MR Imaging–Guided Percutaneous Cryotherapy for Lung Tumors: Initial Experience

Percutaneous Magnetic Resonance Imaging-Guided Coaxial Cutting Needle Biopsy of Pancreatic Lesions: Diagnostic Accuracy and Safety

PURPOSE

To appraise the diagnostic performance of magnetic resonance imaging-guided percutaneous coaxial cutting needle biopsy of pancreatic lesions using a 0.4-T open magnetic resonance imaging scanner with optical tracking navigation.

MATERIALS AND METHODS

This retrospective study included 158 patients who underwent magnetic resonance imaging-guided pancreatic lesion biopsy procedures from May 2019 to December 2020. Two to four specimens were collected from each patient. Pathological diagnosis and clinical follow-ups were conducted to establish the final diagnosis. The procedures were evaluated for sensitivity, specificity, positive and negative predictive values, diagnostic accuracy, and complications. The Cardiovascular and Interventional Radiological Society of Europe guidelines were used to classify complications.

RESULTS

Biopsy pathology revealed 139 pancreatic tumor malignancies and 19 benign pancreatic lesions. Finally, 151 patients were diagnosed with pancreatic malignancy and 7 with benign disease confirmed by surgery, re-biopsy, and clinical follow-up. The sensitivity, specificity, positive and negative predictive value, and accuracy for diagnosis of pancreatic diseases were 92.1%, 100%, 100%, 36.8%, and 92.4%, respectively. The biopsy accuracy was significantly related to the size (≤ 2 cm, 76.2%; 2-4 cm, 94.0%; > 4 cm, 96.2%, P = .02) and not the lesion's location (head of pancreas, 90.7%; neck of pancreas, 88.9%; body of pancreas, 94.3%; tail of pancreas, 96.7%, P = .73). Minor complications included two patients experiencing mild abdominal pain and two with a minor occurrence of hemorrhage.

CONCLUSIONS

Percutaneous magnetic resonance imaging-guided pancreatic lesion biopsy combined with optical navigation has high diagnostic accuracy and is safe for clinical practice. Level of Evidence Level 4, Case-series.

Magnetic Resonance Imaging for Guidance and Follow-up of Thoracic Needle Biopsies and Thermal Ablations

Magnetic resonance imaging (MRI) is used for the guidance and follow-up of percutaneous minimally invasive interventions in many body parts. In the thorax, computed tomography (CT) is currently the most used imaging modality for the guidance and follow-up of needle biopsies and thermal ablations. Compared with CT, MRI provides excellent soft tissue contrast, lacks ionizing radiation, and allows functional imaging. The role of MRI is limited in the thorax due to the low hydrogen proton density and many air-tissue interfaces of the lung, as well as respiratory and cardiac motion. Here, we review the current experience of MR-guided thoracic needle biopsies and of MR-guided thermal ablations targeting lesions in the lung, mediastinum, and the chest wall. We provide an overview of MR-compatible biopsy needles and ablation devices. We detail relevant MRI sequences and their relative advantages and disadvantages for procedural guidance, assessment of complications, and long-term follow-up. We compare the advantages and disadvantages of CT and MR for thoracic interventions and identify areas in need of improvement and additional research.

CT-guided palladium-103 seed brachytherapy for metastatic adenoid cystic carcinoma: a retrospective study to assess initial safety and effectiveness of percutaneous CT fluoroscopy-guided permanent seed brachytherapy

Purpose

Multiple pulmonary metastases present treatment difficulties in available treatment techniques, which are inconvenient or may damage sufficient pulmonary tissue to cause pulmonary crippling. This retrospective study of a single-community practice evaluated responses to computed tomography (CT)-guided ¹⁰³Pd permanent seed brachytherapy (CTGPSB) in adenoid cystic carcinoma (ACC) synchronous pulmonary metastases. The purpose of the current study was to document that metastatic pulmonary ACC lesions can be controlled with CTGPSB.

Material and methods

Twenty-nine discrete lesions in 14 patients were evaluated with serial CT scans. All were treated with CTGPSB. Lesions were tracked over serial CT scans and volumes measured. Primary endpoint was a reduction in tumor volume on subsequent CT scan. Secondary endpoint was occurrence of CTCAE grades 2-5.

Results

There was a 100% measured reduction in tumor volume (n = 29) at follow-up. Follow-up was a mean of 3.13 years. Baseline tumor volume was a mean of 1.85 ml (range, 0.69-9.15 ml). There were two grade 1 and one grade 2 adverse events, which did not require hospitalization.

Conclusions

CTGPSB for the treatment of multiple ACC pulmonary metastases is effective, with minimal acute complications, as shown in small cohort of subjects of the present study. Further studies evaluating specific dosimetry parameters in this free-hand technique are needed to specify minimal and maximal dose constraints.

