2 of 25 (8%) without tumor progression (p = 0.0003). Pre-existing fracture was not associated with subsequent fracture/fracture progression (p = 0.2986). However, patients with prior acetabular radiation therapy or surgery had increased fractures following treatment (p = 0.0380).

CONCLUSION

Complete acetabular tumor ablation during CCC was not associated with superior pain relief compared to subtotal ablation but did result in improved fracture stabilization. Pre-treatment pathologic fractures were not associated with fracture progression, but new/progressive fractures were more frequent in patients with prior radiation therapy or surgery.

Epidural Balloon Placement for Protection of the Spinal Canal During Cryoablation of Paraspinal Lesions

Ablation of paraspinal lesions close to the spinal canal and neuroforamina requires protective measures in order to protect the spinal cord and nerve roots. Various methods of protection have been previously described including infusion of saline and CO₂. Regardless, neuromonitoring should be adjunctively performed when ablating spinal lesions close to neuronal structures. Balloon protection has been previously described during ablation of renal masses. The benefit of balloon protection in paraspinal mass ablation is it physically displaces the nerve roots as opposed to CO₂ or saline which has the potential to insulate but because of its aerosolized or fluid nature may or may not provide definitive continuous protection throughout an ablation. This report details three paraspinal lesions, two of which were successfully ablated with the use of a balloon placed in the epidural space to provide protection to the spinal cord and nerve roots.

Magnetic Resonance-Guided Focused Ultrasound Versus Conventional Radiation Therapy for Painful Bone Metastasis: A Matched-Pair Study

BACKGROUND

Magnetic resonance-guided focused ultrasound (MRgFUS) is an alternative local therapy for patients with painful bone metastasis for whom standard conventional radiation therapy (RT) has failed. However, the therapeutic effects of MRgFUS as a first-line treatment for bone metastasis remain uncertain.

METHODS

A matched-pair study was conducted to compare the therapeutic effects of MRgFUS with those of conventional RT as a first-line treatment for patients with painful bone metastasis. The MRgFUS and RT-treated groups were matched 1:2 by age, sex, primary cancer, pretreatment pain score, and treated site.

RESULTS

According to the criteria for patient eligibility and matching, 21 and 42 patients (total, 63 patients) with bone metastasis treated with MRgFUS and conventional RT, respectively, were enrolled for analyses. The median ages of the MRgFUS and RT-treated patients were 59 and 61 years, respectively. Among the enrolled patients, 52% were male and 48% were female. The results showed that both MRgFUS and RT were effective. However, MRgFUS was more efficient than RT in terms of the time course of pain palliation as it yielded a significantly higher response rate at 1 week after treatment (71% versus 26%, p = 0.0009).

CONCLUSIONS

MRgFUS provides a similar overall treatment response rate but faster pain relief compared with conventional RT and has the potential to serve as the first-line treatment for painful bone metastasis in selected patients.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

[Image-guided tumor ablation]

INTRODUCTION

Ablatives techniques for destroying in situ a tumoral process aim tissular necrosis by the application of several physical principles.

MATERIAL AND METHODS

We searched MEDLINE^®, Embase^®, using (MeSH) words; from January 2005 through May 2017, and we looked for all the studies. Investigators graded the strength of evidence in terms of methodology, language and relevance.

RESULTS

Forty-seven articles were analyzed. We described ablative techniques and sorted them in thermal and non-thermal therapies according to the used physical principle and their frequency of use in the urological pathology.

CONCLUSION

Percutaneous ablative therapies are mini-invasive techniques, which have an important role in tumors focal treatment. This article is a review of the ablative therapies and describes their physical principles, their equipment and their recent technological modifications, which have been developed to improve the clinical success of these techniques.

Surgical treatment for periacetabular metastatic lesions

INTRODUCTION

Periacetabular bone metastasis present with severe pain and functional loss leading to a poor quality of life. Surgical treatment remains challenging.

