Percutaneous cryoablation of metastatic lesions from non-small-cell lung carcinoma: initial survival, local control, and cost observations

Cryoablation and post-progression immune checkpoint inhibition in metastatic melanoma: a phase II trial

Image-guided percutaneous cryoablation is an established minimally invasive oncologic treatment. We hypothesized that cryoablation may modify the immune microenvironment through direct modulation of the tumor, thereby generating an anti-tumor response in tumors refractory to immune checkpoint inhibition (ICI). In this non-randomized phase II single-center study (NCT03290677), subjects with unresectable melanoma progressing on ICI underwent cryoablation of an enlarging metastasis, and ICI was continued for a minimum of two additional cycles. The primary endpoints were safety, feasibility and tumor response in non-ablated lesions. From May 2018 through July 2020, 17 patients were treated on study. The study met its primary endpoints with the combination strategy found to be safe and feasible with an objective response rate of 23.5% and disease control rate of 41% (4 partial response, 3 stable disease). Our data support further study of this synergistic therapeutic approach.

Comparative study of immune response to local tumor destruction modalities in a murine breast cancer model

Introduction

Immunotherapy is revolutionizing the management of multiple cancer types. However, only a subset of patients responds to immunotherapy. One mechanism of resistance is the absence of immune infiltrates within the tumor. In situ vaccine with local means of tumor destruction that can induce immunogenic cell death have been shown to enhance tumor T cell infiltration and increase efficacy of immune checkpoint blockade.

Methods

Here, we compare three different forms of localize tumor destruction therapies: radiation therapy (RT), vascular targeted photodynamic therapy (VTP) and cryoablation (Cryo), which are known to induce immunogenic cell death, with their ability to induce local and systemic immune responses in a mouse 4T1 breast cancer model. The effects of combining RT, VTP, Cryo with anti-PD1 was also assessed.

Results

We observed that RT, VTP and Cryo significantly delayed tumor growth and extended overall survival. In addition, they also induced regression of non-treated distant tumors in a bilateral model suggesting a systemic immune response. Flow cytometry showed that VTP and Cryo are associated with a reduction in CD11b+ myeloid cells (granulocytes, monocytes, and macrophages) in tumor and periphery. An increase in CD8+ T cell infiltration into tumors was observed only in the RT group. VTP and Cryo were associated with an increase in CD4+ and CD8+ cells in the periphery.

Conclusion

These data suggest that cell death induced by VTP and Cryo elicit similar immune responses that differ from local RT.

The safety and response of CT guided percutaneous cryoablation for lung nodules by 17-gauge needles

BACKGROUND

The safety and efficacy of 17-gauge needles used in CT-guided percutaneous cryoablation for lung nodules were explored in this study. The purpose of the study was to compare the findings with earlier research and multi-center clinical trials that used various needle sizes.

METHODS

Between 2016 and 2020, a retrospective study was conducted with approval from the institutional review board. A total of 41 patients were enrolled, and 71 lung nodules were treated in 63 cryoablation procedures using local anesthesia. Complication rates were recorded, and overall survival rates as well as tumor progression-free rates were calculated using the Kaplan-Meier method.

RESULTS

Self-limited hemoptysis was caused by 12.9% of the procedures, and drainage was required for pneumothoraces resulting from 11.3% of them. The overall survival rates at one, two, three, and four years were 97%, 94%, 82%, and 67%, respectively. The tumor progression-free rates at one, two, three, and four years were 86.2%, 77%, 74%, and 65%, respectively.

CONCLUSION

Cryoablation for lung nodules using 17-Gauge needles can achieve similar rates of survival and tumor control rates, similar or even lower complication rates as compared with other studies and multi-center trials using mixed sized needles.

Cryoablation is superior to radiofrequency ablation for the treatment of non-small cell lung cancer: A meta-analysis

This meta-analytical study compared the efficacy of cryoablation and radiofrequency ablation (RFA) in treating non-small cell lung cancer (NSCLC). We searched PubMed, Cochrane, Embase, and Web of Science™ for all relevant articles published until April 2022 that compared the efficacy of RFA and cryoablation in treating NSCLC. We used the Cochrane evaluation tool to assess the risk of bias. The fixed- or random-effects models were used, when appropriate. The primary outcome was a 3-year disease-free survival, whereas recurrence rate and complication rates were secondary outcomes. There were 340 patients divided across the seven studies we included in our meta-analysis. Based on the continuous-type variable analysis, cryoablation was superior to RFA in terms of 3-year disease-free survival (P = 0.003) and complication (P ＜ 0.00001) rates. Similarly, significant reductions in cryoablation were found for recurrence rates (P = 0.05) compared with RFA. Overall, cryoablation was superior to RFA in terms of prognosis and lifespan, regardless of whether systemic metastases occurred in non-small cell lung cancer.

Survival outcomes and quality of life after percutaneous cryoablation for liver metastasis: A systematic review and meta-analysis

BACKGROUND

Liver metastasis is present in a wide range of malignancies, with colorectal cancer as the most common site. Several minimally invasive treatments have been suggested for managing hepatic metastases, and cryoablation is among them, yet not widely used. In this systematic review, we aimed to assess the effectiveness of percutaneous cryoablation in all types of liver metastases.

METHODS

A systematic search was performed in international databases, including PubMed, Scopus, Embase, and Web of Science, to find relevant studies reporting outcomes for percutaneous cryoablation in liver metastasis patients. In addition to baseline features such as mean age, gender, metastasis origin, and procedure details, procedure outcomes, including overall survival, local recurrence, quality of life (QoL), and complications, were extracted from the studies. Random-effect meta-analysis was performed to calculate the mean difference (MD) and 95% confidence interval for comparison of QoL.

RESULTS

We screened 2131 articles. Fifteen studies on 692 patients were included. Mean overall survival ranged from 14.5-29 months. The rate of local recurrence in the included studies ranged from 9.4% to 78%, and local control progression-free survival ranged from 1 to 31 months. The total QoL decreased one week after the cryoablation procedure (-3.08 [95% Confidence interval: -4.65, -1.50], p-value <0.01) but increased one month (5.69 [3.99, 7.39], p-value <0.01) and three months (3.75 [2.25, 5.24], p-value <0.01) after the procedure.

CONCLUSION

Cryoablation is an effective procedure for the treatment of liver metastases, especially in cases that are poor candidates for liver resection. It could significantly improve QoL with favorable local recurrence.

