Diagnostic accuracy and safety of percutaneous MRI-guided biopsy of solid renal masses: single-center results after 4.5 years

Magnetic Resonance Imaging Guidance for Percutaneous Needle Intervention

Magnetic resonance imaging (MRI) is one of the guiding modalities used for percutaneous needle insertion during interventional procedures. MRI guidance has several advantages, including multiplanar imaging capability, superior soft tissue contrast resolution, and the absence of ionizing radiation. When performing MRI-guided procedures, it is important to understand the suitable MRI systems, instruments, and imaging sequences for intervention. Furthermore, needle artifact characteristics must be fully understood to ensure safe and accurate needle insertion. In this article, we present the fundamental knowledge as regards the use of MRI guidance for percutaneous needle insertion and review its usefulness in representative interventional procedures, such as biopsy and tumor ablation.

Magnetic resonance imaging-guided renal biopsy shows high safety and diagnostic yield: a tertiary cancer center experience

OBJECTIVES

To evaluate the technical success and outcomes of renal biopsies performed under magnetic resonance imaging (MRI) using a closed-bore, 1.5-Tesla MRI unit.

MATERIALS AND METHODS

We retrospectively reviewed our institutional biopsy database and included 150 consecutive MRI-guided biopsies for renal masses between November 2007 and March 2020. We recorded age, sex, BMI, tumor characteristics, RENAL nephrometry score, MRI scan sequence, biopsy technique, complications, diagnostic yield, pathologic outcome, and follow-up imaging. Univariate logistic regression was used to assess the association between different parameters and the development of complications. McNemar's test was used to assess the association between paired diagnostic yield measurements for fine-needle aspiration and core samples.

RESULTS

A total of 150 biopsies for 150 lesions were performed in 150 patients. The median tumor size was 2.7 cm. The median BMI was 28.3. The lesions were solid, partially necrotic/cystic, and predominantly cystic in 137, eight, and five patients, respectively. Image guidance using fat saturation steady-state free precession sequence was recorded in 95% of the biopsy procedures. Samples were obtained using both fine-needle aspiration (FNA) and cores in 99 patients (66%), cores only in 40 (26%), and FNA only in three (2%). Tissue sampling was diagnostic in 144 (96%) lesions. No major complication developed following any of the biopsy procedures. The median follow-up imaging duration was 8 years and none of the patients developed biopsy-related long-term complication or tumor seeding.

CONCLUSIONS

MRI-guided renal biopsy is safe and effective, with high diagnostic yield and no major complications.

CLINICAL RELEVANCE STATEMENT

Image-guided renal biopsy is safe and effective, and should be included in the management algorithm of patients with renal masses. Core biopsy is recommended.

KEY POINTS

• MRI-guided biopsy is a safe and effective technique for sampling of renal lesions. • MRI-guided biopsy has high diagnostic yield with no major complications. • Percutaneous image-guided biopsy plays a key role in the management of patients with renal masses.

Diagnostic accuracy of percutaneous core biopsy before cryoablation for small-sized renal cell carcinoma

PURPOSE

To retrospectively determine the diagnostic accuracy of a percutaneous core biopsy performed before cryoablation for small-sized renal cell carcinoma.

METHODS

In this study, 216 patients underwent a percutaneous core biopsy for 242 renal lesions suspected to be renal cell carcinoma on image findings before cryoablation at Kyushu University Hospital. We calculated the success rate of the histological diagnosis and investigated factors that may have contributed to the diagnostic success. Complications caused by the biopsy procedure were also evaluated.

RESULTS

The histological diagnosis was successful in 203 lesions (82.8%). The success rate of the histological diagnosis was 65.4% (34/52 cases) for tumors with a diameter of ≤15 mm and 88.9% (169/190 cases) for those >15 mm. Therefore, tumor diameter was a factor contributing to the histological diagnosis success rate in both univariate and multivariable analyses (P < 0.001). For lesions with a tumor diameter ≤15 mm, the histological diagnosis success rates increased from 50.0% to 76.2% in the presence of pre-lipiodol marking and to 85.7% when the biopsy procedure was performed separately from cryoablation; the latter was statistically significant (P = 0.039). Major complications that may have been caused by the biopsy procedure were grade 3 bleeding and tract seeding (one case each).

CONCLUSION

Percutaneous core biopsy in cryoablation for small-sized renal cell carcinoma had a high diagnostic rate and was safely performed. For lesions with a tumor diameter ≤15 mm, a separate biopsy procedure and pre-lipiodol marking may improve the diagnostic accuracy.

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.