MATERIAL AND METHODS

We reviewed all cases operated at our institution. We analyzed pain scores and functional status as well as complications and their risk factors.

RESULTS

Thirty-five patients underwent curettage and cemented reconstruction. Mean surgical time was 168 min. Mean surgical blood losses were 3150 ml. Major complications were encountered in 23% and minor complications in 29% of cases. We found a significant pain relief (p < 0.0001) and improvement in functional status in the postoperative period (p < 0.0001). A Harrington grade 4 lesion was correlated with a higher complication rate (p-value = 0.002).

CONCLUSIONS

In this series we were able to show that surgical management is an effective option in the treatment of metastatic bone disease to the pelvis. However, this treatment is very complex and associated with very high complication rates. Therefore, adequate patient selection and preoperative management is advocated.

Interventional Treatments of Cancer Pain

Pain is a significant burden for patients with cancer and is particularly prevalent among those with advanced cancer. Appropriate interventional cancer pain therapies complement conventional pain management by reducing the need for systemic opioid therapy and its associated toxicity; however, these therapies are often underutilized. This article reviews techniques, indications, complications, and outcomes of the most common interventional approaches for the management of cancer-related pain. These approaches include intrathecal drug delivery, vertebral augmentation, neurolysis of the celiac, superior hypogastric and ganglion impar plexus', image-guided tumor ablation, and other less commonly performed but potentially beneficial interventions.

AAPT Diagnostic Criteria for Chronic Cancer Pain Conditions

Chronic cancer pain is a serious complication of malignancy or its treatment. Currently, no comprehensive, universally accepted cancer pain classification system exists. Clarity in classification of common cancer pain syndromes would improve clinical assessment and management. Moreover, an evidence-based taxonomy would enhance cancer pain research efforts by providing consistent diagnostic criteria, ensuring comparability across clinical trials. As part of a collaborative effort between the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) and the American Pain Society (APS), the ACTTION-APS Pain Taxonomy initiative worked to develop the characteristics of an optimal diagnostic system. After the establishment of these characteristics, a working group consisting of clinicians and clinical and basic scientists with expertise in cancer and cancer-related pain was convened to generate core diagnostic criteria for an illustrative sample of 3 chronic pain syndromes associated with cancer (ie, bone pain and pancreatic cancer pain as models of pain related to a tumor) or its treatment (ie, chemotherapy-induced peripheral neuropathy). A systematic review and synthesis was conducted to provide evidence for the dimensions that comprise this cancer pain taxonomy. Future efforts will subject these diagnostic categories and criteria to systematic empirical evaluation of their feasibility, reliability, and validity and extension to other cancer-related pain syndromes.

PERSPECTIVE

The ACTTION-APS chronic cancer pain taxonomy provides an evidence-based classification for 3 prevalent syndromes, namely malignant bone pain, pancreatic cancer pain, and chemotherapy-induced peripheral neuropathy. This taxonomy provides consistent diagnostic criteria, common features, comorbidities, consequences, and putative mechanisms for these potentially serious cancer pain conditions that can be extended and applied with other cancer-related pain syndromes.

Surgical treatment of tumours and metastases of the spine by minimally invasive cavity-coblation method

Tumours and metastases of the spine are extremely stressful for patients, especially for elderly multimorbid patients. The modern cavity/coblation method offers a very good therapeutic alternative for such patients. The goal of this article was to evaluate and present the characteristics, significance, opportunities, issues of the minimum invasive cavity/coblation method as well as the results of the treatment of 302 patients with vertebral tumours and metastases.

Tageted bipolar radiofrequency decompression with vertebroplasty for intractable radicular pain due to spinal metastasis: a case report

Metastatic spinal tumors are usually quite difficult to treat. In patients with metastatic spinal tumors, conventional radiotherapy fails to relieve pain in 20–30% of cases and open surgery often causes considerable trauma and complications, which delays treatment of the primary disease. Percutaneous vertebroplasty (PVP) is considered to be useful in achieving rapid pain control and preventing further vertebral collapse due to spinal metastasis. However, symptoms of intraspinal neural compression can be contraindications to PVP. To overcome this problem, we performed PVP following targeted bipolar radiofrequency decompression, and examined the effect of the combined treatment in relieving severe radicular pain related to spinal cord compression caused by malignant metastatic tumors.

