Shape-Sensing Robotic-Assisted Bronchoscopy versus Computed Tomography-Guided Transthoracic Biopsy for the Evaluation of Subsolid Pulmonary Nodules.

INTRODUCTION: Lung cancer remains the leading cause of cancer death worldwide. Subsolid nodules (SSN), including ground-glass nodules (GGNs) and part-solid nodules (PSNs), are slow-growing but have a higher risk for malignancy. Therefore, timely diagnosis is imperative. Shape-sensing robotic-assisted bronchoscopy (ssRAB) has emerged as reliable diagnostic procedure, but data on SSN and how ssRAB compares to other diagnostic interventions such as CT-guided transthoracic biopsy (CTTB) are scarce. In this study, we compared diagnostic yield of ssRAB versus CTTB for evaluating SSN. METHODS: A retrospective study of consecutive patients who underwent either ssRAB or CTTB for evaluating GGN and PSN with a solid component less than 6 mm from February 2020 to April 2023 at Mayo Clinic Florida and Rochester. Clinicodemographic information, nodule characteristics, diagnostic yield, and complications were compared between ssRAB and CTTB. RESULTS: A total of 66 nodules from 65 patients were evaluated: 37 PSN and 29 GGN. Median size of PSN solid component was 5 mm (IQR: 4.5, 6). Patients were divided into two groups: 27 in the ssRAB group and 38 in the CTTB group. Diagnostic yield was 85.7% for ssRAB and 89.5% for CTTB (p = 0.646). Sensitivity for malignancy was similar between ssRAB and CTTB (86.4% vs. 88.5%; p = 0.828), with no statistical difference. Complications were more frequent in CTTB with no significant difference (8 vs. 2; p = 0.135). CONCLUSION: Diagnostic yield for SSN was similarly high for ssRAB and CTTB, with ssRAB presenting less complications and allowing mediastinal staging within the same procedure.

Radiofrequency Ablation of Benign and Malignant Thyroid Nodules.

Thyroid nodule treatment has significantly evolved over recent years with attempts to individualize treatment on the basis of the cause of the nodule and patient performance status. The risks and complications associated with surgery and radioactive iodine have promoted interest in additional therapies such as radiofrequency ablation (RFA). RFA creates an electrical current through a target tissue (thyroid nodule) with resultant tissue heating causing coagulative necrosis. National and international groups are beginning to recognize the role of RFA as a viable therapeutic option in the treatment of thyroid nodules. Based on numerous guidelines, RFA is indicated in the treatment of symptomatic benign nodules and autonomously functioning nodules when surgery is refused or when the patient would not tolerate surgery. The treatment of thyroid malignancy with RFA is controversial, with some groups advocating for its use in the treatment of small papillary thyroid cancers in specific scenarios. The most important aspect of RFA is the preprocedural workup and adequate patient selection. Procedural technique varies among centers. However, RFA is typically performed as a single-day-admission outpatient procedure. Methods such as hydrodissection and a moving shot technique are employed to ensure adequate coverage of the nodule without overtreating the peripheries and damaging sensitive structures. As a result, the procedure is well tolerated, and major complications such as recurrent laryngeal nerve injury and nodule rupture are very rare. In the proper patient cohort, thyroid RFA offers an efficacious and safe option in the management of thyroid nodules. An invited commentary by Filippiadis and Vrachliotis is available online. ©RSNA, 2022.

Safety and Efficacy of Retrograde Pyeloperfusion for Ureteral Protection during Renal Tumor Cryoablation.

