Percutaneous Image-Guided Cryoablation of Musculoskeletal Metastases: Pain Palliation and Local Tumor Control

Computed tomography-derived structural analysis for the likelihood of pathologic fracture in canine antebrachial osteosarcoma

Determining the risk of pathologic fracture in dogs with a primary bone tumor would aid in case selection for in-situ treatment options. Prior research found strong relationships between in vitro strength of canine antebrachii with primary bone tumors and CT-derived metrics. This study assesses the prognosis for pathologic fracture in dogs with distal radial bone tumors using CT-derived structural analysis metrics. CT images of the antebrachium in dogs with aggressive osseous lesions of the radius were used to calculate structural rigidity and failure forces, including axial rigidity (AR), craniocaudal bending rigidity (BR), torsional rigidity (TR), and failure forces for a slightly-curved/asymmetric beam (Fs) or a curved beam (Fc). Metrics were compared with the clinical outcome of radial fracture. Eight of 19 dogs with CT-derived metrics developed a radial fracture. The prognostic potential of the metrics to discriminate fractured and nonfractured bones was analyzed using receiver operating characteristic curves (area under the curve), stepwise logistic regression, and classification regression (CART) analyses. Fc was the most sensitive and specific metric for prognosing fracture occurrence (AUC = 0.864). When dog body weight (BW) was included, all five metrics had AUC > 0.705. Fc was the best predictor of fracture using stepwise logistic regression and CART analysis, followed by BR. An indication of fracture probability can be determined by normalizing Fc or BR with dog BW or by using the logistic regression equation of either metric with dog BW. Results warrant further analysis of a larger cohort to evaluate fracture likelihood in dogs with antebrachial bone neoplasia.

Magnetic resonance-guided focused ultrasound versus percutaneous thermal ablation in local control of bone oligometastases: a systematic review and meta-analysis

BACKGROUND

The percutaneous thermal ablation techniques (pTA) are radiofrequency ablation, cryoablation, and microwave ablation, suitable for the treatment of bone oligometastases. Magnetic resonance-guided focused ultrasound (MRgFUS) is a noninvasive ablation technique.

OBJECTIVES

To compare the effectiveness and safety of MRgFUS and pTA for treating bone oligometastases and their complications.

METHODS

Studies were selected with a PICO/PRISMA protocol: pTA or MRgFUS in patients with bone oligometastases; non-exclusive curative treatment. Exclusion criteria were: primary bone tumor; concurrent radiation therapy; palliative therapy; and absence of imaging at follow-up. PubMed, BioMed Central, and Scopus were searched. The modified Newcastle-Ottawa Scale assessed articles quality. For each treatment (pTA and MRgFUS), we conducted two separate random-effects meta-analyses to estimate the pooled effectiveness and safety. The effectiveness was assessed by combining the proportions of treated lesions achieving local tumor control (LTC); the safety by combining the complications rates of treated patients. Meta-regression analyses were performed to identify any outcome predictor.

RESULTS

A total of 24 articles were included. Pooled LTC rate for MRgFUS was 84% (N = 7, 95% CI 66-97%, I2 = 74.7%) compared to 65% of pTA (N = 17, 95% CI 51-78%, I2 = 89.3%). Pooled complications rate was similar, respectively, 13% (95% CI 1-32%, I2 = 81.0%) for MRgFUS and 12% (95% CI 8-18%, I2 = 39.9%) for pTA, but major complications were recorded with pTA only. The meta-regression analyses, including technique type, study design, tumor, and follow-up, found no significant predictors.

DISCUSSION

The effectiveness and safety of the two techniques were found comparable, even though MRgFUS is a noninvasive treatment that did not cause any major complication. Limited data availability on MRgFUS and the lack of direct comparisons with pTA may affect these findings.

CONCLUSIONS

MRgFUS can be a valid, safe, and noninvasive treatment for bone oligometastases. Direct comparison studies are needed to confirm its promising benefits.

Tumor and Ablation Margin Visibility during Cryoablation of Musculoskeletal Tumors: Comparing Intraprocedural PET/CT Images with CT-Only Images

PURPOSE

To compare tumor and ice-ball margin visibility on intraprocedural positron emission tomography (PET)/computed tomography (CT) and CT-only images and report technical success, local tumor progression, and adverse event rates for PET/CT-guided cryoablation procedures for musculoskeletal tumors.

