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

Advances in Image-Guided Ablation Therapies for Solid Tumors

Image-guided solid tumor ablation methods have significantly advanced in their capability to target primary and metastatic tumors. These techniques involve noninvasive or percutaneous insertion of applicators to induce thermal, electrochemical, or mechanical stress on malignant tissue to cause tissue destruction and apoptosis of the tumor margins. Ablation offers substantially lower risks compared to traditional methods. Benefits include shorter recovery periods, reduced bleeding, and greater preservation of organ parenchyma compared to surgical intervention. Due to the reduced morbidity and mortality, image-guided tumor ablation offers new opportunities for treatment in cancer patients who are not candidates for resection. Currently, image-guided ablation techniques are utilized for treating primary and metastatic tumors in various organs with both curative and palliative intent, including the liver, pancreas, kidneys, thyroid, parathyroid, prostate, lung, breast, bone, and soft tissue. The invention of new equipment and techniques is expanding the criteria of eligible patients for therapy, as now larger and more high-risk tumors near critical structures can be ablated. This article provides an overview of the different imaging modalities, noninvasive, and percutaneous ablation techniques available and discusses their applications and associated complications across various organs.

Application of microwave ablation assisted degradation therapy in surgical treatment of intramedullary chondrosarcoma of extremities

AIM

Clinical diagnosis and surgical treatment of chondrosarcoma (CS) are continuously improving. The purpose of our study is to evaluate the effectiveness of microwave ablation (MWA) assisted degradation therapy in the surgical treatment of intramedullary chondrosarcoma of the extremities, to provide a new reference and research basis for the surgical treatment of CS.

METHODS

We recruited 36 patients with intramedullary CS who underwent MWA assisted extended curettage. Preoperative patient demographics and clinical data were recorded. Surgery was independently assisted by a medical team. Patients were followed up strictly and evaluated for oncological prognosis, radiological results, limb joint function, pain, and complications.

RESULTS

We included 15 men and 21 women (mean age: 43.5 ± 10.1). The average length of the lesion was 8.1 ± 2.5 cm. Based on preoperative radiographic, clinical manifestations, and pathological results of puncture biopsy, 28 patients were preliminarily diagnosed with CS-grade I and eight patients with CS-grade II. No recurrence or metastasis occurred in the postoperative follow-up. The average Musculoskeletal Tumor Society score was 28.8 ± 1.0, significantly better than presurgery. Secondary shoulder periarthritis and abduction dysfunction occurred in early postoperative stage CS of the proximal humerus in some, but returned to normal after rehabilitation exercise. Secondary bursitis occurred at the knee joint in some due to the internal fixation device used in treatment; however, secondary osteoarthritis and avascular necrosis of the femoral head were not observed. Overall, oncological and functional prognoses were satisfactory.

CONCLUSIONS

The application of MWA assisted degradation therapy in intramedullary CS can achieve satisfactory oncology and functional prognosis, providing a new option for the limited treatment of CS.

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.

Cryoablation for the Palliation of Painful Bone Metastasis: A Systematic Review

BACKGROUND

Cryoablation is a minimally invasive procedure to treat painful bone metastases in patients with cancer. We designed a systematic review to understand the safety and effects of cryoablation on the pain and quality of life (QoL) of cancer patients.

METHOD

We searched PubMed, ISI, Cochrane library, and Scopus databases using the keywords "Cryoablation," "Pain," and "Bone metastasis." Inclusion criteria were: (1) Original studies published until September 8, 2022; (2) studies on patients over 18 years and affected by bone metastasis; (3) bone metastasis treated with stand-alone cryoablation; (4) studies reporting patients' pain before and at least one time-point following cryoablation; and (5) English-language studies.

RESULTS

We screened 696 articles. Fifteen studies on 376 patients were included. Time points for pain assessment ranged from 1 day to 6 months. Spine was the most frequent treated location. All studies reported a significant pain reduction between 1 day and 6 months after the cryoablation procedure. The highest mean difference between pre- and post-procedure scores was 5.8 (VAS scale) after 4 weeks. The overall rate of minor and major complications was 12.74%. Cryoablation improved the QoL of cancer patients and decreased the need for analgesics.

CONCLUSION

Cryoablation is a safe and useful procedure for palliating painful bone metastasis and increasing the QoL of cancer patients. Future studies should adopt a standardized pain reporting scale to allow for meta-analysis.

Musculoskeletal Interventional Oncology: A Contemporary Review

Musculoskeletal interventional oncology is an emerging field that addresses the limitations of conventional therapies for bone and soft-tissue tumors. The field's growth has been driven by evolving treatment paradigms, expanding society guidelines, mounting supportive literature, technologic advances, and cross-specialty collaboration with medical, surgical, and radiation oncology. Safe, effective, and durable pain palliation, local control, and stabilization of musculoskeletal tumors are increasingly achieved through an expanding array of contemporary minimally invasive percutaneous image-guided treatments, including ablation, osteoplasty, vertebral augmentation (with or without mechanical reinforcement via implants), osseous consolidation via percutaneous screw fixation (with or without osteoplasty), tumor embolization, and neurolysis. These interventions may be used for curative or palliative indications and can be readily combined with systemic therapies. Therapeutic approaches include the combination of different interventional oncology techniques as well as the sequential application of such techniques with other local treatments, including surgery or radiation. This article reviews the current practice of interventional oncology treatments for the management of patients with bone and soft-tissue tumors with a focus on emerging technologies and techniques.