PURPOSE: To determine safety and efficacy of retrograde pyeloperfusion for ureteral protection during cryoablation of adjacent renal tumors. MATERIALS AND METHODS: Retrospective review of 155 patients treated with renal cryoablation, including adjunctive retrograde pyeloperfusion, from 2005 to 2019 was performed. Ice contacted the ureter in 67 of the 155 patients who represented the study cohort. Median patient age was 68 years old (interquartile range [61, 74]), 52 patients (78%) were male, and 37 tumors (55%) were clear cell histology. Mean tumor size was 3.4 ± 1.3 cm, and 42 tumors (63%) were located at the lower pole. Treatment-related complication and oncologic outcomes were recorded based on a review of post-procedural images and chart review. RESULTS: Technical success of cryoablation was attained in 67 cases (100%), and technical success of pyeloperfusion was attained in 66 cases (99%). A total of 13 patients (19.4%) experienced SIR major C or D complications related to the procedure, including hemorrhage (n = 4), urine leak (n = 3), transient urinary obstruction (n = 2), pulmonary embolism (n = 1), hypertensive urgency (n = 1), acute respiratory failure (n = 1), and ureteropelvic junction (UPJ) stricture (n = 1). No complications were attributable to pyeloperfusion. Three of 45 patients with biopsy-proven renal cell carcinoma experienced local recurrence resulting in local recurrence-free survival of 92% (95% confidence interval, 81.5%-100%) 3 years after ablation. CONCLUSIONS: Retrograde pyeloperfusion of the renal collecting system is a relatively safe and efficacious option for ureteral protection during renal tumor cryoablation. This adjunctive procedure should be considered for patients in whom cryoablation of a renal mass could potentially involve the ureter.

Dual-Energy CT Monitoring of Cryoablation Zone Growth in the Spinal Column and Bony Pelvis: A Laboratory Study.

PURPOSE: To evaluate the use of dual-energy computed tomography (CT) virtual noncalcium imaging (VNCa) to visualize ice ball growth during skeletal cryoablation procedures in the spine and bony pelvis. MATERIALS AND METHODS: Cryoablation was performed in the spine and bony pelvis of swine and human cadavers at 5 and 6 locations, respectively. CT scans were acquired every 2 minutes using a dual-source dual-energy scanner. Artifacts were suppressed using iterative metal artifact reduction, and ablation zones in the bones and surrounding tissue were visualized using multiplanar VNCa and mixed kV imaging. For each probe location and time point, ice detectability was determined and the volume of the ice was measured. RESULTS: At each location, ice was visualized within the bone before reaching critical neural and intraabdominal structures. Within bone, the ice ball could not be visualized on mixed kV images, but was seen using VNCa images before reaching the adjacent soft tissue in 7/11 (64%) scenarios. Volume of the smallest ice ball seen in VNCa images was 18% of the final volume after cryoablation compared with 42% for mixed kV (P = .014). CONCLUSIONS: This application of dual-energy CT and VNCa imaging to cryoablation monitoring permits earlier ice visualization within the vertebral column and pelvic bones in near real time. Because these scanners and imaging techniques increase in availability in interventional suites, cryoablation of tumors along the spine and pelvic bone potentially could be performed with greater confidence.

Development of a robust MRI fiducial system for automated fusion of MR-US abdominal images.

We present the development of a two-component magnetic resonance (MR) fiducial system, that is, a fiducial marker device combined with an auto-segmentation algorithm, designed to be paired with existing ultrasound probe tracking and image fusion technology to automatically fuse MR and ultrasound (US) images. The fiducial device consisted of four ~6.4 mL cylindrical wells filled with 1 g/L copper sulfate solution. The algorithm was designed to automatically segment the device in clinical abdominal MR images. The algorithm's detection rate and repeatability were investigated through a phantom study and in human volunteers. The detection rate was 100% in all phantom and human images. The center-of-mass of the fiducial device was robustly identified with maximum variations of 2.9 mm in position and 0.9° in angular orientation. In volunteer images, average differences between algorithm-measured inter-marker spacings and actual separation distances were 0.53 ± 0.36 mm. "Proof-of-concept" automatic MR-US fusions were conducted with sets of images from both a phantom and volunteer using a commercial prototype system, which was built based on the above findings. Image fusion accuracy was measured to be within 5 mm for breath-hold scanning. These results demonstrate the capability of this approach to automatically fuse US and MR images acquired across a wide range of clinical abdominal pulse sequences.

Percutaneous Cryoablation of Extraabdominal Desmoid Tumors: A 10-Year Experience.

