The cryobiology of cryosurgical injury

2024 multidisciplinary consensus on image-guided lung tumor ablation from the Taiwan Academy of Tumor Ablation

In this article, the multidisciplinary team of the Taiwan Academy of Tumor Ablation, who have expertise in treating lung cancer, present their perspectives on percutaneous image-guided thermal ablation (IGTA) of lung tumors. The modified Delphi technique was applied to reach a consensus on clinical practice guidelines concerning ablation procedures, including a comprehensive literature review, selection of panelists, creation of a rating form and survey, and arrangement of an in-person meeting where panelists agreed or disagreed on various points. The conclusion was a final rating and written summary of the agreement. The multidisciplinary expert team agreed on 10 recommendations for the use of IGTA in the lungs. These recommendations include terms and definitions, line of treatment planning, modality, facility rooms, patient anesthesia settings, indications, margin determination, post-ablation image surveillance, qualified centers, and complication ranges. In summary, IGTA is a safe and feasible approach for treating primary and metastatic lung tumors, with a relatively low complication rate. However, decisions regarding the ablation technique should consider each patient's specific tumor characteristics.

CT-based evaluation of tissue expansion in cryoablation of ex vivo kidney

OBJECTIVES

To evaluate tissue expansion during cryoablation, the displacement of markers in ex vivo kidney tissue was determined using computed tomographic (CT) imaging.

METHODS

CT-guided cryoablation was performed in nine porcine kidneys over a 10 min period. Markers and fiber optic temperature probes were positioned perpendicular to the cryoprobe shaft in an axial orientation. The temperature measurement was performed simultaneously with the acquisitions of the CT images in 5 s intervals. The distance change of the markers to the cryoprobe was determined in each CT image and equated to the measured temperature at the marker.

RESULTS

The greatest increase in the distance between the markers and the cryoprobe was observed in the initial phase of cryoablation. The maximum displacement of the markers was determined to be 0.31±0.2 mm and 2.8±0.02 %, respectively.

CONCLUSIONS

The mean expansion of ex vivo kidney tissue during cryoablation with a single cryoprobe is 0.31±0.2 mm. The results can be used for identification of basic parameters for optimization of therapy planning.

A novel in vitro model of clinical cryoablation to investigate the transition zone for focal tumor ablation

Cryoablation (CA) of solid tumors is highly effective at reducing tumor burden and eliminating small, early stage tumors. However, complete ablation is difficult to achieve and cancer recurrence is a significant barrier to treatment of larger tumors compared to resection. In this study, we explored the relationship between temperature, ice growth, and cell death using a novel in vitro model of clinical CA with the Visual-ICE (Boston Scientific) system, a clinically approved and widely utilized device. We found that increasing the duration of freezing from 1 to 2 min increased ice radius from 3.44 ± 0.13 mm to 5.29 ± 0.16 mm, and decreased the minimum temperature achieved from -22.8 ± 1.3 °C to -45.5 ± 7.9 °C. Furthermore, an additional minute of freezing increased the amount of cell death within a 5 mm radius from 42.5 ± 8.9% to 84.8 ± 1.1%. Freezing at 100% intensity leads to faster temperature drops and a higher level of cell death in the TRAMP-C2 mouse prostate cancer cell line, while lower intensities are useful for slow freezing, but result in less cell death. The width of transition zone between live and dead cells decreased by 0.4 ± 0.2 mm, increasing from one to two cycles of freeze/thaw cycles at 100% intensity. HMGB-1 levels significantly increased with 3 cycles of freeze/thaw compared to the standard 2 cycles. Overall, a longer freezing duration, higher freezing intensity, and more freeze thaw cycles led to higher levels of cancer cell death and smaller transition zones. These results have the potential to inform future preclinical research and to improve therapeutic combinations with CA.

Cryoablation in the liver: how accurately does the iceball predict the ablation zone?

PURPOSE

To evaluate the accuracy with which the iceball predicts the realized ablation zone in patients undergoing cryoablation of the liver.

MATERIALS AND METHODS

Continuous patients who underwent cryoablation of primary or secondary malignancies of the liver were retrospectively reviewed. Iceball and ablation zone dimensions on 1 month follow up imaging were collected in three orientations, the long axis (LA), perpendicular transverse (PTR), and perpendicular craniocaudal (PCC). Factors which may predict differences in the measurements were evaluated with regression analysis. Oncologic outcomes were also collected.

RESULTS

The mean size of the iceball was 5.5 ± 1.1 cm, 3.9 ± 1.1 cm, and 4.4 ± 1.4 cm in the LA, PTR, and PCC orientations, respectively. The mean size of the one-month ablation cavity was 4.3 ± 1.3 cm, 3 ± 1.1 cm, and 3 ± 1.3 cm in the LA, PTR, and PCC orientations, respectively. The iceball was significantly larger than the ablation zone in all orientations (p < 0.001). When comparing HCC and non-HCC patients the Kaplan-Meier analysis of TTLP, the Kaplan Meier curves deviated significantly (p = 0.015, HR 2.26 (95%CI 1.17-4.37)). When a similar analysis was performed looking at TTP again the curves diverged significantly (p = 0.002, HR 2.4 (95%CI 1.37-4.19)).

CONCLUSION

The iceball seems to overestimate the realized ablation zone by about 1 cm in all orientations during hepatic cryoablation.

Investigation of integrated time nanosecond pulse irreversible electroporation against spontaneous equine melanoma

Introduction

Integrated time nanosecond pulse irreversible electroporation (INSPIRE) is a novel tumor ablation modality that employs high voltage, alternating polarity waveforms to induce cell death in a well-defined volume while sparing the underlying tissue. This study aimed to demonstrate the in vivo efficacy of INSPIRE against spontaneous melanoma in standing, awake horses.

Methods

A custom applicator and a pulse generation system were utilized in a pilot study to treat horses presenting with spontaneous melanoma. INSPIRE treatments were administered to 32 tumors across 6 horses and an additional 13 tumors were followed to act as untreated controls. Tumors were tracked over a 43-85 day period following a single INSPIRE treatment. Pulse widths of 500ns and 2000ns with voltages between 1000 V and 2000 V were investigated to determine the effect of these variables on treatment outcomes.

Results

Treatments administered at the lowest voltage (1000 V) reduced tumor volumes by 11 to 15%. Higher voltage (2000 V) treatments reduced tumor volumes by 84 to 88% and eliminated 33% and 80% of tumors when 500 ns and 2000 ns pulses were administered, respectively.

Discussion

Promising results were achieved without the use of chemotherapeutics, the use of general anesthesia, or the need for surgical resection in regions which are challenging to keep sterile. This novel therapeutic approach has the potential to expand the role of pulsed electric fields in veterinary patients, especially when general anesthesia is contraindicated, and warrants future studies to demonstrate the efficacy of INSPIRE as a solid tumor treatment.