MRI-Guided Cryoablation of Hepatic Dome Hepatocellular Carcinomas Using 1-T Open High-Field-Strength Scanner

OBJECTIVE. The objective of our study was to prospectively evaluate the feasibility, safety, and effectiveness of 1-T open MRI-guided percutaneous cryoablation of hepatic dome hepatocellular carcinomas (HCCs). SUBJECTS AND METHODS. Thirty-seven patients with 37 hepatic dome HCCs underwent MRI-guided percutaneous cryoablations. MR fluoroscopy with a freehand technique was applied in the procedure. All lesions ranged in size from 8 to 38 mm. Patients were followed for at least 12 months after cryoablation or until death. Survival period, local tumor control, and complications were recorded. RESULTS. MRI-guided percutaneous cryoablation procedures were successfully performed on all 37 lesions. The technical success rate was 100%. The median follow-up time was 21.0 months (range, 10-26 months). Two patients with local tumor progression at the 4th and 11th month after the procedure were treated with a supplementary cryoablation. One patient died of upper gastrointestinal hemorrhage at the 10th month after cryoablation. Local tumor progression and overall survival rates were 2.7% (1/37) and 100% (37/37) at 6 months and 5.4% (2/37) and 97.3% (36/37) at 1 year, respectively. Postoperative hydrothorax that required chest tube drainage occurred in two patients; no other severe complications occurred. CONCLUSION. Cryoablation of hepatic dome HCCs with 1-T open MRI guidance is a feasible, safe, and effective therapy method.

Percutaneous Cryotherapy for Treatment of Chondroblastoma: Early Experience

Surgical curettage is currently the standard of care for the chondroblastoma, but in peri-articular tumors it is limited by its morbidity. In this preliminary report, we evaluate the feasibility of percutaneous cryotherapy as an alternative ablative treatment for chondroblastoma. Three patients with a chondroblastoma treated by CT scan-guided cryotherapy are presented in this article. Pain permanently disappeared 2 days after the procedure. No local tumor recurrence or cartilage damage was observed by MRI performed 1 year after the intervention. This preliminary case report suggests that percutaneous cryotherapy may be a possible alternative to the current standard of care in chondroblastoma. Further studies are needed to evaluate if this technique offers similar anti-tumoral efficacy while providing better pain relief and less morbidity than curettage.

1.0T MR-guided percutaneous coaxial cutting needle biopsy in pancreatic lesion diagnosis

BACKGROUND

Pancreatic carcinoma is a common cause of cancer deaths worldwide. Biopsy is often required for the initial diagnosis of pancreatic masses. Biopsy can be performed endoscopically or percutaneously with computed tomography (CT) and ultrasound (US) guidance. MRI offers many inherent advantages over CT and US.

PURPOSE/HYPOTHESIS

To prospectively evaluate the feasibility, accuracy, and safety of MRI-guided percutaneous coaxial cutting needle biopsy of pancreatic lesions using an open 1.0T high-field MR scanner.

STUDY TYPE

Prospective.

POPULATION

Thirty-one patients with 31 pancreatic lesions underwent MR-guided percutaneous coaxial cutting needle biopsy.

FIELD STRENGTH/SEQUENCE

1.0T T₂ WI-TSE PDW-aTSE T₁ WI-TFE.

ASSESSMENT

Final diagnosis was confirmed by surgery and clinical follow-up for at least 12 months. The accuracy, sensitivity, and specificity were calculated. Complications were recorded.

STATISTICAL TESTS

There was no statistical analysis in this study.

RESULTS

The procedure was technically successful and final biopsy samples were adequate for histopathological examination in all patients. Biopsy pathology revealed malignant pancreatic tumor in 25 patients (25/31, 80.6%), and benign pancreatic lesions were present in six patients (6/31, 19.4%). The final diagnosis was pancreatic malignancy in 27 patients and benign disease in four patients, which was confirmed by surgery and clinical follow-up. Two biopsy results were false-negative. The diagnostic accuracy in biopsies was 93.5% (29 of 31). The sensitivity to detect a malignant disease was 92.6% (25 of 27), and the specificity was 100%. All patients tolerated the procedure well; minor peripancreatic hemorrhage was found in two patients after the procedure, and none had major complications either during or after the procedure.

DATA CONCLUSION

MRI-guided percutaneous biopsy of pancreatic lesions using an open 1.0T high-field scanner has high diagnostic accuracy, which is feasible and safe for use in clinical practice.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2018;48:382-388.

3.0T MRI for long-term observation of lung nodules post cryoablation: a pilot study

BACKGROUND

The purpose of this study was to use serial magnetic resonance imaging (MRI) examinations to observe changes in malignant lung tumors over time post-cryoablation.

