ﺑﺎﺯﮔﺸﺖ ﺑﻪ ﺻﻔﺤﻪ ﻗﺒﻠﯽ
خرید پکیج
تعداد آیتم قابل مشاهده باقیمانده : 3 مورد
نسخه الکترونیک
medimedia.ir

Image-guided ablation of skeletal metastases

Image-guided ablation of skeletal metastases
Literature review current through: Jan 2024.
This topic last updated: Jan 05, 2023.

INTRODUCTION — Skeletal metastases are a common manifestation of distant relapse from many types of solid cancers, especially those arising in the lung, breast, and prostate. Bone involvement can also be extensive in patients with multiple myeloma, and bone may be a primary or secondary site of disease involvement in patients with lymphoma. For the purpose of this review, all of these will be considered under the term "skeletal metastases." (See "Multiple myeloma: Clinical features, laboratory manifestations, and diagnosis".)

Among patients with advanced malignancy, skeletal metastases represent a prominent source of morbidity due to pain, dysfunction, pathologic fracture, and neurovascular compromise. Bone-related cancer pain is frequently undertreated, with nearly 80 percent of patients experiencing severe pain before a sufficient palliative treatment plan is initiated [1]. (See "Clinical presentation and evaluation of complete and impending pathologic fractures in patients with metastatic bone disease, multiple myeloma, and lymphoma" and "Clinical features and diagnosis of neoplastic epidural spinal cord compression" and "Overview of cancer pain syndromes", section on 'Multifocal bone pain' and "Cancer pain management: General principles and risk management for patients receiving opioids", section on 'The problem of undertreatment'.)

Treatment of skeletal metastases usually requires a multipronged approach that may include analgesics, external beam radiation therapy, surgical management, and/or vertebroplasty/kyphoplasty. A significant proportion of patients with symptomatic skeletal metastases derive no or inadequate pain relief from these measures, or they experience recurrent pain following radiation therapy and require further intervention. Given the limited life expectancy of many of these patients and their coexisting morbidity, minimally invasive methods for local ablation of skeletal metastases have been developed, including radiofrequency ablation, cryoablation, and focused ultrasound. This topic will review image-guided ablation approaches to symptomatic skeletal metastases with additional information on treatment of asymptomatic skeletal metastases for local control.

OVERVIEW OF THE APPROACH TO SYMPTOMATIC SKELETAL METASTASES — The goals of management for symptomatic bone metastases include maximizing pain control, preserving and restoring function, stabilizing the skeleton, and enhancing local tumor control. (See "Epidemiology, clinical presentation, and diagnosis of bone metastasis in adults".)

Optimal therapy typically requires a multipronged, multidisciplinary approach:

Analgesics, glucocorticoids, osteoclast inhibitors (eg, bisphosphonates, denosumab), and bone-targeted radioisotopes can all provide pain relief, and osteoclast inhibitors are useful to decrease the frequency of skeletal-related events in patients with bone metastases. (See "Cancer pain management with opioids: Optimizing analgesia" and "Cancer pain management: Role of adjuvant analgesics (coanalgesics)", section on 'Patients with bone pain' and "Osteoclast inhibitors for patients with bone metastases from breast, prostate, and other solid tumors" and "Bone metastases in advanced prostate cancer: Management", section on 'Bone-targeted radioisotopes'.)

External beam radiation therapy with or without systemic therapy is the standard of care for alleviation of pain caused by skeletal metastases. Reduction in pain is achieved in over 60 percent, and it is complete in nearly one-quarter of patients [2]. Newer radiation techniques, in particular stereotactic body radiation therapy, have been utilized in patients with limited metastatic disease to deliver higher radiation doses in a single or few sessions. (See "Radiation therapy for the management of painful bone metastases", section on 'External beam radiation therapy' and "Radiation therapy techniques in cancer treatment", section on 'Stereotactic radiation therapy techniques'.)

Although retreatment of nonresponders and those with disease progression can be successful, patients may not be able to receive reirradiation because of toxicity or limited tolerance of normal tissues to additional radiation doses. (See "Radiation therapy for the management of painful bone metastases", section on 'Treatment of recurrent or persistent pain'.)

Surgical management of skeletal metastases is generally reserved for those patients with a completed or impending pathologic fracture of a long bone and for spinal metastases that may cause or are causing significant neurologic compromise. (See "Treatment and prognosis of neoplastic epidural spinal cord compression" and "Management of complete and impending pathologic fractures in patients with metastatic bone disease, multiple myeloma, and lymphoma", section on 'Management principles'.)

Less commonly, surgical metastasectomy may be indicated for selected patients with limited metastatic disease and a favorable cancer histology. (See "Role of surgery in patients with metastatic renal cell carcinoma".)

Vertebroplasty/kyphoplasty has generally been for patients with symptomatic spinal metastases without epidural disease or retropulsion of bone fragments into the spinal canal. (See "Management of complete and impending pathologic fractures in patients with metastatic bone disease, multiple myeloma, and lymphoma", section on 'Vertebral augmentation procedures'.)

A significant proportion of patients with symptomatic skeletal metastases derive no or inadequate pain relief from these measures, or they experience recurrent pain following radiation therapy and require further intervention. Given the limited life expectancy of many of these patients and their coexisting morbidity, minimally invasive methods for local ablation of skeletal metastases have been developed:

The earliest reports showed image-guided radiofrequency ablation with monopolar devices to be efficacious in the treatment of symptomatic bone metastases. Over the past decade, other techniques, in particular cryoablation, bipolar radiofrequency ablation, and focused ultrasound, have been used with equivalent outcomes and for specialized applications.

Other newer local ablative techniques being applied to treatment of bone metastases include laser and microwave ablation and irreversible electroporation.

