Clinical T1a Renal Cell Carcinoma with Solitary Diaphragmatic Metastasis in a Patient with von Hippel-Lindau Disease.

We report the case of a 38-year-old man with two von Hippel-Lindau disease-associated T1a renal cell carcinomas (RCCs) (<2 cm in diameter) which developed into a 2.5-cm solitary diaphragmatic metastatic tumor. After diagnosis using percutaneous biopsy, the diaphragmatic metastasis and two RCCs were treated by laparoscopic resection and percutaneous cryoablation, respectively. One year after treatment, the patient survived without local recurrence or distant metastasis. This report describes a rare case of RCC metastasis in VHL disease and its treatment.

Portal Venous Thrombosis after Percutaneous Cryoablation for Renal Cell Carcinoma.

A 50-year-old man with von Hippel-Lindau disease underwent cryoablation (CRA) for two adjacent renal cell carcinomas in the upper pole of his right kidney. Although computed tomography (CT) immediately after CRA revealed involvement of part of the liver parenchyma in the ice-ball, the treatment was completed without complications. Contrast-enhanced CT on day 2 post-CRA revealed a thrombus in the portal vein of segment 6 near the ablated liver parenchyma, prompting the initiation of oral anticoagulation. The patient was discharged on day 4 after CRA without any sequelae, and a follow-up contrast-enhanced CT done 6 weeks later demonstrated resolution of the portal vein thrombus.

Is cryoablation a valid option for renal cell carcinomas in direct contact with critical organs?

PURPOSE: This study aimed to assess the outcomes of percutaneous cryoablation (PCA) for renal cell carcinomas (RCCs) contacting critical organs without intervening fat tissue. MATERIAL AND METHODS: Twenty-three patients with 24 RCCs (mean size, 28.8 mm) contacting critical organs on preprocedural images were included. The organ displacement techniques, technical success, efficacy, and adverse events per Clavien-Dindo classification were retrospectively reviewed. RESULTS: The organs contacting the RCCs included the colon (n = 16), pancreas (n = 3), duodenum (n = 3), small intestine (n = 1), and stomach (n = 1). In all procedures, hydrodissection was conducted, and probe traction was additionally utilized in one to displace organs. Two procedures were terminated with an insufficient ice-ball margin (<6 mm) due to recurring proximity of the colon or thermal sink effect by renal hilar vessels, yielding a technical success rate of 91.6% (22/24). No severe adverse events were noted. All patients were alive without any metastases during a median follow-up of 34.4 months. The primary and secondary technical efficacy rates were 91.6% (22/24) and 95.8% (23/24) of tumors, respectively. CONCLUSION: PCA can be a valid option for RCCs contacting critical organs with a good safety profile and sufficient technical efficacy.

Ablation of Kidney Tumors in Patients with Substantial Kidney Impairment: Current Status.

PURPOSE OF REVIEW: To review the current status of kidney tumor ablation in patients with substantial kidney impairment. RECENT FINDINGS: Few reports of kidney tumor ablation in such patients have recently been published. The reported prevalence of patients with stage 4 or 5 chronic kidney disease (CKD) among patients undergoing ablation is 2.0%-10%. In patients with stage 4 or 5 CKD, local tumor control rates were 88%-100%. The effect of ablation on CKD stage is unclear, and the observed deteriorations in kidney function are consistent with both the effect of cryoablation and the natural course of advanced CKD. According to guidelines, active surveillance may be selected. The goals of treatment are complete tumor removal and maintenance of kidney function, both of which can be met by ablation. Given the limited treatment options, ablation may play a pivotal role in the management of patients with advanced CKD.

Depiction rate of feeding arteries of renal cell carcinoma on four-dimensional computed tomography angiography.