Thermal ablation of hepatocellular carcinoma

Percutaneous treatment of hepatocellular carcinoma (HCC) by means of thermal ablation (TA) has been introduced in clinical guidelines as a potentially curative treatment for the early stages of the disease since the early 2000s. Due to its safety profile and cost-effectiveness, TA can be offered as a first-line treatment for patients with HCC smaller than 3 cm. Thermal ablative techniques are in fact widely available at many centres worldwide and include radiofrequency (RF) and microwave (MW) ablation, with the latter increasingly applied in clinical practice in the last decade. Pre-clinical studies highlighted, as potential advantages of MW-based ablation, the ability to achieve higher temperatures (>100°C) and larger ablation zones in shorter times, with less susceptibility to blood flow-induced heat sink effects. Despite these advantages, there is no evidence of superior overall survival in patients treated with MW as compared to those treated with RF ablation. Local control has been proven to be superior to MW ablation with a similar complication rate. It is expected that further improvement of TA results in the treatment of HCC will result from the refinement of guidance and monitoring tools and the careful assessment of ablation margins. Thermal ablative treatments may also be performed on nodules larger than 3 cm by applying multiple devices or combining percutaneous and intra-arterial approaches. The role of novel immunotherapy regimens in combination with ablation is also currently under evaluation in clinical trials, with several potential benefits. In this review, indications, technical principles, results, and future prospects of TA for the treatment of HCC will be examined.

Sclerotherapy, cryoablation, and surgical fixation of an intraosseous tibial venous malformation

Intraosseous vascular malformations are rare vascular anomalies that present unique treatment challenges due to structural instability, embolization and sclerotherapy resistance, and tendency to recur. Patients may have clinical manifestations including pain, functional impairment, increased fracture risk, and decreased quality of life. Image-guided ablation techniques are emerging interventional treatment options for soft tissue tumors and complicated vascular anomalies. Percutaneous image-guided cryoablation offers a potential alternative as an isolated or adjunct therapy for intraosseous vascular malformations.

Breast Cancer Cryoablation Fundamentals Past and Present: Technique Optimization and Imaging Pearls

Surgical treatment for breast cancer has evolved from radical mastectomy to modified radical mastectomy to breast-conserving surgery. As the de-escalation of surgical treatment for breast cancer continues, nonsurgical treatment for early-stage breast cancer with favorable ancillary features (low grade, positivity for hormone receptors) is being explored. Of the nonsurgical treatment options, cryoablation has demonstrated the greatest appeal, proven to be effective, safe, well tolerated, and feasible in an outpatient setting with local anesthetic alone. Results of past and interim results of current trials of cryoablation of stage I low-grade breast cancer with curative intent are promising, with an overall clinical success rate of 98% and recurrence rates consistent with those expected following lumpectomy. Cryoablation is also an alternative palliative treatment for patients who cannot tolerate or who have disease that is refractory to or recurs after standard-of-care breast cancer treatment and may have immunological therapeutic effects, warranting future research. Understanding the indications and optimal technique for breast cancer cryoablation and understanding typical imaging findings after cryoablation are essential to ensure the success of the procedure in carefully selected patients.

Aneurysmal Bone Cyst of the Pelvis in Children and Adolescents: Effectiveness of Surgical Treatment with Curettage, Cryotherapy and Bone Grafting

BACKGROUND

Aneurysmal bone cysts (ABCs) are benign but locally aggressive cystic lesions of the bone. Pelvic ABCs are extremely rare and hard to treat due to their high risk of local recurrence and the tough access to pelvic bones.

METHODS

In this retrospective study, we evaluated pediatric cases with pelvic ABC treated with curettage, cryotherapy and bone grafting treated in our institution between 2016 and 2022. Complications were recorded, as well as local recurrences. Patients' post-operative functionality was assessed with the MSTS score.

RESULTS

Fourteen consecutive cases were included in our study. Their mean age at surgery was 13.5 years. The mean lesion size was 55 mm. The mean follow-up was 38 months. Two cases (11.8%) had local recurrences, which were successfully treated with further curettage. At their latest FU, 13 cases were continuously disease free (CDF), and one had no evidence of disease (NED). Only one case had a post-operative compilation (wound dehiscence). Patients' mean post-operative MSTS score was 29.6.

CONCLUSIONS

Pelvic ABCs are a challenge, even for the most experienced orthopedic surgeon. Our study suggests that the association of an accurate curettage, intraoperative cryotherapy and bone grafting can be a reliable and effective therapeutic option for large-sized ABCs of the pelvis.

Effects of Inflammatory Cell Death Caused by Catheter Ablation on Atrial Fibrillation

Atrial fibrillation (AF) poses a serious healthcare burden on society due to its high morbidity and the resulting serious complications such as thrombosis and heart failure. The principle of catheter ablation is to achieve electrical isolation by linear destruction of cardiac tissue, which makes AF a curable disease. Currently, catheter ablation does not have a high long-term success rate. The current academic consensus is that inflammation and fibrosis are central mechanisms in the progression of AF. However, artificially caused inflammatory cell death by catheter ablation may have a significant impact on structural and electrical remodeling, which may affect the long-term prognosis. This review first focused on the inflammatory response induced by apoptosis, necrosis, necroptosis, pyroptosis, ferroptosis and their interaction with arrhythmia. Then, we compared the differences in cell death induced by radiofrequency ablation, cryoballoon ablation and pulsed-field ablation. Finally, we discussed the structural and electrical remodeling caused by inflammation and the association between inflammation and the recurrence of AF after catheter ablation. Collectively, pulsed-field ablation will be a revolutionary innovation with faster, safer, better tissue selectivity and less inflammatory response induced by apoptosis-dominated cell death.

Endophytic upper tract urothelial carcinoma in a solitary kidney treated by cryotherapy: an unorthodox case for successful management

BACKGROUND

Nephroureterectomy remains the gold standard treatment for upper tract urothelial carcinoma (UTUC). Considering the high risk of developing renal function impairment after surgery, the rationale for nephron sparing approaches in treatment of UTUC has been raised. In this case, renal cryoablation was able to achieve successful oncologic control while preserving renal function during 5 years of follow up without intraoperative or post operative complications.

CASE PRESENTATION

A 79 year old male presents after three months of macroscopic hematuria. Imaging revealed a 3.6 × 3.1 × 2.7 cm endophytic mass in the interpolar region of the left kidney and an atrophic right kidney. After weighing the lesion's location with the patient's of complex medical history, he was counselled to undergo a minimally invasive percutaneous cryoablation as treatment for his solitary renal mass. A diagnostic dilemma was encountered as imaging suggested a diagnosis of renal cell carcinoma. However, the pre-ablation biopsy established an alternative diagnosis, revealing UTUC. Percutaneous cryoablation became an unorthodox treatment modality for the endophytic component of his UTUC followed by retrograde ureteroscopic laser fulguration. The patient was followed in 3 months, 6 months, then annually with cross sectional imaging by MRI, cystoscopy, urine cytology and renal function testing. After five years of follow-up, the patient did not encountered recurrence of UTUC or deterioration in renal function, thereby maintaining a stable eGFR.

CONCLUSION

Although evidence for nephron-sparing modalities for UTUC is mounting in recent literature, limited data still exists on cryotherapy as a line of treatment for urothelial carcinoma. We report successful management of a low-grade UTUC using cryoablation with the crucial aid of an initial renal biopsy and long-term follow-up. Our results provide insight into the role of cryoablation as a nephron-sparing approach for UTUC.