MATERIALS AND METHODS

This Health Insurance Portability and Accountability Act (HIPAA)-compliant and institutional review board-approved retrospective study evaluated 20 PET/CT-guided cryoablation procedures performed with palliative and/or curative intent to treat 15 musculoskeletal tumors in 15 patients from 2012 to 2021. Cryoablation was performed using general anesthesia and PET/CT guidance. Procedural images were reviewed to determine the following: (a) whether the tumor borders could be fully assessed on PET/CT or CT-only images; and (b) whether tumor ice-ball margins could be fully assessed on PET/CT or CT-only images. The ability to visualize tumor borders and ice-ball margins on PET/CT images was compared with that on CT-only images.

RESULTS

Tumor borders were fully assessable for 100% (20 of 20; 95% CI, 0.83-1) of procedures on PET/CT versus 20% (4 of 20; 95 CI, 0.057-0.44) of procedures on CT only (P < .001). The tumor ice-ball margin was fully assessable in 80% (16 of 20; 95% CI, 0.56-0.94) of procedures using PET/CT versus 5% (1 of 20; 95% CI, 0.0013-0.25) of procedures using CT only (P < .001). Primary technical success was achieved in 75% (15 of 20; 95% CI, 0.51-0.91) of procedures. There was local tumor progression in 23% (3/13; 95% CI, 0.050-0.54) of the treated tumors with at least 6 months of follow-up. There were 3 adverse events (1 Grade 3, 1 Grade 2, and 1 Grade 1).

CONCLUSIONS

PET/CT-guided cryoablation of musculoskeletal tumors can provide superior intraprocedural visualization of the tumor and ice-ball margins compared with that provided by CT alone. Further studies are warranted to confirm the long-term efficacy and safety of this approach.

The New Ice Age of Musculoskeletal Intervention: Role of Percutaneous Cryoablation in Bone and Soft Tissue Tumors

In the rapidly evolving field of interventional oncology, minimally invasive methods, including CT-guided cryoablation, play an increasingly important role in tumor treatment, notably in bone and soft tissue cancers. Cryoablation works using compressed gas-filled probes to freeze tumor cells to temperatures below -20 °C, exploiting the Joule-Thompson effect. This cooling causes cell destruction by forming intracellular ice crystals and disrupting blood flow through endothelial cell damage, leading to local ischemia and devascularization. Coupling this with CT technology enables precise tumor targeting, preserving healthy surrounding tissues and decreasing postoperative complications. This review reports the most important literature on CT-guided cryoablation's application in musculoskeletal oncology, including sarcoma, bone metastases, and bone and soft tissue benign primary tumors, reporting on the success rate, recurrence rate, complications, and technical aspects to maximize success for cryoablation in the musculoskeletal system.

Introduction to interventional radiology's role in palliative care for children with cancer: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

As palliative care continues to be an area of increasing emphasis in pediatric oncology programs, it is important to raise awareness about minimally invasive, image-guided procedures that can supplement more conventional palliative interventions, such as systemic analgesics, external beam radiation, and locoregional anesthesia. These procedures, when performed for appropriately selected patients, can often facilitate discharge from an inpatient facility, and help patients meet their end-of-life goals. This article specifically discusses three palliative procedures performed by interventional radiologists that can assist pediatric palliative care teams in: (a) percutaneous thermal ablation of painful bone metastases, (b) cryoneurolysis, and (c) tunneled drainage catheter placement for malignant pleural effusions and ascites.

Percutaneous Image-Guided Cryoablation of Metastatic Colorectal Adenocarcinoma to the Abdominal Wall

Abdominal wall metastases are rarely seen in primary colorectal cancer; the majority of cases are attributed to seeding from previous procedures. We report a case of percutaneous cryoablation of metastatic colorectal cancer to the abdominal wall with no evidence of recurrence 1 year later.