Treatment of Cancer Pain: A Systematic Review

CONTEXTUALIZATION

One of the biggest problems regarding the treatment of cancer patients is pain, whether due to the cancer or the treatment itself. Therefore, there is a search for treatments that aims to promote an effective treatment in this sense.

PURPOSE

This article aims to verify which are the recent methods used to treat pain in cancer patients in a multidisciplinary sense, and to evaluate their effectiveness.

METHODOLOGY

Systematic reviews, meta-analyses and randomized clinical trials utilizing the LILACS, NCBI, and MEDLINE platforms of the last 5 years were included. The descriptors were pain treatment in oncology, pain management, complementary therapies, and other synonyms, in Portuguese, English and Spanish. This included any technique that was effective in the treatment of cancer pain.

RESULTS

The initial search found 2246 articles, of which 22 were included in the systematic review. Most of these are acupuncture treatments, opioids versus anti-inflammatories versus analgesics, radiotherapy, behavioral therapies, among others. Most articles suggest benefits with these therapies, improved quality of life for patients and tolerable side effects.

CONCLUSION

This study demonstrates the effectiveness of the current methods used in the treatment of pain in cancer patients so that professionals in the area can have more options for treating cancer pain. Despite the important limitations, the guideline for further research and the situations in which treatments have shown effectiveness are present in it.

Efficacy and safety of magnetic resonance-guided focused ultrasound for the treatment of osteoid osteoma: A systematic review and meta-analysis

OBJECTIVE

Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel noninvasive interventional technique for osteoid osteoma (OO). The purpose of this study was to evaluate the efficacy and safety of MRgFUS in the treatment of OO through a systematic review and meta-analysis of pain scores and post-treatment adverse events before and after MRgFUS treatment.

MATERIALS AND METHODS

A comprehensive literature search of PubMed, Embase, Web of science, and Cochrane Library databases was conducted to screen the study literature based on inclusion and exclusion criteria to extract and analyze pre- and post-treatment pain score data, success rates (complete pain relief with no recurrence until the last follow-up), recurrence rates, secondary intervention rates, and complications to evaluate the efficacy and/or safety of MRgFUS for OO.

RESULTS

A total of 113 studies published between 2012 and 2022were collected, resulting in a total sample size of 353 patients. The majority of the studies were prospective and had a follow-up period of 4 weeks or more, and overall, the quality of evidence ranged from low to high. Pain scores at 1 week and 1 month after the merger were 0.62 (9.5% CI:0.28-0.96) and 0.37 (9.5% CI:0.07-0.68), respectively. The success rate of the combination was 92.8% (95% CI: 89.8%-95.7%), the incidence of minor complications (thermal injury at the ablation site) was 0.85%, and no major complications were recorded in any of the included literature.

CONCLUSION

MRgFUS is an effective procedure that is able to treat pain for patients with OO with satisfying efficacy and safety.

PROSPERO

No.CRD42023415573.

Image-Guided Ablation Therapies for Extrahepatic Metastases from Hepatocellular Carcinoma: A Review

The most common sites of extrahepatic metastases from hepatocellular carcinoma (HCC) are the lungs, intra-abdominal lymph nodes, bones, and adrenal glands, in that order. Although systemic therapies are a common treatment for patients with extrahepatic metastases, local ablative therapies for the extrahepatic metastatic lesions can be performed in selected patients. In this article, the literature on image-guided thermal ablation for metastasis to each organ was reviewed to summarize the current evidence. Radiofrequency ablation was the most commonly evaluated technique, and microwave ablation, cryoablation, and percutaneous ethanol injection were also utilized. The local control rate of thermal ablation therapy was relatively favorable, at approximately 70-90% in various organs. The survival outcomes varied among the studies, and several studies reported that the absence of viable intrahepatic lesions was associated with improved survival rates. Since only retrospective data from relatively small studies has been available thus far, more robust studies with prospective designs and larger cohorts are desired to prove the usefulness of thermal ablation for extrahepatic metastases from HCC.

A comparative study of establishing rabbit vertebral tumor model by two ways of CT-guided percutaneous puncture

Objective

To investigate the difference of tumor formation rate of rabbit vertebral tumor model established by percutaneous injection of V×2 tumor tissue suspension and tumor mass under computed tomography (CT) guidance, and the imaging findings of CT, magnetic resonance images (MRI) and positron emission tomography with computed tomography (PET/CT) at 7 days, 14 days and 21 days after implantation, and preliminarily verify the safety and feasibility of microwave ablation (MWA), percutaneous vertebroplasty (PVP) and microwave ablation combined with percutaneous vertebroplasty (MWA + PVP) in rabbit VX2 vertebral tumor model.

