Jean Caudrelier

CIRSE Guidelines on Percutaneous Vertebral Augmentation

Vertebral compression fracture (VCF) is an important cause of severe debilitating back pain, adversely affecting quality of life, physical function, psychosocial performance, mental health and survival. Different vertebral augmentation procedures (VAPs) are used in order to consolidate the VCFs, relief pain,and whenever posible achieve vertebral body height restoration. In the present review we give the indications, contraindications, safety profile and outcomes of the existing percutaneous VAPs.

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

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

Image-Guided Spinal Ablation: A Review

The image-guided thermal ablation procedures can be used to treat a variety of benign and malignant spinal tumours. Small size osteoid osteoma can be treated with laser or radiofrequency. Larger tumours (osteoblastoma, aneurysmal bone cyst and metastasis) can be addressed with radiofrequency or cryoablation. Results on the literature of spinal microwave ablation are scarce, and thus it should be used with caution. A distinct advantage of cryoablation is the ability to monitor the ice-ball by intermittent CT or MRI. The different thermal insulation, temperature and electrophysiological monitoring techniques should be applied. Cautious pre-procedural planning and intermittent intra-procedural monitoring of the ablation zone can help reduce neural complications. Tumour histology, patient clinical-functional status and life-expectancy should define the most efficient and least disabling treatment option.

Curved Needles: Beyond Diagnostic Procedures.

To the Editor, We read with great interest the article of De Filippo et al., published in CVIR 2015 [1]. The authors report using a coaxial 18-G cannula with a 22-G curved needle to circumvent anatomic obstacles and sample lesions deemed inaccessible via a linear approach. We fully agree with the authors’ comments regarding the utility of curved needles for diagnostic procedures; however, the technique may also be useful during non-vascular interventional therapies. We report our experience of using curved needles to facilitate thermoprotection (using hydrodissection and thermal monitoring) during two percutaneous image-guided thermal ablation procedures. The first patient was a 71-year-old male referred to the department of interventional radiology for curative percutaneous CT-guided cryoablation of a 3-cm clear cell carcinoma of the upper pole of the left kidney. The procedure was performed under general anaesthesia in the prone position. Four cryoprobes (IceRod, Galil Medical, Yokneam, Israel) were positioned within the tumour via a posterior approach. Since the lesion was significantly exophytic and abutted the lower pole of the spleen, it was elected to perform hydrodissection to avoid collateral thermal damage. Initial attempts using a straight 22-G spinal needle positioned adjacent to the inferior aspect of the lesion were unsuccessful. Optimal hydrodissection required precise needle placement in the fat-plane between the lesion and spleen, which was inaccessible via a linear approach due to the presence of an overlying rib. We therefore utilised a curved needle within a coaxial straight trocar to perform the procedure. A straight 18-G, 8.8-cm spinal needle was initially introduced along the posterior rib border via a linear approach. We then manually bent a 22-G, 15-cm Chiba needle-tip to the estimated degree of curvature (approximately 30 ) and carefully advanced the curved needle inside the trocar. Control CT scan demonstrated satisfactory needle-tip placement between the lesion and spleen, and hydrodissection was performed using 50 ml aliquots of a 5 % iodinated contrast solution (Visipaque, GE Healthcare, Little Chalfont, UK; 270 mg I/ml) injected via a 50-cm connecting tube, with excellent separation of the target lesion (Fig. 1). A standard doublefreeze cryoablation protocol was conducted without unintended freezing of the spleen. One-month follow-up MRI & Julien Garnon juliengarnon@gmail.com

PET/CT-guided interventions: Indications, advantages, disadvantages and the state of the art

Abstract Positron emission tomography/computed tomography (PET/CT) represents an emerging imaging guidance modality that has been applied to successfully guide percutaneous procedures such as biopsies and tumour ablations. The aim of the present narrative review is to report the indications, advantages and disadvantages of PET/CT-guided procedures in the field of interventional oncology and to briefly describe the experience gained with this new emerging technique while performing biopsies and tumor ablations.