INDICATIONS FOR IMAGE-GUIDED ABLATION — Local nonsurgical ablation of skeletal metastases may be performed for palliation of symptoms or for local tumor control. Most commonly, ablation is used to treat painful skeletal metastases in patients whose disease has progressed or whose pain persists after radiation therapy, or in those who have declined radiation therapy. The National Comprehensive Cancer Network guidelines for adult cancer pain now include thermal ablation as an option to treat metastatic bone pain in the absence of orthopedic emergency [3]. Ablation may also be applied to palliate metastatic lesions that are not painful but are contributing to symptoms of hormone excess (eg, pheochromocytomas) [4]. (See "Paraganglioma and pheochromocytoma: Management of malignant (metastatic) disease", section on 'Nonsurgical ablative therapy'.)

In the palliative setting, ablation of skeletal metastases may also be used as an alternative to surgery to preserve function or prevent pathologic fracture in a weight-bearing bone, in which case it is usually combined with cement instillation (ie, cementoplasty or vertebroplasty) [5,6]. Other percutaneous image-guided techniques using screws or other hardware to stabilize bone metastases at risk of fracture have been developed and may be combined with ablation, particularly in long bones or in the setting of metastases with advanced bone loss [7]. (See "Management of complete and impending pathologic fractures in patients with metastatic bone disease, multiple myeloma, and lymphoma".)

Finally, in patients with limited skeletal metastases, thermal ablation may be performed to achieve local control and, in some cases, disease remission [8-19].

Patient selection — Patients treated with ablation for a painful skeletal metastasis should have a limited number (generally one to three) of skeletal metastases on cross-sectional imaging that correlate with the site(s) of pain on physical examination. A larger number of metastases may be targeted for treatment, if feasible, but patients with widespread metastases are unlikely to achieve meaningful benefit. Patients should experience moderate to severe pain, typically considered to be at least a score of 4 on a standardized 10-point pain scale (figure 1). Patients with pain scores below this level inconsistently respond to ablation and are better treated with oral analgesics. (See "Assessment of cancer pain" and "Cancer pain management with opioids: Optimizing analgesia" and "Cancer pain management: Role of adjuvant analgesics (coanalgesics)", section on 'Patients with bone pain'.)

Generally, osteolytic and mixed osteolytic/osteoblastic bone metastases (table 1) or those that have a prominent soft tissue component are best suited to percutaneous ablation. Osteoblastic lesions may be treated, although they are frequently diffuse when present, and intact bone may present a challenge during ablation device placement. (See "Mechanisms of bone metastases" and "Bone tumors: Diagnosis and biopsy techniques", section on 'Imaging'.)

Lastly, the target lesions should be remote or separable from normal critical structures. A 1 cm or greater margin between the target lesion to be treated and the nearest critical structure is preferred.

Contraindications — There are few absolute contraindications to percutaneous ablation. These include uncorrectable bleeding diatheses, inability of the patient to tolerate the level of anesthesia required to perform the procedure, and inaccessibility of the target lesion from a percutaneous approach.

Active infection is a strong relative contraindication given the potential to seed necrotic, ablated tissue with circulating microorganisms. Additional relative contraindications include widespread skeletal metastases, for which a systemic approach (eg, radionuclide therapy) would be more appropriate, and tumors near critical normal structures, which cannot be displaced or monitored adequately to allow safe ablation. (See "Bone metastases in advanced prostate cancer: Management", section on 'Bone-targeted radioisotopes'.)

Patients with spinal metastases causing severe spinal instability or spinal cord compression warrant surgical evaluation rather than treatment with ablation. Epidural tumor extension of spine metastases is generally not an ideal target for ablative therapy given the potential for neurologic injury to the spinal cord or nerve roots, but ablation may be considered in some nonoperative candidates with the goal of causing retraction of the epidural tumor [20]. Radiation therapy approaches to these patients are discussed elsewhere. (see "Treatment and prognosis of neoplastic epidural spinal cord compression"). Finally, patients with cardiac pacemakers may need special care when treating tumors with radiofrequency ablation.

PREPROCEDURAL IMAGING — Appropriate preprocedural imaging is critical to safe, complete tumor ablation.

Cross-sectional imaging using computed tomography (CT), integrated positron emission tomography (PET)/CT, or magnetic resonance imaging (MRI) may be useful for patient and tumor assessment:

CT is frequently used to guide and monitor the ablation procedure, and it is very useful to demonstrate the target tumor and adjacent structures for treatment planning.

PET/CT offers the added benefit of demonstrating metabolic activity, which can add value for targeting tumors that have ill-defined borders on CT or for targeting previously treated/irradiated tumors that may have surrounding bony changes (sclerosis or lucency) related to treatment effect rather than tumor infiltration.

MRI often depicts the extent of skeletal metastases best and provides additional information regarding adjacent neural structures, which are typically poorly demonstrated with other imaging [21]. Neural structures should be avoided in the ablation target whenever possible.

For palliation of bone pain, an important goal of preprocedural imaging is to allow correlation of the site of pain experienced by the patient to an accessible target tumor. This may require scanning the area of interest with a radiopaque surface marker placed by the patient or provider at the symptomatic site.

In addition, for patients with suspected oligometastatic disease, another goal of preprocedural imaging is to stage the patient accurately in order to prevent unexpected application of focal therapy to a few tumors in a background of diffuse disease involvement.

TECHNIQUES

General aspects — Most bone ablation procedures are performed under general anesthesia, although less complex lesions (ie, superficial, small, easily accessible, predominately osteolytic or soft tissue lesions remote from normal vital structures) may be treated with the patient under moderate sedation (which includes sedatives as well as opioid analgesics). An advantage of lower level sedation is that it permits the use of intraprocedural-focused neurologic physical examination as a means of monitoring vulnerable neural structures.

