Percutaneous image-guided thermal ablation of bone metastases: a retrospective propensity study comparing the safety profile of radio-frequency ablation and cryo-ablation

Bone lesion cryotherapy: pictorial review and review of current evidence

Over the last 2 decades, the development of small probes has enabled percutaneous use of cryotherapy. Cryotherapy, also known as cryoablation, enables the treatment of much larger lesions than other thermal ablation techniques, particularly when using multiple evenly spaced probes. Using rapid cooling to as low as -200°C (at the tip of the probe), reliable, and predictable necrosis can be induced. Probes are usually percutaneously inserted under CT guidance under sedation or general anaesthesia, often as a day case. The procedure is safe with severe complications occurring rarely; the commonest complication is neural injury in lesions closely related to neurovascular bundles. Cryotherapy has been applied to the symptomatic and occasionally curative treatment of bone metastases and a range of primary bone lesions. This review summarizes the published evidence base for the use of cryotherapy in metastatic and primary bone lesions and describes the experience with cryotherapy at the Royal Orthopaedic Hospital, Birmingham, a quaternary bone tumour referral hospital, where cryotherapy has been used for 3 years.

Evaluating the Accuracy and Efficiency of Imaging Modalities in Guiding Ablation for Metastatic Spinal Column Tumors: A Systematic Review

BACKGROUND/OBJECTIVES

Spinal metastases are a frequent and serious complication in cancer patients, often causing severe pain, instability, and neurological deficits. Thermal ablation techniques such as radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (CA) have emerged as minimally invasive treatments. These techniques rely on precise imaging guidance to effectively target lesions while minimizing complications. This systematic review aims to compare the efficacy of different imaging modalities-computed tomography (CT), magnetic resonance imaging (MRI), fluoroscopy, and mixed techniques-in guiding thermal ablation for spinal metastases, focusing on success rates and complications.

METHODS

A systematic literature search was conducted across PubMed, OVID, Google Scholar, and Web of Science databases, yielding 3733 studies. After screening, 51 studies met the eligibility criteria. Data on success rates, tumor recurrence, complications, and patient outcomes were extracted. Success was defined as no procedure-related mortality, tumor recurrence or expansion, or nerve injury. This systematic review followed PRISMA guidelines and was registered with PROSPERO (ID: CRD42024567174).

RESULTS

CT-guided thermal ablation demonstrated high success rates, especially with RFA (75% complete success). Although less frequently employed, MRI guidance showed lower complication rates and improved soft-tissue contrast. Fluoroscopy-guided procedures were effective but had a higher incidence of nerve injury and incomplete tumor control. Mixed imaging techniques, such as CBCT-MRI fusion, showed potential for reducing complications and improving targeting accuracy.

CONCLUSIONS

CT remains the most reliable imaging modality for guiding thermal ablation in spinal metastases, while MRI provides enhanced safety in complex cases. Fluoroscopy, although effective for real-time guidance, presents limitations in soft-tissue contrast. Mixed imaging techniques like CBCT-MRI fusion offer promising solutions by combining the advantages of both CT and MRI, warranting further exploration in future studies.

Percutaneous cryoablation of abdominal wall endometriosis: An analysis of 38 patients

PURPOSE

The purpose of this study was to evaluate the efficacy of percutaneous cryoablation in the treatment of abdominal wall endometriosis (AWE) nodules.

MATERIALS AND METHODS

Thirty-eight women treated for symptomatic AWE nodules with percutaneous cryoablation under ultrasound and computed tomography (CT) guidance between May 2020 and July 2023 were retrospectively included. Pain was estimated using visual analog scale (VAS) and assessed at baseline, three months, six months, and 12 months after percutaneous cryoablation. Baseline VAS score, volume of AWE nodule and magnetic resonance imaging (MRI) features of AWE nodules were compared to those obtained after percutaneous cryoablation. Major complications, if any, were noted.

RESULTS

Thirty-eight women with a median age of 35.5 years (interquartile range [IQR]: 32, 39; range: 24-48 years) and a total of 60 AWE nodules were treated. Percutaneous cryoablation was performed under local or regional anesthesia in 30 women (30/38; 79%). Significant decreases between initial median VAS score (7; IQR: 6, 8; range: 3-10) and median VAS score after treatment at three months (0; IQR: 0, 5; range; 0-8) (P < 0.001), six months (0; IQR: 0, 1; range; 0-10) (P < 0.001) and 12 months (0; IQR: 0, 2; range: 0-7) (P < 0.001) were observed. Percutaneous cryoablation resulted in effective pain relief in 31 out of 38 women (82%) at six months and 15 out of 18 women (83%) at 12 months. Contrast-enhanced MRI at six-month follow-up showed a significant decrease in the volume of AWE nodules and the absence of AWE nodule enhancement after treatment by comparison with baseline MRI (P < 0.001). No major complications were reported.

CONCLUSION

Percutaneous cryoablation is an effective, minimally invasive intervention for the treatment of AWE nodules that conveys minimal or no morbidity.

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.

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

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

Microwave in situ inactivation in the treatment of bone giant cell tumor: a mid-term descriptive study

AIM

To evaluate the mid-term clinical efficacy of microwave in situ inactivation combined with bone grafting or polymethyl methacrylate (PMMA) filling in the treatment of giant cell tumor of bone (GCTB).

METHODS

This is a retrospective, descriptive, and analytical study. A total of 30 GCTB patients received microwave in situ inactivation from January 2012 to January 2020, whose clinical recurrence rate was evaluated at the last follow-up after microwave in situ inactivation surgery. The Musculoskeletal Tumor Society (MSTS) function score was used to evaluate the postoperative clinical panoramic results.