Musculoskeletal oncology and thermal ablation: the current and emerging role of interventional radiology

The role of interventional radiology (IR) is expanding. With new techniques being developed and tested, this radiology subspecialty is taking a step forward in different clinical scenarios, especially in oncology. Musculoskeletal tumoral diseases would definitely benefit from a low-invasive approach that could reduce mortality and morbidity in particular. Thermal ablation through IR has already become important in the palliation and consolidation of bone metastases, oligometastatic disease, local recurrences, and treating specific benign tumors, with a more tailored approach, considering the characteristics of every patient. As image-guided ablation techniques lower their invasiveness and increase their efficacy while the collateral effects and complications decrease, they become more relevant and need to be considered in patient care pathways and clinical management, to improve outcomes. We present a literature review of the different percutaneous and non-invasive image-guided thermal ablation methods that are currently available and that could in the future become relevant to manage musculoskeletal oncologic diseases.

Current treatment landscape for oligometastatic non-small cell lung cancer

The management of patients with advanced non-small cell lung carcinoma (NSCLC) has undergone major changes in recent years. On the one hand, improved sensitivity of diagnostic tests, both radiological and endoscopic, has altered the way patients are staged. On the other hand, the arrival of new drugs with antitumoral activity, such as targeted therapies or immunotherapy, has changed the prognosis of patients, improving disease control and prolonging survival. Finally, the development of radiotherapy and surgical and interventional radiology techniques means that radical ablative treatments can be performed on metastases in any location in the body. All of these advances have impacted the treatment of patients with advanced lung cancer, especially in a subgroup of these patients in which all of these treatment modalities converge. This poses a challenge for physicians who must decide upon the best treatment strategy for each patient, without solid evidence for one optimal mode of treatment in this patient population. The aim of this article is to review, from a practical and multidisciplinary perspective, published evidence on the management of oligometastatic NSCLC patients. We evaluate the different alternatives for radical ablative treatments, the role of primary tumor resection or radiation, the impact of systemic treatments, and the therapeutic sequence. In short, the present document aims to provide clinicians with a practical guide for the treatment of oligometastatic patients in routine clinical practice.

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.

An In Vitro Investigation into Cryoablation and Adjunctive Cryoablation/Chemotherapy Combination Therapy for the Treatment of Pancreatic Cancer Using the PANC-1 Cell Line

As the incidence of pancreatic ductal adenocarcinoma (PDAC) continues to grow, so does the need for new strategies for treatment. One such area being evaluated is cryoablation. While promising, studies remain limited and questions surrounding basic dosing (minimal lethal temperature) coupled with technological issues associated with accessing PDAC tumors and tumor proximity to vasculature and bile ducts, among others, have limited the use of cryoablation. Additionally, as chemotherapy remains the first-line of attack for PDAC, there is limited information on the impact of combining freezing with chemotherapy. As such, this study investigated the in vitro response of a PDAC cell line to freezing, chemotherapy, and the combination of chemotherapy pre-treatment and freezing. PANC-1 cells and PANC-1 tumor models were exposed to cryoablation (freezing insult) and compared to non-frozen controls. Additionally, PANC-1 cells were exposed to varying sub-clinical doses of gemcitabine or oxaliplatin alone and in combination with freezing. The results show that freezing to −10 °C did not affect viability, whereas −15 °C and −20 °C resulted in a reduction in 1 day post-freeze viability to 85% and 20%, respectively, though both recovered to controls by day 7. A complete cell loss was found following a single freeze below −25 °C. The combination of 100 nM gemcitabine (1.1 mg/m2) pre-treatment and a single freeze at −15 °C resulted in near-complete cell death (<5% survival) over the 7-day assessment interval. The combination of 8.8 µM oxaliplatin (130 mg/m2) pre-treatment and a single −15 °C freeze resulted in a similar trend of increased PANC-1 cell death. In summary, these in vitro results suggest that freezing alone to temperatures in the range of −25 °C results in a high degree of PDAC destruction. Further, the data support a potential combinatorial chemo/cryo-therapeutic strategy for the treatment of PDAC. These results suggest that a reduction in chemotherapeutic dose may be possible when offered in combination with freezing for the treatment of PDAC.

Current Management of Oligometastatic Lung Cancer and Future Perspectives: Results of Thermal Ablation as a Local Ablative Therapy

A growing body of evidence shows improved overall survival and progression-free survival after thermal ablation in non-small cell lung carcinoma (NSCLC) patients with a limited number of metastases, combined with chemotherapy or tyrosine kinase inhibitors or after local recurrence. Radiofrequency ablation and microwave ablation are the most evaluated modalities, and target tumor size <3 cm (and preferably <2 cm) is a key factor of technical success and efficacy. Although thermal ablation offers some advantages over surgery and radiotherapy in terms of repeatability, safety, and quality of life, optimal management of these patients requires a multidisciplinary approach, and further randomized controlled trials are required to help refine patient selection criteria. In this article, we present a comprehensive review of available thermal ablation modalities and recent results supporting their use in oligometastatic and oligoprogressive NSCLC disease along with their potential future implications in the emerging field of immunotherapy.

Ablation Techniques in Cancer Pain

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

Musculoskeletal Oncologic Interventions: Proceedings from the Society of Interventional Radiology and Society of Interventional Oncology Research Consensus Panel

Musculoskeletal interventions are increasingly used with palliative and curative intent in the multidisciplinary treatment of oncology patients with bone and soft-tissue tumors. There is an unmet need for high-quality evidence to guide broader application and adoption of minimally invasive interventional technologies to treat these patients. Therefore, the Society of Interventional Radiology Foundation and the Society of Interventional Oncology collaborated to convene a research consensus panel to prioritize a research agenda addressing the gaps in the current evidence. This article summarizes the panel's proceedings and recommendations for future basic science and clinical investigation to chart the course for interventional oncology within the musculoskeletal system. Key questions that emerged addressed the effectiveness of ablation within specific patient populations, the effect of combination of ablation with radiotherapy and/or immunotherapy, and the potential of standardization of techniques, including modeling and monitoring, to improve the consistency and predictability of treatment outcomes.

Image-Guided Percutaneous Ablation of Adrenal Metastases: A Meta-Analysis of Efficacy and Safety

PURPOSE

To evaluate the efficacy and safety of percutaneous ablation of adrenal metastases through a meta-analysis of various image-guided percutaneous ablation techniques.

MATERIALS AND METHODS

A comprehensive literature search of PubMed and Embase databases was performed for studies evaluating the efficacy and/or safety of image-guided percutaneous ablation of adrenal metastases. A total of 37 studies published between 2009 and 2020 were analyzed, comprising a sample size of 959 patients. Proportion estimates of overall survival, local control, and toxicity were analyzed in a pooled meta-analysis. The pooled prevalence of adverse events after ablation was calculated based on common terminology criteria for adverse events (CTCAE) grading.