Methods

Thirty healthy New Zealand rabbits were randomly allocated to tissue suspension group and tumor block group, with 15 rabbits for each group. The VX2 tumor block and mixed suspension were inoculated into the L5 vertebral body under CT-guided percutaneous puncture. The PET/CT, MRI and CT examinations were performed at 7, 14 and 21 days after implantation. Fisher exact probability test was used to compare the success rate of the two implantation methods and the tumor display rate at each time point of the three examination methods. Observe the paralysis of tumor-forming rabbits, and immediately perform MWA/PVP/MWA + PVP treatment according to groups after paralysis to verify the safety and feasibility of treatment.

Results

A total of 18 experimental rabbits were successfully modeled in two groups, of which the success rate was 26.6% (4/15) in tissue suspension group and 93.3% (14/15) in tumor block group, with statistically significant differences between two groups (P < 0.01). The tumor display rates by PET/CT, MRI and CT at each time point after implantation were: 83.3% (15/18), 16.6% (3/18), and 0% (0/18) at 7 days after implantation; 100% (18/18), 88.8% (16/18), and 11.1% (2/18) at 14 days after implantation; and 100% (18/18), 100% (18/18), 77.7% (14/18) at 21 days after implantation. The average paralysis time of 18 experimental rabbits successfully modeled was 24.44 ± 2.38 days, and MWA/PVP/MWA + PVP treatment was performed in groups immediately after paralysis. Except for 2 rabbits who died due to anesthesia overdose during anesthesia before treatment, the remaining 16 rabbits were successfully treated with MWA/PVP/MWA + PVP, and the technical success rate was 100% (16/16). In MWA group, one experimental rabbit was randomly selected and killed after ablation, and histopathological examination (H and E staining) was performed together with 2 experimental rabbits who died of anesthesia. The pathological changes before and after ablation were compared. The survival time of the remaining 15 experimental rabbits varied from 3 to 8 days after treatment.

Conclusion

The success rate of establishing rabbit vertebral tumor model by injecting tumor masses under the CT-guided percutaneous puncture is high, and the following MWA and PVP treatment can be successfully conducted. PET/CT is the most sensitive method for early detection of tumor compared with MRI and CT. Spectral Presaturation with Inversion Recovery (SPIR) sequence can significantly improve the detection rate of smaller tumors by MRI and shorten the detection time.

Palliative Arterial Embolization for Metastases of the Sternum

BACKGROUND

To investigate the safety and efficacy of palliative arterial embolization for metastases of the sternum.

MATERIALS AND METHODS

This study included 10 consecutive patients (5 M, 5 F; mean age 58.1; range 37-70) with metastases of the sternum from different primary tumors, treated with palliative arterial embolization using NBCA-Lipiodol between January 2007 and June 2022. Four patients received a second embolization at the same site, for a total of 14 embolizations. Data on technical and clinical success, as well as changes in tumor size, were collected. All embolization-related complications were evaluated according to the CIRSE classification system for complications.

RESULTS

Post-embolization angiography showed occlusion of more than 90% of the pathological feeding vessels in all procedures. Pain score and analgesic drug consumption were reduced by 50% in all 10 patients (100%, p < 0.05). The mean duration of pain relief was 9.5 months (range 8 to 12 months, p < 0.05). Metastatic tumor size was reduced from a mean of 71.5 cm³ (range 41.6 to 90.3 cm³) pre-embolization to a mean of 67.9 cm³ (range 38.5 to 86.1 cm³) at the 12-month follow-up (p < 0.05). None of the patients experienced embolization-related complications.

CONCLUSION

Arterial embolization is safe and effective as a palliative treatment for patients with metastases of the sternum who did not benefit from radiation therapy or experienced recurrence in symptoms.

Pharmacologic Pain Management: What Radiation Oncologists Should Know

Individuals with cancer experience a host of symptoms, especially when the malignancy is advanced. Pain occurs from the cancer itself or related treatments. Undertreated pain contributes to patient suffering and lack of engagement in cancer-directed therapies. Adequate pain management includes thorough assessment; treatment by radiotherapists or anesthesia pain specialists; anti-inflammatory medications, oral or intravenous opioid analgesics, and topical agents; and attention to the emotional and functional effects of pain, which may involve social workers, psychologists, speech therapists, nutritionists, physiatrists and palliative medicine providers. This review discusses typical pain syndromes arising in cancer patients undergoing radiotherapy and provides concrete recommendations for pain assessment and pharmacologic treatment.