Cryotherapy for low rectal and anal cancer: recommendation and indications

Low rectal cancer is a common gastrointestinal malignancy. Organ preservation in the treatment of low rectal cancer is a challenge. By combining surgical resection with freezing-a complementary treatment for low rectal cancer-the anus can be preserved in some patients. However, we lack unified standards for colorectal cancer cryotherapy. Our hospital has been treating patients with cryotherapy since 1976. In our department, the indications for and contraindications to low rectal and anal cancer treatment are well established. In this paper, we summarize the indications for and contraindications to cryotherapy for colorectal cancer by reviewing the literature, drawing on our experience, and considering current imaging and histological techniques. Our aim is to facilitate clinical discussion and promote appropriate treatment.

Cryoablation and Immunotherapy: An Enthralling Synergy for Cancer Treatment

As less invasive options for surgical tumor removal, minimally invasive ablative techniques have gained popularity. Several solid tumors are being treated with cryoablation, a non-heat-based ablation technique. Cryoablation data in comparison over time demonstrates better tumor response and faster recovery. Combining cryosurgery with other cancer therapies has been explored to improve the cancer-killing process. Cryoablation with the combination of immunotherapy, results in a robust and efficient attack on the cancer cells. This article focuses on investigating the ability of cryosurgery to create a strong antitumor response when combined with immunologic agents resulting in a synergetic effect. To achieve this objective, we combined cryosurgery with immunotherapy using Nivolumab and lpilimumab. Five clinical cases of lymph node, lung cancer, bone, and lung metastasis were followed and analyzed. In this series of patients, percutaneous cryoablation and addressing immunity agents were technically feasible. In the follow-ups, there appeared to be no radiological evidence of new tumor development.

Combining energy-based focal ablation and immune checkpoint inhibitors: preclinical research and clinical trials

Energy-based focal therapy (FT) uses targeted, minimally invasive procedures to destroy tumors while preserving normal tissue and function. There is strong emerging interest in understanding how systemic immunity against the tumor can occur with cancer immunotherapy, most notably immune checkpoint inhibitors (ICI). The motivation for combining FT and ICI in cancer management relies on the synergy between the two different therapies: FT complements ICI by reducing tumor burden, increasing objective response rate, and reducing side effects of ICI; ICI supplements FT by reducing local recurrence, controlling distal metastases, and providing long-term protection. This combinatorial strategy has shown promising results in preclinical study (since 2004) and the clinical trials (since 2011). Understanding the synergy calls for understanding the physics and biology behind the two different therapies with distinctive mechanisms of action. In this review, we introduce different types of energy-based FT by covering the biophysics of tissue-energy interaction and present the immunomodulatory properties of FT. We discuss the basis of cancer immunotherapy with the emphasis on ICI. We examine the approaches researchers have been using and the results from both preclinical models and clinical trials from our exhaustive literature research. Finally, the challenges of the combinatory strategy and opportunities of future research is discussed extensively.

Measurement Analysis of Ice Ball Size during CT-Guided Cryoablation Procedures for Better Prediction of Final Ice Ball Size and Avoidance of Complications

Introduction Cryoablation is the destruction of living tissue by the application of extreme freezing temperature. There has been an increase in the use of cryoablation in the management of musculoskeletal lesions, in particular fibromatosis.

Aim This study aimed to measure the average and relative increase in size of the cryoablation ice ball after the first (10 minutes) and second freeze cycles (20 minutes) to accurately predict the size of the ice ball between first and second freezes to help prevent any unwanted damage of the nearby skin and neurovascular structures. This is especially important when ablating in relatively small body parts such as in the appendicular skeleton.

Material and Methods Eight patients treated with cryoablation over a 12-month period for fibromatosis were, included in the study. The size and volume of the ice ball were measured during the first and second cycle of cryoablation.

Results The average patient age of the cohort was 35.6 years old (min 28 and max 43). There was female predominance in the study (3:2, F:M). There was a significant increase (26%) in the linear dimensions and almost doubling in the volume of the ice ball between freeze cycles (p-value = 0.0037 for dimensions and p-value = 0.0002 for volumes).

Conclusion This pilot study is a preliminary attempt to predict the eventual size of the ice ball during cryoablation procedures when treating cases of fibromatosis. This should help in planning cryoablation to ensure decrease morbidity by preventing injury to adjacent critical structures (neurovascular bundle and skin).

Nerve Protection During Prostate Cryosurgery

Cryosurgery is a minimally invasive approach to the treatment of focal prostate cancer (PCa). A major complication is the cryoinjury to the cavernous nerve in the neurovascular bundle (NVB). This nerve cryoinjury halts conduction of action potentials (APs) and can eventually result in erectile dysfunction and therefore diminished quality of life for the patient. Here, we propose the application of cryoprotective agents (CPA) to the regions of the nerves in the NVB, prior to prostate cryosurgery, to minimize non-recoverable loss of AP conduction. We modeled a cryosurgical procedure based on data taken during a clinical case and applied ex-vivo porcine phrenic nerves and rat sciatic nerve with temperature profile of NVB. The APs were measured before and after the CPA exposures and during 3 h of recovery. Comparisons of AP amplitude recovery with various CPA compositions reveal that certain CPAs (e.g., 5% DMSO + 7.5% Trehalose and 5% M22 for porcine and rat nerves, respectively) showed little or no toxicity and effective cryoprotection from freezing (on average 48% and 30% of recovered AP, respectively). In summary, we demonstrate that neural conduction can be preserved after exposure to freezing conditions if CPAs are properly selected and deployed onto the nerve.

In-situ cryo-immune engineering of tumor microenvironment with cold-responsive nanotechnology for cancer immunotherapy

Cancer immunotherapy that deploys the host's immune system to recognize and attack tumors, is a promising strategy for cancer treatment. However, its efficacy is greatly restricted by the immunosuppressive (i.e., immunologically cold) tumor microenvironment (TME). Here, we report an in-situ cryo-immune engineering (ICIE) strategy for turning the TME from immunologically "cold" into "hot". In particular, after the ICIE treatment, the ratio of the CD8+ cytotoxic T cells to the immunosuppressive regulatory T cells is increased by more than 100 times in not only the primary tumors with cryosurgery but also distant tumors without freezing. This is achieved by combining cryosurgery that causes "frostbite" of tumor with cold-responsive nanoparticles that not only target tumor but also rapidly release both anticancer drug and PD-L1 silencing siRNA specifically into the cytosol upon cryosurgery. This ICIE treatment leads to potent immunogenic cell death, which promotes maturation of dendritic cells and activation of CD8+ cytotoxic T cells as well as memory T cells to kill not only primary but also distant/metastatic breast tumors in female mice (i.e., the abscopal effect). Collectively, ICIE may enable an efficient and durable way to leverage the immune system for combating cancer and its metastasis.

