Radiologically guided percutaneous cryotherapy for soft tissue tumours: A promising treatment

Long-term outcomes after percutaneous cryoablation of abdominal wall endometriosis

OBJECTIVE

To retrospectively evaluate the long-term outcomes after percutaneous cryoablation of abdominal wall endometriosis (AWE).

METHOD

The Institutional Review Board approved this retrospective observational review of 40 consecutive patients, of a median age of 37 years (interquartile range [IQR] 32-40 years), presenting with a total of 52 symptomatic AWE nodules. All patients underwent cryoablation between January 2013 and May 2022 with a minimum follow-up period of 12 months. Outcomes were assessed using a visual analog scale (VAS) that measured pain, as well as by magnetic resonance imaging (MRI). The pain-free survival rates were derived using the Kaplan-Meier estimator. Adverse events were analyzed and graded using the classification system of the Cardiovascular and Interventional Radiological Society of Europe.

RESULTS

The median follow-up time was 40.5 months (IQR 26.5-47.2 months). The median VAS score before cryoablation was 8 (IQR 7-9). Complete relief of symptoms was documented in 80% (32/40) of patients at 3 months after initial cryoablation and correlated with the absence of residual endometriosis nodules on MRI. The median pain-free survival rates were 89.2% [95% CI, 70.1-96.4%] at 36 months and 76.8% [95% CI, 55.3-83.8%] after 60 months. No patient or lesion characteristics were found to be prognostic of failure. No major adverse events or side effects were reported in long term.

CONCLUSION

Cryoablation safely and effectively afforded long-term pain relief for patients with AWE nodules.

CLINICAL RELEVANCE STATEMENT

AWE cryoablation was found to be safe and effective in the long-term.

KEY POINTS

• Cryoablation is highly effective with 80% of patients experiencing complete relief of AWE symptoms after a single procedure. • Cryoablation is safe without long-term adverse events or side effects. • The median pain-free survival rates are 89.2% at 36 months and 76.8% at 60 months.

Treatment of adenomyosis, abdominal wall endometriosis and uterine leiomyoma with interventional radiology: A review of current evidences

Interventional radiology shows promises in the field of women's health, particularly in pelvic interventions. This review article discusses the latest advancements in interventional radiology techniques for pelvic conditions affecting women including adenomyosis, abdominal wall endometriosis and uterine leiomyoma. Extraperitoneal endometriosis involving the abdominal wall may be treated by percutaneous thermal ablation, such as cryoablation, whereas uterine leiomyoma and adenomyosis can be managed either using percutaneous thermal ablation or using uterine artery embolization. Continued research and development in interventional radiology will further enhance the minimally-invasive interventions available for women's health, improving outcomes and quality of life for this large patient population of women.

Diffusion weighted imaging changes in extra-abdominal desmoid tumor after cryotherapy

Desmoid tumors (DT) are rare benign tumors with a local invasion potential and recurrence. It is characterized on histology by an abnormal fibroblastic proliferation in a collagenous stroma, in variable proportions leading to heterogeneity of the lesion signal on magnetic resonance imaging (MRI). Current guidelines propose watchful waiting but in case of progression or symptoms, cryotherapy may be a therapeutic option in its extra-abdominal form. Tumor recurrence is mostly detected based on post-contrast magnetic resonance imaging (MRI). Although DWI sequence is the key-sequence for tumor detection in oncologic imaging, there are very few data in literature on diffusion weighted imaging (DWI) in DT generally and even fewer on DT after cryotherapy. DWI changes after cryotherapy may be confusing and suspicious of residual tumor or tumor recurrence when displaying low ADC values; thus knowledge of possible DWI patterns after cryotherapy of DT seem paramount. We found that the early changes of DT after cryotherapy are hyperintensity on DWI sequence with low ADC values (<1.00 × 10^-3mm²/s), without corresponding enhancement and a later decrease in signal of the treated lesion on DWI. The freezing-thawing cycles of cryotherapy turn DT into gelatinous necrosis with a slow resorption rate, as reported in the only few studies referring of changes of DWI signals after cryotherapy, which are on renal and prostate models. Hyperintensity on DWI with low ADC values may be seen in early MRI follow-up after cryotherapy of extra-abdominal DT, corresponding with tumor necrosis changes and should not be mistaken with recurrence.KEY MESSAGESMagnetic resonance imaging is the modality of choice for desmoid tumor (DT) follow-up, mainly based on contrast uptake which make data on diffusion weighted imaging (DWI) very rare.Cryotherapy is an accepted therapeutic option for DT that will lead to tumor necrosis.Hyperintensity on DWI with low apparent diffusion coefficient values is a possible expected early pattern on DWI after cryotherapy of DT.