OBJECTIVE: Extraabdominal desmoid (EAD) tumors pose a therapeutic challenge because they often recur locally and behave aggressively. Accepted management options include surgery, radiation, chemotherapy, and observation. The objective of this study was to assess the safety and efficacy of percutaneous cryoablation for the treatment of EAD tumors. MATERIALS AND METHODS: A retrospective search of our cryoablation database was performed to identify patients with EAD tumors treated with percutaneous cryoablation between June 15, 2004, and June 15, 2014. During this 10-year time period, we treated 18 patients with 26 discrete tumors during 31 treatment sessions. After cryoablation, contrast-enhanced MRI or CT was performed. Any enhancing soft tissue was considered viable EAD tumor and was measured in three planes. RESULTS: Of the 26 EAD tumors treated, follow-up imaging with IV contrast material was available for 23 tumors. The mean imaging follow-up was 16.2 ± 20.0 (SD) months. All 31 sessions were technically successful procedures. No residual viable EAD tumor was observed in nine of 23 tumors (39.1%). Some degree of volume reduction was evident in 22 of 23 tumors (95.7%). Progressive disease was observed in one of the 23 tumors (4.3%). Of the cases with residual or progressive disease, the recurrence occurred at the margin of the treated tumor in all cases. No major complications were observed, and none of the complications was more severe than Clavien-Dindo grade I. CONCLUSION: Percutaneous cryoablation is a safe, effective, and repeatable treatment for achieving local control of EAD tumors.

Percutaneous cryoablation of stage T1b renal cell carcinoma: technique considerations, safety, and local tumor control.

PURPOSE: To describe the technical methods, safety, and local tumor control rate associated with percutaneous cryoablation of stage T1b renal cell carcinoma (RCC). MATERIALS AND METHODS: A retrospective review of a percutaneous renal ablation registry was used to identify 46 patients with a total of 46 biopsy-proven RCC lesions measuring 4.1-7.0 cm treated with cryoablation between 2003 and 2011. The main outcome parameters investigated were adjunctive maneuvers, complications, and local tumor progression, and cancer-specific survival rates. Complication rates were categorized and recorded using the Clavien-Dindo classification system. Progression-free and cancer-specific survival rates were estimated using the Kaplan-Meier method. RESULTS: The mean treated RCC size was 4.8 cm (range, 4.1-6.4 cm). Prophylactic tumor embolization was performed in 7 patients (15%), ipsilateral ureteral stents were placed in 7 patients (15%), and hydrodisplacement of bowel was performed in the treatment of 16 tumors (35%). A single technical failure (2.2%) was observed at the time of ablation. Thirty-six tumors (78%) had follow-up imaging at 3 months or later following ablation, including a single recurrence at 9 months after ablation. The mean duration of follow-up for the 35 RCC tumors that did not recur was 2.0 years (range, 0.3-6.1 y). Estimated local progression-free survival rate at 3 years was 96.4%. Of the 46 cryoablation procedures, there were 7 complications (15.2%) of grade II or worse. CONCLUSIONS: The results suggest that cryoablation represents a valid treatment alternative for select patients with clinical stage T1b RCC. Complications are frequent enough that multidisciplinary patient management should be considered.

Feasibility and oncologic control after percutaneous image guided ablation of metastatic renal cell carcinoma.

PURPOSE: We assessed the safety, local control and oncologic efficacy of percutaneous ablation in the treatment of metastatic renal cell carcinoma. MATERIALS AND METHODS: A retrospective review was performed of 61 patients who underwent 74 ablation procedures to treat 82 metastatic renal cell carcinoma lesions with the intent of local eradication. Technical success, local tumor control, complications and patient survival were analyzed according to standard criteria. RESULTS: Four (4.9%) technical failures were observed while 2 patients were lost to followup. Time to recurrence was assessed for the subset of 76 (93%) tumors that were followed after ablation. Six (of 76, 7.9%) tumors recurred at a mean of 1.6 years after ablation (median 1.4, range 0.6 to 2.9). Thus, known overall local tumor control was achieved in 70 of 80 (87.5%) tumors. Estimated local recurrence-free survival rates (95% CI, number still at risk) at 1, 2 and 3 years after ablation were 94% (88-100, 41), 94% (88-100, 32) and 83% (70-97, 17), respectively. Estimated overall survival rates (95% CI, number still at risk) at 1, 2 and 3 years after ablation were 87% (79-97, 42), 83% (73-94, 31) and 76% (63-90, 19), respectively. CONCLUSIONS: Image guided ablation of metastatic renal cell carcinoma is a relatively safe procedure with acceptable local control rates. Ablation may offer patients a minimally invasive option of local tumor eradication and warrants a role in the multimodal treatment approach for select patients.