Role of interventional radiology in pain management in oncology patients

This article reviews the current evidence of interventional radiology procedures for patients suffering with debilitating cancer pain, refractory to conventional therapies. Cancer pain is notoriously difficult to treat. Up to 90% of cancer patients experience pain with 56-82% of cancer pain controlled inadequately. Cancer pain influences a patient's ability to perform normal daily activities, causes higher risk of depression, and reduces quality of life. Pain-free status has been universally voted as a "good death". Alternative minimally invasive options include nerve blocks, neurolysis, bone ablation, spine and peripheral musculoskeletal augmentation techniques, embolisation, and cordotomy with evidence highlighting improved pain control, reduced analgesic requirements, and improved quality of life. Unfortunately, awareness and availability of these procedures is limited, potentially leaving patients suffering during their remaining life. The purpose of this review is to describe the basic concepts of interventional radiology techniques for pain palliation in oncology patients. In addition, emphasis will be given upon the need for an individually tailored approach aiming to augment efficacy and safety.

Clinical guidelines for microwave ablation of spinal metastases

Spinal metastases are the most common source of morbidity in patients with cancer. Recently, microwave ablation has produced satisfactory results in the management of spinal metastases. However, there is still controversy in terms of clinical treatment, such as indication, power, time, and temperature. To standardize the application of microwave ablation technology and reduce the risk of surgical-related complications in spinal metastases, in this report, we aimed to summarize the current evidence and clinical experience of microwave ablation and developed a clinical guideline, initiated by the Musculoskeletal Tumor Group of the Committee for Minimally Invasive Therapy in Oncology of the Chinese Anti-Cancer Association. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used in to rate the quality of evidence and the strength of recommendations, and the Reporting Items for Practice Guidelines in Healthcare (RIGHT) checklist was strictly followed to report the guideline. Finally, 15 evidence-based recommendations were formulated based on the 15 most concerned clinical questions among orthopedic surgeons, oncologists, and interventional radiologists in China. This guideline aims to promote the science-based normalization of microwave ablation for the treatment of spinal metastases.

Juxtametallic Bipolar Bone Radiofrequency Ablation: Thermal Monitoring in an Ex-Vivo Model with Specimen MRI and Histopathologic Correlation

PURPOSE

To measure the ablation zone temperature and nontarget tissue temperature during radiofrequency (RF) ablation in bone containing metal instrumentation versus no metal instrumentation (control group).

MATERIALS AND METHODS

Ex vivo experiments were performed on 15 swine vertebrae (control, n = 5; titanium screw, n = 5; stainless steel screw, n = 5). Screws and RF ablation probe were inserted identically under fluoroscopy. During RF ablation (3 W, 5 minutes), temperature was measured 10 mm from RF ablation centerpoint and in muscle contacting the screw. Magnetic resonance (MR) imaging, gross pathologic, and histopathologic analyses were performed on 1 specimen from each group.

RESULTS

Ablation zone temperatures at 2.5 and 5 minutes increased by 12.2 °C ± 2.6 °C and 21.5 °C ± 2.1 °C (control); 11.0 °C ± 4.1 °C and 20.0 °C ± 2.9 °C (juxta-titanium screw), and 10.0 °C ± 3.4 °C and 17.2 °C ± 3.5 °C (juxta-stainless steel) screw; differences among groups did not reach significance by analysis of variance (P = .87). Mixed-effects linear regression revealed a statistically significant increase in temperature over time in all 3 groups (4.2 °C/min ± 0.4 °C/min, P < .001). Compared with the control, there was no significant difference in the temperature change over time for titanium (-0.3 °C/min ± 0.5 °C/min, P = .53) or steel groups (-0.4 °C/min ± 0.5 °C/min, P = .38). The mean screw temperature at the final time point did not show a statistically significant change compared with baseline in either the titanium group (-1.2 °C ± 2.3 °C, P = .50) or steel group (2.6 °C ± 2.9 °C, P = .11). MR imaging and pathologic analyses revealed homogeneous ablation without sparing of the peri-hardware zones.

CONCLUSIONS

Adjacent metallic instrumentation did not affect the rate of or absolute increase in temperature in the ablation zone, did not create peri-metallic ablation inhomogeneities, and did not result in significant nontarget heating of muscle tissue in contact with the metal instrumentation.

Managing Chronic Neuropathic Pain: Recent Advances and New Challenges

Aim. Neuropathic pain affects 7–10% of the population, with most of the patients receiving inadequate and incomplete treatment. Owing to the high financial burden and the poor quality of life of the patients and their caretakers, there is a dire need to address the challenges in diagnosing and treating chronic neuropathic pain. Methods. This literature review was conducted to review novel treatments and related challenges through a systematic search from sources such as PubMed, Google Scholar with the combination of MESH words such as neuropathic pain, management of neuropathic pain. Articles from non-English literature, reports without human subjects, animal studies, and abstracts/posters were excluded. However, human studies and studies published in English were included. Result. This review article discusses novel treatment modalities while acknowledging the challenges medical workers face while encountering neuropathic pain. Despite the recent advances in diagnosis and treatment modalities, several challenges still exist. Hence, there is still a need to explore the various treatment modalities, emphasizing the cause and underlying pathophysiology of neuropathic pain. Conclusion. We recommend integrated multimodal treatment with the current treatment facility, including various medical disciplines. However, a personalized approach would work the best depending on the ’patient’s medical history. Therefore, this article recommends an integrated, cause-specific, cost-effective approach to address this problem of chronic neuropathic pain.