PURPOSE: To retrospectively evaluate the depiction rate of feeding arteries in biopsy-proven clear cell renal cell carcinoma (CCRCC) on four-dimensional computed tomography angiography (4D-CTA) images. MATERIALS AND METHODS: This study included 22 patients with 22 CCRCC and 30 feeding arteries treated with transcatheter renal artery embolization. The depiction rate of the feeding arteries on preprocedural 4D-CTA was evaluated. Images were acquired by 320-row multi-detector computed tomography (CT) 15‒36 s after starting to inject a contrast agent (600 mg/kg iodine) intravenously into patients at 2.1 s intervals (11 phases). Two board-certified radiologists retrospectively assessed the feeder depiction rate in all 11 phases with reference to the procedural images as the gold standard. Discrepancies were resolved by consultation with a third radiologist. RESULTS: Among the feeders, 11 (36.7%) were segmental or lobar, and 19 (63.3%) were interlobar or arcuate arteries. The feeder depiction rate was the highest (25 [83.3%] of 30) in the 5th phase (delay, 23.4 s) where the gap in contrast enhancement between the renal artery and cortex was the largest. This was followed by the 6th (23 [76.7%] of 30), 4th (22 [73.3%] of 30]), and 7th (21 [70.0%] of 30) phases. The overall rate of depicting feeding arteries in the 11 phases of 4D-CTA was 28 (93.3%) of 30. CONCLUSIONS: The depiction rate of CCRCC feeding arteries including lobar or smaller artery branches by 4D-CTA was favorable. The feeding arteries were optimally visualized during the phase with the largest contrast gap between the renal artery and cortex.

Overexpression of lysophospholipid acyltransferase, LPLAT10/LPCAT4/LPEAT2, in the mouse liver increases glucose-stimulated insulin secretion.

Postprandial hyperglycemia is an early indicator of impaired glucose tolerance that leads to type 2 diabetes mellitus (T2DM). Alterations in the fatty acid composition of phospholipids have been implicated in diseases such as T2DM and nonalcoholic fatty liver disease. Lysophospholipid acyltransferase 10 (LPLAT10, also called LPCAT4 and LPEAT2) plays a role in remodeling fatty acyl chains of phospholipids; however, its relationship with metabolic diseases has not been fully elucidated. LPLAT10 expression is low in the liver, the main organ that regulates metabolism, under normal conditions. Here, we investigated whether overexpression of LPLAT10 in the liver leads to improved glucose metabolism. For overexpression, we generated an LPLAT10-expressing adenovirus (Ad) vector (Ad-LPLAT10) using an improved Ad vector. Postprandial hyperglycemia was suppressed by the induction of glucose-stimulated insulin secretion in Ad-LPLAT10-treated mice compared with that in control Ad vector-treated mice. Hepatic and serum levels of phosphatidylcholine 40:7, containing C18:1 and C22:6, were increased in Ad-LPLAT10-treated mice. Serum from Ad-LPLAT10-treated mice showed increased glucose-stimulated insulin secretion in mouse insulinoma MIN6 cells. These results indicate that changes in hepatic phosphatidylcholine species due to liver-specific LPLAT10 overexpression affect the pancreas and increase glucose-stimulated insulin secretion. Our findings highlight LPLAT10 as a potential novel therapeutic target for T2DM.

Prospective evaluation of core number of biopsy for renal tumor: are multiple cores preferable?

PURPOSE: This single-center, single-arm, prospective, open-label study was conducted to evaluate the optimal number of cores (single or multiple) in renal tumor biopsy. MATERIALS AND METHODS: Forty-four biopsies of 44 tumors (mean diameter, 2.7 ± 1.0 cm; range, 1.6-5.0 cm) were included. Biopsy was performed under ultrasound or computed tomography fluoroscopy guidance using an 18-gauge cutting needle and the co-axial method. Two or more specimens were obtained, which were divided into first and subsequent specimens. "First specimen" and "all specimens" were histologically evaluated (i.e., appropriateness of specimen, histological diagnosis, subtype, and Fuhrman grade of renal cell carcinoma [RCC]) blindly and independently by two board-certified pathologists. RESULTS: Multiple specimens were successfully and safely obtained in all the biopsies. All tumors were histologically diagnosed; 40 malignancies included 39 RCCs and 1 solitary fibrous tumor, and 4 benign lesions included 2 angiomyolipomas, 1 oncocytoma, and 1 capillary hemangioma. In all RCCs, the subtype could be determined (32 clear cell RCCs, 4 chromophobe RCCs, and 3 papillary RCCs), and the Furman grade was determined in 38 RCCs. When only the first specimen was evaluated, 22.7% of the specimens were inappropriate for diagnosis, and 34 (77.3%) were histologically diagnosed. The diagnostic yield was significantly lower than that of all specimens (P = 0.0044). Univariate analysis revealed that smaller lesions were a significant predictor of diagnostic failure (P = 0.020). CONCLUSION: Biopsy with multiple cores significantly improved diagnostic yield. Thus, operators should obtain multiple cores during renal tumor biopsy.