Usefulness of R.E.N.A.L. nephrometry scoring system for predicting outcomes and complications of percutaneous ablation of 751 renal tumors.

PURPOSE: We applied the R.E.N.A.L. (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior and location relative to polar lines) nephrometry scoring system to renal tumors treated with percutaneous ablation to determine whether this score is associated with oncological outcomes and complications. MATERIALS AND METHODS: A total of 751 renal tumors were treated at 679 percutaneous ablation sessions in 627 patients at our institution between 2000 and 2012. Of these renal masses 430 (57%) were treated with cryoablation and the remaining 321 were treated with radio frequency ablation. R.E.N.A.L. tumor scores were analyzed to determine the association of the score with ablation treatment outcomes and complications according to Clavien criteria. RESULTS: The mean ± SD R.E.N.A.L. nephrometry score of all ablated tumors was 6.7 ± 1.9. Those treated with cryoablation had higher scores than those treated with radio frequency ablation (mean 7.2 ± 1.9 vs 6.1 ± 1.8, p <0.001). We identified a total of 28 local treatment failures (3.7%) in the 751 tumors during a mean computerized tomography/magnetic resonance imaging followup of 27.9 ± 27.8 months. There was a significant association between R.E.N.A.L. nephrometry score and local treatment failure. Mean nephrometry score was 7.6 ± 2.2 vs 6.7 ± 1.9 for tumors with vs without local treatment failure (p <0.001). Of the 679 ablation treatments 38 (5.6%) major (grade 3 or greater) patient complications occurred. There was a significant association between R.E.N.A.L. nephrometry score and major complications. Patients with vs without a major complication had a mean nephrometry score of 8.1 ± 2.0 vs 6.8 ± 1.9 (p <0.001). CONCLUSIONS: The R.E.N.A.L. nephrometry scoring system predicts treatment efficacy and complications following percutaneous renal ablation.

Emerging Indications for Interventional Oncology: Expert Discussion on New Locoregional Treatments.

Interventional oncology (IO) employs image-guided techniques to perform minimally invasive procedures, providing lower-risk alternatives to many traditional medical and surgical therapies for cancer patients. Since its advent, due to rapidly evolving research development, its role has expanded to encompass the diagnosis and treatment of diseases across multiple body systems. In detail, interventional oncology is expanding its role across a wide spectrum of disease sites, offering a potential cure, control, or palliative care for many types of cancer patients. Due to its widespread use, a comprehensive review of the new indications for locoregional procedures is mandatory. This article summarizes the expert discussion and report from the "MIOLive Meet SIO" (Society of Interventional Oncology) session during the last MIOLive 2022 (Mediterranean Interventional Oncology Live) congress held in Rome, Italy, integrating evidence-reported literature and experience-based perceptions. The aim of this paper is to provide an updated review of the new techniques and devices available for innovative indications not only to residents and fellows but also to colleagues approaching locoregional treatments.

Percutaneous cryoablation of solitary sporadic renal cell carcinomas.