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

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

Resolution of Pain after Percutaneous Image-Guided Cryoablation of Extraperitoneal Endometriosis

PURPOSE

To retrospectively evaluate the relief of pain after percutaneous image-guided cryoablation of symptomatic extraperitoneal endometriosis (EE).

MATERIAL AND METHODS

From 2017 to 2022, cryoablation of EE was performed at a single institution on a total of 47 lesions in 42 consecutive patients (median age, 37 years; interquartile range [IQR], 33-39.5 years). Patient and procedural characteristics were reviewed retrospectively. Tolerance and outcomes in terms of pain and patient satisfaction were evaluated.

RESULTS

The median follow-up duration was 13.5 months (IQR, 1.1-37.7 months) after cryoablation. The median pain-free survival rate was 93.8% (95% confidence interval [CI], 77.3-98.4) at 6 months and 82.7% (95% CI, 58.8-93.5) after 12 months. Pain decreased from a median of 8/10 (IQR, 7-9) on the visual analog scale to 0/10 (IQR, 0-1) at the last follow-up (P < .0001). The median Patient Global Impression of Change score recorded at the last follow-up was 1/7 (IQR, 1-2). The efficacy rate of cryoablation to avoid secondary surgery was 92.8% (39/42) per patient and 93.6% (44/47) per nodule treated. Four patients (9.5%, 4/42) experienced an adverse event in the days following the procedure, and 1 patient (2%) experienced a severe adverse event.

CONCLUSIONS

Percutaneous cryoablation is safe and effective in significantly reducing pain and obtaining local control of EE.

Transarterial Embolization and Percutaneous Ablation of Primary and Metastatic Soft Tissue Tumors

Soft tissue tumors (STTs) include a range of benign and malignant tumors originating from soft tissues. Transarterial and percutaneous therapies are image-guided and minimally invasive approaches for managing primary and metastatic STTs. The objective of this review is to discuss transarterial and percutaneous therapies by examining the current literature, including indications, patient selection, safety, and effectiveness. Transarterial therapies (e.g., transarterial bland embolization and transarterial chemoembolization) involve the delivery of either embolic or chemotherapeutic particles using a catheter into arteries feeding the tumor, resulting in localized tumor destruction. Percutaneous therapies (e.g., radiofrequency ablation, cryoablation, irreversible electroporation, laser ablation, and magnetic resonance-guided high-intensity focused ultrasound) involve the delivery of either hot or cold temperatures, electrical current, laser, or ultrasound to specifically target tumor cells. Both therapies have been shown to be safe and effective for reducing morbidity and local control of STTs, specifically in patients who are surgically inoperable or who are unresponsive to conventional therapies. Accurate diagnosis, staging, and histological subtype identification are crucial for treatment selection. A multidisciplinary approach, a thorough understanding of tissue anatomy and surrounding structures, as well as individualized strategies based on assessment are essential for optimal patient care.

Percutaneous Microwave Ablation of Desmoid Fibromatosis

Objective

To demonstrate the feasibility of percutaneous microwave ablation in desmoid fibromatosis with respect to tumor volume control and improvement in the quality of life.

Materials and Methods

Twelve microwave ablations were performed in 9 patients with a histological diagnosis of desmoid fibromatosis between January 2010 and January 2019. The study population included 6 female and 3 male, with an age range of 21–76 years (mean = 46.6 years; standard deviation [SD] = 19.3 years). The mean major axis of the tumors was 10.9 cm (SD = 5.2 cm) and mean lesion volume was 212.7 cm³ (SD = 213 cm³). Their anatomical distribution was as follows: 3 lesions in the thigh, 2 in the gluteus, 2 in the leg and 2 in the periscapular region. We evaluated the reduction in tumor volume and improvement in the quality of life based on the Eastern Cooperative Oncology Group (ECOG) scale.