Percutaneous radiofrequency ablation of painful spinal metastasis: a systematic literature assessment of analgesia and safety

Abstract Purpose: Radiofrequency ablation (RFA) is the most common percutaneous technique applied to treat painful spinal metastasis; however, experience in this field is somehow still limited. A systematic literature research was performed to understand the effects of RFA in terms of analgesia and safety. Materials and methods: Inclusion criteria for the studies were as follows: (1) randomised controlled or non-randomised studies with a prospective or retrospective design; (2) population made up of adults with spinal metastasis; (3) spinal metastasis treated with RFA alone or in combination/comparison with other treatments; (4) studies reporting about patients’ pain before and at least one time-point following RFA; and (5) English-language studies. Results: Seven hundred and thirty-three articles were screened and 8 (4 prospective, 4 retrospective) matched the inclusion criteria. Study population ranged between 10 and 92 patients across studies. Five out of eight studies reported a highly effective pain management (≥4 points of pain reduction between baseline and the last time-point available); 2/8 studies reported moderate results (≥2 points of pain reduction between baseline and the last time-point available). All studies combined RFA with cement augmentation in the vast majority of patients (40–100%) or metastasis (94–95.8%). Grade I–IIIa neural complications were reported in up to 16% of the cases and were always managed conservatively or with steroids. Conclusions: RFA, combined with vertebral augmentation in most of the cases, is effective and safe in achieving short- to mid-term (from 1 week to 6 months) analgesia in patients affected by painful spinal metastasis.

Low-power bipolar radiofrequency ablation and vertebral augmentation for the palliative treatment of spinal malignancies

Abstract Aim: To investigate the analgesic properties and the safety of low power bipolar radiofrequency ablation (RFA) performed with internally cooled electrodes and vertebral augmentation for the treatment of painful spinal malignancies. Materials and methods: Consent was waived for retrospective study participation. Review of electronic records identified 11 consecutive patients (6 females; 5 males; mean age 61.3 ± 11.6 years) with one-index painful spinal tumour, who were treated between June 2016 and October 2017 with bipolar RFA and vertebral augmentation. Patients were treated if they presented with focal pain (≥4/10 on a 0–10 visual analogic scale in the 24-h period) corresponding to a metastatic vertebral level on cross sectional imaging. The Wilcoxon test was used to evaluate the significance of the post-operative pain. Results: Lumbar levels were treated in 72.7% cases; metastatic epidural involvement was noted in 81.8% cases; 54.5% patients received associated treatments in addition to RFA, which was coupled to vertebral augmentation in all cases. Two (18.2%) complications were noted. Mean pain score measured at last clinical follow-up available (mean 1.9 ± 1.4 months) was 3.5 ± 2 (versus 7.8 ± 1.1 at baseline; p <0.01). Conclusions: Low-power bipolar RFA performed with internally cooled electrodes and coupled to vertebral augmentation provides safe and effective early analgesia in patients affected by painful spinal malignancies.

MRI-Guided Cryoablation of In-Transit Metastases from Cutaneous Melanoma: A Brief Report on a Preliminary Experience

This study aims to discuss MRI-guided cryoablation (CA) of in-transit (IT) metastases from melanoma and to retrospectively present our preliminary experience in such a specific field. Three female patients (mean age 55.6 years; range 39–64) were included, and eight IT metastases (mean size 12.4 ± 6.5 mm, range: 5–25) were treated in three different sessions. Technical success was 100%; and mean procedural time 129.3 ± 103 min. (range 42–243). Primary local tumour control was 100% at 1-, 6- and 12-month follow-up; and 87.5% at 18-month follow-up. Two complications were recorded (one minor and one major). MRI-guided CA is a novel therapy, which may be included in the armamentarium of local therapies of IT metastases.