Do Liquid Nitrogen-treated Tumor-bearing Nerve Grafts Have the Capacity to Regenerate, and Do They Pose a Risk of Local Recurrence? A Study in Rats

BACKGROUND

Under most circumstances, the resection of soft tissue sarcomas of the extremities can be limb-sparing, function-preserving oncologic resections with adequate margins. However, en bloc resection may require resection of the major peripheral nerves, causing poor function in the extremities. Although liquid nitrogen treatment has been used to sterilize malignant bone tumors, its use in the preparation of nerve grafts has, to our knowledge, not been reported. Hence, this study aimed to investigate the tumor recurrence and function after peripheral nerve reconstruction using liquid nitrogen-treated tumor-bearing nerves in a rat model.

QUESTIONS/PURPOSES

(1) Do liquid nitrogen-treated frozen autografts have regeneration capabilities? (2) Do liquid nitrogen-treated tumor-bearing nerves cause any local recurrences in vivo in a rat model?

METHODS

Experiment 1: Twelve-week-old female Wistar rats, each weighing 250 g to 300 g, were used. A 10-mm-long section of the right sciatic nerve was excised; the prepared nerve grafts were bridge-grafted through end-to-end suturing. The rats were grouped as follows: an autograft group, which underwent placement of a resected sciatic nerve after it was sutured in the reverse orientation, and a frozen autograft group, which underwent bridging of the nerve gap using a frozen autograft. The autograft was frozen in liquid nitrogen, thawed at room temperature, and then thawed in distilled water before application. The third group was a resection group in which the nerve gap was not reconstructed. Twenty-four rats were included in each group, and six rats per group were evaluated at 4, 12, 24, and 48 weeks postoperatively. To assess nerve regeneration after reconstruction using the frozen nerve graft in the nontumor rat model, we evaluated the sciatic functional index, tibialis anterior muscle wet weight ratio, electrophysiologic parameters (amplitude and latency), muscle fiber size (determined with Masson trichrome staining), lower limb muscle volume, and immunohistochemical findings (though neurofilament staining and S100 protein produced solely and uniformly by Schwann cells associated with axons). Lower limb muscle volume was calculated via CT before surgery (0 weeks) and at 4, 8, 12, 16, 20, 24, 32, 40, and 48 weeks after surgery. Experiment 2: Ten-week-old female nude rats (F344/NJcl-rnu/rnu rats), each weighing 100 g to 150 g, were injected with HT1080 (human fibrosarcoma) cells near the bilateral sciatic nerves. Two weeks after injection, the tumor grew to a 10-mm-diameter mass involving the sciatic nerves. Subsequently, the tumor was resected with the sciatic nerves, and tumor-bearing sciatic nerves were obtained. After liquid nitrogen treatment, the frozen tumor-bearing nerve graft was trimmed to a 5-mm-long tissue and implanted into another F344/NJcl-rnu/rnu rat, in which a 5-mm-long section of the sciatic nerve was resected to create a nerve gap. Experiment 2 was performed with 12 rats; six rats were evaluated at 24 and 48 weeks postoperatively. To assess nerve regeneration and tumor recurrence after nerve reconstruction using frozen tumor-bearing nerve grafts obtained from the nude rat with human fibrosarcoma involving the sciatic nerve, the sciatic nerve's function and histologic findings were evaluated in the same way as in Experiment 1.

RESULTS

Experiment 1: The lower limb muscle volume decreased once at 4 weeks in the autograft and frozen autograft groups and gradually increased thereafter. The tibialis anterior muscle wet weight ratio, sciatic functional index, muscle fiber size, and electrophysiologic evaluation showed higher nerve regeneration potential in the autograft and frozen autograft groups than in the resection group. The median S100-positive areas (interquartile range [IQR]) in the autograft group were larger than those in the frozen autograft group at 12 weeks (0.83 [IQR 0.78 to 0.88] versus 0.57 [IQR 0.53 to 0.61], difference of medians 0.26; p = 0.04) and at 48 weeks (0.86 [IQR 0.83 to 0.99] versus 0.74 [IQR 0.69 to 0.81], difference of median 0.12; p = 0.03). Experiment 2: Lower limb muscle volume decreased at 4 weeks and gradually increased thereafter. The median muscle fiber size increased from 0.89 (IQR 0.75 to 0.90) at 24 weeks to 1.20 (IQR 1.08 to 1.34) at 48 weeks (difference of median 0.31; p< 0.01). The median amplitude increased from 0.60 (IQR 0.56 to 0.67) at 24 weeks to 0.81 (IQR 0.76 to 0.90) at 48 weeks (difference of median 0.21; p < 0.01). Despite tumor involvement and freezing treatment, tumor-bearing frozen grafts demonstrated nerve regeneration activity, with no local recurrence observed at 48 weeks postoperatively in nude rats.

CONCLUSION

Tumor-bearing frozen nerve grafts demonstrated nerve regeneration activity, and there was no tumor recurrence in rats in vivo.

CLINICAL RELEVANCE

A frozen nerve autograft has a similar regenerative potential to that of a nerve autograft. Although the findings in a rat model do not guarantee efficacy in humans, if they are substantiated by large-animal models, clinical trials will be needed to evaluate the efficacy of tumor-bearing frozen nerve grafts in humans.

Alternatives to whole gland treatment for localized prostate cancer: a review of novel focal therapies

PURPOSE OF REVIEW

The mainstays of the management of clinically localized prostate cancer have historically rested upon active surveillance, radiation therapy, or radical prostatectomy. Although both radiation and surgical treatment of localized prostate cancer can achieve excellent oncologic outcomes, the subsequent potential adverse effects of urinary stress incontinence and erectile dysfunction are unappealing to patients. This has led to investigational studies centered upon focal treatment of the cancerous lesion, with the aim to improve quality-of-life outcomes. In this review, we describe numerous novel modalities, including nanoparticle ablation and irreversible electroporation, which are being utilized for the focal treatment of clinically localized prostate cancer.

RECENT FINDINGS

Although many of these novel therapies are in their investigational infancy, several have revealed very promising results both in their post-treatment pathologic outcomes as well as objective quality-of-life measures.

SUMMARY

Initial data regarding novel focal therapy for prostate cancer treatment show promising short-term outcomes in regards to oncologic and quality-of-life assessments. Further investigational studies are needed to determine inclusion criteria for the selection of optimal candidates.

Microwave ablation vs. cryoablation for treatment of primary and metastatic pulmonary malignant tumors

At present, minimally invasive surgery is one of the primary strategies for the treatment of malignant pulmonary tumors. Although, there are some comparative studies between microwave ablation and radiofrequency for the treatment of malignant pulmonary tumors, there are few studies that have investigated the comparison between microwave ablation and cryoablation. The aim of the study was to retrospectively compare the efficacy and complications of microwave ablation (MWA) and cryoablation in the treatment of malignant pulmonary tumors. A retrospective analysis was performed on 48 patients with malignant lung tumors treated with MWA or cryoablation in The Third Hospital of Mianyang and The Affiliated Hospital of North Sichuan Medical College between June 2014 and June 2018. Of these patients, 29 received MWA and 19 received cryoablation. Intraprocedural pain was evaluated by using the visual analog scale (VAS). The intraprocedural pain, response rates, overall survival (OS) and complications rates were compared between the MWA group and cryoablation group. The results showed that the patients in the MWA group experienced more pain than those in cryoablation group as the MWA group VAS scores were much higher than those in cryoablation group (P<0.001). The overall response rate of the MWA group [21/29 (72.41%)] was not significantly different from the cryoablation group [14/19 (73.68%)] (P=0.92). The 6-, 12-, 24- and 36-month OS rates in the MWA group and cryoablation group were 92.72, 81.28, 64.54 and 54.91%, and 94.07, 81.13, 57.33 and 43.04%, respectively. No significant differences were found in the OS rate between the two groups (P=0.79). The complication rates in the MWA and cryoablation groups were 34.48 and 36.84%, respectively; there was no significant difference between the two groups (P=0.59). No patients died during the perioperative period. Cryoablation had a similar therapeutic effect compared with MWA in the treatment of pulmonary malignant tumors, but was associated with less pain.