Automated Feeder-Detection Software for Renal Cell Carcinoma Embolization: A Retrospective Evaluation of Detection Rate Using Transarterial Time-Resolved Computed Tomography Angiography.

PURPOSE: To evaluate the detection rate of feeding arteries in renal cell carcinoma with automated feeder-detection software and determine the optimal imaging phase for accurate feeder detection with transarterial time-resolved computed tomography angiography. MATERIALS AND METHODS: The performance of automated feeder-detection software was retrospectively evaluated using transarterial renal time-resolved computed tomography angiography images of 15 renal cell carcinomas (mean size, 22.1 mm); the images were obtained via the renal artery using a hybrid angio-CT system with 320-row computed tomography, across nine phases with 0.5-s intervals over a contrast delay time of 1.0-5.0 s. Automated feeder-detection software was applied to each phase in all tumors (135 image series in total). The feeder-detection rate (i.e., sensitivity) in each phase was evaluated, and the number of false feeders demonstrated by the software was counted for each tumor. RESULTS: A total of 22 feeders were identified. The feeder-detection rate was the highest (95.5% [21/22]) at delay times of 1.5 s and 2.0 s and lower in later phases. At delay times of 1.0 s and 1.5 s, the software demonstrated no or only a few (≤ 3) false feeders in 93.3% (14/15) of the tumors. In later phases, however, many (≥ 4) false feeders were observed in > 50% of tumors. CONCLUSION: The automated feeder-detection software showed a favorable feeder-detection rate and may be useful in transarterial embolization for renal cell carcinoma. The optimal delay time to avoid the demonstration of false feeders and achieve a high detection accuracy was 1.5 s. LEVEL OF EVIDENCE IV: Case Series.

Time course of complications after small renal mass biopsy: evaluation of initial follow-up images.

PURPOSE: To retrospectively assess the time course of complications after image-guided small renal mass biopsy using initial follow-up imaging. MATERIALS AND METHODS: A total of 190 masses (mean, 2.1 ± 0.70 cm; range, 0.6-3.8 cm) were assessed using initial computed tomography (43 non-enhanced and 141 enhanced) or magnetic resonance imaging (five non-enhanced and one enhanced) after biopsy. Initial follow-up imaging was classified into two groups (i.e., with or without hematoma) and various factors were compared. RESULTS: The masses were histologically diagnosed in all patients except one. Post-procedural complications included 129 Grade I hematomas, 1 Grade I hemothorax, 9 Grade II hematomas, and 1 Grade IIIa pneumothorax. Residual 28 Grade I and 6 Grade II hematomas and 8 new complications (6 small hematomas, 1 pseudoaneurysm, and 1 arteriovenous fistula) were observed on the initial follow-up imaging obtained at a median of 21 days (3-90 days) after the biopsy. On the initial follow-up imaging, the groups with and without hematoma differed significantly in the following factors: age (P = 0.04), size (P = 0.02), guided images (P < 0.01), hematoma at the end of the procedure (P < 0.01), and days after biopsy (P < 0.01). Although three masses exhibited > 25% shrinkage, no significant change was observed in mass diameter on initial follow-up imaging (mean, 2.1 ± 0.71 cm; P = 0.90). CONCLUSION: Initial follow-up imaging after a biopsy revealed improvements in most of the complications, a few new complications, and an unchanged mass diameter.

Robotic systems in interventional oncology: a narrative review of the current status.

