Lung microwave ablation - an in vivo swine tumor model experiment to evaluate ablation zones.

PURPOSE: To evaluate microwave ablation (MWA) algorithms, comparing pulsed and continuous mode in an in vivo lung tumor mimic model. MATERIALS AND METHODS: A total of 43 lung tumor-mimic models of 1, 2 or 3 cm were created in 11 pigs through an intra-pulmonary injection of contrast-enriched minced muscle. Tumors were ablated under fluoroscopic and 3D-CBCT-guidance using a single microwave antenna. Continuous (CM) and pulsed mode (PM) were used. According to tumor size, 3 different algorithms for both continuous and pulsed mode were used. The ablation zones were measured using post-procedural 3D-CBCT and on pathologic specimens. RESULTS: Two radiologists measured the ablation zones on CBCT and they significantly correlated with macroscopic and microscopic pathological findings: r = 0.75 and 0.74 respectively (p < 0.0001) (inter-observer correlation r = 0.9). For 1, 2 and 3 cm tumors mimics lesions (TMLs), mean maximal and transverse ablation diameters were 3.6 [Formula: see text] 0.3 × 2.2 [Formula: see text] 0.3 cm; 4.1 [Formula: see text] 0.5 × 2.6 [Formula: see text] 0.3 cm and 4.8 [Formula: see text] 0.3 × 3.2 [Formula: see text] 0.3 cm respectively using CM; And, 3.0 [Formula: see text] 0.2 × 2.1 [Formula: see text] 0.2 cm; 4.0 [Formula: see text] 0.4 × 2.7 [Formula: see text] 0.4 cm and 4.6 [Formula: see text] 0.4 × 3.2 [Formula: see text] 0.4 cm respectively for PM, without any significant difference except for 1 cm TMLs treated by PM ablation which were significantly smaller (p = 0.009) The sphericity index was 1.6, 1.6, 1.5 and 1.4, 1.5, 1.4 at 1, 2 and 3 cm for CM and PM respectively, p = 0.07, 0.14 and 0.13 for 1, 2 and 3 cm tumors mimics. CONCLUSION: Microwave ablation for 1-3 cm lung tumors were successfully realized but with a moderate reproducibility rate, using either CM or PM. Immediate post ablation CBCT can accurately evaluate ablation zones.

Image-guided lung metastasis ablation: a literature review.

Purpose: To review the available options of percutaneous ablation of lung metastasis. Methods: General indications, prognostic factors, and image guidance of percutaneous lung ablations were reviewed. Specificities, technical aspects, advantages and limitations of each technic were highlighted. Complications and follow up where also reviewed. Results: Image-guided, percutaneous ablation is of interest for patients with a limit number (<3-5) small metastases (<2-3 cm). Other predictive factors have been reported such as the disease-free interval, the primary tumor, or the proximity with large vessels or bronchus. Radiofrequency ablation (RFA) is the most reported technic, with local control rate >90% for small tumors, and a very low complication rate. Microwave (MWA) and cryoablation are alternative technics developed in the last 15 years to overcome RFA limitations, with encouraging results. Larger ablations zones and less heat sink effect have been described with MWA. On the other hand, cryoablation allows painless treatments under conscious sedation and/or local anesthesia, high accessibility of difficult locations and promising results on prospective multicenter series. Although irreversible electroporation (IRE) could be used for lesions close to main blood vessels as it is not limited by the heat sink effect and does not have significant effects on connective tissue, allowing to treat lesions near to vital organs, preliminary results for lung metastasis are disappointing. Conclusion: Percutaneous ablation of lung metastases, whatever technic is used, is feasible, with high local control rate, and acceptable complication rate. Although indications seem clear enough, validation through controlled trials is mandatory.

Prospective pilot study of CT-guided microwave ablation in the treatment of osteoid osteomas.

PURPOSE: The aims of this work were to assess the feasibility and efficacy of CT-guided microwave ablation (MWA) in the treatment of osteoid osteomas (OOs). MATERIALS AND METHODS: Thirteen consecutive patients (range 11-31 years old) presenting with OO were prospectively included and treated by CT-guided MWA. Power and duration of MWA were both recorded. The patient's pain was assessed using a numeric pain rating scale (NRS), and side effects were recorded during procedures, after 1 day, 7 days and 1 month. The nidus vascularization and the volume of necrosis induced by MWA were assessed using contrast-enhanced MRI. Success was defined as the complete relief of the patient's pain 1 month after the first procedure, associated with necrosis of the nidus on follow-up MRI. RESULTS: The success rate was up to 92.3% (12/13). At 1 day, 7 days and 1 month, the median NRSs were respectively 5 [interquartile range (IQR) 2-5], 0 (IQR 0-1) and 0 (IQR 0-0). Side effects observed were one partial and self-resolving lesion of a sensory branch of the radial nerve and two skin burns. The median power of the MWA used was 60 W (IQR 50-60) with a 1.5-min duration (IQR 1-2), leading to MWA-induced necrosis measuring on average 23 × 15 × 16 mm. CONCLUSION: CT-guided MWA of OO has a success rate that appears to be almost similar to that of laser or radiofrequency ablation, but care must be taken to prevent nerve or skin lesions.