Five-Year Outcomes of Concomitant Maze Procedure Using Nitrous Oxide versus Argon-Based Cryoablation

BACKGROUND

Cryoablation is effective for ablating the myocardium but maintaining the structure of the ablated tissue. However, data comparing nitrous oxide (N₂O)-based and argon gas-based cryoprobes are limited.

METHODS

This study was a follow-up study of a single-center, prospective, randomized controlled trial in which 60 patients were randomly allocated to either the N₂O group or the argon group. The primary endpoint of this study was sinus rhythm maintenance, and the key secondary endpoint was a composite of major adverse cardiovascular and cerebrovascular events (MACCEs) (i.e., cardiac death, stroke, major bleeding, and readmission for heart failure).

RESULTS

The baseline and operative characteristics of the patients in the N₂O and argon groups were comparable. At the 5-year follow-up, the rate of sinus rhythm maintenance was 81.8% in the N₂O group, whereas it was 78.5% in the argon group (p > 0.999). No significant differences in the rate of freedom from MACCEs (80.6% in the N₂O group vs. 81.9% in the argon group; P = .978) was observed at the 5-year follow-up. The left atrial volume index decreased over time from 114.65 mL/m² to 65.74 mL/m² (P < .0001) and reached similar values in the two groups (P = .279) at the 5-year follow-up.

CONCLUSIONS

Both N₂O- and argon gas-based cryoprobes showed similar rates of sinus rhythm maintenance and freedom from MACCEs at the 5-year follow-up. Both cryoprobes might have similar efficacy and safety in the arrested heart in the long term.

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.

Local recurrence and other oncologic outcomes after percutaneous image-guided tumor ablations on stageT1b renal cell carcinoma: a systematic review and network meta-analysis

OBJECTIVE

A systematic review of clinical trials on thermal ablation of T1b RCC was conducted to assess oncologic outcomes of those procedures. The primary endpoint was the rate of local recurrence. Secondary endpoints included technical efficacy, progression to metastatic disease, cancer-specific mortality, complications and renal function decrease.

METHODS

PubMed (MEDLINE) and Embase databases were searched in June 2020 for eligible trials following the PRISMA selection process. Prevalence of local recurrence and per procedural major adverse effects were calculated using double arcsine transformation and a random-effects model.

RESULTS

Nine clinical trials (all retrospective) involving 288 patients with T1b renal clear cell carcinoma treated with either percutaneous microwave ablation, cryoablation or radiofrequency ablation were analyzed. Using a random-effects model, the overall prevalence of local recurrence following percutaneous ablation was 0.08 (0.04-0.14; p = 0.05). Primary technical efficacy was 226/263 (86%) patients and secondary technical efficacy was 247/263 (94%). Overall, 10/176 (6%) patients presented metastatic locations following the ablation. Major adverse effects prevalence was 0.09 (0.06-0.14; p = 0.05).

CONCLUSIONS

Thermal ablations are feasible, safe, and effective to treat T1b renal clear cell carcinoma. More trials are necessary to determine the rate of the evidence of the benefit.HighlightsThermal ablations are feasible and safe to treat T1b renal clear cell carcinoma.Oncologic outcomes appear to be very good on both local control and distant progression.Due to small number and heterogeneity of studies more trials are necessary to determine the rate of the evidence of the benefit.

Imaging of the thorax after percutaneous thermal ablation of lung malignancies

Image-guided thermal ablation is a minimally invasive treatment option for patients with early stage non-small cell lung cancer or metastatic disease to the lungs. Percutaneous ablation treats malignant tumours in situ, which precludes histopathological evaluation of the ablated tumours. Imaging studies are used as surrogates to assess technical and clinical success. Although it is not universally accepted, a common protocol for surveillance imaging includes contrast-enhanced computed tomography (CT) at 1, 3, 6, 9, 12, 18, 24 months, and yearly thereafter. Integrated 2-[¹⁸F]-fluoro-2-deoxy-d-glucose positron-emission tomography (PET)/CT imaging is recommended at 3 and 12 months and when recurrent disease is suspected. There is a complex evolution of the ablation zone on CT and PET imaging studies. The zone of ablation, initially larger than the ablated tumour, undergoes gradual involution. In the process, it may cavitate and resemble a lung abscess. Different contrast-enhancement and radionuclide uptake patterns in and around the ablation zone may indicate a wide range of diagnostic possibilities from a normal physiological response to local progression. Ultimately, the zone of ablation may be replaced by a variety of findings including linear bands of density, pleural thickening, or residual necrotic tumour. Diagnostic and interventional radiologists interpreting post-ablation imaging studies must have a clear understanding of the ablation process and imaging findings on surveillance studies. Accurate and timely recognition of complications and/or local recurrence is necessary to guide further therapy. The purpose of this article is to review imaging protocols and salient imaging findings after thermal ablation of lung malignancies.

Management of the Cavity After Removal of Giant Cell Tumor of the Bone

Purpose: To find out the most appropriate management scheme through the analysis and comparison of different inactivation methods and filling materials. Method: A systematic literature search was performed using the terms, anhydrous ethanol, phenol, hypertonic saline, cryotherapy, thermal therapy, bone reconstruction, GCTB, and etc., Selected articles were studied and summarized. The mechanism, clinical effects, and influence on bone repair of various methods are presented. Recent developments and perspectives are also demonstrated. Recent Findings: Compared to curettage alone, management of the residual cavity can effectively reduce the recurrence of giant cell tumours of bone. It is a complex and multidisciplinary process that includes three steps: local control, cavity filling, and osteogenic induction. In terms of local control, High-speed burring can enlarge the area of curettage but may cause the spread and planting of tumour tissues. Among the inactivation methods, Anhydrous ethanol, and hyperthermia therapy are relatively safe and efficient. The combination of the two may achieve a better inactivation effect. When inactivating the cavity, we need to adjust the approach according to the invasion of the tumour. Filling materials and bone repair should also be considered in management.

CT evaluation of patent artery after percutaneous cryoablation of renal cell carcinoma

PURPOSE

The purpose of this retrospective study was to determine the incidence of persistent patent artery after percutaneous cryoablation of renal cell carcinoma (RCC) and the relationship between patent arteries one month after cryoablation and early tumor progression.