A Multimodal Clinical Approach for the Treatment of Bone Metastases in Solid Tumors

Context

Bone metastasis (BM) is a frequent complication of cancer, representing the third most common site of secondary spread in solid cancers behind the lung and liver. Bone metastasis is found in up to 90% of prostate and breast cancer patients. They can cause significant complications, such as pathological fractures and paralysis of the spine, which decrease daily functioning and quality of life (QoL) and worsen prognosis. The growing life expectancy of cancer patients due to improvements in systemic therapies may further increase BM's eventuality and clinical burden in cancer patients.

Evidence Acquisition

Four physicians from five different specialties were interviewed and resumed the most relevant literature of the last 20 years focusing on pain treatment in BM patients.

Results

Treatment for BM ideally involves various types of specialists and assessments. The disease status and patient background should be considered, requiring holistic care and expertise from various medical specialties.

Conclusions

Interventional, nuclear medicine, radiotherapy, and mini-invasive techniques can be safe and effective for relieving pain and modifying health-related QoL in BM patients.

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.

Image-Guided Percutaneous Ablation for Primary and Metastatic Tumors

Image-guided percutaneous ablation methods have been further developed during the recent two decades and have transformed the minimally invasive and precision features of treatment options targeting primary and metastatic tumors. They work by percutaneously introducing applicators to precisely destroy a tumor and offer much lower risks than conventional methods. There are usually shorter recovery periods, less bleeding, and more preservation of organ parenchyma, expanding the treatment options of patients with cancer who may not be eligible for resection. Image-guided ablation techniques are currently utilized for the treatment of primary and metastatic tumors in various organs including the liver, pancreas, kidneys, thyroid and parathyroid, prostate, lung, bone, and soft tissue. This article provides a brief review of the various imaging modalities and available ablation techniques and discusses their applications and associated complications in various organs.

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.

Needleless Ablation of Osteoid Osteoma and Osteoblastoma: The Emergent Role of MRgFUS

Osteoblastoma (OB) and osteoid osteoma (OO) are benign bone-forming tumors, with nearly identical basic microscopic features. The main difference is dimension (OO has usually a nidus measuring <2 cm in diameter). In addition, OB is biologically more active than OO, with a tendency to grow in size. Historically, treatments have included surgical resection and analgesics, although invasiveness and poor tolerance have led to the current standard of care moving toward interventional radiology, where radiofrequency ablation (RFA) represents the most diffuse technique. Magnetic resonance-guided focused ultrasound surgery (MRgFUS) has recently emerged as another innovative alternative treatment, providing tumor ablation through a needleless and ionizing radiation-free modality. In addition, this technique has the ability to guarantee a very precise and controlled increase in temperature, delivering small amounts of energy that can accurately destroy only the lesion, avoiding healthy surrounding tissues. The present review focuses on MRgFUS as the less invasive, safe, effective, and durable treatment option for the management of osteoid osteoma and osteoblastoma, including a description of technical details, indications and outcomes.

Percutaneous image-guided cryoablation of spinal metastases: A systematic review

Percutaneous cryoablation (PCA) is a minimally invasive technique that has been recently used to treat spinal metastases with a paucity of data currently available in the literature. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Prospective or retrospective studies concerning metastatic spinal neoplasms treated with current generation PCA systems and with available data on safety and clinical outcomes were included. In the 8 included studies (7 retrospective, 1 prospective), a total of 148 patients (females = 63%) underwent spinal PCA. Tumors were located in the cervical (3/109 [2.8%], thoracic (74/109 [68.8%], lumbar (37/109 [33.9%], and sacrococcygeal (17/109 [15.6%] regions. Overall, 187 metastatic spinal lesions were treated. Thermo-protective measures (e.g., carbo-/hydro-dissection, thermocouples) were used in 115/187 [61.5%] procedures. For metastatic spinal tumors, the pooled mean difference (MD) in pain scores from baseline on the 0-10 numeric rating scale was 5.03 (95% confidence interval [CI]: 4.24 to 5.82) at a 1-month follow-up and 4.61 (95% CI: 3.27 to 5.95) at the last reported follow-up (range 24-40 weeks in 3/4 studies). Local tumor control rates ranged widely from 60% to 100% at varying follow-ups. Grade I-II complications were reported in 9/148 [6.1%] patients and grade III-V complications were reported in 3/148 [2.0%]) patients. PCA, as a stand-alone or adjunct modality, may be a viable therapy in appropriately selected patients with painful spinal metastases who were traditionally managed with open surgery and/or radiation therapy.

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.