Molecular Imaging Diagnosis of Renal Cancer Using 99mTc-Sestamibi SPECT/CT and Girentuximab PET-CT-Current Evidence and Future Development of Novel Techniques

Novel molecular imaging opportunities to preoperatively diagnose renal cell carcinoma is under development and will add more value in limiting the postoperative renal function loss and morbidity. We aimed to comprehensively review the research on single photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography computed tomography (PET-CT) molecular imaging and to enhance the urologists' and radiologists' knowledge of the current research pattern. We identified an increase in prospective and also retrospective studies that researched to distinguish between benign and malignant lesions and between different clear cell renal cell carcinoma subtypes, with small numbers of patients studied, nonetheless with excellent results on specificity, sensitivity and accuracy, especially for ^99mTc-sestamibi SPECT/CT that delivers quick results compared to a long acquisition time for girentuximab PET-CT, which instead gives better image quality. Nuclear medicine has helped clinicians in evaluating primary and secondary lesions, and has lately returned with new and exciting insights with novel radiotracers to reinforce its diagnostic potential in renal carcinoma. To further limit the renal function loss and post-surgery morbidity, future research is mandatory to validate the results and to clinically implement the diagnostic techniques in the context of precision medicine.

Precision Imaging Guidance in the Era of Precision Oncology: An Update of Imaging Tools for Interventional Procedures

Interventional oncology (IO) procedures have become extremely popular in interventional radiology (IR) and play an essential role in the diagnosis, treatment, and supportive care of oncologic patients through new and safe procedures. IR procedures can be divided into two main groups: vascular and non-vascular. Vascular approaches are mainly based on embolization and concomitant injection of chemotherapeutics directly into the tumor-feeding vessels. Percutaneous approaches are a type of non-vascular procedures and include percutaneous image-guided biopsies and different ablation techniques with radiofrequency, microwaves, cryoablation, and focused ultrasound. The use of these techniques requires precise imaging pretreatment planning and guidance that can be provided through different imaging techniques: ultrasound, computed tomography, cone-beam computed tomography, and magnetic resonance. These imaging modalities can be used alone or in combination, thanks to fusion imaging, to further improve the confidence of the operators and the efficacy and safety of the procedures. This article aims is to provide an overview of the available IO procedures based on clinical imaging guidance to develop a targeted and optimal approach to cancer patients.

Fabrication of Fe3O4@PVA microspheres by one-step electrospray for magnetic resonance imaging during transcatheter arterial embolization

Magnetic resonance imaging (MRI) has attracted increasing attention as a feasible alternative or adjunctive imaging modality for X-ray digital subtraction angiography because of the high tissue resolution and non-ionization radiation. In this study, a one-step electrospray method was developed to fabricate PVA microspheres encapsulated with in situ synthesized Fe₃O₄ nanoparticles. Fe₃O₄@PVA microspheres were mono-dispersed black spheres with a wide range of sizes (262-958 µm). The in situ-synthesized Fe₃O₄ nanoparticles were used as the contrast agent of MRI and the cross-linkers of PVA matrixes for the embolization purpose. In vivo evaluation of renal arteries of normal rabbits showed that Fe₃O₄@PVA microspheres had good embolic effect and enhanced capability of MRI. In vitro and in vivo biosafety assessment confirmed that Fe₃O₄@PVA microspheres had favorable biocompatibility. The DOX-loaded Fe₃O₄@PVA microspheres showed a typical drug-sustained release profile. These results suggest that the prepared DOX-loaded Fe₃O₄@PVA microspheres have the function of MRI, embolotherapy and chemotherapy. We expect our study could provide a simple and useful approach for the systematic design, fabrication, and application of a new type of magnetic microspheres as a triple-functional embolic agent for the development of MRI-guided TACE. STATEMENT OF SIGNIFICANCE: Due to the low tissue resolution and hazardous ionization radiation of X-ray digital subtraction angiography, it is beneficial to study MR imaging embolic microspheres for the development of MRI-guided TACE. In this study, a one-step electrospray method was firstly developed to fabricate PVA microspheres encapsulated with in situ synthesized Fe₃O₄ nanoparticles. Then, chemotherapeutic agent (DOX), contrast media of MRI (Fe₃O₄) and embolic agent (PVA matrix) were combined together in one body (DOX-loaded Fe₃O₄@PVA microspheres) to achieve the triple effects of chemotherapy, MR imaging and embolization. This triple-functional embolic agent offers potential for the future development of MRI-guided TACE.

Hemothorax After a Renal Biopsy With Ablation, a Rare Complication: A Case Report and Review of the Literature

Renal biopsy is an important diagnostic test which is used to extract kidney tissue with the help of a biopsy needle. It is frequently performed under ultrasonography or CT guidance. As with every other procedure, renal biopsy also carries some risks. Common complications of renal biopsy are damage to adjacent organs. Hemothorax is an exceedingly rare complication of renal biopsy. We report a case of a middle-aged female who developed a left-sided hemothorax after undergoing percutaneous renal biopsy with ablation and conducted a literature review of this rare complication.