Feasibility of Intraoperative Nerve Monitoring in Preventing Thermal Damage to the "Nerve at Risk" During Image-Guided Ablation of Tumors

PURPOSE

To assess feasibility of intraoperative neurophysiologic monitoring (IONM) during image-guided, percutaneous thermal ablation of tumors.

MATERIALS AND METHODS

From February 2009 to October 2013, a retrospective review of all image-guided percutaneous thermal ablation interventions using IONM was performed and data was compiled using electronic medical records and imaging studies.

RESULTS

Twelve patients were treated in 13 ablation interventions. In 4 patients, real-time feedback from the monitoring neurologist was used to adjust applicator placement and ablation settings. IONM was technically feasible in all procedures and there were no complications related to monitoring or ablation. All nerves at risk remained intact and of the 11 patients who could be followed, none developed new nerve deficit up to a minimum of 2 months after ablation.

CONCLUSION

IONM is safe and feasible for use during image-guided thermal ablation of tumors in the vicinity of nerves. Outcomes in this study demonstrate its potential utility in image-guided ablation interventions.

Interventional MSK procedures: the hip

Percutaneous musculoskeletal procedures are widely accepted as low invasive, highly effective, efficient and safe methods in a vast amount of hip pathologies either in diagnostic or in therapeutic management. Hip intra-articular injections are used for the symptomatic treatment of osteoarthritis. Peritendinous or intrabursal corticosteroid injections can be used for the symptomatic treatment of greater trochanteric pain syndrome and anterior iliopsoas impingement. In past decades, the role of interventional radiology has rapidly increased in metastatic disease, thanks to the development of many ablative techniques. Image-guided percutaneous ablation of skeletal metastases provides a minimally invasive treatment option that appears to be a safe and effective palliative treatment for localized painful lytic lesion. Methods of tumour destruction based on temperature, such as radiofrequency ablation (RFA) and cryotherapy, are performed for the management of musculoskeletal metastases. MR-guided focused ultrasound surgery provides a non-invasive alternative to these ablative methods. Cementoplasty is now widely used for pain management and consolidation of acetabular metastases and can be combined with RFA. RFA is also used to treat benign tumours, namely osteoid osteomas. New interventional procedures such as percutaneous screw fixation are also proposed to treat non-displaced or minimally displaced acetabular roof fractures.

Quantifying temperature-dependent T1 changes in cortical bone using ultrashort echo-time MRI

PURPOSE

To demonstrate the feasibility of using ultrashort echo-time MRI to quantify T1 changes in cortical bone due to heating.

METHODS

Variable flip-angle T1 mapping combined with 3D ultrashort echo-time imaging was used to measure T1 in cortical bone. A calibration experiment was performed to detect T1 changes with temperature in ex vivo cortical bone samples from a bovine femur. Ultrasound heating experiments were performed using an interstitial applicator in ex vivo bovine femur specimens, and heat-induced T1 changes were quantified.

RESULTS

The calibration experiment demonstrated that T1 increases with temperature in cortical bone. We observed a linear relationship between temperature and T1 with a linear coefficient between 0.67 and 0.84 ms/°C over a range of 25-70°C. The ultrasound heating experiments showed increased T1 changes in the heated regions, and the relationship between the temperature changes and T1 changes was similar to that of the calibration.

CONCLUSION

We demonstrated a temperature dependence of T1 in ex vivo cortical bone using a variable flip-angle ultrashort echo-time T1 mapping method.