Percutaneous management of bone metastases: State of the art

Interventional radiology is playing an increasingly important role in the local treatment of bone metastases; this treatment is usually done with palliative intent, although in selected patients it can be done with curative intent. Two main groups of techniques are available. The first group, centered on bone consolidation, includes osteoplasty/vertebroplasty, in which polymethyl methacrylate (PMMA) is injected to reinforce the bone and relieve pain, and percutaneous osteosynthesis, in which fractures with nondisplaced or minimally bone fragments are fixed in place with screws. The second group centers on tumor ablation. tumor ablation refers to the destruction of tumor tissue by the instillation of alcohol or by other means. Thermoablation is the preferred technique in musculoskeletal tumors because it allows for greater control of ablation. Thermoablation can be done with radiofrequency, in which the application of a high frequency (450 Hz-600 Hz) alternating wave to the tumor-bone interface achieves high temperatures, resulting in coagulative necrosis. Another thermoablation technique uses microwaves, applying electromagnetic waves in an approximate range of 900 MHz-2450 MHz through an antenna that is placed directly in the core of the tumor, stimulating the movement of molecules to generate heat and thus resulting in coagulative necrosis. Cryoablation destroys tumor tissue by applying extreme cold. A more recent, noninvasive technique, magnetic resonance-guided focused ultrasound surgery (MRgFUS), focuses an ultrasound beam from a transducer placed on the patient's skin on the target lesion, where the waves' mechanical energy is converted into thermal energy (65 °C-85 °C). Treatment should be planned by a multidisciplinary team. Treatment can be done with curative or palliative intent. Once the patient is selected, a preprocedural workup should be done to determine the most appropriate technique based on a series of factors. During the procedure, protective measures must be taken and the patient must be closely monitored. After the procedure, patients must be followed up.

Percutaneous management of bone metastases: state of the art

Interventional radiology is playing an increasingly important role in the local treatment of bone metastases; this treatment is usually done with palliative intent, although in selected patients it can be done with curative intent. Two main groups of techniques are available. The first group, centered on bone consolidation, includes osteoplasty / vertebroplasty, in which polymethyl methacrylate (PMMA) is injected to reinforce the bone and relieve pain, and percutaneous osteosynthesis, in which fractures with nondisplaced or minimally bone fragments are fixed in place with screws. The second group centers on tumor ablation. Tumor ablation refers to the destruction of tumor tissue by the instillation of alcohol or by other means. Thermoablation is the preferred technique in musculoskeletal tumors because it allows for greater control of ablation. Thermoablation can be done with radiofrequency, in which the application of a high frequency (450 Hz-600Hz) alternating wave to the tumor-bone interface achieves high temperatures, resulting in coagulative necrosis. Another thermoablation technique uses microwaves, applying electromagnetic waves in an approximate range of 900MHz to 2450MHz through an antenna that is placed directly in the core of the tumor, stimulating the movement of molecules to generate heat and thus resulting in coagulative necrosis. Cryoablation destroys tumor tissue by applying extreme cold. A more recent, noninvasive technique, magnetic resonance-guided focused ultrasound surgery (MRgFUS), focuses an ultrasound beam from a transducer placed on the patient's skin on the target lesion, where the waves' mechanical energy is converted into thermal energy (65°C-85°C). Treatment should be planned by a multidisciplinary team. Treatment can be done with curative or palliative intent. Once the patient is selected, a preprocedural workup should be done to determine the most appropriate technique based on a series of factors. During the procedure, protective measures must be taken and the patient must be closely monitored. After the procedure, patients must be followed up.

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 of sacral metastases: Assessment of pain relief and local tumor control

PURPOSE

To retrospectively report on safety, pain relief and local tumor control achieved with percutaneous ablation of sacral bone metastases.

MATERIALS AND METHODS

From February 2009 to June 2020, 23 consecutive patients (12 women and 11 men; mean age, 60±8 [SD] years; median, 60; range: 48-80 years) with 23 sacral metastases underwent radiofrequency (RFA) or cryo-ablation (CA), with palliative or curative intent at our institution. Patients' demographics and data pertaining to treated metastases, procedure-related variables, safety, and clinical evolution following ablation were collected and analyzed. Pain was assessed with numerical pain rating scale (NPRS).

RESULTS

Sixteen (70%) patients were treated with palliative and 7 (30%) with curative intent. Mean tumor diameter was 38±19 (SD) mm (median, 36; range: 11-76). External radiation therapy had been performed on five metastases (5/23; 22%) prior to ablation. RFA was used in 9 (39%) metastases and CA in the remaining 14 (61%). Thermo-protective measures and adjuvant bone consolidation were used whilst treating 20 (87%) and 8 (35%) metastases, respectively. Five (22%) minor complications were recorded. At mean 31±21 (SD) (median, 32; range: 2-70) months follow-up mean NPRS was 2±2 (SD) (median, 1; range: 0-6) vs. 5±1 (median, 5; range: 4-8; P<0.001) at the baseline. Three metastases out of 7 (43%) undergoing curative ablation showed local progression at mean 4±4 (SD) (median, 2; range: 1-8) months follow-up.

CONCLUSION

Percutaneous ablation of sacral metastases is safe and results in significant long-lasting pain relief. Local tumor control seems sub-optimal; however, further investigations are needed to confirm these findings due to paucity of data.