RESULTS

Of the 959 included patients, 320 (33.3%) underwent radiofrequency ablation, 72 (7.5%) microwave ablation, 95 (9.9%) cryoablation, and 46 (4.8%) ethanol injections for treatment of adrenal metastases. The remaining 426 (44.4%) patients were from studies involving a mixture of the 4 listed percutaneous ablation techniques. The pooled 1-year local control rate was 80% (95% confidence interval [CI], 76%-83%). The pooled 1-year overall survival rate was 77% (95% CI, 70%-83%). The overall rate of severe adverse events after ablation (CTCAE grade 3 or higher) was 16.1%. The overall rate of low-grade adverse events after ablation (CTCAE grade 2 or lower) was 32.6%. Approximately 21.9% (n = 203) of patients experienced intraprocedural hypertensive crises, the majority of which were reversed with antihypertensive medications.

CONCLUSIONS

This study demonstrates that image-guided percutaneous ablation can be effective in achieving acceptable short- to mid-term local tumor control and overall survival with a moderate safety profile.

Percutaneous Cryoablation: Safety and Efficacy for Pain Palliation of Metastases to Pleura and Chest Wall

PURPOSE

To assess safety and efficacy of percutaneous cryoablation for pain palliation of metastases to pleura and chest wall.

MATERIALS AND METHODS

This retrospective single-center cohort study included 22 patients (27% female, mean age 63 y ± 11.4) who underwent 25 cryoablation procedures for pain palliation of 39 symptomatic metastases measuring 5.1 cm ± 1.9 (range, 2.0-8.0 cm) in pleura and chest wall between June 2012 and December 2017. Pain intensity was assessed using a numerical scale (0-10 points). Statistical tests t test, χ², and Wilcoxon signed rank were performed.

RESULTS

Patients were followed for a median of 4.1 months (interquartile range [IQR], 2.3-10.1; range, 0.1-36.7 mo) before death or loss to follow-up. Following cryoablation, pain intensity decreased significantly by a median of 4.5 points (IQR, 2.8-6; range, 0-10 points; P = .0002 points, Wilcoxon signed rank). Pain relief of at least 3 points was documented following 18 of 20 procedures. Pain relief occurred within a median of 1 day following cryoablation (IQR, 1-2; range, 1-4 d) and lasted for a median of 5 weeks (IQR, 3-17; range, 1-34 wk). Systemic opioid requirements decreased in 11 of 22 patients (50%) by an average of 56% ± 34. Difference in morphine milligram equivalents was not significant (P = .73, Wilcoxon signed rank). No procedure-related complications occurred despite previous radiation of 7 tumors. Of 25 procedures, 22 (88%) were performed on an outpatient basis.

CONCLUSIONS

Percutaneous cryoablation for metastases to pleura and chest wall can safely provide significant pain relief within days following a single session.

Imaging findings during and after percutaneous cryoablation of hepatic tumors

OBJECTIVE

Imaging plays a key role in the assessment of patients before, during, and after percutaneous cryoablation of hepatic tumors. Intra-procedural and early post-procedure imaging with CT and MRI is vital to the assessment of technical success including adequacy of ablation zone coverage. Recognition of the normal expected post-procedure findings of hepatic cryoablation such as ice ball formation, hydrodissection, and the normal appearance of the ablation zone is crucial to be able to differentiate from complications including vascular, biliary, or non-target organ injury. Delayed imaging is essential for determination of clinical effectiveness and detection of unexpected findings such as residual unablated tumor and local tumor progression. The purpose of this article is to review the spectrum of expected and unexpected imaging findings that may occur during or after percutaneous cryoablation of hepatic tumors.

CONCLUSION

Differentiating expected from unexpected findings during and after hepatic cryoablation helps radiologists identify residual or recurrent tumor and detect procedure-related complications.

Percutaneous Microwave Ablation and Cementoplasty: Clinical Utility in the Treatment of Painful Extraspinal Osseous Metastatic Disease and Myeloma

OBJECTIVE. The purpose of this study was to review the efficacy and durability of pain control and local tumor control using microwave ablation and cementoplasty in treating extraspinal osseous tumors. Painful osseous metastases are a common cause of cancer-related morbidity. Percutaneous thermal ablation presents an attractive minimally invasive option in this vulnerable patient group. MATERIALS AND METHODS. A retrospective review included 65 patients (35 men, 30 women) with 77 tumors who underwent image-guided microwave ablation and cementoplasty at a tertiary referral academic center over 18 months. Procedural efficacy was determined with a visual analog scale before the procedure and 24 hours, 2-4 weeks, and 20-24 weeks after the procedure. Locoregional control was assessed at follow-up cross-sectional imaging. RESULTS. The 77 tumors were in the following locations: ilium, 38; acetabulum on supraacetabular region, 23; femur, five; humerus, four; shoulder, four; sternum, three. The tumors were 15 multiple myelomas and metastases from cancers of the following organs: colon, nine; lung, 15; breast, 12; thyroid, seven; prostate, three; and kidney, four. Complete, successful ablation of all 77 tumors was achieved. Mean ablation time was 6 minutes 15 seconds (SD, 12 seconds), and mean energy used was 5.49 (SD, 2.97) kJ. The mean visual analog scale scores were 6.32 (SD, 1.94) before the procedure, 1.01 (SD, 1.24) at 24 hours, 1.71 (SD, 1.31) at 2-4 weeks, and 2.01 (SD, 1.42) at 20-24 weeks. Follow-up imaging at 20-24 weeks showed no local progression in 42 of 65 patients (64.6%). Six patients died 24-52 weeks after the procedure. No procedure-related complications were reported. CONCLUSION. Microwave ablation is efficacious in alleviating pain due to osseous metastases. The modality has promise for locoregional control of metastases, particularly in the context of oligometastatic (limited disseminated) disease.

Hemodynamic instability during percutaneous ablation of extra-adrenal metastases of pheochromocytoma and paragangliomas: a case series

Background

Surgical manipulation of pheochromocytomas and paragangliomas (PPGLs) may induce large hemodynamic oscillations due to catecholamine release. Little is known regarding hemodynamic instability during percutaneous ablation of PPGLs. We examined intraprocedural hemodynamic variability and postoperative complications related to percutaneous ablation of extra-adrenal metastases of PPGL.

Methods

From institutional PPGL registry we identified patients undergoing ablation of extra-adrenal PPGL metastases from January 1, 2000, through December 31, 2016. We reviewed medical records for clinical characteristics and hospital outcomes. Tumors were categorized as functional or nonfunctional based on preprocedural fractionated catecholamine and metanephrine profiles.