Helical coil electrode radiofrequency ablation designed for application in osteolytic vertebral tumors--initial evaluation in a porcine model

BACKGROUND CONTEXT

Radiofrequency ablation (RFA) is emerging as a complementary treatment for vertebral metastases. Traditional RFA induces frictional heating leading to local tissue necrosis but often yields small, incomplete, and inhomogeneous zones of ablation in bone. We have developed a new bone-specific RFA electrode that uses a nontraditional frequency (27.12 MHz) and geometry (helical), exploiting a magnetic field and an electric field to generate larger and more comprehensive treatment zones.

PURPOSE

The purpose of the study was to evaluate the feasibility and safety of the Bone Coil RFA electrode in the spine.

STUDY DESIGN

This is a preclinical in vivo study based on basic science.

METHODS

Under institutional approval, six healthy Yorkshire pigs received a sham and an RF treatment in two adjacent cervical vertebrae. To deploy the Bone Coil RFA device in dense porcine vertebrae, a surgical approach was required; an irrigated coring drill bit created a cylindrical path in the vertebral bodies through which the RFA electrodes were placed. The electronic circuit was completed by four grounding pads. Treatment was delivered for 10 minutes at 20 W (n=1), 25 W (n=1), and 30 W (n=4). To monitor the thermal rise and for safety, fiber-optic probes recorded temperatures in the center of each coil and near the spinal foramen. After the procedure, animals were monitored for 2 weeks. Magnetic resonance imaging (MRI) was completed immediately after treatment and at 14 days. Magnetic resonance image segmentation and histology were used to evaluate the ablation volume.

RESULTS

Comprehensive treatment of the porcine vertebrae was demonstrated by temperature monitoring, MRI, and histology. Large zones of RF ablation were obtained (RF: 3.72±0.73 cm3 vs. sham: 1.98±0.16 cm3, p<.05), confined within the vertebral body. Internal temperatures were elevated with RF (66.1 °C-102.9 °C), without temperature rise outside of the vertebrae (38.2 °C ± 1.5 °C). Mobility, neurological responses, and behavior were normal, consistent with preprocedural examination. Magnetic resonance imaging best visualized ablation at Day 14. Histology revealed comprehensive homogeneous coagulative necrosis with little peripheral sign of repair.

CONCLUSIONS

The Bone Coil RFA device created large intravertebral ablation volumes with no neurologic sequelae. Radiofrequency thermal ablation (clearly distinguished from the much smaller effects arising from core drilling) corresponded to the homogeneous necrosis visible on histology.

[Tumours and metastases of the spine : cavity/coblation surgery and vertebroplasty/kyphoplasty]

BACKGROUND

Radical surgery for metastases in the spine is in many cases not possible, includingthe higher risk of surgery in older patients with co-morbidities. The aims of treatment are: minimally invasive and maximally effective tumour removal, fracture position, stabilization, pain reduction, and improved quality of life. The specific features and problems of diagnosis and treatment using the cavity/coblation method, , the surgical technique, and the results of the treatment of 250 patients with spinal tumours/metastases are presented.

MATERIALS AND METHODS

Tumour resection is carried out by plasma field, via percutaneous trans-/extrapedicular access, followed by kyphoplasty. Clinical and radiological follow-up was carried out postoperatively, including data on pain reduction and improvement of quality of life.

RESULTS

Within 6 years (March 2008t February 2014) a total of 250 patients, or 812 spines were treated. In 59 cases dorsal percutaneous instrumentation and straightening were carried out. Minimal blood loss and a very low complication rate were recorded. After surgery, significant pain reduction, satisfaction, early mobilization, and improvement in quality of life were demonstrated in all patients. Immediate radio- and chemotherapy could be carried out. In 38 cases cement escaped laterally into the intervertebral space, but this had no clinical relevance. 188 patients have since died because of tumour manifestations.

CONCLUSIONS

The cavity/coblation method has been demonstrated to be a safe, minimally invasive procedure, with good short- and long-term results and lower complication rates. A comprehensive diagnostic, including tumour staging, the correct indication, and prognosis estimation, is important.

