Introduction
Definitions
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Curative treatment The therapeutic goal of curative treatment is to completely and definitively ablate the tumour.
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Palliative treatment The therapeutic goal of palliative treatment is not to completely ablate the tumour but to achieve pain palliation.
Consolidation Techniques
Ablation Techniques
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Chemical ablation Injection of ethanol is used to ablate osteolytic bone tumours as well as achieve pain management (neurolysis) [9].
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Thermal ablation procedures consist of the following:1.Laser photocoagulation Thermoablation is produced with near-infrared wavelength lasers (neodymium yttrium aluminum garnet [Nd:YAG] diode laser 800–1000 nm).2.Radiofrequency ablation Thermoablation is produced by altering the electric current at the tip of the electrode, thus causing local ionic agitation and subsequent frictional heat.
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Radiofrequency ionisation (decompression ablation technique) consists of the following:1.Low-temperature bipolar technique: This produces a plasma field at the tip of the electrode that breaks the intermolecular bonds, thus creating a cavity inside the tissue, which leads in turn to decompression.
Treatment Strategy
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histology of the tumour with differentiation of benign and malignant tumours;
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careful evaluation of the patient’s general condition;
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understanding of the disease process;
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appreciation of the degree of bone destruction (consolidation);
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thorough working knowledge of available treatment options and multidisciplinary decision making; and
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precision of the treatment goal, i.e., curative or palliative.
Tumour Biopsy
Curative Percutaneous Bone Tumour Management
Indications
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Benign lesions1.Osteoid osteoma;2.osteoblastoma (when the maximum diameter is <3cm); and3.chondroblastoma.
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Malignant lesions (primary or secondary in nonsurgical patients) are made by multidisciplinary decision. Treatement is reserved for slow-growing cancers with the following typical features:1.with <3 proven locations, and2.measuring <3 cm in diameter.
Palliative Percutaneous Bone Tumour Management
Indications
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pain palliation;
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tumour reduction;
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prevention of impending pathologic fractures; and/or
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decompression and debulking of bone tumours (especially for tumours bulging into the spinal canal).
Procedure Set-Up and Sedation
General Considerations
Procedure Set-Up
Sedation
Types of Image Guidance
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Fluoroscopy is the most commonly used imaging modality for skeletal interventions, especially when real-time imaging is needed (e.g., cement injection during cementoplasty).
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Ultrasound can be used in superficial lytic tumours, i.e., those with a soft-tissue component.
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Computed axial tomography (CAT) guidance provides high-resolution images that are useful for tumour ablation (three-dimensional [3-D] imaging is necessary) and help decrease the complication rate.
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Magnetic resonance imaging (MRI) guidance is promising for its thermal-monitoring capacity. It also offers the possibility of 3-D imaging, which is necessary for tumour ablation.
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Flat-panel cone-beam CAT is becoming more accurate, faster, and therefore very promising.
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Multimodality imaging, which is associated with fluoroscopy and CAT scan, allows faster, safer, and more accurate procedures and is particularly useful for complex cases (e.g., spine).
Review of Techniques
Cementoplasty
Patient Selection and Technique
Patient Outcome
Chemical Ablation with Ethanol
Patient Selection and Technique
Patient Outcome
Complications
Laser Ablation
Patient Selection and Technique
Osteoid Osteomas
Painful Bone Metastases
Patient Outcome
Major Complications
Recurrence Rate
RFA
Patient Selection and Technique
Major Indications
Patient Outcome
Complications
Cryoablation
Patient Selection and Technique
Patient Outcome
Complications
Radiofrequency Ionization
Patient Selection and Technique
Patient Outcome
Complications
Thermal Insulation and Monitoring
Thermal Insulation
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RFA Saline is not a suitable solution (because of its high electrical conductivity), and dextrose in water 5% has been advocated.
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Cryoablation Carbon dioxide can be used to displace the nontarget structures away from the treatment zone, thus creating an excellent thermal insulator blanket. Fluid is not suitable because it can freeze in contact with the ice ball. In ultrasound-guided interventions, CO2 dissection cannot be used (the ring-down artifact from gas deteriorates the image).
Thermal Monitoring
Conclusion: Proposed Treatment Strategy
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Precise clinical evaluation of the patient is mandatory and should include origin and location of pain, previous treatment, patient-tolerated anaesthesia, and life expectancy.
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Whole-body 3-D imaging should be used to precisely analyze the lesions and their relation to surrounding structures.
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Multidisciplinary decision making is required to choose the most efficient and least disabling technique.