Results

Twenty-one patients (14 female [67%]) underwent 38 ablations. Twenty-four ablations were performed in patients with functional metastatic lesions, and 14 were in nonfunctional lesions. Intraprocedural use of potent vasodilators for hypertension was higher for patients with functional tumors (P = 0.02); use of vasopressors for hypotension was similar for functional and nonfunctional tumors (P = 0.74). Mean (±SD) intraprocedural blood pressure range (maximum–minimum blood pressure) during 38 procedures was greater for functional than nonfunctional tumors [systolic: 106 (±48) vs 64 (±30) mm Hg, P = 0.005; diastolic: 58 (±22) vs 35 (±14) mm Hg, P = 0.002; mean arterial: 84 (±43) vs 47 (±29) mm Hg, P = 0.007]. Complications included 5 unplanned intensive care unit admissions (3 for precautionary monitoring, 1 for recalcitrant hypotension, and 1 for hypertensive crisis), 1 case of postoperative bleeding, and 1 death.

Conclusions

Substantial hemodynamic instability may develop during ablation of functional and nonfunctional PPGL metastases. When anesthesia is provided for ablation of metastatic PPGLs in radiology suites, preparation for hemodynamic management should match standards used for surgical resection.

Thermal Ablation of Bone Metastases

Image-guided, minimally invasive, percutaneous thermal ablation of bone metastases has unique advantages compared with surgery or radiation therapy. Thermal ablation of osseous metastases may result in significant pain palliation, prevention of skeletal-related events, and durable local tumor control. This article will describe current thermal ablation techniques utilized to treat bone metastases, summarize contemporary evidence supporting such thermal ablation treatments, and outline an approach to percutaneous ablative treatment.

Efficacy and Safety of Percutaneous Microwave Ablation and Cementoplasty in the Treatment of Painful Spinal Metastases and Myeloma

BACKGROUND AND PURPOSE

Painful spinal metastases are a common cause of cancer-related morbidity. Percutaneous ablation presents an attractive minimally invasive alternative to conventional therapies. We performed a retrospective review of 69 patients with 102 painful spinal metastases undergoing microwave ablation and cementoplasty to determine the efficacy and safety of this treatment.

MATERIALS AND METHODS

Procedures were performed between January 2015 and October 2016 with the patient under general anesthesia using image guidance for 102 spinal metastases in 69 patients in the following areas: cervical (n = 2), thoracic (n = 50), lumbar (n = 34), and sacral (n = 16) spine. Tumor pathologies included the following: multiple myeloma (n = 10), breast (n = 27), lung (n = 12), thyroid (n = 6), prostate (n = 5), colon (n = 4), renal cell (n = 3), oral squamous cell (n = 1), and adenocarcinoma of unknown origin (n = 1). Procedural efficacy was determined using the visual analog scale measured preprocedurally and at 2-4 weeks and 20-24 weeks postprocedure. Tumor locoregional control was assessed on follow-up cross-sectional imaging. Procedural complications were recorded to establish the safety profile.

RESULTS

The median ablation time was 4 minutes 30 seconds ± 7 seconds, and energy dose, 4.1 ± 1.6 kJ. Median visual analog scale scores were the following: 7.0 ± 1.8 preprocedurally, 2 ± 1.6 at 2-4 weeks, and 2 ± 2.1 at 20-24 weeks. Eight patients died within 6 months following the procedure. Follow-up imaging in the surviving patients at 20-24 weeks demonstrated no locoregional progression in 59/61 patients. Two complications were documented (S1 nerve thermal injury and skin burn).

CONCLUSIONS

Microwave ablation is an effective and safe treatment technique for painful spinal metastases. Further studies may be helpful in determining the role of microwave ablation in locoregional control of metastases.

Cryoablation of cardiophrenic angle lymph node metastases: a case report

Background

Cardiophrenic angle lymph node metastases are relatively rare. Surgical resection is the main treatment for cardiophrenic angle lymph node metastasis, but it is not always possible.

Case presentation

Here, we report our initial experience with cryoablation of a cardiophrenic angle lymph node metastasis from liver cancer. As the cardiophrenic angle lymph node metastasis was located close to the heart, about 200 mL of 0.9% saline was injected into the pericardium to separate the heart from the target area. The cardiophrenic angle lymph node metastasis was successfully ablated, without any complications.

Conclusions

Cryoablation may be a suitable alternative treatment for cardiophrenic angle lymph node metastasis.

Increasing Role of Image-Guided Ablation in the Treatment of Musculoskeletal Tumors

In the last decade, percutaneous treatment of musculoskeletal (MSK) tumors has become more established in routine clinical care while also undergoing a number of advancements. Ablative techniques to palliate painful skeletal metastases have gained wide acceptance, while goals for ablation have evolved to include local control of oligometastases and desmoid tumors. Bone consolidation or augmentation is now frequently used in conjunction with or instead of ablation of skeletal tumors to stabilize pathologic fractures or prevent further morbidity that could result from fractures caused by tumor progression. These procedures have traditionally been performed with cement injection, although additional percutaneous consolidation or stabilization devices have been developed. Techniques to monitor the ablation zone and adjacent structures intraprocedurally are now applied to increase the number of tumors amenable to treatment. These include methods to depict, displace, or monitor critical structures adjacent to targeted MSK tumors. Finally, the role of ablation in the comprehensive care of patients with MSK tumors continues to change with the evolving triage of patients between radiation therapy, surgical resection and stabilization, and percutaneous ablative and consolidative management.

Retrospective Review of Percutaneous Image-Guided Ablation of Oligometastatic Prostate Cancer: A Single-Institution Experience

PURPOSE

To retrospectively review and report the efficacy and safety of percutaneous image-guided ablation (cryoablation or radiofrequency ablation) in the treatment of oligometastatic prostate cancer.

MATERIALS AND METHODS

An institutional registry was retrospectively reviewed and revealed 16 patients with oligometastatic prostate cancer (median age, 67 y; range, 50-86 y) who underwent percutaneous image-guided ablation to treat 18 metastatic sites. A subgroup of 7 patients with 8 metastases were androgen-deprivation therapy (ADT)-naïve and underwent ablation to delay initiation of ADT. Local tumor control, progression-free survival (PFS), ADT-free survival, and procedural complications were analyzed.