Interstitial ultrasound ablation of vertebral and paraspinal tumours: parametric and patient-specific simulations

PURPOSE

Theoretical parametric and patient-specific models are applied to assess the feasibility of interstitial ultrasound ablation of tumours in and near the spine and to identify potential treatment delivery strategies.

METHODS

3D patient-specific finite element models (n = 11) of interstitial ultrasound ablation of tumours associated with the spine were generated. Gaseous nerve insulation and various applicator configurations, frequencies (3 and 7 MHz), placement trajectories, and tumour locations were simulated. Parametric studies with multilayered models investigated the impacts of tumour attenuation, tumour dimension, and the thickness of bone insulating critical structures. Temperature and thermal dose were calculated to define ablation (>240 equivalent minutes at 43 °C (EM43 °C)) and safety margins (<45 °C and <6 EM43 °C), and to determine performance and required delivery parameters.

RESULTS

Osteolytic tumours (≤44 mm) encapsulated by bone could be successfully ablated with 7 MHz interstitial ultrasound (8.1-16.6 W/cm(2), 120-5900 J, 0.4-15 min). Ablation of tumours (94.6-100% volumetric) 0-14.5 mm from the spinal canal was achieved within 3-15 min without damaging critical nerves. 3 MHz devices provided faster ablation (390 versus 930 s) of an 18 mm diameter osteoblastic (high bone content) volume than 7 MHz devices. Critical anatomy in proximity to the tumour could be protected by selection of appropriate applicator configurations, active sectors, and applied power schemas, and through gaseous insulation. Preferential ultrasound absorption at bone surfaces facilitated faster, more effective ablations in osteolytic tumours and provided isolation of ablative energies and temperatures.

CONCLUSIONS

Parametric and patient-specific studies demonstrated the feasibility and potential advantages of interstitial ultrasound ablation treatment of paraspinal and osteolytic vertebral tumours.

Pain palliation in patients with bone metastases using magnetic resonance-guided focused ultrasound with conformal bone system: a preliminary report

PURPOSE

We evaluated the safety and effectiveness of the Magnetic Resonance-guided Focused Ultrasound (MRgFUS) with the ExAblate Conformal Bone System for the palliation of painful bone metastases.

MATERIALS AND METHODS

Our Institutional Review Board approved this study, and all patients gave informed consent prior to enrollment. A total of six painful metastatic bone lesions in five patients were treated using MRgFUS with the ExAblate Conformal Bone System for pain palliation. The follow-up sessions were at 3 days, 2 weeks, 1, 2, and 3 months, and 1 year after treatment. Efficacy was evaluated by the changes in visual analog scale (VAS) scores. At 3-months and 1-year follow-ups, unenhanced computed tomography and contrast-enhanced MR imaging examinations were performed. All adverse events were assessed to evaluate treatment safety.

RESULTS

All patients showed significant pain relief within 2 weeks. Two patients experienced complete pain reduction that lasted for 1 year. Two other patients showed pain relief measured as VAS scores of 2 and 4 on their last follow-up. Although the remaining patient had experienced significant pain relief in two lesions, the VAS score re-increased on his last follow-up. The size of the enhancing soft tissue mass in metastatic lesions decreased, and new bone formation was seen on follow-up images. Although adverse events were not serious, non-specific leg pain and second degree skin burn were noted.

CONCLUSION

MRgFUS was demonstrated to be effective palliative treatment within 2 weeks in selected patients with painful bone metastases.