Fluoroscopy may be useful as the guidance modality for some ablation procedures given near universal availability of fluoroscopy in interventional suites and efficiency of needle applicator placement with this imaging modality. However, this approach does not allow for direct image-based monitoring of the ablation zone, which is not visible radiographically, and thus is best suited for treatment of small tumors remote from the spinal cord or other vital structure using modern equipment with predictable ablation zone sizes.

Most ablation procedures are performed under appropriate cross-sectional imaging guidance to facilitate ablation zone monitoring and avoidance of critical structures. Computed tomography (CT) is the most commonly used modality for guidance given its widespread availability and excellent delineation of tumor and surrounding structures. While magnetic resonance imaging (MRI) provides superior tumor depiction in bone, the MRI suite is a difficult environment for most procedures, and MRI-compatible instruments remain limited. Ultrasound may be used for some superficial, predominately soft tissue lesions, particularly in the ribs or extremities.

The target lesion should be separated from adjacent critical structures [21]. This can be accomplished through patient positioning or through displacement techniques using fluid (hydrodisplacement), balloons, or gas [22,23].

Most ablative techniques require percutaneous placement of applicators into the target tumor. Ablation applicators may be placed directly into soft tissue metastases or into osteolytic skeletal metastases that have destroyed or thin overlying cortex. To penetrate osteoblastic metastases or lesions that are deep to intact cortical bone, bone access devices (eg, bone biopsy needles or automatic bone drills) may be required.

The ablation zone should typically be monitored during the procedure with real-time imaging. Vulnerable adjacent nerves may be monitored electrophysiologically or by physical examination if lower level sedation is used [24]. Following ablation, instillation of long-acting local anesthetic medication along the periosteum may diminish postprocedural pain. A short-course of steroids may be administered to limit postprocedural myositis from ablated surrounding musculature or minimize the effects of neural thermal injury and perineural swelling [25,26].

Radiofrequency ablation — Radiofrequency ablation (RFA) has been the most commonly used thermal ablation technique for tumors, including bone metastases. RFA relies upon a needle electrode to deliver a high frequency (450 to 600 kHz) alternating current that passes into the tissue from the tip of the electrode. As the ions within the tissue attempt to follow the change in the direction of the alternating current, their movement results in frictional heating of the tissue. The temperature within the tissue becomes elevated beyond 60°C, and cells begin to die, resulting in a region of coagulative necrosis surrounding the electrode. Grounding pads placed on the skin surface complete the electrical circuit for monopolar systems, whereas current passes between two points along the electrode or between two electrodes in bipolar systems.

Various needle applicators are available, generally 14 to 21 gauge, with shafts that are insulated except for the 1 to 3 cm terminus placed in the tumor. Systems to use multiple needle applicators or those with expandable tips have been developed to create larger ablation zones. In addition, manufacturers have developed bipolar RFA systems to generate ablation zones that are tailored to the shape and size of the vertebral bodies [27,28].One such bipolar RFA electrode has an articulating tip that facilitates treatment in locations that are difficult to reach, such as the posterior vertebral body from a transpedicular approach [29]. No one generator or applicator has been shown to be superior to another from the standpoint of efficacy.

Cryoablation — Cryoablation procedures employ needle applicators (cryoprobes) to transmit room temperature, pressurized argon and helium gases to the tumor in order to cause localized tissue freezing and thawing, respectively, along their distal uninsulated tips. By the Joule-Thomson effect, expansion of the argon gas between different chambers within each cryoprobe leads to immediate cooling about the tip to less than -100°C. As intracellular and extracellular fluid freezes, tissue destruction results from cell membrane disruption by ice crystals, cellular dehydration, and vascular thrombosis at temperatures below -20 to -40°C. The resultant ice ball is visible by CT, MRI, and ultrasound, with complete cell death occurring approximately 3 to 5 mm deep to the visible 0°C ice ball margin [30]. Following the freeze cycle, helium is introduced, which generates heat with expansion within the cryoprobe and allows thawing of the ice ball for probe removal. Typically, two freeze-thaw cycles are performed for each tumor.

The applicators for cryoablation may be 17 gauge or 1.2 to 2.4 mm diameter in caliber.

Focused ultrasound — Focused ultrasound (FUS), also called high-intensity focused ultrasound (HIFU), is a novel, noninvasive method of tumor ablation. Typically using MRI guidance, FUS energy is directed at the target, raising the temperature at the imaged focal point and, thus, producing thermal tissue ablation and tissue destruction. This is done by positioning the targeted lesion directly above a water bath within the MRI table that contains the phased array transducer [31]. Acoustic coupling is accomplished by placing a coupling gel pad with degassed water between the patient and the chamber containing the transducer. Sonications are then performed to the MRI-defined treatment volume, with temperature rise monitored with magnetic resonance phase map imaging. Acoustic power is adjusted during the treatment so as not to exceed the thermal dose threshold between 65 and 85°C. The sonication duration is approximately 30 seconds, with a cool-down duration of approximately 90 seconds between sonications. These are continued until the entire target volume has been treated.

FUS has the advantage of being completely noninvasive [31]. The high acoustic absorption of bone makes it particularly amenable to this technology, and osteoblastic as well as osteolytic metastases can be similarly treated. A direct acoustic window to the target lesion is needed, as bowel or neurologic structures intervening between the skin and skeletal tumor are at risk of injury. This technique is limited to the treatment of more-superficial tumors, rather than those that can be safely reached and effectively treated with other traditional percutaneous ablative modalities.

Other emerging percutaneous ablative techniques — Several additional thermal and nonthermal ablative techniques that are available to treat tumors in the liver, kidneys, and lungs have been applied to skeletal metastases in limited series. These technologies include microwave ablation, laser ablation (or laser interstitial thermal therapy), and irreversible electroporation.