Multi-Level Vertebroplasty for 6 or More Painful Osteoporotic Vertebral Body Compression Fractures Performed in the Same Procedural Setting: A Safety and Efficacy Report in Cancer Patients.

PURPOSE: To assess safety and efficacy of multi-level vertebroplasty, when treating 6 or more levels in the same procedural setting for the management of osteoporotic vertebral compression fractures (oVCF) in cancer patients. MATERIALS AND METHODS: Single institution retrospective review from 2015 to 2019 of patients treated for multi-level oVCF in a single session procedural setting by vertebroplasty of 6 or more levels. Procedure outcomes collected included procedural complications, pre- and 4 week post-procedure pain score by numeric rating scale, opioid usage, and vertebral height changes. RESULTS: In total, 197 vertebral levels were treated in 24 procedures (mean 8.2 ± 1.8 levels). Mean procedure duration was 167 + / - 41 min, and mean postoperative hospitalization duration was 2.1 + / - 1.9 days. Four grade I or II complications occurred according to CIRSE classification. Two patients had a symptomatic pulmonary cement embolism; although there was no statistical difference between pre- and postoperative mean blood saturation (95.9 + / - 1.7% and 94.8 + / - 2.0%, respectively, p = 0.066). Pain score significantly improved after treatment (6.5 ± 1.3 vs 3.2 + / - 1.4, p < 0.0001) with a mean decrease of 3.3 (51%). Post-procedure daily opioid use also significantly improved (mean 35.8 + / - 36.8 mg/24 h vs 18.5 + / - 27.8 mg/24 h, p = 0.0089), with a mean decrease of 17.3 mg/24 h (48%). Refracture was found in 2 of 105 levels treated (1.9%), and no difference was found in thoraco-lumbar height and angulation. Five patients experienced new painful fractures at a non-treated level. CONCLUSION: Multi-level vertebroplasty for 6 or more levels is a safe and effective treatment for the management of multi-level oVCF in cancer patients.

Percutaneous Fixation by Internal Cemented Screws of the Sternum.

PURPOSE: To evaluate the feasibility, efficacy and safety of sternal percutaneous fixation by internal cemented screw (FICS) using fluoroscopy and/or CT needle guidance. MATERIALS AND METHODS: This retrospective single-center study analyzed 9 consecutive cancer patients managed with percutaneous FICS for sternal fracture fixation or osteolytic metastasis consolidation, from May 2014 to February 2019. Eastern Cooperative Oncology Group performance status, Numeric Pain Rating Scale (NPRS) and opioid use were studied preoperatively and postoperatively. Sternal images at last follow-up appointment were also collected. RESULTS: Among the 9 patients, 7 had a sternal fracture with 5 being displaced. The technical feasibility was 100%. Both NPRS score significantly decreased from 5.6/10 ± 2.8 to 1.1/10 ± 1.6, and analgesic consumption was significantly improved (p = 0.03) after intervention. No post-procedural complications requiring surgical correction or screw displacement occurred after a mean imaging follow-up that exceeded 1 year (mean follow-up duration, 401.8 days ± 305.8). CONCLUSION: Image-guided sternal percutaneous FICS is feasible and safe. It reduces pain and analgesic consumption related to pathologic fracture of the sternum.

Image-guided tumour biopsies in a prospective molecular triage study (MOSCATO-01): What are the real risks?

PURPOSE: To evaluate efficacy, complications and preprocedural risk factors for percutaneous image-guided core needle biopsy of malignant tumours for genomic tumour analysis. MATERIALS AND METHODS: Procedural data for core biopsies performed at a single centre for the MOSCATO-01 clinical trial were prospectively recorded between December 2011 and March 2016. Data assessed included patient demographics, tumour characteristics, procedural outcomes and complications. RESULTS: A total of 877 biopsies were performed under computed tomography (38.4%) or ultrasound guidance (61.6%) for tumours in the liver (n = 363), lungs (n = 229), lymph nodes (n = 138), bones (n = 15) and other miscellaneous sites (n = 124). Each biopsy harvested a mean 4.4 samples [1-15], with adequate tumour yield for genomic analysis in 95.3% of cases. Procedural complications occurred in 89 cases (10.1%), with minor grade I complications in 59 (66.3%); grade II in 16 (18%) and grade III in 14 (15.7%). No grade IV complications and no procedure-related death occurred. The most common complications were pneumothorax (51/89, 57.3%), haemorrhage (24/89, 27%) and pain (8/89, 8.9%). Predictive factors for complications by univariate analysis included biopsied organ (lung vs other), sample number, prone position, lesion size, lesion depth and biopsy approach. By multivariate analysis, only pulmonary biopsy was a significant risk factor (odds ratio = 27.23 [4.93-242.76], p < 0.01). CONCLUSION: Percutaneous image-guided core needle biopsy in cancer patients provides an effective method to obtain molecular screening samples, with an overall low complication rate. Lung mass biopsies present a higher risk of complication, although complications are manageable by minimally invasive techniques without prolonged sequelae.