Transarterial Embolization of Bone Metastases

Embolization of bone metastases is most commonly performed for hypervascular tumors prior to surgical resection. When employed in this fashion embolization can significantly decrease perioperative hemorrhage and improve surgical outcomes. In addition, embolization of bone metastases may lead to local tumor control and decreased tumoral associate bone pain. Careful techniques and choice of embolic material are required when performing embolization of bone lesions to ensure low procedural complications and high rates of clinical success.⁴ The indications, technical considerations, and complications associated with embolization of metastatic hypervascular bone lesions will be discussed in this review with subsequent case examples.

Minimally Invasive Interventional Procedures for Metastatic Bone Disease: A Comprehensive Review

Metastases are the main type of malignancy involving bone, which is the third most frequent site of metastatic carcinoma, after lung and liver. Skeletal-related events such as intractable pain, spinal cord compression, and pathologic fractures pose a serious burden on patients’ quality of life. For this reason, mini-invasive treatments for the management of bone metastases were developed with the goal of pain relief and functional status improvement. These techniques include embolization, thermal ablation, electrochemotherapy, cementoplasty, and MRI-guided high-intensity focused ultrasound. In order to achieve durable pain palliation and disease control, mini-invasive procedures are combined with chemotherapy, radiation therapy, surgery, or analgesics. The purpose of this review is to summarize the recently published literature regarding interventional radiology procedures in the treatment of cancer patients with bone metastases, focusing on the efficacy, complications, local disease control and recurrence rate.

Interventional Palliation of Painful Extraspinal Musculoskeletal Metastases

The musculoskeletal system is commonly involved by metastases, and skeletal-related events such as intractable pain due to direct osseous tumor involvement, pathologic fracture, and neurologic deficits as a result of nerve compression often adversely affect patient's quality of life. There have been substantial advances in percutaneous minimally invasive musculoskeletal oncologic interventions for the management of patients with musculoskeletal metastases including thermal ablations, cementation with or without osseous reinforcement via implants, osteosynthesis, neurolysis, and palliative injections which are progressively incorporated in clinical practice. These interventions are performed, in conjunction with or supplemented by adjuvant radiation therapy, systemic therapy, surgery, or analgesics, to achieve durable pain palliation, local tumor control, or cure. This article reviews minimally invasive percutaneous image-guided musculoskeletal oncologic interventions for the management of patients with extraspinal musculoskeletal metastases.

Interventional Management of Painful Vertebral Body Metastases

Management of osseous metastatic disease has advanced over the years with the advent of ablation and interventional technologies. Painful metastatic vertebral body lesions have been particularly studied in the recent years, as open surgery is usually reserved for emergent cord compression. Minimally invasive options in managing these lesions include percutaneous vertebral augmentation, percutaneous ablation, and embolization. This article will include an overview of these procedures including the most recent literature.

CIRSE Standards of Practice on Thermal Ablation of Bone Tumours

Background

Percutaneous thermal ablation is an effective, minimally invasive means of treating a variety of focal benign and malignant osseous lesions. To determine the role of ablation in individual cases, multidisciplinary team (MDT) discussion is required to assess the suitability and feasibility of a thermal ablative approach, to select the most appropriate technique and to set the goals of treatment i.e. curative or palliative.

Purpose

This document will presume the indication for treatment is clear and approved by the MDT and will define the standards required for the performance of each modality. CIRSE Standards of Practice documents are not intended to impose a standard of clinical patient care, but recommend a reasonable approach to, and best practices for, the performance of thermal ablation of bone tumours.

Methods

The writing group was established by the CIRSE Standards of Practice Committee and consisted of five clinicians with internationally recognised expertise in thermal ablation of bone tumours. The writing group reviewed the existing literature on thermal ablation of bone tumours, performing a pragmatic evidence search using PubMed to search for publications in English and relating to human subjects from 2009 to 2019. Selected studies published in 2020 and 2021 during the course of writing these standards were subsequently included. The final recommendations were formulated through consensus.

Results

Recommendations were produced for the performance of thermal ablation of bone tumours taking into account the biologic behaviour of the tumour and the therapeutic intent of the procedure. Recommendations are provided based on lesion characteristics and thermal modality, for the use of tissue monitoring and protection, and for the appropriately timed application of adjunctive procedures such as osseus consolidation and transarterial embolisation.