Interventional oncology offers minimally invasive treatments for malignant tumors for curative and palliative purposes based on the percutaneous insertion of needles or catheters into the target location under image guidance. Robotic systems have been gaining increasing attention as tools that provide potential advantages for image-guided interventions. Among the robotic systems developed for intervention, those relevant to the oncology field are mainly those for guiding or driving the needles in non-vascular interventional procedures such as biopsy and tumor ablation. Needle-guiding robots support planning the needle path and align the needle robotically according to the planned trajectory, which is combined with subsequent manual needle insertion by the physician through the needle guide. Needle-driving robots can advance the needle robotically after determining its orientation. Although a wide variety of robotic systems have been developed, only a limited number of these systems have reached the clinical phase or commercialization thus far. The results of previous studies suggest that such interventional robots have the potential to increase the accuracy of needle placement, facilitate out-of-plane needle insertion, decrease the learning curve, and reduce radiation exposure. On the other hand, increased complexity and costs may be a concern when using robotic systems compared with conventional manual procedures. Further data should be collected to comprehensively assess the value of robotic systems in interventional oncology.

Omental Abscess after Laparoscopic Proximal Gastrectomy Successfully Treated with Percutaneous Drainage.

We report the case details of a 65-year-old Japanese man with an omental abscess that was discovered 43 days after he underwent a laparoscopic proximal gastrectomy for gastric cancer. His chief complaint was mild abdominal pain that had persisted for several days. The abscess was diagnosed as a rare postoperative complication. We hesitated to perform a reoperation given the invasiveness of general anesthesia and surgery, plus the possibility of postoperative adhesions and because the patient's general condition was stable and he had only mild abdominal pain. Percutaneous drainage using a 10.2-F catheter was performed with the patient under conscious sedation and computed tomography-fluoroscopy guidance, with no complications. After the procedure, the size of the abscess cavity was remarkably reduced, and 23 days later the catheter was withdrawn.

Image-Guided Ablation Therapies for Extrahepatic Metastases from Hepatocellular Carcinoma: A Review.

The most common sites of extrahepatic metastases from hepatocellular carcinoma (HCC) are the lungs, intra-abdominal lymph nodes, bones, and adrenal glands, in that order. Although systemic therapies are a common treatment for patients with extrahepatic metastases, local ablative therapies for the extrahepatic metastatic lesions can be performed in selected patients. In this article, the literature on image-guided thermal ablation for metastasis to each organ was reviewed to summarize the current evidence. Radiofrequency ablation was the most commonly evaluated technique, and microwave ablation, cryoablation, and percutaneous ethanol injection were also utilized. The local control rate of thermal ablation therapy was relatively favorable, at approximately 70-90% in various organs. The survival outcomes varied among the studies, and several studies reported that the absence of viable intrahepatic lesions was associated with improved survival rates. Since only retrospective data from relatively small studies has been available thus far, more robust studies with prospective designs and larger cohorts are desired to prove the usefulness of thermal ablation for extrahepatic metastases from HCC.

Complications of Percutaneous Cryoablation for Renal Tumors and Methods for Avoiding Them.

Percutaneous cryoablation of renal tumors is widely used because of its high efficacy and safety. This high safety can be attributed, at least in part, to the visibility of the ablated area as an "ice ball". This therapy has fewer complications (incidence, 0-7.2%) and is less invasive than surgery. Minor bleeding is inevitable in most kidney-related procedures, and indeed the most common complication of this therapy is bleeding (hematoma and hematuria). However, patients require treatment such as transfusion or transarterial embolization in only 0-4% of bleeding cases. Various other complications such as ureteral or collecting system injury, bowel injury, nerve injury, skin injury, infection, pneumothorax, and tract seeding also occur, but they are usually minor and asymptomatic. However, operators should know and avoid the various complications associated with this therapy. This study aimed to summarize the complications of percutaneous cryoablation for renal tumors and provide some techniques for achieving safe procedures.

Renal cryoablation combined with prior transcatheter arterial embolization in non-dialysis patients with stage 4 or 5 chronic kidney disease: a retrospective study.