Microwave ablation is a heat-based technique similar to RFA that uses percutaneously placed antennae (typically 17 gauge) to transmit microwave spectrum energy (915 MHz or 2.45 GHz) to a target tumor. Oscillation of water molecules within the tissue about the antennae leads to localized heating, which reaches greater temperatures faster and should theoretically penetrate intact bone better than RFA [32].

Laser ablation utilizes neodymium-doped yttrium aluminum garnet (Nd:YAG) or diode laser fibers that are small in caliber and flexible. These fibers are placed coaxially through a thin access needle into the target tumor. These devices are more commonly used to treat small osseous lesions, such as osteoid osteomas, rather than metastases. (See "Nonmalignant bone lesions in children and adolescents", section on 'Osteoid osteoma'.)

Irreversible electroporation is a novel ablation technology that utilizes direct electrical pulses to create nanoscale defects or pores in cell membranes; these defects disrupt cellular homeostasis, leading to apoptotic cell death [33,34]. Electroporation can either be reversible or irreversible, the latter leading to cell death.

The direct electrical pulses in irreversible electroporation are deposited using multiple applicators; the electrical pulses form an electrical field whose magnitude decreases from the applicators outward to the tissue. Cells immediately adjacent to the applicators undergo cell death by virtue of irreversibly increased cellular permeability.

There is one irreversible electroporation system that is US Food and Drug Administration (FDA)-approved for use in the United States for surgical ablation of soft tissue [35]. The system utilizes monopolar electrodes with a retractable sheath that allows the active tip to be adjusted between 1 and 4 cm. The generator allows for the simultaneous use of up to six electrodes to a maximum delivery of 50 A and 3000 V. This modality provides a nonthermal approach to tumor ablation with preservation of underlying acellular structures, but the literature on its application in the skeletal system is largely preclinical [36,37].

OUTCOMES

Efficacy

Bone pain — For patients who have persistent or recurrent pain attributed to one or a few skeletal sites after palliative radiation therapy, are not amenable to radiation therapy, or refuse radiation therapy, local thermal ablation is an important therapeutic option. The benefits of some form of thermal ablation (radiofrequency ablation [RFA], microwave ablation, cryoablation, or MR-guided focused ultrasound) were addressed in a systematic review of 11 studies; compared with baseline, all techniques achieved a mean pain reduction of 91 percent at four weeks, and 95 percent at 12 weeks [38]. MR-guided focused ultrasound was associated with the highest complication rate.

Data on individual techniques are reported below:

Prospective, single-arm, multicenter trials have shown RFA and cryoablation to be safe and highly effective for treatment of symptomatic skeletal metastases (table 2) [9,39-43]. Patients treated with cryoablation had clinically significant improvement in worst pain scores, with a drop from 7.1 out of 10 prior to treatment to 3.6 out of 10 at eight weeks and 1.4 out of 10 at six months [42]. Single-institution retrospective studies have shown an increased rate of complete pain response in patients treated with either RFA or cryoablation in combination with radiation therapy compared with radiation therapy or ablation alone [44,45].

A large, randomized, controlled, multicenter phase III trial has shown focused ultrasound (FUS) to be effective in the treatment of painful bone metastases [46], confirming the results of earlier retrospective reports [47] and three small single-center prospective trials [48-50].

In this trial, 147 patients were randomized 3:1 to FUS versus a sham procedure [46]. The primary endpoint, improvement in self-reported pain score without an increase in pain medications three months post-treatment, was achieved by significantly more patients in the FUS group than the sham control group (64 versus 20 percent). The most common treatment-related adverse event was sonication-related pain, which was reported by one-third of treated patients and generally resolved on the treatment day. Among the adverse events lasting more than one week, the most serious were two pathologic fractures (one outside the treatment location) and one third-degree skin burn.

An FUS device has gained US Food and Drug Administration (FDA) approval in the United States for treatment of bone metastases based on the phase III trial [51].

Small case series and a systematic review also support benefit from microwave and laser ablation to treat skeletal metastases, although the data are more limited [52-60]. These studies demonstrate that multiple types of ablation therapies are effective for palliation of pain due to metastatic skeletal disease.

Local tumor control — Case series, most using cryoablation, have shown that thermal ablation can achieve a high degree of local tumor control of bone and soft tissue oligometastasis:

In a single-center review of cryoablation to treat musculoskeletal oligometastases from a range of histologies, local control was achieved in 45 of 52 tumors (87 percent) at median follow-up of 21 months [8].

Cryoablation has been found to be beneficial in the treatment of limited metastases from non-small cell lung carcinoma (NSCLC) [10]. Among 24 bone and nonvisceral soft tissue metastases from NSCLC, local control was achieved in 87 percent. Similarly, local control of metastatic renal cell carcinoma involving bone and soft tissue was achieved in 83 to 98 percent of lesions treated [10,11,61]. Ablation of sarcoma metastases to the musculoskeletal system showed local control rates of 70 percent overall and 100 percent in patients with limited disease [12].

Spinal metastases can be treated with focal ablative therapy; however, stabilization of vertebral bodies at risk for fracture is an important component of the treatment approach. (See "Overview of therapeutic approaches for adult patients with bone metastasis from solid tumors", section on 'General approach to the patient'.)

In a report of 14 patients treated with cryoablation for spinal metastases, local control was achieved in 30 of 31 treated tumors at a median follow-up of 10 months [9]. Bipolar RFA, often in combination with augmentation, can also provide local control of spinal metastases. A retrospective case series showed a high short-term radiographic local control rate following combined RFA and vertebroplasty of spinal metastases [62].

A separate single-institution, retrospective study showed improved local control in spinal metastases treated with combined bipolar RFA and radiation therapy compared with RFA alone [63].