MATERIALS AND METHODS

One hundred and fifty-nine patients (112 men, 47 women; mean age, 63.6±14.6 [SD] years; age range: 21-91 years) who underwent percutaneous cryoablation for 186 RCCs (mean diameter, 1.9±0.6 [SD] cm; range: 0.7-4.0cm) were retrospectively included. After cryoablation, patients underwent contrast-enhanced computed tomography (CT) with ≤2-mm slice thickness within one week from cryoablation, and at one, three, and six months. The time course of patent artery in the ablated renal parenchyma after cryoablation was the primary endpoint. The relationships between patent arteries one month after cryoablation and treatment effectiveness, tumor vascularity, tumor enhancement one month after cryoablation, tumor subtype, and renal function changes were evaluated as secondary endpoints.

RESULTS

CT showed patent arteries in the ablated renal parenchyma within one week in 166 RCCs (89.2%), at one month in 54 RCCs (29.0%), at three months in 8 RCCs (4.3%), and at six months in 2 RCCs (1.1%). The presence of patent artery one month after cryoablation was significantly associated with tumor enhancement at the same time point (P=0.015). There was no association between patent arteries one month after cryoablation and treatment effectiveness (P=0.693).

CONCLUSION

Patent arteries in the ablated renal parenchyma are commonly observed on CT examination after percutaneous cryoablation of RCC. However, they gradually disappear and do not require specific treatment.

Rate of Freeze Impacts the Survival and Immune Responses Post Cryoablation of Melanoma

The emergence of ablative therapies has revolutionized the treatment of inoperable solid tumors. Cryoablation stands out for its uniqueness of operation based on hypothermia, and for its ability to unleash the native tumor antigens, resulting in the generation of anti-tumor immune responses. It is not clearly understood how alterations in the rate of freeze impact the immune response outcomes. In this study, we tested fast freeze and slow freeze rates for their locoregional effectiveness and their ability to elicit immune responses in a B16F10 mouse model of melanoma. Tumor bearing mice treated with fast freeze protocol survived better than the ones treated with slow freeze protocol. Fast freeze resulted in a higher magnitude of CD4+ and CD8+ T-cell responses, and a significantly extended survival post re-challenge. Thus, fast freeze rate should be applied in any future studies employing cryoablation as an in vivo vaccination tool in conjunction with targeted immunotherapies.

Asian Conference on Tumor Ablation Guidelines for Adrenal Tumor Ablation

Thermal ablation is a good alternative treatment in patients who are unable to undergo adrenalectomy. Even though the Asian Conference on Tumor Ablation (ACTA) has been held for many years, adrenal ablation guidelines have not been established. No guidelines for adrenal ablation are established in American and European countries, either. The aim of this review was to introduce the first version of ACTA guidelines for adrenal tumor ablation.

The role of imaging in the management of renal masses

The wide availability of cross-sectional imaging is responsible for the increased detection of small, usually asymptomatic renal masses. More than 50 % of renal cell carcinomas (RCCs) represent incidental findings on noninvasive imaging. Multimodality imaging, including conventional US, contrast-enhanced US (CEUS), CT and multiparametric MRI (mpMRI) is pivotal in diagnosing and characterizing a renal mass, but also provides information regarding its prognosis, therapeutic management, and follow-up. In this review, imaging data for renal masses that urologists need for accurate treatment planning will be discussed. The role of US, CEUS, CT and mpMRI in the detection and characterization of renal masses, RCC staging and follow-up of surgically treated or untreated localized RCC will be presented. The role of percutaneous image-guided ablation in the management of RCC will be also reviewed.

Temperature Plays an Essential Regulatory Role in the Tumor Immune Microenvironment

In recent years, emerging immunotherapy has been included in various malignant tumor treatment standards. Temperature has been considered to affect different pathophysiological reactions such as inflammation and cancer for a long time. However, in tumor immunology research, temperature is still rarely considered a significant variable. In this review, we discuss the effects of room temperature, body temperature, and the local tumor temperature on the tumor immune microenvironment from multiple levels and perspectives, and we discuss changes in the body's local and whole-body temperature under tumor conditions. We analyze the current use of ablation treatment-the reason for the opposite immune effect. We should pay more attention to the therapeutic potential of temperature and create a better antitumor microenvironment that can be combined with immunotherapy.

Image-guided Cryotherapy for Musculoskeletal Tumors

BACKGROUND

This article represents a review of the use of image-guided cryotherapy in the treatment of musculoskeletal tumor lesions. Cryotherapy is able to induce a lethal effect on cancer cells through direct and indirect mechanisms. In this manuscript, we combined our experience with that of other authors who have published on this topic in order to provide indications on when to use cryotherapy in musculoskeletal oncology.

DISCUSSION

Image-Guided percutaneous cryotherapy is a therapeutic method now widely accepted in the treatment of patients with musculoskeletal tumors. It can be used both for palliative treatments of metastatic bone lesions and for the curative treatment of benign bone tumors, such as osteoid osteoma or osteoblastoma. In the treatment of bone metastases, cryotherapy plays a major role in alleviating or resolving disease-related pain, but it has also been demonstrated that it can have a role in local disease control. In recent years, the use of cryotherapy has also expanded for the treatment of both benign and malignant soft tissue tumors.

CONCLUSION

Percutaneous cryotherapy can be considered a safe and effective technique in the treatment of benign and malignant musculoskeletal tumors. Cryotherapy can be considered the first option in benign tumor lesions, such as osteoid osteoma, and a valid alternative to radiofrequency ablation. In the treatment of painful bone metastases, it must be considered secondarily to other standard treatments (radiotherapy, bisphosphonate therapy, and chemotherapy) when they are no longer effective in controlling the disease or when they cannot be repeated (for example, radiotherapy).

Ice Inhibition for Cryopreservation: Materials, Strategies, and Challenges

Cryopreservation technology has developed into a fundamental and important supporting method for biomedical applications such as cell-based therapeutics, tissue engineering, assisted reproduction, and vaccine storage. The formation, growth, and recrystallization of ice crystals are the major limitations in cell/tissue/organ cryopreservation, and cause fatal cryoinjury to cryopreserved biological samples. Flourishing anti-icing materials and strategies can effectively regulate and suppress ice crystals, thus reducing ice damage and promoting cryopreservation efficiency. This review first describes the basic ice cryodamage mechanisms in the cryopreservation process. The recent development of chemical ice-inhibition molecules, including cryoprotectant, antifreeze protein, synthetic polymer, nanomaterial, and hydrogel, and their applications in cryopreservation are summarized. The advanced engineering strategies, including trehalose delivery, cell encapsulation, and bioinspired structure design for ice inhibition, are further discussed. Furthermore, external physical field technologies used for inhibiting ice crystals in both the cooling and thawing processes are systematically reviewed. Finally, the current challenges and future perspectives in the field of ice inhibition for high-efficiency cryopreservation are proposed.

Asian Conference on Tumor Ablation guidelines for renal cell carcinoma

Thermal ablation has been established as an alternative treatment for renal cell carcinoma (RCC) in patients who are poor candidates for surgery. However, while American and European guidelines have been established for American and European patients, respectively, no ablation guidelines for Asian patients with RCCs have been established many years after the Asian Conference on Tumor Ablation (ACTA) had been held. Given that Western guidelines are difficult to apply to Asian patients due to differences in body habitus, economic status, and insurance systems, the current review sought to establish the first version of the ACTA guidelines for treating a RCC with thermal ablation.