Interventional Techniques for Bone and Musculoskeletal Soft Tissue Tumors: Current Practices and Future Directions - Part I. Ablation

Musculoskeletal (MSK) image-guided oncologic intervention is an established field within radiology. Numerous studies have described its clinical benefits, safety, cost effectiveness, patient satisfaction, and improved quality of life, thereby establishing image-guided oncologic intervention as a preferred pathway in treating patients presenting with specific benign MSK tumors. But there is a paradigm shift on the horizon because these techniques may also support established pillars (surgery, systemic treatment, radiotherapy) in the treatment of malignant MSK tumors. Unlike benign tumors, where they are used as primary therapy lines with curative intent, such interventions can be selected for malignant tumors as adjuvant treatment in painful or unstable bone or soft tissue lesions or as more palliative therapy strategies. Using examples from our clinical practices, we elaborate on the benefits of applying a multidisciplinary approach (traditionally involving MSK radiologists, oncologists, orthopaedic surgeons, microbiologists, pathologists, physiotherapists, and pain management experts), ideally within a sarcoma treatment center to deliver a patient-specific therapy plan and illustrate methods to assess the benefits of this model of care.In this article, we review the current repertoire of ablation techniques, demonstrate why such procedures offer value-based alternatives to conventional treatments of specific tumors, and reflect on future directions. Additionally, we review the advantages and limitations of each technique and offer guidance to improve outcomes.

Percutaneous microwave ablation of bone tumors: a systematic review

AIM

To systematically review microwave ablation (MWA) protocols, safety, and clinical efficacy for treating bone tumors.

MATERIALS AND METHODS

A systematic literature search was conducted using PubMed, the Cochrane Library, EMBASE, and Web of Science database. Data concerning patient demographics, tumor characteristics, procedure, complications, and clinical outcomes were extracted and analyzed.

RESULTS

Seven non-comparative studies (6 retrospective, 1 prospective) were included accounting for 249 patients and 306 tumors (244/306 [79.7%] metastases; 25/306 [8.2%] myelomas, and 37/306 [12.1%] osteoid osteomas [OO]). In malignant tumors, MWA power was 30-70 W (except in one spinal tumors series where a mean power of 13.3 W was used) with pooled mean ablation time of 308.3 s. With OO, MWA power was 30-60 W with mean ablation time of 90-102 s. Protective measures were very sporadically used in 5 studies. Additional osteoplasty was performed in 199/269 (74.0%) malignant tumors. Clinically significant complications were noted in 10/249 (4.0%) patients. For malignant tumors, estimated pain reduction on the numerical rating scale was 5.3/10 (95% confidence intervals [95%CI] 4.6-6.1) at 1 month; and 5.3/10 (95% CI 4.3-6.3) at the last recorded follow-up (range 20-24 weeks in 4/5 studies). For OO, at 1-month follow-up, effective pain relief was noted in 92.3-100% of patients.

CONCLUSION

MWA is effective in achieving pain relief at short- (1 month) and mid-term (4-6 months) for painful OO and malignant bone tumors, respectively. Although MWA seems safe, further prospective studies are warranted to further assess this aspect, and to standardize MWA protocols.

KEY POINTS

• Large heterogeneity exists across literature about ablation protocols used with microwave ablation applied for the treatment of benign and malignant bone tumors. • Although microwave ablation of bone tumors appears safe, further studies are needed to assess this aspect, as current literature does not allow definitive conclusions. • Nevertheless, microwave ablation is effective in achieving pain relief at short- (1 month) and mid-term (4-6 months) for painful osteoid osteomas and malignant bone tumors, respectively.

Advanced Interventional Pain Management Approach to Neoplastic Disease Outside the Spine

Neoplastic disease of the musculoskeletal system may result in serious morbidity and mortality secondary to cancer related bone pain, pathologic fracture, altered structural mechanics, and involvement of adjacent structures.¹ Recent advances in cancer detection and treatment have allowed more patients to live longer. The prevalence of osseous metastatic disease has increased to 100,000 new patients developing bone metastases each year.² These patients are seeing long-term exposure to chemotherapy and radiation leading to increased skeletal events, morbidity, and a negative impact on quality of life. Bone metastases in conjunction with poor bone quality often prevent surgical therapy. Utilization of thermal ablation in this patient population is supported by contemporary literature and offers a minimally invasive approach to pain palliation, local tumor control, and decreased morbidity with unique advantages compared to surgery or radiation.³ In addition to spine disease, interventional radiologists are able to meaningfully impact pelvic, shoulder girdle, and long bone metastases. Adding to ablation we have in our repertoire the ability to provide structural support utilizing cement and/or screw fixation as an adjunct for both pain palliation and mechanical stabilization.^4-6 These novel therapies have allowed more patients with metastatic disease to be treated. The focus of this chapter is to highlight importance of patient selection, ablative modality selection, integration of cementoplasty (also described as osteoplasty) and osseous fixation, and procedural techniques/strategy in the pelvis and other common sites of bone metastases outside the spine.