Early limited data have demonstrated local control using FUS in some patients [64].

Complications — Complications from ablation of skeletal metastases include injury to structures during applicator placement, as can occur in any percutaneous invasive procedure, as well as complications related to specific ablation technologies, typically thermal injuries. Potential injuries include perforation of bowel or bladder, infection, fistula formation, and muscular injury around the ablation site.

Thermal injury of neural structures may cause weakness, paralysis, paresthesias, dysesthesia, or anesthesia; these injuries are frequently temporary but may be permanent. RFA may cause skin burns at the grounding pad sites, whereas cryoablation can cause frostbite if the ice ball transgresses the skin.

Most importantly, pathologic fracture can occur at the metastatic site or in adjacent bone included in the ablation zone. Cementoplasty may offer structural support following ablation of metastases at risk for fracture [62,65,66].

Trials of RFA and cryoablation have reported serious (≥grade 3) complication rates of 0 to 10 percent (mostly pain, neurologic compromise, and pathologic fractures) [40-42,67-69]. A high-volume, single-center, 10-year experience with cryoablation in bone tumors showed a total complication rate of 9.5 percent and major complication rate of 2.5 percent, with secondary fracture occurring in 1.2 percent of cases [70].

CHOICE OF METHOD — There are no randomized trials comparing different ablation approaches for management of symptomatic skeletal metastases. A retrospective propensity-matched analysis of 50 patients treated for painful solitary osteolytic osseous metastases suggested that complete pain response rate and the reduction in opioid medication requirements were superior with cryoablation compared with monopolar radiofrequency ablation (RFA) [71]. In addition, another single-institution comparative retrospective series suggested higher immediate postprocedural pain requirements following RFA as compared with cryoablation for bone metastases [72]. However, these studies used monopolar RFA devices rather than the bipolar devices that have been more recently developed specifically to treat spine tumors.

Each treatment modality has its advantages and disadvantages, and the choice of ablation technology typically depends on several factors, including individual proceduralist preference and local expertise [20,73]:

RFA provides fast, effective ablation with minimal bleeding risk; however, the ablation zone cannot be monitored easily with routine clinical imaging methods and patients often experience increased periprocedural pain after treatment with monopolar electrodes. Newer bipolar RFA devices designed for the spine allow better conformation of ablation zone shape and size to the vertebral body. These electrodes contain imbedded thermocouples to provide temperature feedback. For these bipolar RFA devices, patients can be treated with moderate sedation, and their feedback can be used to avoid neural injury, as pain precedes permanent neurologic injury.

Cryoablation delivers safe, effective ablation with easy monitoring of the ablation zone with cross-sectional imaging (and thus, more-precise targeting of the treatment field), less periprocedural pain compared with monopolar RFA [74], and the ability to treat large tumors more readily, visualize the ablation zone adjacent to critical structures, and avoid injury; its disadvantages include greater expense, due to multiple probes used in the procedure rather than overlapping ablations, and a longer procedure time. The larger potential ablation zone produced with cryoablation systems, while advantageous when treating many tumors, may sometimes be difficult to use in the spine due to poor visualization of the ice ball in intact bone using computed tomography (CT) imaging. Moreover, as the ice can propagate through intact bone, the spinal canal may be more susceptible to thermal effect compared with RFA.

FUS ablation has the advantage of being completely noninvasive, eliminating the need for image-guided interventional skills. Moreover, FUS systems provide immediate thermal feedback by magnetic resonance thermographic imaging. Each FUS sonication destroys a very small amount of tissue, which may be beneficial in avoiding nontarget thermal injury but adds to the time of the procedure. Disadvantages also include the high cost of the equipment and the inability to treat claustrophobic patients or those in which MRI is contraindicated. Furthermore, tumors in deep locations with intervening structures cannot be treated as these critical structures cannot be displaced as may be done in RFA or cryoablation procedures.

Microwave energy is less susceptible to heat sink effect and tissue impedance, which should result in more thorough and effective tumor killing within the ablation zone [32]. Intact bone provides less of a barrier to microwave energy deposition, unlike with RFA. Multiple microwave antennas may be used simultaneously and with high power to create large ablation zones. This ability can be advantageous when treating large tumors remote from vital structures, but it can be challenging when treating tumors in the spinal column.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Management of bone metastases in solid tumors".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

Basics topics (see "Patient education: Bone metastases (The Basics)")

SUMMARY AND RECOMMENDATIONS

Indications for image-guided ablation

Optimal treatment of skeletal metastases usually requires a collaborative approach.

External beam radiation therapy is a standard approach for symptomatic skeletal metastases, achieving pain reduction in over 60 percent, which is complete in nearly one-quarter of patients. A significant proportion do not experience complete pain relief or develop recurrent pain after radiation therapy. (See 'Overview of the approach to symptomatic skeletal metastases' above.)

For patients with persistent or recurrent pain attributed to one or a few skeletal sites after palliative radiation therapy and who are not surgical candidates, local thermal ablation is an important therapeutic option.

Patients should have at least moderate pain levels, pain referable to a limited number of metastases that are visible on imaging, and target lesions that are remote (or separable) from normal critical structures. (See 'Indications for image-guided ablation' above.)

Other indications for thermal ablation of skeletal metastases include palliation of hormone secretion due to a metastatic hormone-producing tumor in bone, prevention of complications from progressive spinal metastases in weight-bearing bones, and local disease control in nonoperative candidates.

Contraindications

Absolute contraindications to thermal ablation include uncorrectable bleeding diatheses, inability of the patient to tolerate the level of anesthesia required to perform the procedure, and inaccessibility of the target lesion from a percutaneous approach.