Results

An average tumor volume reduction of 70.4% (SD = 24.9) was achieved, while the quality of life (ECOG scale) improved in 88.9% of patients.

Conclusion

Percutaneous microwave ablation may potentially be a safe, effective, and promising technique for controlling tumor volume and improving the quality of life in patients with desmoid fibromatosis.

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).

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.

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.

Determination of a tactile feedback strategy for use in robotized percutaneous procedures

Remote manipulation in robotized percutaneous procedures can offer increased safety to radiologists as well as patients. Providing feedback to the radiologist on needle-tissue interactions is however mandatory in addition to the medical images. A tactile feedback strategy is developed in this paper. Two types of information are considered: tissue puncture and nature of tissues. A haptic device is developed for that purpose, using a tactile display to provide information. Adequate signals are identified experimentally, with analysis of reaction times and the ability to discriminate one information from the other.

The Use of Cryotherapy to Treat Infantile Digital Fibromatosis with a Functional Deficit: A Case Report

Infantile Digital Fibromatosis (IDF) is a rare benign lesion that can affect the fingers, often appearing at birth or early on in life. Treatment is controversial due to a high recurrence rate following surgical excision, and the tendency of the lesions to regress or resolve completely after the age of one year. Functional loss has rarely been described. We describe a case of IDF with joint contracture and significant functional deficit that was treated with cryotherapy and post procedural occupational therapy with an excellent result. Indications for treatment and cryotherapy as a therapeutic modality for IDF are discussed.

Role of interventional radiology in the management of musculoskeletal soft-tissue lesions

The lesions of the soft tissues are rare and extremely heterogeneous; even if the surgical treatment is usually the standard therapy, the role of the interventional radiology (IR) in this field is growing up for multiple reasons. First, because the imaging alone usually is not able to ensure a definitive diagnosis, IR has a basic role in the staging: the percutaneous biopsy is infact an irreplaceable step. Moreover, biopsy is necessary not only for histologic evaluations but also for the biochemical and molecular studies. Furthermore, the proved safety and effectiveness of IR in a multiple oncologial applications prompt a wider use also in this field.

Image-Guided Thermal Ablative Therapies in the Treatment of Sarcoma

OPINION STATEMENT

Percutaneous thermal ablation, including microwave ablation (MWA), radiofrequency ablation (RFA), and cryoablation, is a well-established focal treatment option for primary and metastatic malignancies. While published literature specific to ablation of sarcomas is relatively lacking compared with non-sarcomatous malignancies, what is available is promising. In situations where a focal treatment option is desired, strong consideration should be given to percutaneous thermal ablation, in addition to surgery and radiation therapy. A significant advantage of percutaneous thermal ablation over surgery and radiation includes the repeatability of ablation, as there is no absolute limit on the number of times an ablation can be performed. Compared with surgery, ablation offers the potential of decreased recovery time, a less invasive procedure, and is often performed in patients deemed not medically fit for surgery.

Percutaneous cryoablation of symptomatic venous malformations as a second-line therapeutic option: a five-year single institution experience

PURPOSE

To report the mid-term outcomes of percutaneous cryoablation (PCA) performed as second-line therapeutic option of venous malformations (VM).

MATERIAL AND METHODS

From 2011 to 2015, PCA was offered in 24 patients (mean age: 31 years, range: 12-64) as second-line treatment for recurrence of symptoms after sclerotherapy and when resection was not possible (due to lesion location or previous failure) or refused by the patient. Adverse effects were recorded, disease-free survival (DFS) and local tissue control (LTC) rates were calculated based on symptoms and volume evolution.