RESULTS

Local tumor control was achieved in 15 of 18 metastases (83%) at a median follow-up of 27 months (range, 5-56 mo). Local tumor recurrence was found in 3 of 18 metastases (17%), with a median time to local recurrence of 3.5 months (range, 3-38 mo). Estimated PFS rates at 12 and 24 months were 56% (95% confidence interval [CI], 30%-76%) and 43% (95% CI, 19%-65%), respectively. In the 7 ADT-naïve patients, local tumor control was achieved in all metastases, and the median ADT-free survival period was 29 months. There were no major procedural complications.

CONCLUSIONS

In this cohort of patients with oligometastatic prostate cancer, percutaneous image-guided ablation was feasible and well tolerated and achieved acceptable local tumor control rates. Percutaneous ablation may be of particular utility in patients who wish to delay initiation of ADT.

Expanding role of percutaneous ablative and consolidative treatments for musculoskeletal tumours

Interventional approaches to musculoskeletal tumours have significantly changed over the last several years, and new treatments continue to be developed. All ablative modalities are currently applied to the treatment of bone tumours, including radiofrequency, cryo-, microwave, and laser ablation devices. Indications for ablation of bone and soft-tissue tumours have expanded beyond palliation of painful bone metastases and eradication of osteoid osteomas to the local control of oligometastatic disease from a number of primary tumours and ablation of desmoid tumours. In addition, tools for consolidation of bone tumours at risk of pathological fracture have also expanded. With these developments, ablation has become the primary treatment for osteoid osteomas and, at some institutions, desmoid tumours. It may be the primary or secondary treatment for palliation of painful bone tumours, frequently used in patients with pain refractory to or recurrent after radiation therapy. It is used as a treatment for limited metastatic disease or for metastases that grow disproportionately in patients with multifocal metastases, either in combination with systemic therapy or to reserve systemic therapy and its toxicity for more widespread disease progression. Moreover, percutaneous methods to consolidate bone at risk of fracture have become more commonplace, aided by techniques using materials beyond typical bone cement.

Local Therapy for Limited Metastatic Non-Small Cell Lung Cancer: What Are the Options and Is There a Benefit?

Distant metastasis is common in non-small cell lung cancer (NSCLC) and typically associated with poor prognosis. Aggressive local therapy including surgery and/or radiation for limited metastatic disease from colorectal cancer and sarcoma is associated with survival benefit and has become part of the standard of care. In this article, we review the literature and ongoing studies concerning surgery, radiation, and radiofrequency ablation for oligometastatic NSCLC.

Percutaneous image-guided cryoablation: current applications and results in the oncologic field

Percutaneous imaging-guided cryoablation (PICA) is a recently developed technique, which applies extreme hypothermia to destroy tumours under close imaging surveillance. It is minimally invasive, safe, repeatable, and does not interrupt or compromise other oncologic therapies. It presents several advantages over more established heat-based thermal ablation techniques (e.g. radiofrequency ablation; RFA) including intrinsic analgesic properties, superior monitoring capability on multi-modal imaging, ability to treat larger tumours, and preservation of tissue collagenous architecture. There has been a recent large increase in reports evaluating the utility of PICA in a wide range of patients and tumours, but systematic analysis of the literature is challenging due to the rapid pace of change and predominance of extensively heterogeneous level III studies. The precise onco-therapeutic role of PICA has not been established. This narrative review outlines the available evidence for PICA in a range of tumours. Current indications include curative therapy of small T1a renal tumours; curative/palliative therapy of small primary/secondary lung tumours where RFA is unsuitable; palliation of painful bone metastases; and urologic treatment of organ-confined prostate cancer. There is growing evidence to support its use for small hepatic tumours, and encouraging results have been obtained for breast tumours, extra-abdominal desmoid tumours, and management of higher-stage tumours and oligometastatic disease. However, the overall evidence base is weak, effectively restricting PICA to cases where standard therapy and RFA are unsuitable. As the technique and evidence continue to mature, the benefits of this emerging technique will hopefully become more widely available to cancer patients in the future.

IMAGE-GUIDED THERMAL ABLATION OF ADRENAL METASTASES: HEMODYNAMIC AND ENDOCRINE OUTCOMES

OBJECTIVE

Image-guided thermal ablation of adrenal metastases has been increasingly used for local tumor control. This procedure has been associated with hypertensive urgency; however, endocrine complications have not been clearly described. Our objective was to assess the hemodynamic behavior and risk for adrenal insufficiency related to adrenal ablation. Additionally, we sought to understand the utility of preprocedural α-blockade to prevent periprocedural hemodynamic complications.

METHODS

This was a retrospective study of patients undergoing image-guided ablation of adrenal metastases between 2003 and 2015 at our institution. We reviewed electronic medical records to obtain clinical information, including α-blockade preparation, periprocedural hemodynamic parameters, interventions, and postablation adrenal function.

RESULTS

Thermal ablation was performed in 58 patients (46 men [79%]; median age, 66 years) with 60 adrenal metastases ablated in 62 sessions. Alpha-blockade was used pre-ablation in 49 (79%) sessions; it was associated with less hypertensive urgency (23 [47%] for α-blockade vs. 10 [77%] for no α-blockade; P = .048) but higher need for vasopressors (22 [45%] for α-blockade vs. 1 [8%] for no α-blockade; P = .02) during ablation. Adrenal insufficiency occurred in 13 (22%) patients, of whom 10 had history of contralateral adrenalectomy or metastases, and only 3 of 13 had a normal-appearing contralateral adrenal gland.

CONCLUSION

Hemodynamic changes during ablation of adrenal metastases are common. Pre-ablation α-blockade decreases the severity of the hypertensive episode, at the expense of higher need for vasopressors periprocedurally. Adrenal function should be assessed after adrenal metastasis ablation, as adrenal insufficiency may occur after such treatment.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone BP = blood pressure CT = computed tomography DBP = diastolic blood pressure HR = heart rate IQR = interquartile range IV = intravenous MAP = mean arterial pressure MWA = microwave ablation RFA = radiofrequency ablation SBP = systolic blood pressure.

Role of Local Ablative Therapy in Patients with Oligometastatic and Oligoprogressive Non-Small Cell Lung Cancer

Because of an improved understanding of lung cancer biology and improvement in systemic treatment, an oligometastatic state in which metastatic disease is present at a limited number of anatomic sites is being increasingly recognized. An oligoprogressive state, which is a similar but distinct entity, refers to disease progression at a limited number of anatomic sites, with continued response or stable disease at other sites of disease. Such an oligoprogressive state is best described in patients with NSCLC treated with molecular targeted therapy. Possible explanations for development of the oligoprogressive state include the presence of underlying clonal heterogeneity and extrinsic selection pressure due to the use of targeted therapy. Traditionally, local ablative therapy (LAT) has been limited to symptom palliation in patients with advanced NSCLC, but the presence of oligometastatic or oligoprogressive disease provides a unique opportunity to evaluate the role of LAT such as surgery, radiation therapy, radiofrequency ablation, or cryoablation. There is increasing evidence to support the clinical benefit of LAT in patients with NSCLC with limited metastatic disease and in selected individuals in whom resistance to targeted therapies develops. In the latter instance, adequate treatment of drug-resistant clones by LAT could potentially help in avoiding switching systemic therapy prematurely. This review focuses on the biology of oligometastatic and oligoprogressive NSCLC and describes the role of LAT in the treatment of these conditions.