Relative contraindications include widespread skeletal metastases, the presence of active infection, or tumor location adjacent to a critical normal structure that cannot be displaced or monitored adequately to allow safe ablation. (See 'Contraindications' above.)

Imaging – Preprocedural imaging should enable correlation of painful sites on physical examination with visible target lesions, guide safe percutaneous access to the skeletal metastases, and assess for nearby vital structures, particularly nerves, to be avoided and/or monitored during treatment. (See 'Preprocedural imaging' above.)

Choice of technique

Radiofrequency ablation (RFA), cryoablation, and focused ultrasound (FUS) are all effective ablative treatments for palliation of symptomatic skeletal metastases. There are no randomized trials comparing these procedures, and the choice of ablation technique must consider availability, patient preference, and local expertise.

Microwave ablation, laser ablation, and irreversible electroporation are emerging ablation technologies that cannot yet be recommended with the same confidence as RFA, cryoablation, or FUS. (See 'Efficacy' above.)

Outcomes

In a systemic review, all techniques of thermal ablation achieved a mean pain reduction of 91 percent at 4 weeks and 95 percent at 12 weeks, compared with baseline. MR-guided focused ultrasound was associated with the highest complication rate. (See 'Bone pain' above.)

Case series, most using cryoablation, have shown that thermal ablation can achieve a high degree of local tumor control of bone and soft tissue oligometastasis. (See 'Local tumor control' above.)

The main complications of thermal ablation are injury to structures during applicator placement, perforation of bowel or bladder, infection, fistula formation, pathologic fracture, and injury to neural structures, which may cause weakness, paralysis, paresthesias, dysesthesia, or anesthesia.

RFA may cause skin burns at the grounding pad sites, whereas cryoablation can cause frostbite if the ice ball transgresses the skin. FUS may be associated with pathologic fractures, skin burns, and injury to structures, including neural tissue, within the sonication pathway. (See 'Complications' above.)