A Microthermal Sensor for Cryoablation Balloons

Treatment of atrial fibrillation by cryoablation of the pulmonary vein (PV) suffers from an inability to assess probe contact, tissue thickness, and freeze completion through the wall. Unfortunately, clinical imaging cannot be used for this purpose as these techniques have resolutions similar in scale (∼1 to 2 mm) to PV thickness and therefore are unable to resolve changes within the PV during treatment. Here, a microthermal sensor based on the "3ω" technique which has been used for thin biological systems is proposed as a potential solution and tested for a cryoablation scenario. First, the sensor was modified from a linear format to a serpentine format for integration onto a flexible balloon. Next, using numerical analyses, the ability of the modified sensor on a flat substrate was studied to differentiate measurements in limiting cases of ice, water, and fat. These numerical results were then complemented by experimentation by micropatterning the serpentine sensor onto a flat substrate and onto a flexible balloon. In both formats (flat and balloon), the serpentine sensor was experimentally shown to: (1) identify tissue contact versus fluid, (2) distinguish tissue thickness in the 0.5 to 2 mm range, and (3) measure the initiation and completion of freezing as previously reported for a linear sensor. This study demonstrates proof of principle that a serpentine 3ω sensor on a balloon can monitor tissue contact, thickness, and phase change which is relevant to cryo and other focal thermal treatments of PV to treat atrial fibrillation.

Cryotherapy mediates histopathological and microstructural changes during the treatment of skin and subcutaneous tumors in dogs

The therapeutic effects of cryotherapy on skin and subcutaneous tumors in dogs were retrospectively studied in 20 dogs with 37 tumor lesions, of which 30 were benign and seven were malignant. Our results showed that during follow-up, 94.5% of lesions were completely exfoliated, without relapse or metastasis (mean time = 245.7 days). To investigate the effects of cryotherapy, we compared histopathological observations and microstructural changes in healthy tissues and tumor tissues, before and after cryotherapy. After cryotherapy, both normal skin and tumor tissue exhibited edema and hyperemia, with inflammatory cell infiltration. The cell nuclei exhibited pyknosis, disintegration and necrosis, and tight junctions were decreased in size. Cell morphology was varied, along with fragmented cell nuclear envelopes, crenulated nuclei and indistinct and necrotic intracellular organelles. Vacuoles were apparent in the cytoplasm and intercellular desmosomes were absent. These observations suggested that cryosurgery inhibited skin and subcutaneous tumors via cold-induced injury to cells, and cellular microenvironment changes induced by apoptosis. The results suggested that cryosurgery prevented skin and subcutaneous tumors via cold-induced injury to cells, and cellular microenvironment changes induced by apoptosis. We believe these data will provide general cryotherapy guidance to scientists and veterinary surgeons.

Evaluation of Temperature Distribution Around the Probe in Cryoablation of Lipiodol-Mixed-Tissue Phantom

PURPOSE

To determine whether lipiodol, which has low thermal conductivity, influences ice ball formation during cryoablation of a lipiodol-mixed-tissue phantom.

MATERIALS AND METHODS

Lipiodol-mixed-tissue phantoms were created by injecting lipiodol (4-6 ml) into the renal arteries of ex vivo porcine kidneys (lipiodol group). A cryoprobe (CryoHit^™ Needle S) with a holder that was set with thermocouples at various positions around the cryoprobe was inserted. After freezing for 300 s, the followings were evaluated: ice ball size on CT, temperature distribution around the cryoprobe, and calculated distances at 0 °C and - 20 °C. Each variable was compared between lipiodol group (n = 6) those obtained in a control group without lipiodol injection (n = 6).

RESULTS

Mean ice ball diameter (width/length) on CT was 22.1 ± 2.3/22.9 ± 2.3 mm in the lipiodol group and 21.6 ± 0.7/22.2 ± 1.3 mm in the control group. Mean cryoprobe temperature was - 118 ± 3.0 °C in the lipiodol group and - 117 ± 2.6 °C in the control group. In both groups, temperature at the 3 mm thermocouple reached approximately - 50 °C and was < 0 °C within ~ 10 mm of the cryoprobe. Temperature of 0/- 20 °C occurred at a mean distance from the cryoprobe of 11.1 ± 0.5/6.9 ± 0.4 mm in the lipiodol group and 11.0 ± 0.2/6.9 ± 0.2 mm in the control group. There was no significant difference in any variable between the groups.

CONCLUSION

The inclusion of lipiodol in a tissue phantom had no negative effects on ice ball formation that were related to thermal conductivity.

Breast Cancer Cryoablation: Assessment of the Impact of Fundamental Procedural Variables in an In Vitro Human Breast Cancer Model

INTRODUCTION

Breast cancer is the most prominent form of cancer and the second leading cause of death in women behind lung cancer. The primary modes of treatment today include surgical excision (lumpectomy, mastectomy), radiation, chemoablation, anti-HER2/neu therapy, and/or hormone therapy. The severe side effects associated with these therapies suggest a minimally invasive therapy with fewer quality of life issues would be advantageous for treatment of this pervasive disease. Cryoablation has been used in the treatment of other cancers, including prostate, skin, and cervical, for decades and has been shown to be a successful minimally invasive therapeutic option. To this end, the use of cryotherapy for the treatment of breast cancer has increased over the last several years. Although successful, one of the challenges in cryoablation is management of cancer destruction in the periphery of the ice ball as the tissue within this outer margin may not experience ablative temperatures. In breast cancer, this is of concern due to the lobular nature of the tumors. As such, in this study, we investigated the level of cell death at various temperatures associated with the margin of a cryogenic lesion as well as the impact of repetitive freezing and thawing methods on overall efficacy.

METHODS

Human breast cancer cells, MCF-7, were exposed to temperatures of -5°C, -10°C, -15°C, -20°C, or -25°C for 5-minute freeze intervals in a single or repeat freeze-thaw cycle. Samples were thawed with either passive or active warming for 5 or 10 minutes. Samples were assessed at 1, 2, and 3 days post-freeze to assess cell survival and recovery. In addition, the modes of cell death associated with freezing were assessed over the initial 24-hour post-thaw recovery period.

RESULTS

Exposure of MCF-7 cells to -5°C and -10°C resulted in minimal cell death regardless of the freeze/thaw conditions. Freezing to a temperature of -25°C resulted in complete cell death 1 day post-thaw with no cell recovery in all freeze/thaw scenarios evaluated. Exposure to a single freeze event resulted in a gradual increase in cell death at -15°C and -20°C. Application of a repeat freeze-thaw cycle (dual 5-minute freeze) resulted in an increase in cell death with complete destruction at -20°C and near complete death at -15°C (day 1 survival: single -15°C freeze/thaw = 20%; repeated -15°C freeze/thaw = 4%). Analysis of thaw interval time (5 vs 10 minute) demonstrated that the shorter 5-minute thaw interval between freezes resulted in increased cell destruction. Furthermore, investigation of thaw rate (active vs passive thawing) demonstrated that active thawing resulted in increased cell survival thereby less effective ablation compared with passive thawing (eg, -15°C 5/10/5 procedure survival, passive thaw: 4% vs active thaw: 29%).