Incidence and clinical sequelae of portal and hepatic venous thrombosis following percutaneous cryoablation of liver tumors

PURPOSE

To assess the incidence and sequelae of portal and hepatic venous thrombosis after percutaneous cryoablation of hepatic tumors.

METHODS

From November 1998 through December 2010, 223 hepatic tumors were cryoablated during 170 ablation procedures in 135 patients. 24-h post-procedure MR images were reviewed retrospectively by two abdominal radiologists in consensus to identify tumor ablations that developed one or more new portal or hepatic venous thromboses in or outside the ablation zone. On follow-up MRI and CT examinations the outcomes of thromboses were classified as resolved, partially recanalized, persistent, or propagated.

RESULTS

Venous thrombosis developed in association with 54 (24%) of 223 tumor ablations treated during 53 (31%) ablation procedures in 39 (28.8%) patients (15 women, 24 men; age range 40-82 years, mean 59 years). Of these 54 thromboses, 49 (91%) were located in portal vein branches, four (7%) in both portal and hepatic vein branches, and one (2%) in a hepatic vein branch. Thrombosed veins were outside but abutted the ablation zone in 36 (66.7%), and within it in 18 (33.3%). On follow-up imaging (n = 49), thrombi resolved in 29 (59%), partially recanalized in two (4%), persisted in 18 (37%) and propagated from sub-segmental or segmental branches to the left or right portal branches in five (10%). No thrombus propagated to the main portal vein or inferior vena cava.

CONCLUSION

Portal and hepatic vein branch thromboses are common in small branches following percutaneous cryoablation of hepatic tumors and most resolve spontaneously without sequelae.

Percutaneous High-Energy Microwave Ablation for the Treatment of Pulmonary Tumors: A Retrospective Single-Center Experience

PURPOSE

To evaluate the safety and efficacy of percutaneous high-energy microwave ablation (MWA) for the treatment for pulmonary tumors.

MATERIALS AND METHODS

A retrospective review was undertaken of 44 patients (21 men, 23 women; median age, 66 y; range, 17-89 y) who underwent 62 sessions of high-energy MWA for 87 pulmonary tumors at a single tertiary referral center between June 2012 and June 2014. Primary tumor origin was sarcoma (n = 23), colorectal (n = 16), lung (n = 2), esophageal (n = 1), breast (n = 1), and bladder (n = 1). Median tumor size was 12 mm (range, 6-45 mm). Technical success was recorded contemporaneously, complication rate at 30 days was recorded prospectively, and technique effectiveness was assessed by longitudinal follow-up CT scan.

RESULTS

Primary technical success was achieved in 94% of ablation sessions. The median follow-up interval was 15 months (range, 6.2-29.5 mo) during which time local tumor progression was observed in two of 87 tumors (technique effectiveness 98%). Pneumothorax requiring chest tube insertion occurred in 19%; delayed pneumothorax occurred in four patients. No hemoptysis, infection, or other complications were recorded.

CONCLUSIONS

High-energy MWA is safe and effective for the destruction of lung tumors.

Percutaneous tumor ablation tools: microwave, radiofrequency, or cryoablation--what should you use and why?

Image-guided thermal ablation is an evolving and growing treatment option for patients with malignant disease of multiple organ systems. Treatment indications have been expanding to include benign tumors as well. Specifically, the most prevalent indications to date have been in the liver (primary and metastatic disease, as well as benign tumors such as hemangiomas and adenomas), kidney (primarily renal cell carcinoma, but also benign tumors such as angiomyolipomas and oncocytomas), lung (primary and metastatic disease), and soft tissue and/or bone (primarily metastatic disease and osteoid osteomas). Each organ system has different underlying tissue characteristics, which can have profound effects on the resulting thermal changes and ablation zone. Understanding these issues is important for optimizing clinical results. In addition, thermal ablation technology has evolved rapidly during the past several decades, with substantial technical and procedural improvements that can help improve clinical outcomes and safety profiles. Staying up to date on these developments is challenging but critical because the physical properties underlying the different ablation modalities and the appropriate use of adjuncts will have a tremendous effect on treatment results. Ultimately, combining an understanding of the physical properties of the ablation modalities with an understanding of the thermal kinetics in tissue and using the most appropriate ablation modality for each patient are key to optimizing clinical outcomes. Suggested algorithms are described that will help physicians choose among the various ablation modalities for individual patients.

Percutaneous tumor ablation tools: microwave, radiofrequency, or cryoablation--what should you use and why?

Image-guided thermal ablation is an evolving and growing treatment option for patients with malignant disease of multiple organ systems. Treatment indications have been expanding to include benign tumors as well. Specifically, the most prevalent indications to date have been in the liver (primary and metastatic disease, as well as benign tumors such as hemangiomas and adenomas), kidney (primarily renal cell carcinoma, but also benign tumors such as angiomyolipomas and oncocytomas), lung (primary and metastatic disease), and soft tissue and/or bone (primarily metastatic disease and osteoid osteomas). Each organ system has different underlying tissue characteristics, which can have profound effects on the resulting thermal changes and ablation zone. Understanding these issues is important for optimizing clinical results. In addition, thermal ablation technology has evolved rapidly during the past several decades, with substantial technical and procedural improvements that can help improve clinical outcomes and safety profiles. Staying up to date on these developments is challenging but critical because the physical properties underlying the different ablation modalities and the appropriate use of adjuncts will have a tremendous effect on treatment results. Ultimately, combining an understanding of the physical properties of the ablation modalities with an understanding of the thermal kinetics in tissue and using the most appropriate ablation modality for each patient are key to optimizing clinical outcomes. Suggested algorithms are described that will help physicians choose among the various ablation modalities for individual patients.

CT-guided percutaneous cryoablation of central lung tumors

PURPOSE

Cryoablation has been successfully used to treat lung tumors. However, the safety and effectiveness of treating tumors adjacent to critical structures has not been fully established. We describe our experience with computed tomography (CT)-guided percutaneous cryoablation of central lung tumors and the role of ice ball monitoring.