METHODS

The study protocol was approved by Institutional Review Board, and written informed consent was obtained from each participant in accordance with the Declaration of Helsinki. Patients with primary or metastatic lung tumors eligible for cryoablation were included in this prospective study. Cryoablation was performed according to standard procedures. Unenhanced and dynamic contrast-enhanced MRI scans were performed pre-cryoablation and at 1 day, 1 week, and 3-, 6-, and 12 months after cryoablation. At each time point, the signal intensity of the ablated zone on both T₁WI and T₂WI images, and volume and characteristics of the ablation zone were examined, and changes over time analyzed.

RESULTS

A total of 26 nodules in 23 patients were included in the study. The mean patient age was 53.7 ± 13.6 years, and 57.7% were males. Ablation zone volume increased to 1 week after the procedure, and then returned to baseline by 3 months. Cavitation post-cryoablation was found in 34.6% (9/26) of the nodules 1 month after treatment. Two types of time-signal intensity curves post-cryoablation were found: a straight line representing no definite enhancement from 1-day to 1-month, and an inflow curve representing mild delayed enhancement from month 3 to month 12. Local progression was associated with an incomplete hypointense rim around the ablation zone and absence of cavitation post-treatment.

CONCLUSIONS

Characteristic changes are present on MRI after cryoablation of lung tumors. A complete hypointense rim and cavitation may be signs of adequate treatment and that local tumor progression is less likely.

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.

MRI-guided celiac plexus neurolysis for pancreatic cancer pain: Efficacy and safety

PURPOSE

To prospectively determine the efficacy and safety of magnetic resonance imaging (MRI)-guided celiac plexus neurolysis (CPN) for pancreatic cancer pain.

MATERIALS AND METHODS

In all, 39 patients with pancreatic cancer underwent 0.23T MRI-guided CPN with ethanol via the posterior approach. The pain relief, the opioid intake, and pain interference with appetite, sleep, and communication in patients were assessed after CPN during a 4-month follow-up period. The complications were also evaluated during or after CPN.

RESULTS

CPN procedures were successfully completed for all patients. Minor complications included diarrhea (9 of 39; 23.1%), orthostatic hypotension (14 of 39; 35.9%), and local backache (20 of 39; 51.3%). No major complication occurred. Pain relief was observed in 36 (92.3%), in 15 (40.5%), and in 11 (35.5%) patients at 1-, 2-, and 3-month visits, respectively. The median duration of pain relief was 2.9 months (95% confidence interval [CI], 2.4-3.4). The opioid intake significantly decreased at the 1-, 2-, and 3-month visits (P < 0.001, < 0.001, = 0.001 respectively), and there was significant improvement in sleep at the 1-, 2-, and 3-month visits (P < 0.001, < 0.001, = 0.001 respectively), and appetite and communication were significantly improved at the 1- and 2-month visits (all P < 0.001); all compared with baseline.

CONCLUSION

MRI-guided CPN appears to be an effective and minimally invasive procedure for palliative pain management of pancreatic cancer. J. MAGN. RESON. IMAGING 2016;44:923-928.

Real-Time MRI-Guided Cardiac Cryo-Ablation: A Feasibility Study

INTRODUCTION

MRI-based ablation provides an attractive capability of seeing ablation-related tissue changes in real time. Here we describe a real-time MRI-based cardiac cryo-ablation system.

METHODS

Studies were performed in canine model (n = 4) using MR-compatible cryo-ablation devices built for animal use: focal cryo-catheter with 8 mm tip and 28 mm diameter cryo-balloon. The main steps of MRI-guided cardiac cryo-ablation procedure (real-time navigation, confirmation of tip-tissue contact, confirmation of vessel occlusion, real-time monitoring of a freeze zone formation, and intra-procedural assessment of lesions) were validated in a 3 Tesla clinical MRI scanner.

RESULTS

The MRI compatible cryo-devices were advanced to the right atrium (RA) and right ventricle (RV) and their position was confirmed by real-time MRI. Specifically, contact between catheter tip and myocardium and occlusion of superior vena cava (SVC) by the balloon was visually validated. Focal cryo-lesions were created in the RV septum. Circumferential ablation of SVC-RA junction with no gaps was achieved using the cryo-balloon. Real-time visualization of freeze zone formation was achieved in all studies when lesions were successfully created. The ablations and presence of collateral damage were confirmed by T1-weighted and late gadolinium enhancement MRI and gross pathological examination.

CONCLUSION

This study confirms the feasibility of a MRI-based cryo-ablation system in performing cardiac ablation procedures. The system allows real-time catheter navigation, confirmation of catheter tip-tissue contact, validation of vessel occlusion by cryo-balloon, real-time monitoring of a freeze zone formation, and intra-procedural assessment of ablations including collateral damage.