Results

Percutaneous thermal ablation has an established role in the successful management of bone lesions, with both curative and palliative intent. This Standards of Practice document provides up-to-date recommendations for the safe performance of thermal ablation of bone tumours.

CT-guided cryoablation for management of bone metastases: a single center experience and review of the literature

Thermal ablation techniques are procedures of growing interest for management of bone metastases. Among these, cryoablation is probably the most advanced. It allows treatment of large and irregular volumes of pathological tissue, real-time evaluation of the area of ablation and appears less painful than heat-based ablative techniques like radiofrequency and microwaves. Literature shows the effectiveness of cryoablation in the management of bone metastases in terms of pain palliation, but also its employment with curative intent is recommended. We reviewed the outcomes of cryoablation procedures performed in our radiology department over the last seven years, confirming the results in terms of pain palliation and local control of disease. We retrospectively evaluated results of 28 procedures of cryoablation, of which 17 treated with palliative and 11 with curative intent. In a 3-month follow-up study, we recorded an overall reduction of pain (evaluated using a VAS 0-10 scale) between pre- and post-treatment. The mean values dropped from 6.9 (SD: ± 1.3) to 3.5 (SD ± 2.6) (p < 0.0001). In the group of patients treated for local tumor control (follow-up: 22.4 months), we recorded a stability and/or reduction in volume of the lesion in 10 out 11 patients. No major complications were recorded.

Ablation Techniques in Cancer Pain

Painful bone metastases are a frequently encountered problem in oncology practice. The skeletal system is the third most common site of metastatic disease and up to 85% of patients with breast, prostate, and lung cancer may develop bone metastases during the course of their disease.

Bone Metastases: State of the Art in Minimally Invasive Interventional Oncology

Bone is the third most common site involved by cancer metastases, and skeleton-related events such as intractable pain due to direct osseous tumor involvement, pathologic fracture, and neurologic deficits as a consequence of nerve or spinal cord compression often affect patients' functional independence and quality of life unfavorably. The annual medical-economic burden related to bone metastases is a substantial component of the total direct medical cost estimated by the National Institutes of Health. There have been substantial recent advances in percutaneous image-guided minimally invasive musculoskeletal oncologic interventions for the management of patients with osseous metastatic disease. These advances include thermal ablation, cementation with or without osseous reinforcement with implants, osteosynthesis, thermal and chemical neurolyses, and palliative injections, which are progressively incorporated into the management paradigm for such patients. These interventions are performed in conjunction with or are supplemented by adjuvant radiation therapy, systemic therapy, surgery, or analgesic agents to achieve durable pain palliation, local tumor control, or cure, and they provide a robust armamentarium for interventional radiologists to achieve safe and effective treatment in a multidisciplinary setting. In addition, these procedures are shifting the patient management paradigm in modern-era practice. The authors detail the state of the art in minimally invasive percutaneous image-guided musculoskeletal oncologic interventions and the role of radiologists in managing patients with skeletal metastases. ^©RSNA, 2021.

Preoperative cryoablation of a hypervascular bone metastasis: A case of effective devascularization before preoperative embolization

Image-guided cryoablation has become a common approach for the palliative treatment of painful metastatic bone lesions, and indications for this procedure have expanded to include local control of bone metastases. We report a case in which cryoablation was performed on a large hypervascular renal cell carcinoma bone metastasis before surgical fixation of an impending fracture. In this case, cryoablation reduced the patient's pain but also appeared to result in devascularization of the tumor, thus obviating the need for preoperative embolization. This case raises the possibility that image-guided cryoablation may represent an alternative to preoperative embolization for vascular tumors while also serving a palliative function.

Cryoablation for Palliation of Painful Bone Metastases: The MOTION Multicenter Study

PURPOSE

To assess the clinical effectiveness of cryoablation for palliation of painful bone metastases.

MATERIALS AND METHODS

MOTION (Multicenter Study of Cryoablation for Palliation of Painful Bone Metastases) (ClinicalTrials.gov NCT02511678) was a multicenter, prospective, single-arm study of adults with metastatic bone disease who were not candidates for or had not benefited from standard therapy, that took place from February 2016 to March 2018. At baseline, participants rated their pain using the Brief Pain Inventory-Short Form (reference range from 0 to 10 points); those with moderate to severe pain, who had at least one metastatic candidate tumor for ablation, were included. The primary effectiveness endpoint was change in pain score from baseline to week 8. Participants were followed for 24 weeks after treatment. Statistical analyses included descriptive statistics and logistic regression to evaluate changes in pain score over the postprocedure follow-up period.