CONCLUSIONS

In summary, these in vitro findings suggest that freezing to temperatures of 25°C results in a high degree of breast cancer cell destruction. Furthermore, the data demonstrate that the application of a repeat freeze procedure with a passive 5-minute or 10-minute thaw interval between freeze cycles increases the minimal lethal temperature to the -15°C to -20°C range. The data also demonstrate that the use of an active thawing procedure between freezes reduces ablation efficacy at temperatures associated with the iceball periphery. These findings may be important to improving future clinical applications of cryoablation for the treatment of breast cancer.

Cryoablation of Extra-Abdominal Desmoid Tumors: A Single-Center Experience with Literature Review

Cryoablation (CA) has gained popularity in the treatment of benign and malignant musculoskeletal tumors. While extra-abdominal desmoid (EAD) tumors are not malignant, they remain challenging to treat because of their high local recurrence rate. We reviewed all EAD tumors treated with CA at our institution between November 2012 and March 2020. Fourteen procedures were performed on nine females and one male (mean age, 33 ± 18 years) as either first-line (n = 4) or salvage therapy (n = 6) with curative intent (n = 8) or tumor debulking (n = 2). Mean tumor size was 63.6 cm³ (range, 3.4–169 cm³). Contrast-enhanced MRI was performed before treatment and at 3-, 6-, and 12-month follow-up. Treatment outcome was based on the change in enhanced tumor volume (ET-V). For curatively treated patients, the mean ET-V change was −97 ± 7%, −44 ± 143%, and +103 ± 312% at 3, 6, and 12 months, respectively. For debulking patients, the mean ET-V change was −98 ± 4%, +149 ± 364%, and +192 ± 353% at 3, 6, and 12 months, respectively. During a mean follow-up of 53.7 months (range, 12–83 months), one grade III and one grade IV complication were noted. We found CA to be safe and well tolerated in patients with EAD.

Liquid Metal Hybrid Platform-Mediated Ice-Fire Dual Noninvasive Conformable Melanoma Therapy

Cryoablation and photothermal therapy are anticancer therapeutic strategies that destroy tumors by external energy intervention of achieving extremely low temperature and very high temperature in a short time. Compared to traditional surgical resection, radiotherapy, and chemotherapy, they have the advantages of being minimally invasive and having less side effects. However, single cryoablation or photothermal therapy itself has limited therapeutic accuracy, which greatly restricts its clinical application. There is still a common phenomenon that the energy transport at the tumor target site cannot be accurately controlled in space and time dimensions, resulting in limited thermal effect and difficulty to form a conformable treatment area, which will result in low targeted killing efficiency, and tumor cells will become residual and undergo metastasis and recurrence. Herein, a multimodal therapy of cryoablation combined with photothermal therapy was proposed. To further enhance the therapeutic performance, a liquid metal hybrid platform, which is composed of a high-thermal-conductivity liquid metal paste and high-photothermal-conversion-efficiency liquid metal nanoparticles, is mediated for cryoablation and photothermal therapy. Cold and heat synergistic effects are realized through this multimodal therapy. Due to the liquid metal hybrid platform, enhanced antitumor efficacy is achieved in vitro and in vivo. More importantly, the liquid metal hybrid platform-mediated dual therapy is totally noninvasive and does not show obvious systemic toxicity. Collectively, this study has first realized ice (cryoablation)-fire (photothermal therapy) dual noninvasive therapy by one liquid metal platform and demonstrated superior antitumor effect for melanoma treatment. This work explores a new promising multimodal cancer therapy strategy based on the liquid metal platform, which has great potential application in cancer treatment in the future.

Ablative therapies for hepatic and biliary tumors: endohepatology coming of age

Ablative therapies refer to minimally invasive procedures performed to destroy abnormal tissue that may arise with many conditions, and can be achieved clinically using chemical, thermal, and other techniques. In this review article, we explore the different ablative therapies used in the management of hepatic and biliary malignancies, namely hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), with a particular focus on radiofrequency ablation (RFA) and photodynamic therapy (PDT) techniques.

Translation of Cryobiological Techniques to Socially Economically Deprived Populations—Part 2: Cryosurgery

Cold and cryogenic temperatures are used for treating cancer and other pathological conditions in various fields of medicine. Cryosurgery, which resides at the interface of medicine and engineering, has attracted the interest of engineers, scientists, and medical doctors. Recently, particularly since the end of the 1980s, technological developments in cryotherapy equipment and enormous advances in imaging techniques, such as computed tomography and ultrasonography, have allowed surgeons and interventional radiologists to precisely guide cryogenic probes into tumors while avoiding damage to surrounding tissues. Extensive studies have allowed us to conclude that the use of cryogenics facilitates the successful treatment of solid tumors in various organs such as lung, liver, bones, kidneys, prostate, etc. Its simplicity of use, effectiveness, low cost, and limited demand on hospital infrastructure and personnel have made cryosurgery particularly suitable for the treatment of patients of socio-economically deprived populations.

Active surveillance and focal ablation for small renal masses: a better solution for comorbid patients

The natural history of small renal masses (SRM) is still not well understood and they are frequently incidentally diagnosed in elderly patients. Therefore, there is a need for less invasive options sparing the patient from the side-effects related to conventional surgical treatment. PubMed and Medline database search was performed to look for new findings on active surveillance and focal therapy for SRM. Sixty-one articles published between 2002 and 2018 were selected for the purpose of the review. There is growing evidence confirming the safety of active surveillance in patients at surgical risk and there appears to be a satisfactory intermediate-term outcome of focal treatment of SRM. In the group of elderly patients with a decreased life expectancy active surveillance appears to be the most appropriate approach. The future of minimally invasive therapy appears bright, especially with the improvement of new imaging modalities.

Cryoablation-activated enhanced nanodoxorubicin release for the therapy of chemoresistant mammary cancer stem-like cells

Anticancer nanodoxorubicin with targeting ability, thermal responsive and pH sensitive characteristic is fabricated. Nanodrug could realize controllable and enhanced drug release when cryoablation is applied at the target tumor site.

Radiofrequency Ablation, Where It Stands in Interventional Radiology Today

Radiofrequency ablation (RFA) is one of the first developed minimally invasive definitive cancer therapies. The safety and efficacy of RFA is well documented and has led to its incorporation into multiple international societal guidelines. By expanding on the body of knowledge acquired during the clinical use of RFA, alternative ablative technologies have emerged and are successfully competing for locoregional therapy market share. The adaption of newer ablative technologies is leading to a rapid decline in the utilization of RFA by interventional radiologists despite the lack of proven superiority. In their 2010 article, Hong and Georgiades stated "… RFA is likely to remain the mainstay of ablations for small tumors until sufficient experience emerges for the widespread acceptance for alternative ablative modalities." Within a decade of this publication, has this time arrived?