The surgical treatment of pelvic bone metastases

Pelvic bone metastases are a growing concern in the field of orthopedic surgery. Patients with pelvic metastasis are individually different with different needs of treatment in order to attain the best possible quality of life despite the advanced stage of disease. A holistic collaboration among the oncologist, radiation therapist, and orthopedic surgeon is mandatory. Special attention has to be directed to osteolytic lesions in the periacetabular region as they can provoke pathological fractures and subsequent functional impairment. Different reconstruction techniques for the pelvis are available; the choice depends on the patient's prognosis, size of the bone defect, and response of the tumor to adjuvant treatment. If all the conservative treatments are exhausted and the patient is not eligible for surgery, one of the various percutaneous ablation procedures can be considered. We propose a pelvic analogue to the treatment algorithm in long bone metastasis and a scoring system in pelvic metastasis. This algorithm aims to simplify the teamwork and to avoid under- or overtreatment of pelvic bone metastases.

Image-guided cryoablation for the treatment of painful musculoskeletal metastatic disease: a single-center experience

PURPOSE

The role of image-guided thermal ablation techniques for the nonoperative local management of painful osseous metastatic disease has expanded during recent years, and several advantages of cryoablation in this setting have emerged. The purpose of this study is to retrospectively evaluate and report a single-center experience of CT-guided percutaneous cryoablation in the setting of painful musculoskeletal metastatic disease.

METHODS

This study was approved by the institutional review board and is compliant with the Health Insurance Portability and Accountability Act. Electronic medical records of all patients who underwent percutaneous image-guided palliative cryoablation at our institution were reviewed (n = 61). An intent-to-treat analysis was performed. Records were reviewed for demographic data and anatomical data, primary tumor type, procedure details, and outcome-including change in analgesic requirements (expressed as morphine equivalent dosages), pain scores (utilizing the clinically implemented visual analog scale), subsequent therapies (including radiation and/or surgery), and complications during the 24 h following the procedure and at 3 months. Patients were excluded (n = 7) if data were not retrospectively identifiable at the defined time points.

RESULTS

Fifty-four tumors were ablated in 50 patients. There were statistically significant decreases in the median VAS score and narcotic usage at both 24 h and 3 months (p < 0.000). Six patients (11%) incurred complications related to their therapy. Two patients had no relief at 24 h, of which both reported worsened pain at 3 months. One patient had initial relief but symptom recurrence at 3 months. Four patients went on to have radiation therapy of the ablation site at some point following the procedure.

CONCLUSIONS

CT-guided cryoablation is a safe, effective, reproducible procedural option for the nonoperative local treatment of painful musculoskeletal metastatic disease.

Bone and soft tissue ablation

Bone and soft tissue tumor ablation has reached widespread acceptance in the locoregional treatment of various benign and malignant musculoskeletal (MSK) lesions. Many principles of ablation learned elsewhere in the body are easily adapted to the MSK system, particularly the various technical aspects of probe/antenna design, tumoricidal effects, selection of image guidance, and methods to reduce complications. Despite the common use of thermal and chemical ablation procedures in bone and soft tissues, there are few large clinical series that show longitudinal benefit and cost-effectiveness compared with conventional methods, namely, surgery, external beam radiation, and chemotherapy. Percutaneous radiofrequency ablation of osteoid osteomas has been evaluated the most and is considered a first-line treatment choice for many lesions. Palliation of painful metastatic bone disease with thermal ablation is considered safe and has been shown to reduce pain and analgesic use while improving quality of life for cancer patients. Procedure-related complications are rare and are typically easily managed. Similar to all interventional procedures, bone and soft tissue lesions require an integrated approach to disease management to determine the optimum type of and timing for ablation techniques within the context of the patient care plan.

Ablation of musculoskeletal metastases: pain palliation, fracture risk reduction, and oligometastatic disease

Thermal ablation is an effective, minimally invasive alternative to conventional therapies in the palliation of painful musculoskeletal metastases and an emerging approach to obtain local tumor control in the setting of limited metastatic disease. Various thermal ablation technologies have been applied to bone and soft tissue tumors and may be used in combination with percutaneous cement instillation for skeletal lesions with or at risk for pathologic fracture. This article reviews current practices of percutaneous ablation of musculoskeletal metastases with an emphasis on radiofrequency ablation and cryoablation of painful skeletal metastases.