RESULTS

A total of 66 participants (mean age, 60.8 years ± 14.3 [standard deviation]; 35 [53.0%] men) were enrolled and received cryoablation; 65 completed follow-up. Mean change in pain score from baseline to week 8 was -2.61 points (95% CI: -3.45, -1.78). Mean pain scores improved by 2 points at week 1 and reached clinically meaningful levels (more than a 2-point decrease) after week 8; scores continued to improve throughout follow-up. Quality of life improved, opioid doses were stabilized, and functional status was maintained over 6 months. Serious adverse events occurred in three participants.

CONCLUSION

Cryoablation of metastatic bone tumors provided rapid and durable pain palliation, improved quality of life, and offered an alternative to opioids for pain control.Keywords: Ablation Techniques, Metastases, Pain Management, Radiation Therapy/OncologySupplemental material is available for this article.© RSNA, 2021.

Percutaneous thermal ablation alone or in combination with cementoplasty for renal cell carcinoma osseous metastases: Pain palliation and local tumour control

INTRODUCTION

To evaluate the safety and efficacy of minimally invasive percutaneous thermal ablation alone or in combination with cementoplasty for pain palliation and local tumour control of renal cell carcinoma osseous metastases.

METHODS

Imaging-guided thermal ablation was performed in 59 renal cell carcinoma osseous metastatic tumours in 23 patients (concomitant cementoplasty in 43 tumours) selected following multidisciplinary consultations to achieve local tumour control and pain palliation (75%, 44/59) or pain palliation alone (25%, 15/59) in this retrospective study. Tumour characteristics, procedural details and complications were documented. Pain palliation was assessed using pre- and post-procedural Numeric Rating Scale scores at 1-week, 1-month, 3-month and 6-month time intervals. Pre- and post-procedural cross-sectional imaging was reviewed to assess local tumour control rates at 3-month, 6-month, and 12-month post-treatment time intervals.

RESULTS

All procedures were technically successful and performed as pre-operatively planned. The median pre- and post-procedural Numeric Rating Scale scores were 8.0 and 3.0 (at all time intervals), respectively (P < 0.001). Local tumour control rates were 100% (40/40), 100% (36/36) and 85% (28/33) at ≥3 months, ≥6 months and ≥12 months post-procedural time intervals, respectively. There was 1 minor complication (1.7%, 1/59).

CONCLUSIONS

Percutaneous thermal ablation alone or in combination with cementoplasty is safe and effective for pain palliation and local tumour control of renal cell carcinoma osseous metastases.

Image-guided percutaneous cryoablation of unresectable sacrococcygeal chordoma: Feasibility and outcome in a selected group of patients with long term follow-up

BACKGROUND

Chordoma is a rare malignant tumor of the axial skeleton. Percutaneous cryoablation (PCA) is a minimally invasive technique that allows freezing of tumors under imaging control. The purpose of our retrospective study was to investigate the outcome of PCA in a selected cohort of patients with sacrococcygeal chordoma, with a minimum of 5 years follow-up.

MATERIALS AND METHODS

Four patients were treated in 10 sessions. The mean follow-up was 57.3 months. We evaluated the feasibility, the procedure-related complications, the impact on pain control and oncological outcomes.

RESULTS

Freezing of 100% of the tumor volume was possible in 60%. Pain control was not reliably evaluable. Local recurrence occurred in 90% of the treated lesions; the mean time to progression was 8.1 months (range 1.5-16). At last follow-up, one patient had died of the disease, one of another cause and one was receiving the best supportive care. The only patient alive without the disease had received additional carbon-ion radiotherapy. The 5-year survival rate after index PCA was 50%.

CONCLUSION

Complete freezing of the tumor was technically challenging, mainly due to the complex local anatomy. Recurrence occurred in 90% of the lesions treated. PCA should be considered with caution in the curative management of sacrococcygeal chordoma.