UNLABELLED: What's known on the subject? and What does the study add? Percutaneous renal cryoablation is a safe and effective treatment for patients with small renal masses, who are poor surgical candidates. Oncological outcomes from previous percutaneous ablation studies are difficult to interpret because of the large number of patients treated with a history of RCC (38% in our experience) and the large number of treated renal masses without a pathology-proven diagnosis. This cryoablation study addresses these issues by evaluating only solitary, sporadic biopsy-proven RCC. Oncological outcomes and complications were also evaluated by tumour T-stage, which allows some degree of comparison with previously published surgical results. OBJECTIVE: • To evaluate retrospectively our single institution experience with percutaneous cryoablation of solitary, sporadic renal cell carcinomas (RCCs), and to compare the efficacy and safety of this technique for treatment of different T-stage RCC. PATIENTS AND METHODS: • 116 patients were treated with percutaneous cryoablation for a solitary, sporadic biopsy-proven RCC in a single treatment session between November 2003 and November 2010. • The technical success of the ablation procedure, complications and evidence for local or metastatic tumour recurrence were evaluated for each patient. RESULTS: • 83 patients (72%) were treated for a stage T1a RCC, 27 patients (23%) for a stage T1b RCC, and six patients (5%) for a stage T2 RCC. • Technical success was achieved in the treatment of 115 of 116 (99%) renal tumours. The single technical failure occurred in the treatment of a 4.3-cm RCC. • Local recurrent tumour was identified in one of 88 patients (1%) with follow-up computed tomography (CT) or magnetic resonance imaging available for review >3 months from the time of ablation. The median (range) imaging follow-up in these patients was 21 (3-73) months. The local tumour recurrence was identified on CT 11 months after the ablation procedure in a patient treated for a 2.7 cm RCC. • None of the patients developed metastatic RCC. • The major complication rate was 4% for patients with stage T1a tumours, 15% for those with stage T1b tumours, and 33% for those with stage T2 tumours. There were no procedural-related deaths. CONCLUSIONS: • Percutaneous renal cryoablation of RCC can be performed with high technical success in patients with tumours up to, and beyond 7 cm in maximum diameter. • The tumour recurrence rate after percutaneous renal cryoablation was low, and recurrence was not related to tumour size in this group of patients. • Statistically significant higher complication rates were seen with treatment of larger (higher T-stage) RCCs.

PSMA as a Theranostic Target in Hepatocellular Carcinoma: Immunohistochemistry and 68 Ga-PSMA-11 PET Using Cyclotron-Produced 68 Ga.

Prostate-specific membrane antigen (PSMA) is a validated target for molecular diagnostics and targeted radionuclide therapy. Our purpose was to evaluate PSMA expression in hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), and hepatic adenoma (HCA); investigate the genetic pathways in HCC associated with PSMA expression; and evaluate HCC detection rate with 68 Ga-PSMA-11 positron emission tomography (PET). In phase 1, PSMA immunohistochemistry (IHC) on HCC (n = 148), CCA (n = 111), and HCA (n = 78) was scored. In a subset (n = 30), messenger RNA (mRNA) data from the Cancer Genome Atlas HCC RNA sequencing were correlated with PSMA expression. In phase 2, 68 Ga-PSMA-11 PET was prospectively performed in patients with treatment-naïve HCC on a digital PET scanner using cyclotron-produced 68 Ga. Uptake was graded qualitatively and semi-quantitatively using standard metrics. On IHC, PSMA expression was significantly higher in HCC compared with CCA and HCA (P < 0.0001); 91% of HCCs (n = 134) expressed PSMA, which principally localized to tumor-associated neovasculature. Higher tumor grade was associated with PSMA expression (P = 0.012) but there was no association with tumor size (P = 0.14), fibrosis (P = 0.35), cirrhosis (P = 0.74), hepatitis B virus (P = 0.31), or hepatitis C virus (P = 0.15). Overall survival tended to be longer in patients without versus with PSMA expression (median overall survival: 4.2 vs. 1.9 years; P = 0.273). FGF14 (fibroblast growth factor 14) mRNA expression correlated positively (rho = 0.70; P = 1.70 × 10-5 ) and MAD1L1 (Mitotic spindle assembly checkpoint protein MAD1) correlated negatively with PSMA expression (rho = -0.753; P = 1.58 × 10-6 ). Of the 190 patients who met the eligibility criteria, 31 patients with 39 HCC lesions completed PET; 64% (n = 25) lesions had pronounced 68 Ga-PSMA-11 standardized uptake value: SUVmax (median [range] 9.2 [4.9-28.4]), SUVmean 4.7 (2.4-12.7), and tumor-to-liver background ratio 2 (1.1-11). Conclusion: Ex vivo expression of PSMA in neovasculature of HCC translates to marked tumor avidity on 68 Ga-PSMA-11 PET, which suggests that PSMA has the potential as a theranostic target in patients with HCC.