Cryoablation Does Not Prevent from Diaphragmatic Hernia

To the Editor, We read with great interest the article by Alberti et al. [1], regarding the incidence and risk factors for diaphragmatic hernia following lung percutaneous radiofrequency ablation (RFA). Although rare and often asymptomatic, post-ablation diaphragmatic hernia is a potentially serious complication which may require surgical repair [1] and has even resulted in fatality after hepatic RFA [2]. Thermal injury to the Diaphragm should therefore be avoided whenever possible during ablation procedures. Artificial ascites [3] and pneumothorax have been used to physically separate the target organ from the diaphragm and avoid unintended thermal damage during liver and lung RFA, respectively. However, depending on the case, these techniques may be technically challenging and sometimes impossible to perform. Alberti et al. [1] suggest that using cryoablation rather than RFA may help to reduce the risk of diaphragmatic injury, since the underlying collagenous architecture is better preserved following freezing than heating. We report the first (to our knowledge) case of post-cryoablation diaphragmatic hernia, which developed 6 months after percutaneous liver cryoablation of a lesion located next to the diaphragm. A 42-year-old female patient was referred to the department of interventional radiology for management of a growing hepatic hemangioma located in the upper part of segment 8, close to the diaphragm (Fig. 1). Before 6 years, she had undergone hepatic resection for a symptomatic giant hemangioma in the left lobe. Although the current lesion was asymptomatic, early treatment was considered appropriate to prevent future secondary symptoms. Due to the location of the lesion, surgery was deemed to be too invasive, and percutaneous ablation was therefore offered as a first-line therapy. It was elected to performMRI-guided cryoablation, since the very steep approach and proximity to the diaphragm necessitated precise probe placement and continuous visualisation of the ablation zone. Under general anaesthesia, four cryoprobes (IceRod, Galil Medical, Yokneam, Israel) were inserted into the lesion under realtime MRI guidance, using a lateral ascending approach. A standard 10 min freeze–10 min thaw–10 min freeze protocol was performed with complete coverage of the lesion within the iceball. A small part of the diaphragm was also encompassed within the cryoablation zone (Fig. 2). There & Julien Garnon juliengarnon@gmail.com

A Pitfall of Cryoadhesional Displacement During Cryoablation of Lung Metastasis to Require Modification of Triple-Freeze Protocol

To the Editor, Percutaneous image-guided cryoablation is an emerging technique which has recently been applied to the treatment of pulmonary malignancy, with promising initial results [1, 2]. A specific advantage of cryoablation lies in making use of its intrinsic cryoadhesional properties to enhance procedural efficacy. Modern treatment systems include a ‘‘Stick mode’’ setting, which creates approximately a -20 C isotherm around the probe tip. While insufficient to cause reliable cytotoxicity, the iceball effectively freezes the probe to adjacent structures, fixing it in position (cryoadhesion) and enabling the adherent structure to be displaced by manipulating the external portion of the probe (cryoadhesional displacement) [3]. This method (referred to as ‘‘Stick and Freeze’’ [4]) has been successfully applied to facilitate safe and effective ablation of lesions in close proximity to critical structures [3, 4]. We recently utilised this technique to treat a central lung metastasis using a standard triple-freeze protocol [5], but encountered a previously unreported pitfall in which cryoadhesion was lost during the thawing phase, resulting in loss of lesion displacement. We present our solution to this problem in the form of a modified triple-freeze protocol to maintain cryoadhesion, and review the potential consequences of and alternatives to our approach to managing this unusual problem. A 54-year-old woman was referred to the department of interventional radiology for the curative ablation of a single lung metastasis from colonic carcinoma. Patient gave informed consent to undergo the procedure. The procedure was performed using CT-guidance, with the patient under general anaesthesia in the prone position. Planning CTscan demonstrated an irregular pulmonary nodule at the left cardiophrenic angle, abutting the pericardium (in the region of the phrenic nerve) and diaphragm, and in close proximity to the subdiaphragmatic gastric fundus (Fig. 1). Cryoablation was considered the most appropriate therapy due to potential to apply cryoadhesional displacement using the ‘‘stick mode’’ setting to retract and ablate the nodule well away from critical mediastinal structures. The first cryoprobe (IceSphere, Galil Medical, Yokneam, Israel) was introduced using a posterior descending approach, and positioned in direct contact with the medial aspect of the tumour. 100 % freezing power was applied for 30 s to fix the probe to the lesion; cryoadhesion & Julien Garnon juliengarnon@gmail.com