RESULTS

Mean follow-up was 18.7 months (6-48). Nine (37.5%, 9/24) adverse effects occurred and three (12.5%, 3/24) were severe. Mean pain assessed by visual analog scale (VAS) was 41.7 mm (0-80) before treatment and 20.3 mm (0-80) (p=0.01) after. Mean volume decreased significantly after treatment from 22.4 cm³ (0.9-146) to 8.35 cm³ (0-81.3) (p<0.001). Pain recurred in nine patients and size of one lesion increased. The DFS and LTC rates were 54% [95%CI: 22.94-77.27] and 93.33% [61.26-99.03] at 24 months, respectively. Only VM volume >10 cm³ was associated with a higher risk of local recurrence (p=0.05).

CONCLUSION

PCA as second-line treatment appears to be safe and effective for local control of VM according to mid-term results.

KEY POINTS

• Percutaneous cryoablation of venous malformations appeared well tolerated. • Size of venous malformations decreased significantly after percutaneous cryoablation (p<0.001). • Pain decreased significantly after percutaneous cryoablation of venous malformations (p=0.01).

Evaluating Soft-Tissue Lumps and Bumps

Patients presenting with soft-tissue lumps and bumps are commonly encountered by both primary care physicians and orthopaedic surgeons. Though common, the initial evaluation and management of a soft-tissue mass can be challenging for many clinicians due to the considerable overlap in the presentation of benign and malignant tumors. Furthermore, a myriad of conditions, ranging from infection to trauma, can present with a soft-tissue mass. Subsequently, the correct diagnosis is often delayed or missed which may ultimately lead to inappropriate treatment. The propose of this article is to review the fundamental elements of a successful soft-tissue mass work-up and to provide the clinician with a systematic approach to the evaluation, diagnosis and management of the patient with a soft-tissue tumor.

Cryoablation of Abdominal Wall Endometriosis: A Minimally Invasive Treatment

OBJECTIVE

The objective of this study is to present cryoablation as a minimally invasive definitive treatment for abdominal wall endometriosis. We describe our experience with the outpatient application of cryoablation to treat symptomatic abdominal wall endometriosis in three patients.

CONCLUSION

This feasibility study shows that minimally invasive cryoablation treated abdominal wall endometriosis in three patients and provided a prompt clinical response.

Mid-term outcomes after percutaneous cryoablation of symptomatic abdominal wall endometriosis: comparison with surgery alone in a single institution

OBJECTIVES

To compare the outcomes of percutaneous image-guided cryoablation of symptomatic abdominal wall endometriosis (AWE) versus surgery alone.

METHODS

From 2004 to 2016, cryoablation or surgery alone was performed under local (n = 5) or general anaesthesia (n = 15) for AWE in a single institution in 7 (mean age, 36.1 years) and 13 (mean age, 31.9 years) patients, respectively. Fifteen lesions were treated by cryoablation (mean size, 2.3 cm; range, 0.5-7 cm) and 16 by surgery (2.5 cm; 1.1-3.4 cm). Tolerance, efficacy and patient and procedural characteristics were compared.

RESULTS

Median follow-up was 22.5 (range, 6-42) months after cryoablation and 54 (14-149) after surgery. The median procedure and hospitalisation durations were 41.5 min (24-66) and 0.8 days (0-1) after cryoablation, and 73.5 min (35-160) and 2.8 days (1-12 days) after surgery (both P = 0.01). Three patients (23.1%) had severe complications and nine aesthetic sequels (69.2%) after surgery, none after cryoablation (P = 0.05). The median 12- and 24-month symptom free-survival rates were 100% and 66.7% (95% CI, 5.4; 94.5) after cryoablation and 92% (55.3; 98.9) after surgery at both time points (P = 0.45).

CONCLUSIONS

Cryoablation presents similar effectiveness to surgery alone for local control of AWE while reducing hospitalisation duration and complications. Any aesthetic sequels were associated with the cryoablation treatment.

KEY POINTS

• Hospitalisation is shorter after cryoablation than after surgery of abdominal wall endometriosis. • A significantly lower rate of complications is observed after cryoablation compared to surgery. • Cryoablation of abdominal wall endometriosis presents similar effectiveness to surgery alone. • A significant reduction of pain is observed 6 months after treatment. • A significant reduction of abdominal wall endometriosis is observed at 6 months.