Percutaneous cryoablation of anterior renal masses: technique, efficacy, and safety.

OBJECTIVE: The safety and efficacy of renal tumor ablation are related, in part, to tumor location. Anterior tumors present a challenge due to the risk of injury to adjacent structures. The purpose of this study was to review the techniques, complications, and short-term outcomes of percutaneous cryoablation of anterior renal masses at a single institution. MATERIALS AND METHODS: We retrospectively identified the cases of 35 patients with 38 anterior renal masses managed with percutaneous imaging-guided cryoablation of renal tumors from March 2003 through February 2009. The technical success of the ablation procedure, serious complications, and evidence of local tumor recurrence were evaluated for each patient. RESULTS: The average maximal diameter of the anterior renal masses was 2.9 cm (SD, 0.9 cm; range, 1.4-4.8 cm). A single cryoablation procedure was performed for treatment of each patient, and technically successful ablation was achieved for all 38 tumors. A single severe adverse event occurred in one of the 35 patients (3% major complication rate). This patient had a pulmonary embolism (diagnosed at CT angiography the day after ablation). He recovered and was discharged from the hospital with anticoagulant medication only 2 days after the procedure. No local tumor recurrence was identified in any of the 29 patients who underwent follow-up contrast-enhanced CT or MRI with images available for review 3 months or longer from the time of ablation (mean, 18 months; range, 3-45 months). CONCLUSION: Percutaneous cryoablation of anterior renal masses can be performed with high technical success and low complication rates. The lack of local renal tumor recurrence at short-term follow-up evaluation in this study is encouraging, but long-term follow-up is necessary to ensure the durability of treatment.

Trends in Musculoskeletal Ablation: Emerging Indications and Techniques.

Image-guided percutaneous thermal ablation plays an increasingly important role in the multidisciplinary management of musculoskeletal lesions. Established indications for ablation in this setting include the treatment of osteoid osteomas, palliation of painful skeletal metastases, local control of oligometastatic disease, and consolidation of bone tumors at risk for fracture. Emerging indications include the treatment of symptomatic soft tissue masses such as extra-abdominal desmoid tumors and abdominal wall endometriosis. This review will discuss considerations in patient selection and preprocedural workup, ablation technology and techniques, strategies to avoid complications, and expected outcomes of ablation in the musculoskeletal system.

Percutaneous ureteral biopsy: safety and diagnostic yield.

PURPOSE: To evaluate safety and diagnostic yield of percutaneous CT-guided biopsy of extrarenal upper urinary tract lesions. MATERIALS AND METHODS: Retrospective review of our institutional database of image-guided biopsies yielded 44 CT-guided percutaneous biopsies in 44 unique patients that targeted ureteral (30, 68%) or other non-renal upper urinary tract lesions (14, 32%) between January 1, 2000 and May 1, 2017. Indications, pre-biopsy imaging, biopsy technique, peri-procedural antithrombotic use, complications including bleeding defined by Society of Interventional Radiology criteria, pathology results, and subsequent imaging were reviewed up to 3 months after the procedure to evaluate safety and diagnostic yield. RESULTS: Mean patient age was 66 (range 27-88) and 23/44 patients were male. The majority (34/44) of lesions were sampled with an 18-gauge biopsy device via a 17-gauge introducer needle, and the remaining 10/44 lesions were sampled with a 19/20 gauge system. The mean number of core samples obtained was 4 (range 2-10). No major complications occurred. Specifically, no patient developed a urine leak or urinary obstruction. Minor complications occurred in 3/44 (7%) biopsies, all retroperitoneal hemorrhages that did not require transfusion or other intervention. Biopsy was adequate for pathologic examination in 41 of 44 (93%) cases. Among patients undergoing surgical resection, biopsy diagnosis was concordant with surgical pathology in 9/10 (90%) cases and discordant in 1/10 (10%). CONCLUSION: CT-guided percutaneous biopsy of upper urinary tract lesions can be performed safely, with high diagnostic yield, and with a high rate of concordance on subsequent surgical pathology.