RESULTS

All patients were followed up for 21 to 110 months, with an average of 63.79 months. Distal femur (40%) and proximal tibia (28%) had a higher rate of GCTB incidence. Seventeen percent of tumor patients suffered from associated pathologic fracture. The rate of Campanacci classification stage III was 60%. The average MSTS score was evaluated as 27.53 points overall at the last follow-up. In terms of complications, three, two, two and one cases developed fat liquefaction, controllable tissue rejection reaction, incision infection and degenerative changes around lesion joint, respectively, without in situ recurrences and reoperation as well as distant lung metastasis.

CONCLUSIONS

The method of microwave in situ inactivation combined with bone grafting or PMMA filling is prudently recommended as one of the options for the limb salvage treatment of giant cell tumor of long and periarticular bone.

LEVEL OF EVIDENCE

IV: case series.

Emerging Indications for Interventional Oncology: Expert Discussion on New Locoregional Treatments

Interventional oncology (IO) employs image-guided techniques to perform minimally invasive procedures, providing lower-risk alternatives to many traditional medical and surgical therapies for cancer patients. Since its advent, due to rapidly evolving research development, its role has expanded to encompass the diagnosis and treatment of diseases across multiple body systems. In detail, interventional oncology is expanding its role across a wide spectrum of disease sites, offering a potential cure, control, or palliative care for many types of cancer patients. Due to its widespread use, a comprehensive review of the new indications for locoregional procedures is mandatory. This article summarizes the expert discussion and report from the "MIOLive Meet SIO" (Society of Interventional Oncology) session during the last MIOLive 2022 (Mediterranean Interventional Oncology Live) congress held in Rome, Italy, integrating evidence-reported literature and experience-based perceptions. The aim of this paper is to provide an updated review of the new techniques and devices available for innovative indications not only to residents and fellows but also to colleagues approaching locoregional treatments.

Comparative analysis of the immune response to RFA and cryoablation in a colon cancer mouse model

The immune response to radiofrequency ablation (RFA) and cryoablation (CRA) was characterized and compared in a colon cancer mouse model. All studies were conducted under a research protocol approved by the National Institutes of Health, Clinical Center, Animal Care and Use Committee. BALB/cJ mice were inoculated with CT26 cells, and randomized to RFA, CRA, or sham treatment. Mice were sacrificed 3 days post-treatment, and tumor, spleen, and serum were harvested. Cell death was determined by Caspase-3 immunohistochemical and TUNEL stains. Immune response was analyzed using flow cytometry, serum cytokine assay and immunohistochemistry. Cell death, necrosis, and apoptosis induced by ablation were comparable in RFA and CRA. Decreased frequency of systemic T-regulatory cells was found in the CRA group. Both RFA and CRA reduced frequencies of several myeloid-derived suppressor cell (MDSC) subpopulations. RFA induced pro-inflammatory cytokine secretion including TNF-α and IL-12 as well as anti-inflammatory cytokines IL-5, and IL-10. CRA augmented secretion of a wider array of cytokines compared to RFA with both pro- and anti-inflammatory properties including IL-1β, IL-5, IL-6, IL-10, and KC GRO. In the tumor microenvironment, RFA reduced the number of T-regulatory cells, a finding not observed with CRA. Reduction of immune suppression via decreases in T-regulatory cells and MDSC was found to be induced by RFA or CRA. CRA augmented a wider range of cytokines than RFA, which were mainly pro-inflammatory, but also anti-inflammatory. In the tumor microenvironment, RFA demonstrated more pronounced anti-tumoral immunity. Further delineation of specific immunomodulation induced by ablation could inform drug-device development and may play a role in future hypothesis-driven immunomodulatory paradigms that combine immunotherapy drugs with tumor destruction for the treatment of metastatic colon cancer.

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

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

Interventional Radiology in the Management of Metastases and Bone Tumors

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

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.

Percutaneous image-guided cryoablation of spinal metastases: over 10-year experience in two academic centers

OBJECTIVES

To report on safety and clinical effectiveness of cryoablation for the treatment of spinal metastases (SM) in patients needing pain palliation or local tumor control (LTC).

METHODS

All consecutive patients with SM who underwent cryoablation from May 2008 to September 2020 in two academic centers were retrospectively identified and included in the present analysis. Patient characteristics, goal of treatment (curative/palliative), SM characteristics, procedural details, and clinical outcomes (pain relief; local tumor control [LTC]) were analyzed.

RESULTS

There were 74 patients (35 women; median age 61 years) accounting for 105 SM. Additional cementoplasty was used for 76 SM (76/105; 72.4%). There were 9 complications (out of 105 SM [8.5%]; 2 major and 7 minor) in 8 patients. Among the 64 (64/74; 86.5%) patients with painful SM, the mean Numerical Pain Rating Scale dropped from 6.8 ± 2.2 (range, 0-10) at the baseline to 4.1 ± 2.4 (range, 0-9; p < 0.0001) at 24 h, 2.5 ± 2.6 (range, 0-9; p < 0.0001) at 1 month, and 2.4 ± 2.5 (range, 0-9; p < 0.0001) at the last available follow-up (mean 14.7 ± 19.6 months; median 6). Thirty-four patients (34/64; 53.1%) were completely pain-free at the last follow-up. At mean 25.9 ± 21.2 months (median 16.5) of follow-up, LTC was achieved in 23/28 (82.1%) SM in 21 patients undergoing cryoablation with curative intent.

CONCLUSION

Cryoablation of SM, often performed in combination with vertebral augmentation, is safe, achieves fast and sustained pain relief, and provides high rates of LTC at mean 2-year follow-up.

KEY POINTS

•Cryoablation of spinal metastases is safe. •Cryoablation of spinal metastases allows rapid and sustained pain relief. •The mean 2-year rate of local tumor control after cryoablation of spinal metastases is 82.1%.

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.