Hydrodissection of the Retro-Sternal Space to Protect the Pericardium During Sternal Cryoablation

PURPOSE

To report the retro-sternal space hydrodissection technique used to displace the heart and the pericardium posteriorly for thermoprotection ahead of sternal cryoablation (CA).

METHODS AND MATERIALS

Between May 2015 and March 2020, hydrodissection of the retro-sternal space was performed in 5 consecutive patients (5 female; mean age 55.2 ± 9.3 years, range 41-65) who underwent percutaneous image-guided cryoablation of the sternum. The number of needles required, the implemented approach, volume of injectate to achieve hydrodissection, hydrodissection procedure time, distance between the lesion and the pericardium before and after hydrodissection, distance between the ice-ball and the pericardium, technical success and complications were retrospectively assessed.

RESULTS

Technical success, defined as the completion of a full dual freeze protocol without contact between the ice-ball and the pericardium, was achieved in all cases (5/5, 100%). One to two needles were used to perform hydrodissection via a perpendicular (3/5) or an anterior oblique approach (2/5) and a mean hydrodissection procedure time of 10.4 ± 2.6 min (range 8-14). Minimum distance between the lesion and the pericardium increased from mean 5.8 ± 3.8 mm (range 0-10) before hydrodissection to a mean 22.2 ± 5.8 mm (range 18-32) after, with a mean distance between the final ice-ball and the pericardium of 11.6 ± 8.7 mm (range 7-27). A mean of 198 ± 79.8 mL (range 90-290) of iodinated contrast was injected. There were no immediate, short- or medium-term complication noted.

CONCLUSION

Hydrodissection of the retro-sternal space is a feasible technique for sternal cryoablation in order to protect the pericardium from freezing for sternal cryoablation.

Utility of Motor and Somatosensory Evoked Potentials for Neural Thermoprotection in Ablations of Musculoskeletal Tumors

PURPOSE

To characterize the utility of monitoring transcranial electrical motor evoked potentials (TCeMEPs) and somatosensory evoked potentials (SSEPs) for neural thermoprotection during musculoskeletal tumor ablations.

MATERIALS AND METHODS

Retrospective review of 29 patients (16 male; median age, 46 y; range, 7-77 y) who underwent musculoskeletal tumor radiofrequency ablation (n = 8) or cryoablation (n = 22) with intraprocedural TCeMEP and SSEP monitoring was performed. The most common tumor histologies were osteoid osteoma (n = 6), venous malformation (n = 5), sarcoma (n = 5), renal cell carcinoma (n = 4), and non-small-cell lung cancer (n = 3). The most common tumor sites were spine (n = 22) and lower extremities (n = 4). Abnormal TCeMEP change was defined by 100-V increase above baseline threshold activation for a given myotome; abnormal SSEP change was defined by 60% reduction in baseline amplitude and/or 10% increase in latency.

RESULTS

Abnormal changes in TCeMEP (n = 9; 30%) and/or SSEP (n = 5; 17%) occurred in 12 procedures (40%) and did not recover in 5 patients. Patients with unchanged TCeMEP/SSEP activities throughout the procedure (n = 18) did not have motor or sensory symptoms after the procedure; 3 (60%) with unrecovered activity changes and 2 (29%) with transient activity changes had new motor (n = 1) or sensory (n = 4) symptoms. Relative risk for neurologic sequelae for patients with unrecovered TCeMEP/SSEP changes vs those with transient or no changes was 7.50 (95% confidence interval, 1.66-33.9; P = .009).

CONCLUSIONS

Abnormal activity changes of TCeMEP or SSEP during percutaneous ablative procedures correlate with postprocedural neurologic sequelae.