Safety and Efficacy of Percutaneous Image-guided Cryoablation of Completely Endophytic Renal Masses.

OBJECTIVE: To evaluate the safety, efficacy, and oncologic control of percutaneous image-guided cryoablation in the treatment of completely endophytic renal masses. Percutaneous image-guided cryoablation is a minimally invasive and effective treatment for small renal masses. Image-guided cryoablation is an attractive treatment for completely endophytic tumors given the challenge in visualization of such lesions during surgical extirpation. MATERIALS AND METHODS: A retrospective study evaluating percutaneous cryoablation of completely endophytic renal masses with normal overlying renal cortex was performed. From January 2003 to December 2015, 200 endophytic renal masses (RENAL score 3 - endophytic/exophytic) were identified from an internal renal ablation database. After imaging review, 49 tumors with completely intact overlying renal cortex in 47 patients were included in the study. Outcomes, including complications and oncologic efficacy were evaluated according to standard nomenclature. RESULTS: Patients comprised 37 men and 10 women (mean age 64.0 years) who underwent 48 cryoablation procedures to treat 49 renal masses. Mean tumor size was 2.5 ± 0.5 cm. Major complications occurred following 5 of the 48 (10%) procedures. Forty of 46 (87%) tumors with imaging follow-up were recurrence-free at a mean of 56 months. Five of six local recurrences were successfully retreated with cryoablatoin. CONCLUSION: Percutaneous thermal ablation of completely endophytic renal masses is a relatively safe procedure associated with acceptable complication and local tumor control rates. Given the complexities associated with partial nephrectomy, percutaneous cryoablation may be considered an alternative treatment for these select patients. Long-term follow-up studies are necessary to determine the durable efficacy of this treatment.

Low kV versus dual-energy virtual monoenergetic CT imaging for proven liver lesions: what are the advantages and trade-offs in conspicuity and image quality? A pilot study.

PURPOSE: Single-energy low tube potential (SE-LTP) and dual-energy virtual monoenergetic (DE-VM) CT images both increase the conspicuity of hepatic lesions by increasing iodine signal. Our purpose was to compare the conspicuity of proven liver lesions, artifacts, and radiologist preferences in dose-matched SE-LTP and DE-VM images. METHODS: Thirty-one patients with 72 proven liver lesions (21 benign, 51 malignant) underwent full-dose contrast-enhanced dual-energy CT (DECT). Half-dose images were obtained using single tube reconstruction of the dual-source SE-LTP projection data (80 or 100 kV), and by inserting noise into dual-energy projection data, with DE-VM images reconstructed from 40 to 70 keV. Three blinded gastrointestinal radiologists evaluated half-dose SE-LTP and DE-VM images, ranking and grading liver lesion conspicuity and diagnostic confidence (4-point scale) on a per-lesion basis. Image quality (noise, artifacts, sharpness) was evaluated, and overall image preference was ranked on per-patient basis. Lesion-to-liver contrast-to-noise ratio (CNR) was compared between techniques. RESULTS: Mean lesion size was 1.5 ± 1.2 cm. Across the readers, the mean conspicuity ratings for 40, 45, and 50 keV half-dose DE-VM images were superior compared to other half-dose image sets (p < 0.0001). Per-lesion diagnostic confidence was similar between half-dose SE-LTP compared to half-dose DE-VM images (p ≥ 0.05; 1.19 vs. 1.24-1.32). However, SE-LTP images had less noise and artifacts and were sharper compared to DE-VM images less than 70 keV (p < 0.05). On a per-patient basis, radiologists preferred SE-LTP images the most and preferred 40-50 keV the least (p < 0.0001). Lesion CNR was also higher in SE-LTP images than DE-VM images (p < 0.01). CONCLUSION: For the same applied dose level, liver lesions were more conspicuous using DE-VM compared to SE-LTP; however, SE-LTP images were preferred more than any single DE-VM energy level, likely due to lower noise and artifacts.

Myxoid hepatocellular neoplasms: imaging appearance of a unique mucinous tumor variant.