Bone metastases: a comprehensive review of the literature

The last report of the World Health Organization (WHO) stated that approximately four million people experience bone pain due to malignant diseases. Among them, metastatic bone pain is one of the most important sources of complaint. The estimated median survival in the presence of bone metastases ranks from 10 to 12 weeks. Bone represents a potential target of distant metastases for the majority of malignant tumours. However, the exact incidence of bone metastases is unknown. Bone metastases have an important socio-economic impact, and due to the enhancement of the overall survivorship, their incidence is increasing. Malignant neoplasms such as lung, thyroid, renal cancer, multiple myeloma, and melanoma often metastasize to the bone. Bone metastases commonly localize to the spinal column, pelvis, shoulder, and distal femur. The proper treatment for painful skeletal metastases is still unknown. Hence, the purpose of this review of the literature was to update current evidence concerning the aetiogenesis, biological behaviour, and treatment algorithms for painful skeletal metastases.

Evaluation of microwave ablation for local treatment of dogs with distal radial osteosarcoma: A pilot study

OBJECTIVE

To evaluate the feasibility and safety of microwave ablation (MWA) as a modality to induce tumor necrosis within distal radial osteosarcoma (OSA).

STUDY DESIGN

Pilot study.

ANIMALS

Six client-owned dogs with distal radius OSA confirmed by cytological examination.

METHODS

Dogs underwent computed tomography for surgical planning before general anesthesia for fluoroscopy-guided ablation. Computed tomography was repeated 48 hours after MWA, before amputation. The ablated tumor was evaluated with histopathology.

RESULTS

Six dogs underwent MWA of distal radius OSA. A lower power setting (30 W) was selected for the first two dogs to avoid collateral soft tissue damage. The power was increased to 75 W for the last four dogs. The temperature was maintained between 45°C and 55°C (113 °F-131 °F) at the bone/soft tissue interface. Tumor necrosis varied between 30% and 90% (median, 55%) according to histopathology. No intraoperative or periprocedural complications were observed.

CONCLUSION

Microwave ablation induced variable tumor necrosis and did not induce immediate postablation complications in these six dogs with distal radius OSA.

CLINICAL SIGNIFICANCE

These results justify further evaluation of MWA as a potential modality to treat primary bone lesions in dogs.

Multimodality imaging of adult rhabdomyosarcoma: the added value of hybrid imaging

Rhabdomyosarcoma (RMS) represents more than 50% of paediatric soft tissue tumours. Conversely, it is extremely rare among adults, where it shows peculiar biological and clinical features that are still poorly investigated. RMS patients should be referred to a Sarcoma Centre, where the contribution of experienced radiologists plays a relevant role in the diagnostic assessment of the disease, including precise localisation, staging, image-guided biopsy, response evaluation after treatment and follow-up. Besides CT and MRI, hybrid imaging including positron emission tomography (PET)/CT and PET/MRI are giving an increasing contribution to provide functional insights about tumour biology and to improve the diagnostic accuracy of the imaging work-up. This review paper provides a revision of the pathology, clinical and radiological features of adult RMS, with a particular focus on the growing role of hybrid PET-based imaging.

Clinical indications for image-guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR)-part I, shoulder

BACKGROUND

Image-guided interventional procedures around the shoulder are commonly performed in clinical practice, although evidence regarding their effectiveness is scarce. We report the results of a Delphi method review of evidence on literature published on image-guided interventional procedures around the shoulder with a list of clinical indications.

METHODS

Forty-five experts in image-guided musculoskeletal procedures from the ESSR participated in a consensus study using the Delphic method. Peer-reviewed papers regarding interventional procedures around the shoulder up to September 2018 were scored according to the Oxford Centre for Evidence-based Medicine levels of evidence. Statements on clinical indications were constructed. Consensus was considered as strong if more than 95% of experts agreed and as broad if more than 80% agreed.

RESULTS

A total of 20 statements were drafted, and 5 reached the highest level of evidence. There were 10 statements about tendon procedures, 6 about intra-articular procedures, and 4 about intrabursal injections. Strong consensus was obtained in 16 of them (80%), while 4 received broad consensus (20%).

CONCLUSIONS

Literature evidence on image-guided interventional procedures around the shoulder is limited. A strong consensus has been reached for 80% of statements. The ESSR recommends further research to potentially influence treatment options, patient outcomes, and social impact.

KEY POINTS

• Expert consensus produced a list of 20 evidence-based statements on clinical indications of image-guided interventional procedures around the shoulder. • The highest level of evidence was reached for five statements. • Strong consensus was obtained for 16 statements (80%), while 4 received broad consensus (20%).

Minimally Invasive Stabilization Using Screws and Cement for Pelvic Metastases: Technical Considerations for the Pelvic "Screw and Glue" Technique

Metastatic disease involving the pelvis is common, often resulting in significant pain and disability. Several percutaneous interventions for unstable pelvic metastatic disease have been described, including osteoplasty, ablation, and screw fixation, that when used alone or in combination can significantly reduce pain and disability from metastatic bone disease. While it is possible to make a significant impact in patient care with basic principles and techniques, certain advanced techniques can extend the application of percutaneous interventions while minimizing morbidity.