Retrospective analysis of CT-guided percutaneous cryoablation for treatment of painful osteolytic bone metastasis

This study aimed to evaluate the safety and effectiveness of CT-guided percutaneous cryoablation for treatment of painful osteolytic bone metastases. A total of 26 patients (36 bone metastases) treated with CT-guided percutaneous cryoablation between May 2012 and June 2016 were enrolled in this retrospective study. All procedures were performed under local anesthesia. A visual analog scale (VAS) was used to evaluate pain before the procedure and at 1 day, 1 month, 3 months, and 6 months after the procedure. Complications during and after the procedure were recorded and graded by the Clavien-Dindo classification. The mean VAS pain score was 7.1 ± 1.1 (range, 4-10) before cryoablation. It was significantly lower at all timepoints after treatment: 2.1 ± 1.7 (P < 0.0001) at 1 day after treatment, 1.3 ± 1.8 (P < 0.0001) at 1 month, 1.6 ± 1.7 (P < 0.0001) at 3 months, and 1.8 ± 1.3 (P < 0.0001) at 6 months. The response rates were 91.7%, 94.4%, 91.7%, and 94.4%, respectively, at 1 day, 1 month, 3 months, and 6 months after cryoablation; the complete response rates were 22.2%, 41.7%, 36.1%, and 22.2%, respectively. Adverse events (skin frostbite, nerve injury, pathologic fracture) occurred in 3 patients. CT-guided percutaneous cryoablation under local anesthesia appears to be a safe and effective treatment for painful osteolytic bone metastases. Prospective clinical trials on large samples needed to confirm this conclusion.

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.

Percutaneous Minimally Invasive Thermal Ablation of Musculoskeletal Lesions: Usefulness of PET-Computed Tomography

This article discusses the role of PET-computed tomography in percutaneous minimally invasive ablation of osseous metastases including diagnosis and preprocedural factors related to patient selection and procedure planning, intraprocedural imaging guidance, and posttreatment imaging assessment.

Percutaneous Image-Guided Ablation in the Treatment of Osseous Metastases from Non-small Cell Lung Cancer

INTRODUCTION

Percutaneous image-guided ablation is an emerging minimally invasive therapy for patients with metastatic bone disease for whom radiation therapy is ineffective or contraindicated. The purpose of this study was to examine the safety and efficacy of percutaneous ablation in achieving pain palliation and local tumor control of osseous metastases from non-small cell lung cancer (NSCLC).

METHODS

A retrospective review was performed of 76 musculoskeletal metastases in 45 patients treated with percutaneous ablation. 63% (48/76) were treated with radiofrequency ablation (RFA), 35% (27/76) with cryoablation, and 1.3% (1/76) with microwave ablation (MWA). In 70% (53/76) of cases, associated cementoplasty was performed. Primary outcomes measured were pre- and post-procedure pain scores 4 weeks after treatment and local tumor control at 3-, 6-, and 12-month follow-up.

RESULTS

Mean age of the cohort was 63.6 ± 9.5 years. Median tumor diameter was 3.60 cm (range 1.0-10.0 cm). Mean and median pain scores before treatment were 7.5 ± 2.3 and 8.0, respectively. Post-procedure, patients reported significantly decreased pain scores at 4 weeks (mean, 3.7 ± 3.5; median, 3.0; p < 0.00001). Radiographic local tumor control rates were 83% (35/42) at 3 months, 77% (23/30) at 6 months, and 68% (17/25) at 12 months after treatment. The overall complication rate was 2.6% (2/76).

CONCLUSION

Percutaneous tumor ablation is a well-tolerated, minimally invasive procedure associated with improving pain palliation and achieving local tumor control of osseous metastases from NSCLC.

LEVEL OF EVIDENCE

Level 4, case series.

Metastatic Osseous Pain Control: Bone Ablation and Cementoplasty

Nociceptive and/or neuropathic pain can be present in all phases of cancer (early and metastatic) and are not adequately treated in 56 to 82.3% of patients. In these patients, radiotherapy achieves overall pain responses (complete and partial responses combined) up to 60 and 61%. On the other hand, nowadays, ablation is included in clinical guidelines for bone metastases and the technique is governed by level I evidence. Depending on the location of the lesion in the peripheral skeleton, either the Mirels scoring or the Harrington (alternatively the Levy) grading system can be used for prophylactic fixation recommendation. As minimally invasive treatment options may be considered in patients with poor clinical status or limited life expectancy, the aim of this review is to detail the techniques proposed so far in the literature and to report the results in terms of safety and efficacy of ablation and cementoplasty (with or without fixation) for bone metastases. Percutaneous image-guided treatments appear as an interesting alternative for localized metastatic lesions of the peripheral skeleton.