PURPOSE: To describe the imaging appearance of myxoid hepatocellular neoplasms (MHNs), including adenomas and carcinomas, a recently described pathologically unique tumor variant. MATERIALS AND METHODS: Single-institution review of pathologically proven MHNs revealed 4 patients with imaging prior to resection. All available cross-sectional imaging was then retrospectively reviewed in consensus using specified descriptive characteristics previously published for hepatocellular adenoma subtypes. Imaging characteristics on magnetic resonance imaging (MRI), ultrasound (US), and computed tomography (CT) were reviewed. RESULTS: MHNs were predominantly markedly T2 hyperintense with thin internal septations, circumscribed with lobulated margins, and demonstrated heterogeneous enhancement on arterial phase that became more homogenous on delayed phases. The lesions were hypodense on CT with similar enhancement characteristics as on MRI. On US, they were mildly hyperechoic and heterogeneous with posterior acoustic enhancement. CONCLUSION: MHNs show distinct imaging features that may allow accurate noninvasive diagnosis and differentiation from other hepatic lesions, including cavernous hemangioma, focal nodular hyperplasia, and other variants of hepatocellular adenoma or carcinoma. Differentiation between benign and malignant MHN may not be possible by imaging, possibly necessitating earlier definitive therapy or surgical management.

Iatrogenic cardiac papillary fibroelastoma: a study of 12 cases (1990 to 2000).

Cardiac papillary fibroelastoma (PFE) is a rare, benign, slow-growing tumor of the endocardium. Whether it represents a reactive tumoral lesion or a true neoplasm remains a matter of debate. However, an anecdotal association of PFEs with previous cardiac surgery has been reported. The current study was undertaken to determine the frequency and nature of iatrogenic events associated with PFEs and to provide a comprehensive review of the topic. The study group comprised 12 cases seen between 1990 and 2000, with specimens from 7 women and 5 men. Six developed postoperatively and 6 developed after thoracic irradiation. The 9 Mayo cases represented 18% of all surgically excised PFEs during the study period. The mean age at operation was 54 years (range, 29 to 79 years). The mean interval between the iatrogenic event and excision of the tumor was 18 years (range, 9 to 31 years). In 58% of cases, the presence of multiple tumors was either confirmed pathologically (41.7%) or strongly suggested by echocardiography (16.6%). Among patients who had undergone previous cardiac surgery, PFEs were found in the chamber closest to the procedure. Similarly, in patients who had received radiation therapy, tumors developed in the left atrium, in the right ventricle and atrium, and on the tricuspid valve within the radiation field. In conclusion, iatrogenic PFEs may be relatively common among all such tumors, are frequently multiple, and often involve nonvalvular endocardial surfaces.

Help of third-year medical students decreases first-year medical students' negative psychological reactions on the first day of gross anatomy dissection.

The assistance of third-year medical students (MS3) may be an easy, inexpensive, educational method to decrease physical and emotional stress among first-year medical students (MS1) on the first day of gross anatomy dissection. In the academic years 2000-2001 and 2001-2002, a questionnaire on the emotional and physical reactions on the first day of dissection was distributed to 84 MS1 at Mayo Medical School (Rochester, MN); 74 (88%) responded. Student perceptions were assessed on a 5-point Likert scale. The 42 second-year medical students (MS2) whose first academic year was 1999-2000 were used as a control group, because they had not had assistance from MS3. MS2 completed the same questionnaire (59% response rate). Data were collected from MS1 on the day of their first gross anatomy dissection. The most frequent reactions were headache, disgust, grief or sadness, and feeling light-headed. Significant differences (alpha < 0.05) were found with use of the chi(2) test to compare the emotional and physical reactions of MS1 and MS2. MS1 had significantly fewer physical reactions (64% vs. 88%), reporting lower levels of anxiety (23% vs. 48%), headache (14% vs. 36%), disgust (9% vs. 20%), feeling light-headed (11% vs. 24%), and reaction to the smell of the cadaver and laboratory (8% vs. 52%). MS1 commented that having MS3 at the dissection table was extremely helpful. They relied less on their peers and felt they learned more efficiently about the dissection techniques and anatomical structures. Using MS3 as assistants is one method to reduce fear and anxiety on the first day of gross anatomy dissection.