CT guided cryoablation for locally recurrent or metastatic bone and soft tissue tumor: initial experience

Background

Historically, local control of recurrent sarcomas has been limited to radiotherapy when surgical re-resection is not feasible. For metastatic carcinomas to the bone or soft tissue, radiotherapy and some interventional radiology treatment along with other systemic therapies have been widely advocated due to the possibility of disseminated disease. These techniques are effective in alleviating pain and achieving local control for some tumor types, but it has not been effective for prolonged local control of most tumors. Recently, cryoablation has been reported to have satisfactory results in lung and liver carcinoma treatment. In this study, we analyzed the clinical outcome of CT-guided cryoablation for malignant bone and soft tissue tumors to elucidate potential problems associated with this procedure.

Methods

Since 2011, 11 CT-guided cryoablations in 9 patients were performed for locally recurrent or metastatic bone and soft tissue tumors (7 males and 2 females) at our institute. The patients’ average age was 74.8 years (range 61–86) and the median follow up period was 24.1 months (range 5–48). Histological diagnosis included renal cell carcinoma (n = 4), dedifferentiated liposarcoma (n = 2), myxofibrosarcoma (n = 2), chordoma (n = 1), hepatocellular carcinoma (n = 1), and thyroid carcinoma (n = 1). Cryoablation methods, clinical outcomes, complications, and oncological outcomes were analyzed.

Results

There were 5 recurrent tumors and 6 metastatic tumors, and all cases had contraindication to either surgery, chemotherapy or radiotherapy. Two and 3 cycles of cryoablation were performed for bone and soft tissue tumors, respectively. The average length of the procedure was 101.1 min (range 63–187), and the average number of probes was 2.4 (range 2–3). Complications included 1 case of urinary retention in a patient with sacral chordoma who underwent prior carbon ion radiotherapy, 1 transient femoral nerve palsy, and 1 minor wound complication. At the final follow up, 4 patients showed no evidence of disease, 2 were alive with disease, and 3 died of disease.

Conclusions

Reports regarding CT-guided cryoablation for musculoskeletal tumors are rare and the clinical outcomes have not been extensively studied. In our case series, CT-guided cryoablation had analgesic efficacy and there were no cases of local recurrence post procedure during the follow-up period. Although collection of further data regarding use of this technique is necessary, our data suggest that cryoablation is a promising option in medically inoperable musculoskeletal tumors.

Hemodynamic and neural responses to renal denervation of the nerve to the clipped kidney by cryoablation in two-kidney, one-clip hypertensive rats

Renal artery stenosis is increasing in prevalence. Angioplasty plus stenting has not proven to be better than medical management. There has been a reluctance to use available denervation methodologies in this condition. We studied conscious, chronically instrumented, two-kidney, one-clip (2K-1C) Goldblatt rats, a model of renovascular hypertension, to test the hypothesis that renal denervation by cryoablation (cryo-DNX) of the renal nerve to the clipped kidney decreases mean arterial pressure (MAP), plasma and tissue ANG II, and contralateral renal sympathetic nerve activity (RSNA). Five-week-old male Sprague-Dawley rats underwent sham (ShC) or right renal artery clipping (2K-1C), placement of telemetry transmitters, and pair-feeding with a 0.4% NaCl diet. After 6 wk, rats were randomly assigned to cryo-DNX or sham cryotreatment (sham DNX) of the renal nerve to the clipped kidney. MAP was elevated in 2K-1C and decreased significantly in both ShC cryo-DNX and 2K-1C cryo-DNX. Tissue norepinephrine was ∼85% lower in cryo-DNX kidneys. Plasma ANG II was higher in 2K-1C sham DNX but not in 2K-1C cryo-DNX vs ShC. Renal tissue ANG II in the clipped kidney decreased after cryo-DNX. Baseline integrated RSNA of the unclipped kidney was threefold higher in 2K-1C versus ShC and decreased in 2K-1C cryo-DNX to values similar to ShC. Maximum reflex response of RSNA to baroreceptor unloading in 2K-1C was lower after cryo-DNX. Thus, denervation by cryoablation of the renal nerve to the clipped kidney decreases not only MAP but also plasma and renal tissue ANG II levels and RSNA to the contralateral kidney in conscious, freely moving 2K-1C rats.