PURPOSE: To retrospectively evaluate cryoablation combined with prior transcatheter arterial embolization (TAE) for renal cell carcinoma (RCC) in non-dialysis patients with stage 4 or 5 chronic kidney disease (CKD). MATERIALS AND METHODS: Patients with stage 4 or 5 CKD undergoing TAE and cryoablation for RCC between May 2012 and October 2021 were included. TAE was selectively performed using iodized oil with absolute ethanol or gelatin sponge 1-14 days before cryoablation. Local efficacy, safety, and changes in renal function were evaluated. RESULTS: Nine patients (seven men and two women; median age, 64 years; range 52-88 years) with nine RCCs (mean diameter, 3.0 ± 1.0 cm; range 1.7-4.7 cm) were included. The mean pre-treatment estimated glomerular filtration rate (eGFR) was 24.2 ± 5.6 ml/min/1.73 m2 (range 10.4-29.2 ml/min/1.73 m2). The mean amount of contrast medium used in TAE was 58 ± 29 ml (range 40-128 ml). Except in one patient (grade 3 pyelonephritis), no grade ≥ 3 complications occurred. During the follow-up period (median, 18 months; range 7-54 months), no local tumor progression occurred. In two patients with pre-treatment eGFR of < 20 ml/min/1.73 m2, hemodialysis was initiated at 3 and 19 months after cryoablation. At their last follow-up, the remaining seven patients showed a decrease of 6.2 ± 5.3 ml/min/1.73 m2 (range 0.7-17.2 ml/min/1.73 m2) in their eGFR. CONCLUSION: Cryoablation combined with TAE for RCC in non-dialysis patients with stage 4 or 5 CKD was effective and safe, with an acceptable impact on renal function.

Navicular Bone Fracture after Radiofrequency Ablation in a Patient with Osteoid Osteoma.

Osteoid osteoma (OO) is a benign bone tumor that presents with nocturnal pain. Computed tomography (CT)- guided radiofrequency ablation (RFA) has been widely performed for OO, and major adverse events post-RFA are rare. We report a case of OO in the left navicular bone of a 15-year-old male. He underwent RFA for OO, and the pain improved temporarily. At the 1-month follow-up, the patient complained of left foot pain, and a CT examination revealed a fracture of the ablated navicular bone. Fractures are rare but must be taken into account after bone RFA.

Liver-specific overexpression of lipoprotein lipase improves glucose metabolism in high-fat diet-fed mice.

The liver is the main organ that regulates lipid and glucose metabolism. Ectopic lipid accumulation in the liver impairs insulin sensitivity and glucose metabolism. Lipoprotein lipase (LPL), mainly expressed in the adipose tissue and muscle, is a key enzyme that regulates lipid metabolism via the hydrolysis of triglyceride in chylomicrons and very-low-density lipoproteins. Here, we aimed to investigate whether the suppression level of hepatic lipid accumulation via overexpression of LPL in mouse liver leads to improved metabolism. To overexpress LPL in the liver, we generated an LPL-expressing adenovirus (Ad) vector using an improved Ad vector that exhibited considerably lower hepatotoxicity (Ad-LPL). C57BL/6 mice were treated with Ad vectors and simultaneously fed a high-fat diet (HFD). Lipid droplet formation in the liver decreased in Ad-LPL-treated mice relative to that in control Ad vector-treated mice. Glucose tolerance and insulin resistance were remarkably improved in Ad-LPL-treated mice compared to those in control Ad vector-treated mice. The expression levels of fatty acid oxidation-related genes, such as peroxisome proliferator-activated receptor α, carnitine palmitoyltransferase 1, and acyl-CoA oxidase 1, were 1.7-2.0-fold higher in Ad-LPL-treated mouse livers than that in control Ad-vector-treated mouse livers. Furthermore, hepatic LPL overexpression partly maintained mitochondrial content in HFD-fed mice. These results indicate that LPL overexpression in the livers of HFD-fed mice attenuates the accumulation of lipid droplets in the liver and improves glucose metabolism. These findings may enable the development of new drugs to treat metabolic syndromes such as type 2 diabetes mellitus and non-alcoholic fatty liver disease.

Evidence on percutaneous radiofrequency and microwave ablation for liver metastases over the last decade.