MATERIALS AND METHODS

Eight patients with 11 malignant central lung tumors (nine metastatic, two primary; mean, 2.6 cm; range, 1.0-4.5 cm) located adjacent to mediastinal or hilar structures were treated using CT-guided cryoablation in 10 procedures. Technical success and effectiveness rates were calculated, complications were tabulated and intraprocedural imaging features of ice balls were described.

RESULTS

All procedures were technically successful; imaging after 24 hours demonstrated no residual tumor. Five tumors recurred, three of which were re-ablated successfully. A hypodense ice ball with well-defined margin was visible during the first (n=6, 55%) or second (n=11, 100%) freeze, encompassing the entire tumor in all patients, and abutting (n=7) or minimally involving (n=4) adjacent mediastinal and hilar structures. Pneumothorax developed following six procedures (60%); percutaneous treatment was applied in three of them. All patients developed pleural effusions, with one patient requiring percutaneous drainage. Transient hemoptysis occurred after six procedures (60%), but all cases improved within a week. No injury occurred to mediastinal or hilar structures.

CONCLUSION

CT-guided percutaneous cryoablation can be used to treat central lung tumors successfully. Although complications were common, they were self-limited, treatable, and not related to tumor location. Ice ball monitoring helped maximize the amount of tumor treated, while avoiding critical mediastinal and hilar structures.

Cryoablation of a small pulmonary nodule with pure ground-glass opacity: a case report

Treatments for pure ground-glass nodules (GGNs) include limited resection; however, surgery is not always possible in patients with limited pulmonary functional reserve. In such patients, cryoablation may be a suitable alternative to treat a pure GGN. Here, we report our initial experience with cryoablation of a pure GGN that remained after repeated surgical resection in a patient with multiple GGNs. A 5-mm-sized pure GGN in the left lower lobe was cryoablated successfully without recurrence at the 6-month follow-up.

Image-guided cryoablation for the treatment of painful musculoskeletal metastatic disease: a single-center experience

PURPOSE

The role of image-guided thermal ablation techniques for the nonoperative local management of painful osseous metastatic disease has expanded during recent years, and several advantages of cryoablation in this setting have emerged. The purpose of this study is to retrospectively evaluate and report a single-center experience of CT-guided percutaneous cryoablation in the setting of painful musculoskeletal metastatic disease.

METHODS

This study was approved by the institutional review board and is compliant with the Health Insurance Portability and Accountability Act. Electronic medical records of all patients who underwent percutaneous image-guided palliative cryoablation at our institution were reviewed (n = 61). An intent-to-treat analysis was performed. Records were reviewed for demographic data and anatomical data, primary tumor type, procedure details, and outcome-including change in analgesic requirements (expressed as morphine equivalent dosages), pain scores (utilizing the clinically implemented visual analog scale), subsequent therapies (including radiation and/or surgery), and complications during the 24 h following the procedure and at 3 months. Patients were excluded (n = 7) if data were not retrospectively identifiable at the defined time points.

RESULTS

Fifty-four tumors were ablated in 50 patients. There were statistically significant decreases in the median VAS score and narcotic usage at both 24 h and 3 months (p < 0.000). Six patients (11%) incurred complications related to their therapy. Two patients had no relief at 24 h, of which both reported worsened pain at 3 months. One patient had initial relief but symptom recurrence at 3 months. Four patients went on to have radiation therapy of the ablation site at some point following the procedure.

CONCLUSIONS

CT-guided cryoablation is a safe, effective, reproducible procedural option for the nonoperative local treatment of painful musculoskeletal metastatic disease.

Cryoablation of sternal metastases for pain palliation and local tumor control

PURPOSE

To determine safety and effectiveness of cryoablation of sternal metastases for pain palliation and local tumor control.

MATERIALS AND METHODS

A tumor ablation database was retrospectively reviewed for sternal cryoablation procedures performed between January 2005 and June 2013, which yielded 15 procedures to treat 12 sternal metastases in 12 patients (five men). Median patient age was 57 years (range, 38-80 y). Metastases arose from five primary sites (breast, lung, kidney, ampulla, and thyroid), and median tumor size was 3.8 cm (range, 2.2-7.5 cm). Seven patients (58%) underwent cryoablation for pain palliation, and five (42%) underwent cryoablation for local tumor control of oligometastatic disease. Clinical outcomes (including complications, local tumor control, and pain response) were evaluated retrospectively.

RESULTS

Mean pain scores decreased from 7.0 ± 1.9 (median, 7; range, 4-10) at baseline to 1.8 ± 1.2 (median, 1.5; range, 0-4) following cryoablation (P = .00049). Two patients had durable pain palliation, and four had greater than 1 month of pain relief, with a median duration of 5.7 months (range, 1.5-14.7 mo). Two patients in whom recurrent pain developed underwent repeat cryoablation, with durable pain relief. Allowing for a single repeat treatment, local tumor control was achieved in four of five patients (80%) treated for this indication, with median follow-up of 8.4 months (range, 2.6-13.6 mo). In one patient (8%), an infectious complication developed that was successfully treated with antibiotics on an outpatient basis.

CONCLUSIONS

Cryoablation is a safe and potentially effective treatment for patients with painful sternal metastases and can achieve local tumor control in select patients.

Cryotherapy with concurrent CpG oligonucleotide treatment controls local tumor recurrence and modulates HER2/neu immunity

Percutaneous cryoablation is a minimally invasive procedure for tumor destruction, which can potentially initiate or amplify antitumor immunity through the release of tumor-associated antigens. However, clinically efficacious immunity is lacking and regional recurrences are a limiting factor relative to surgical excision. To understand the mechanism of immune activation by cryoablation, comprehensive analyses of innate immunity and HER2/neu humoral and cellular immunity following cryoablation with or without peritumoral CpG injection were conducted using two HER2/neu(+) tumor systems in wild-type (WT), neu-tolerant, and SCID mice. Cryoablation of neu(+) TUBO tumor in BALB/c mice resulted in systemic immune priming, but not in neu-tolerant BALB NeuT mice. Cryoablation of human HER2(+) D2F2/E2 tumor enabled the functionality of tumor-induced immunity, but secondary tumors were refractory to antitumor immunity if rechallenge occurred during the resolution phase of the cryoablated tumor. A step-wise increase in local recurrence was observed in WT, neu-tolerant, and SCID mice, indicating a role of adaptive immunity in controlling residual tumor foci. Importantly, local recurrences were eliminated or greatly reduced in WT, neu tolerant, and SCID mice when CpG was incorporated in the cryoablation regimen, showing significant local control by innate immunity. For long-term protection, however, adaptive immunity was required because most SCID mice eventually succumbed to local tumor recurrence even with combined cryoablation and CpG treatment. This improved understanding of the mechanisms by which cryoablation affects innate and adaptive immunity will help guide appropriate combination of therapeutic interventions to improve treatment outcomes.