Long-term local disease control in a recurrent soft-tissue sarcoma of the thigh treated by radiofrequency ablation

In 2008, we performed radiofrequency ablation (RFA) in an elderly patient with a large recurrent soft-tissue sarcoma of the thigh, previously treated with surgery and radiotherapy. After ablation, a marked shrinkage of tumor was obtained. Further local recurrences occurred during follow-up, all safely treated by RFA, with local control of the disease maintained until 6-year follow-up. RFA was safe, effective, and repeatable for soft-tissue sarcoma recurrences, and allowed long-term local control of the disease.

Percutaneous image-guided ablation of bone and soft tissue tumours: a review of available techniques and protective measures

Background

Primary or metastatic osseous and soft tissue lesions can be treated by ablation techniques.

Methods

These techniques are classified into chemical ablation (including ethanol or acetic acid injection) and thermal ablation (including laser, radiofrequency, microwave, cryoablation, radiofrequency ionisation and MR-guided HIFU). Ablation can be performed either alone or in combination with surgical or other percutaneous techniques.

Results

In most cases, ablation provides curative treatment for benign lesions and malignant lesions up to 3 cm. Furthermore, it can be a palliative treatment providing pain reduction and local control of the disease, diminishing the tumour burden and mass effect on organs. Ablation may result in bone weakening; therefore, whenever stabilisation is undermined, bone augmentation should follow ablation depending on the lesion size and location.

Conclusion

Thermal ablation of bone and soft tissues demonstrates high success and relatively low complication rates. However, the most common complication is the iatrogenic thermal damage of surrounding sensitive structures. Nervous structures are very sensitive to extremely high and low temperatures with resultant transient or permanent neurological damage. Thermal damage can cause normal bone osteonecrosis in the lesion’s periphery, surrounding muscular atrophy and scarring, and skin burns. Successful thermal ablation requires a sufficient ablation volume and thermal protection of the surrounding vulnerable structures.

Teaching points

• Percutaneous ablations constitute a safe and efficacious therapy for treatment of osteoid osteoma.

• Ablation techniques can treat painful malignant MSK lesions and provide local tumour control.

• Thermal ablation of bone and soft tissues demonstrates high success and low complication rates.

• Nerves, cartilage and skin are sensitive to extremely high and low temperatures.

• Successful thermal ablation occasionally requires thermal protection of the surrounding structures.

Standardization of selection criteria for percutaneous image-guided cryoablation of recurrent soft-tissue sarcomas

PURPOSE

Percutaneous image-guided cryoablation has not been validated for local management of recurrence of soft tissue sarcoma (STS) of the trunk or limbs. This study aims to identify selection criteria for cryoablation in order to standardize indications of this treatment.

PATIENTS AND METHODS

Between 2000 and 2010, 46 patients (57 tumors) presenting local recurrences of STS of the trunk or limbs and treated following standards of care were selected from our institutional database. Eligibility for cryoablation was assessed by two radiologists according to predefined criteria: maximal diameter size of the tumor ≤10cm, distance to skin >5mm, distance to neurovascular structures 3mm at least, absence of articular involvement and planned cryoablation covering the entire lesion volume. Characteristics and outcomes were compared.

RESULTS

There was nearly perfect agreement for all criteria (k coefficient ranging from 0.83 to 0.98) between both readers. A subgroup of 13patients was identified as eligible for cryoablation. Locations to the trunk, pelvic girdle or shoulder were significantly more present in the cryoablation group (P=0.002). In this group, tumors were mainly located deeply (P=0.002) with great axes ≤5cm (P=0.044). High local tumor aggressiveness (P=0.016) and differentiated myxoid liposarcoma or myxofibrosarcoma (P=0.007) were more frequent in the eligible group.

CONCLUSION

Based on these criteria, two groups of patients with local relapse of STS can be identified. These results may improve the standardization of selection of patients who could be candidates for cryoablation.