PURPOSE: This review aimed to summarize the treatment outcomes of percutaneous radiofrequency ablation (RFA) and microwave ablation (MWA) for metastatic liver tumors based on the findings of published studies over the last decade. MATERIALS AND METHODS: Literature describing the survival outcomes of ablation therapy for liver metastases was explored using the PubMed database on April 26, 2022, and articles published in 2012 or later were selected. The included studies met the following criteria: (i) English literature, (ii) original clinical studies, and (iii) literature describing overall survival (OS) of thermal ablation for metastatic liver tumors. All case reports and cohort studies with fewer than 20 patients and those that evaluated ablation for palliative purposes were excluded. RESULTS: RFA was the most commonly used method for ablation, while MWA was used in several recent studies. RFA and MWA for liver metastases from various primary tumors have been reported; however, majority of the studies focused on colorectal cancer. The local control rate by RFA and MWA varied widely among the studies, ranging approximately 50-90%. Five-year survival rates of 20-60% have been reported following ablation for colorectal liver metastases by a number of studies, and several reports of 10-year survival rates were also noted. CONCLUSION: Comparative studies of local therapies for colorectal liver metastases demonstrated that RFA provides comparable survival outcomes to surgical metastasectomy and stereotactic body radiation therapy.

Percutaneous cryoablation combined with prior transcatheter arterial embolization for renal cell carcinomas of 3 cm or larger: a prospective study.

BACKGROUND: We prospectively evaluated the safety and efficacy of percutaneous cryoablation combined with transcatheter renal arterial embolization for the treatment of tumors ≥ 3 cm in diameter. METHODS: We included patients aged ≥ 20 years with histologically proven renal cell carcinoma with a tumor diameter ≥ 3 cm who were inoperable or refused surgery. Prior to ablation, transcatheter arterial embolization was performed using a mixture of absolute ethanol and iodized oil. All cryoablation procedures were performed percutaneously under computed tomography fluoroscopy guidance. The primary endpoint was safety, which was evaluated for adverse events using CTCAE version 4.0. The secondary endpoint was survival; overall survival, progression-free survival, and cancer-specific survival were calculated. RESULTS: From October 2013 to March 2016, 19 patients (mean age, 75 ± 13 years; 5 women, 14 men) were prospectively enrolled. The mean tumor diameter was 3.9 ± 0.7 (range 3.1-5.3) cm. Four grade 3 hematologic adverse events occurred, while no symptomatic grade ≥ 3 events occurred. The median follow-up period was 68 (range 52-84) months. During the follow-up period, two patients developed local tumor progression at 3 and 42 months after the initial ablative procedure; no patient showed distant metastasis. Two patients died from causes other than RCC. Overall survival, progression-free survival, and cause-specific survival were 100%, 95%, and 100% at 3 years, and 95%, 84%, and 100% at 5 years, respectively. CONCLUSION: Percutaneous cryoablation combined with prior TAE for the treatment of tumors ≥ 3 cm in diameter was safe and achieved favorable survival.

Up-to-date evidence on image-guided thermal ablation for metastatic lung tumors: a review.

The aim of this review was to summarize the latest evidence on image-guided thermal ablation therapies for lung metastases. PubMed was used to search for relevant articles that reported the oncological outcomes of thermal ablation for metastatic lung tumors, and those published in 2010 or later were selected for review. Ablative therapies were applied for lung metastases from various types of primary tumors, but most commonly colorectal ones. Radiofrequency ablation (RFA) was the most evaluated technique, followed by microwave ablation (MWA). The local control rates of ablative therapies were generally favorable, approximately 80-90% in many studies. Representative studies demonstrated promising overall survival rates of approximately 50% or higher 5 years after ablation for lung metastases from colorectal cancer or mixed types of primary tumors. Nevertheless, the survival outcomes varied depending on the type of primary tumor and background factors of patients such as other metastases and comorbidities. Several studies had aimed to compare the outcomes of various ablative therapies such as RFA, MWA, and cryoablation; however, conclusive data are not yet available to determine the most appropriate ablation modality for lung metastases. Further data accumulation is needed, especially for long-term outcomes and comparisons with other therapies.