  1. Janjan N. Bone metastases: approaches to management. Semin Oncol 2001; 28:28.
  2. Rich SE, Chow R, Raman S, et al. Update of the systematic review of palliative radiation therapy fractionation for bone metastases. Radiother Oncol 2018; 126:547.
  3. NCCN Clinical Practice Guidelines in Oncology. Available at: https://www.nccn.org/professionals/physician_gls/ (Accessed on December 16, 2020).
  4. McBride JF, Atwell TD, Charboneau WJ, et al. Minimally invasive treatment of metastatic pheochromocytoma and paraganglioma: efficacy and safety of radiofrequency ablation and cryoablation therapy. J Vasc Interv Radiol 2011; 22:1263.
  5. Wallace AN, Robinson CG, Meyer J, et al. The Metastatic Spine Disease Multidisciplinary Working Group Algorithms. Oncologist 2015; 20:1205.
  6. Kurup AN, Schmit GD, Atwell TD, et al. Palliative Percutaneous Cryoablation and Cementoplasty of Acetabular Metastases: Factors Affecting Pain Control and Fracture Risk. Cardiovasc Intervent Radiol 2018; 41:1735.
  7. Deschamps F, de Baere T, Hakime A, et al. Percutaneous osteosynthesis in the pelvis in cancer patients. Eur Radiol 2016; 26:1631.
  8. McMenomy BP, Kurup AN, Johnson GB, et al. Percutaneous cryoablation of musculoskeletal oligometastatic disease for complete remission. J Vasc Interv Radiol 2013; 24:207.
  9. Tomasian A, Wallace A, Northrup B, et al. Spine Cryoablation: Pain Palliation and Local Tumor Control for Vertebral Metastases. AJNR Am J Neuroradiol 2016; 37:189.
  10. Bang HJ, Littrup PJ, Currier BP, et al. Percutaneous cryoablation of metastatic lesions from non-small-cell lung carcinoma: initial survival, local control, and cost observations. J Vasc Interv Radiol 2012; 23:761.
  11. Bang HJ, Littrup PJ, Goodrich DJ, et al. Percutaneous cryoablation of metastatic renal cell carcinoma for local tumor control: feasibility, outcomes, and estimated cost-effectiveness for palliation. J Vasc Interv Radiol 2012; 23:770.
  12. Vaswani D, Wallace AN, Eiswirth PS, et al. Radiographic Local Tumor Control and Pain Palliation of Sarcoma Metastases within the Musculoskeletal System with Percutaneous Thermal Ablation. Cardiovasc Intervent Radiol 2018; 41:1223.
  13. Barral M, Auperin A, Hakime A, et al. Percutaneous Thermal Ablation of Breast Cancer Metastases in Oligometastatic Patients. Cardiovasc Intervent Radiol 2016; 39:885.
  14. Deschamps F, Farouil G, Ternes N, et al. Thermal ablation techniques: a curative treatment of bone metastases in selected patients? Eur Radiol 2014; 24:1971.
  15. Erie AJ, Morris JM, Welch BT, et al. Retrospective Review of Percutaneous Image-Guided Ablation of Oligometastatic Prostate Cancer: A Single-Institution Experience. J Vasc Interv Radiol 2017; 28:987.
  16. Littrup PJ, Bang HJ, Currier BP, et al. Soft-tissue cryoablation in diffuse locations: feasibility and intermediate term outcomes. J Vasc Interv Radiol 2013; 24:1817.
  17. Gardner CS, Ensor JE, Ahrar K, et al. Cryoablation of Bone Metastases from Renal Cell Carcinoma for Local Tumor Control. J Bone Joint Surg Am 2017; 99:1916.
  18. Hirbe AC, Jennings J, Saad N, et al. A Phase II Study of Tumor Ablation in Patients with Metastatic Sarcoma Stable on Chemotherapy. Oncologist 2018; 23:760.
  19. Winkelmann MT, Clasen S, Pereira PL, Hoffmann R. Local treatment of oligometastatic disease: current role. Br J Radiol 2019; 92:20180835.
  20. Tomasian A, Jennings JW. Percutaneous Minimally Invasive Thermal Ablation of Osseous Metastases: Evidence-Based Practice Guidelines. AJR Am J Roentgenol 2020; 215:502.
  21. Kurup AN, Morris JM, Schmit GD, et al. Neuroanatomic considerations in percutaneous tumor ablation. Radiographics 2013; 33:1195.
  22. Farrell MA, Charboneau JW, Callstrom MR, et al. Paranephric water instillation: a technique to prevent bowel injury during percutaneous renal radiofrequency ablation. AJR Am J Roentgenol 2003; 181:1315.
  23. Kam AW, Littrup PJ, Walther MM, et al. Thermal protection during percutaneous thermal ablation of renal cell carcinoma. J Vasc Interv Radiol 2004; 15:753.
  24. Kurup AN, Schmit GD, Morris JM, et al. Avoiding Complications in Bone and Soft Tissue Ablation. Cardiovasc Intervent Radiol 2017; 40:166.
  25. Philip A, Gupta S, Ahrar K, Tam AL. A spectrum of nerve injury after thermal ablation: a report of four cases and review of the literature. Cardiovasc Intervent Radiol 2013; 36:1427.
  26. Bing F, Garnon J, Tsoumakidou G, et al. Imaging-guided percutaneous cryotherapy of bone and soft-tissue tumors: what is the impact on the muscles around the ablation site? AJR Am J Roentgenol 2014; 202:1361.
  27. Anchala PR, Irving WD, Hillen TJ, et al. Treatment of metastatic spinal lesions with a navigational bipolar radiofrequency ablation device: a multicenter retrospective study. Pain Physician 2014; 17:317.
  28. Cazzato RL, Garnon J, Caudrelier J, et al. Low-power bipolar radiofrequency ablation and vertebral augmentation for the palliative treatment of spinal malignancies. Int J Hyperthermia 2018; 34:1282.
  29. Hillen TJ, Anchala P, Friedman MV, Jennings JW. Treatment of metastatic posterior vertebral body osseous tumors by using a targeted bipolar radiofrequency ablation device: technical note. Radiology 2014; 273:261.
  30. Georgiades C, Rodriguez R, Azene E, et al. Determination of the nonlethal margin inside the visible "ice-ball" during percutaneous cryoablation of renal tissue. Cardiovasc Intervent Radiol 2013; 36:783.
  31. Choi J, Raghavan M. Diagnostic imaging and image-guided therapy of skeletal metastases. Cancer Control 2012; 19:102.
  32. Brace CL. Radiofrequency and microwave ablation of the liver, lung, kidney, and bone: what are the differences? Curr Probl Diagn Radiol 2009; 38:135.
  33. Rubinsky B, Onik G, Mikus P. Irreversible electroporation: a new ablation modality--clinical implications. Technol Cancer Res Treat 2007; 6:37.
  34. Davalos RV, Mir IL, Rubinsky B. Tissue ablation with irreversible electroporation. Ann Biomed Eng 2005; 33:223.
  35. Nanoknife system. http://www.angiodynamics.com/products/nanoknife (Accessed on October 28, 2019).
  36. Tam AL, Figueira TA, Gagea M, et al. Irreversible Electroporation in the Epidural Space of the Porcine Spine: Effects on Adjacent Structures. Radiology 2016; 281:763.
  37. Schoellnast H, Monette S, Ezell PC, et al. Acute and subacute effects of irreversible electroporation on nerves: experimental study in a pig model. Radiology 2011; 260:421.
  38. Gennaro N, Sconfienza LM, Ambrogi F, et al. Thermal ablation to relieve pain from metastatic bone disease: a systematic review. Skeletal Radiol 2019; 48:1161.