Bone and soft tissue ablation

Bone and soft tissue tumor ablation has reached widespread acceptance in the locoregional treatment of various benign and malignant musculoskeletal (MSK) lesions. Many principles of ablation learned elsewhere in the body are easily adapted to the MSK system, particularly the various technical aspects of probe/antenna design, tumoricidal effects, selection of image guidance, and methods to reduce complications. Despite the common use of thermal and chemical ablation procedures in bone and soft tissues, there are few large clinical series that show longitudinal benefit and cost-effectiveness compared with conventional methods, namely, surgery, external beam radiation, and chemotherapy. Percutaneous radiofrequency ablation of osteoid osteomas has been evaluated the most and is considered a first-line treatment choice for many lesions. Palliation of painful metastatic bone disease with thermal ablation is considered safe and has been shown to reduce pain and analgesic use while improving quality of life for cancer patients. Procedure-related complications are rare and are typically easily managed. Similar to all interventional procedures, bone and soft tissue lesions require an integrated approach to disease management to determine the optimum type of and timing for ablation techniques within the context of the patient care plan.

Ablation of musculoskeletal metastases: pain palliation, fracture risk reduction, and oligometastatic disease

Thermal ablation is an effective, minimally invasive alternative to conventional therapies in the palliation of painful musculoskeletal metastases and an emerging approach to obtain local tumor control in the setting of limited metastatic disease. Various thermal ablation technologies have been applied to bone and soft tissue tumors and may be used in combination with percutaneous cement instillation for skeletal lesions with or at risk for pathologic fracture. This article reviews current practices of percutaneous ablation of musculoskeletal metastases with an emphasis on radiofrequency ablation and cryoablation of painful skeletal metastases.

Percutaneous imaging-guided cryoablation of liver tumors: predicting local progression on 24-hour MRI

OBJECTIVE

The purpose of this study was to determine which MRI features observed 24 hours after technically successful percutaneous cryoablation of liver tumors predict subsequent local tumor progression and to describe the evolution of imaging findings after cryoablation.

MATERIALS AND METHODS

Thirty-nine adult patients underwent technically successful imaging-guided percutaneous cryoablation of 54 liver tumors (hepatocellular carcinoma, 8; metastases, 46). MRI features pertaining to the tumor, ablation margin, and surrounding liver 24 hours after treatment were assessed independently by two readers. Fisher exact or Wilcoxon rank sum tests (significant p values < 0.05) were used to compare imaging features in patients with and without subsequent local tumor progression. Imaging features of the ablation margin, treated tumor, and surrounding liver were evaluated on serial MRI in the following year.

RESULTS

A minimum ablation margin of 3 mm or less was observed in 11 (78.6%) of 14 tumors with and 15 of 40 (37.5%) without progression (p = 0.012). A blood vessel bridging the ablation margin was noted in 11 of 14 (78.6%) tumors with and nine of 40 (22.5%) without progression (p < 0.001). The incidence of tumor enhancement 24 hours after cryoablation was similar for tumors with (10/14, 71.4%) or without (25/40, 62.5%) local progression (p = 0.75). MRI enabled assessment of the entire cryoablation margin in 49 of 54 (90.7%) treated tumors.

CONCLUSION

MRI features at 24 hours after liver cryoablation that were predictive of local tumor progression included a minimum ablation margin less than or equal to 3 mm and a blood vessel bridging the ablation margin. Persistent tumor enhancement is common after liver cryoablation and does not predict local tumor progression.

A single-institution experience in image-guided thermal ablation of adrenal gland metastases

PURPOSE

To assess safety, technical success, local control, and survival associated with percutaneous image-guided adrenal ablation.

MATERIALS AND METHODS

Adult patients with adrenal metastases who underwent percutaneous image-guided adrenal ablation during the years 2003-2012 were identified. There were 32 patients with 37 adrenal tumors identified. Technical success, safety, local control, and survival were analyzed according to standard criteria.

RESULTS

In 32 patients (25 men and 7 women; mean age, 66 y; age range, 44-88 y) with 37 adrenal tumors, 35 ablation procedures were performed. One patient with an 8.2-cm tumor underwent planned cryoablation debulking fully anticipating untreated margins owing to close proximity of the pancreas (ie, the intent was to diminish tumor burden rather than a curative intervention). Of the 36 patients treated with curative intent, technical success was achieved in 35 (97%) tumors. Follow-up imaging was performed on 34 of 37 tumors (excluding patients with intentional debulking [n = 1], technical failure [n = 1], and absence of follow-up [n = 1]). Local recurrence developed in 3 (8.8%) of 34 tumors. Local tumor control was achieved in 31 lesions at a mean of 22.7 months of follow-up. Recurrence-free survival and overall survival at 36 months were 88% and 52%, respectively, with a median survival of 34.5 months. A Common Terminology Criteria for Adverse Events version 4 grade 3 or 4 complication was observed in three (8.6%) ablation procedures.

CONCLUSIONS

Image-guided ablation is safe and effective for local control of metastatic adrenal tumors and provides a minimally invasive alternative to surgical resection in appropriately selected patients.

Mechanisms of cryoablation: clinical consequences on malignant tumors

While the destructive actions of a cryoablative freeze cycle are long recognized, more recent evidence has revealed a complex set of molecular responses that provides a path for optimization. The importance of optimization relates to the observation that the cryosurgical treatment of tumors yields success only equivalent to alternative therapies. This is also true of all existing therapies of cancer, which while applied with curative intent; provide only disease suppression for periods ranging from months to years. Recent research has led to an important new understanding of the nature of cancer, which has implications for primary therapies, including cryosurgical treatment. We now recognize that a cancer is a highly organized tissue dependent on other supporting cells for its establishment, growth and invasion. Further, cancer stem cells are now recognized as an origin of disease and prove resistant to many treatment modalities. Growth is dependent on endothelial cells essential to blood vessel formation, fibroblasts production of growth factors, and protective functions of cells of the immune system. This review discusses the biology of cancer, which has profound implications for the diverse therapies of the disease, including cryosurgery. We also describe the cryosurgical treatment of diverse cancers, citing results, types of adjunctive therapy intended to improve clinical outcomes, and comment briefly on other energy-based ablative therapies. With an expanded view of tumor complexity we identify those elements key to effective cryoablation and strategies designed to optimize cancer cell mortality with a consideration of the now recognized hallmarks of cancer.