  39. Callstrom MR, Charboneau JW, Goetz MP, et al. Image-guided ablation of painful metastatic bone tumors: a new and effective approach to a difficult problem. Skeletal Radiol 2006; 35:1.
  40. Goetz MP, Callstrom MR, Charboneau JW, et al. Percutaneous image-guided radiofrequency ablation of painful metastases involving bone: a multicenter study. J Clin Oncol 2004; 22:300.
  41. Dupuy DE, Liu D, Hartfeil D, et al. Percutaneous radiofrequency ablation of painful osseous metastases: a multicenter American College of Radiology Imaging Network trial. Cancer 2010; 116:989.
  42. Callstrom MR, Dupuy DE, Solomon SB, et al. Percutaneous image-guided cryoablation of painful metastases involving bone: multicenter trial. Cancer 2013; 119:1033.
  43. Bagla S, Sayed D, Smirniotopoulos J, et al. Multicenter Prospective Clinical Series Evaluating Radiofrequency Ablation in the Treatment of Painful Spine Metastases. Cardiovasc Intervent Radiol 2016; 39:1289.
  44. Di Staso M, Zugaro L, Gravina GL, et al. A feasibility study of percutaneous Radiofrequency Ablation followed by Radiotherapy in the management of painful osteolytic bone metastases. Eur Radiol 2011; 21:2004.
  45. Di Staso M, Gravina GL, Zugaro L, et al. Treatment of Solitary Painful Osseous Metastases with Radiotherapy, Cryoablation or Combined Therapy: Propensity Matching Analysis in 175 Patients. PLoS One 2015; 10:e0129021.
  46. Hurwitz MD, Ghanouni P, Kanaev SV, et al. Magnetic resonance-guided focused ultrasound for patients with painful bone metastases: phase III trial results. J Natl Cancer Inst 2014; 106.
  47. Catane R, Beck A, Inbar Y, et al. MR-guided focused ultrasound surgery (MRgFUS) for the palliation of pain in patients with bone metastases--preliminary clinical experience. Ann Oncol 2007; 18:163.
  48. Liberman B, Gianfelice D, Inbar Y, et al. Pain palliation in patients with bone metastases using MR-guided focused ultrasound surgery: a multicenter study. Ann Surg Oncol 2009; 16:140.
  49. Gianfelice D, Gupta C, Kucharczyk W, et al. Palliative treatment of painful bone metastases with MR imaging--guided focused ultrasound. Radiology 2008; 249:355.
  50. Napoli A, Anzidei M, Marincola BC, et al. Primary pain palliation and local tumor control in bone metastases treated with magnetic resonance-guided focused ultrasound. Invest Radiol 2013; 48:351.
  51. Magnetic Resonance Guided Focused Ultrasound Surgery System (MRgFUS). Available at: http://www.accessdata.fda.gov/cdrh_docs/pdf11/P110039b.pdf (Accessed on November 30, 2012).
  52. Ahrar K, Stafford RJ. Magnetic resonance imaging-guided laser ablation of bone tumors. Tech Vasc Interv Radiol 2011; 14:177.
  53. Pusceddu C, Sotgia B, Fele RM, Melis L. Treatment of bone metastases with microwave thermal ablation. J Vasc Interv Radiol 2013; 24:229.
  54. Simon CJ, Dupuy DE, Mayo-Smith WW. Microwave ablation: principles and applications. Radiographics 2005; 25 Suppl 1:S69.
  55. Kastler A, Alnassan H, Pereira PL, et al. Analgesic effects of microwave ablation of bone and soft tissue tumors under local anesthesia. Pain Med 2013; 14:1873.
  56. Pusceddu C, Sotgia B, Fele RM, et al. Combined Microwave Ablation and Cementoplasty in Patients with Painful Bone Metastases at High Risk of Fracture. Cardiovasc Intervent Radiol 2016; 39:74.
  57. Aubry S, Dubut J, Nueffer JP, et al. Prospective 1-year follow-up pilot study of CT-guided microwave ablation in the treatment of bone and soft-tissue malignant tumours. Eur Radiol 2017; 27:1477.
  58. Deib G, Deldar B, Hui F, et al. Percutaneous Microwave Ablation and Cementoplasty: Clinical Utility in the Treatment of Painful Extraspinal Osseous Metastatic Disease and Myeloma. AJR Am J Roentgenol 2019; 212:1377.
  59. Khan MA, Deib G, Deldar B, et al. Efficacy and Safety of Percutaneous Microwave Ablation and Cementoplasty in the Treatment of Painful Spinal Metastases and Myeloma. AJNR Am J Neuroradiol 2018; 39:1376.
  60. Cazzato RL, de Rubeis G, de Marini P, et al. Percutaneous microwave ablation of bone tumors: a systematic review. Eur Radiol 2021; 31:3530.
  61. Welch BT, Callstrom MR, Morris JM, et al. Feasibility and oncologic control after percutaneous image guided ablation of metastatic renal cell carcinoma. J Urol 2014; 192:357.
  62. Wallace AN, Tomasian A, Vaswani D, et al. Radiographic Local Control of Spinal Metastases with Percutaneous Radiofrequency Ablation and Vertebral Augmentation. AJNR Am J Neuroradiol 2016; 37:759.
  63. Prezzano KM, Prasad D, Hermann GM, et al. Radiofrequency Ablation and Radiation Therapy Improve Local Control in Spinal Metastases Compared to Radiofrequency Ablation Alone. Am J Hosp Palliat Care 2019; 36:417.
  64. Napoli A, Anzidei M, Marincola BC, et al. MR imaging-guided focused ultrasound for treatment of bone metastasis. Radiographics 2013; 33:1555.
  65. Castañeda Rodriguez WR, Callstrom MR. Effective pain palliation and prevention of fracture for axial-loading skeletal metastases using combined cryoablation and cementoplasty. Tech Vasc Interv Radiol 2011; 14:160.
  66. Kurup AN, Callstrom MR. Ablation of skeletal metastases: current status. J Vasc Interv Radiol 2010; 21:S242.
  67. Callstrom MR, Atwell TD, Charboneau JW, et al. Painful metastases involving bone: percutaneous image-guided cryoablation--prospective trial interim analysis. Radiology 2006; 241:572.
  68. Levy J, Hopkins T, Morris J, et al. 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. J Vasc Interv Radiol 2020; 31:1745.
  69. Jennings JW, Prologo JD, Garnon J, et al. Cryoablation for Palliation of Painful Bone Metastases: The MOTION Multicenter Study. Radiol Imaging Cancer 2021; 3:e200101.
  70. Auloge P, Cazzato RL, Rousseau C, et al. Complications of Percutaneous Bone Tumor Cryoablation: A 10-year Experience. Radiology 2019; 291:521.
  71. Zugaro L, DI Staso M, Gravina GL, et al. Treatment of osteolytic solitary painful osseous metastases with radiofrequency ablation or cryoablation: A retrospective study by propensity analysis. Oncol Lett 2016; 11:1948.
  72. Thacker PG, Callstrom MR, Curry TB, et al. Palliation of painful metastatic disease involving bone with imaging-guided treatment: comparison of patients' immediate response to radiofrequency ablation and cryoablation. AJR Am J Roentgenol 2011; 197:510.
  73. Callstrom MR, Kurup AN. Percutaneous ablation for bone and soft tissue metastases--why cryoablation? Skeletal Radiol 2009; 38:835.
  74. Masala S, Guglielmi G, Petrella MC, et al. Percutaneous ablative treatment of metastatic bone tumours: visual analogue scale scores in a short-term series. Singapore Med J 2011; 52:182.
Topic 83808 Version 16.0

References

آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