Update on Percutaneous Ablation for Sarcoma.

PURPOSE OF REVIEW: To provide an update on the current state of percutaneous thermal ablation in the treatment of sarcoma. RECENT FINDINGS: Data continue to accrue in support of ablation for local control and palliation of specific sarcoma subtypes such as extra-abdominal desmoid fibromatosis and for broader indications such as the treatment of oligometastatic disease. The synergistic possibilities of various combination therapies such as cryoablation and immunotherapy represent intriguing areas of active investigation. Histotripsy is an emerging non-invasive, non-thermal ablative modality that may further expand the therapeutic arsenal for sarcoma treatment. Percutaneous thermal ablation is a valuable tool in the multidisciplinary management of sarcoma, offering a minimally invasive adjunct to surgery and radiation therapy. Although there remains a paucity of high-level evidence specific to sarcomas, ablation techniques are demonstrably safe and effective for achieving local tumor control and providing pain relief in select patients and are of particular benefit in those with metastatic disease or requiring palliative care.

Percutaneous Cryoablation of Plasmacytomas: Oncologic Effectiveness and Adverse Events.

PURPOSE: To evaluate the oncologic outcomes and adverse events associated with cryoablation of plasmacytomas. MATERIALS AND METHODS: Retrospective review of an institutional percutaneous ablation database showed that 43 patients underwent 46 percutaneous cryoablation procedures for treatment of 44 plasmacytomas between May 2004 and March 2021. The treatment of 25 (25 of 44, 56.8%) tumors was augmented with bone consolidation/cementoplasty. The median patient age was 64 years (interquartile range [IQR], 54-69), and 30 of 43 (69.8%) patients were men. The median maximum plasmacytoma diameter was 5.0 cm (IQR, 3.1-7.0). Thirty of 44 (68.2%) tumors were periacetabular, vertebral, or located in the iliac wing. Twenty-nine of 44 (65.9%) cryoablated plasmacytomas were recurrent tumors after prior external beam radiation therapy (EBRT). Survival analyses were performed using the Kaplan-Meier method. Adverse events were graded using Society of Interventional Radiology criteria. RESULTS: The 5-year estimated local tumor recurrence-free survival was 85.3% (95% CI, 74.1%-98.1%), the 5-year estimated new plasmacytoma-free survival was 49.9% (95% CI, 33.9%-73.4%), and the 5-year estimated overall survival was 70.4% (95% CI, 56.9%-87.1%). Nine of 46 (19.6%) major adverse events occurred in 8 patients, including 3 of 46 (6.5%) new or progressive pathologic fractures at the ablation site requiring surgical intervention, 3 of 46 (6.5%) nerve injuries, 1 of 46 (2.2%) avascular necrosis and femoral head collapse, 1 of 46 (2.2%) septic arthritis, and 1 of 46 (2.2%) acute renal failure caused by rhabdomyolysis. CONCLUSIONS: Percutaneous cryoablation is a viable treatment option for patients with plasmacytomas, including those with recurrent plasmacytomas after EBRT. Postcryoablation adverse events are relatively common.

Image-guided tumor ablation in gynecologic oncology: Review of interventional oncology techniques and case examples highlighting a collaborative, multidisciplinary program.

As interventional oncology services within radiology mature, image-guided ablation techniques are increasingly applied to recurrent gynecologic malignancies. Ablation may be performed using thermal techniques like cryoablation, microwave ablation, or radiofrequency ablation, as well as non-thermal ones, such as focused ultrasound or irreversible electroporation. Feasibility and approach depend on tumor type, size, number, anatomic location, proximity of critical structures, and goals of therapy. Current indications include local control of limited metastatic disease or palliation of painful bone metastases refractory or unsuitable to conventional therapies. Technical aspects of these procedures, including methods to protect nearby critical structures are presented through illustrative examples. Cases amenable to image-guided ablation include, but are not limited to, hepatic or pulmonary metastases, musculoskeletal metastases, retroperitoneal nodal metastases, pelvic side wall disease, abdominal wall disease, and vaginal or vulvar tumors. Protective maneuvers, such as hydro-displacement of bowel, neuromonitoring, and retrograde pyeloperfusion through ureteral stents, permit safe ablation despite close proximity to vulnerable nerves or organs. Image-guided ablation offers an alternative modality to achieve local tumor control without the risks associated with surgery or systemic treatment in appropriately selected patients. A multidisciplinary approach to use of image-guided ablation includes collaboration between gynecologic oncology, interventional radiology, anesthesia, urology and radiation oncology teams allowing for appropriate patient-centered case selection. Long-term follow up and additional studies are needed to determine the oncologic benefits of such techniques.

A Single-Institution Experience in Percutaneous Image-Guided Cryoablation of Lymph Node Metastases.

OBJECTIVE. The purpose of this study was to assess the feasibility, safety, and efficacy of percutaneous cryoablation for the treatment of lymph node metastases. MATERIALS AND METHODS. In this single-institution retrospective study 55 patients were identified who underwent CT-guided cryoablation of metastatic lymph nodes between November 2006 and September 2019. Patient demographics, disease characteristics, and procedural details were recorded. The primary endpoints were technical success and major complications. The secondary endpoints were time to local and time to distant progression. Complications were graded according to the Society of Interventional Radiology consensus guidelines. RESULTS. The study sample comprised 55 patients (42 men, 13 women; mean age 64 ± 12 years) who underwent 61 cryoablation procedures to treat 65 lymph node metastases. Targeted nodes measured 1.7 ± 1.2 cm in mean short-axis diameter. Technical success was achieved in 60 of 61 cryoablation procedures (98%). Adjunctive maneuvers performed to protect adjacent structures included hydrodissection (n = 40), ureteral stenting (n = 3), and neural monitoring (n = 3). There were two Society of Interventional Radiology major complications (3%): pneumothorax (n = 1) and bleeding (n = 1). Local tumor control was achieved in treatment of 53 of 65 (82%) nodal metastases within a median of 25 months (range, 1-121 months) of follow-up. Local progression occurred in 12 of 65 cases (18%); the median time to recurrence was 11 months. CONCLUSION. Percutaneous cryoablation of nodal metastases is feasible and safe. Further investigation is warranted to assess the long-term efficacy of this technique and to define its role in oncologic care.

Improving Root Cause Analysis of Patient Safety Events in Radiology.

Patient safety events occur in health care, and root cause analysis (RCA) meetings held after these incidents often reveal valuable insights into systemic barriers between optimal processes or stated policies and actual practice, providing critical opportunities for improvement. The patient safety team that facilitates RCA meetings in the radiology department at the authors' institution received feedback suggesting dissatisfaction with the RCA process. The team followed a structured process improvement framework to analyze the root causes of this dissatisfaction and create a better system. Using a post-RCA survey to target satisfaction scores as an improvement goal, the team successfully increased participant and facilitator satisfaction levels with sustained results. The patient safety team applied structured process improvement methodologies to their own daily work, learning lessons about measuring difficult processes and choosing appropriate metrics, the benefits of standardized work, and how to continuously improve a quality program. In the course of improving the satisfaction of employees participating in the RCA process, a more robust, continuously improving patient safety program has emerged to enhance the ability of those within the department to report, learn from, and hopefully prevent patient safety events in the future.©RSNA, 2020.

Implementing a Radiology Residency Quality Curriculum to Develop Physician Leaders and Increase Value for Patients.

Diagnostic and interventional radiology residency programs must educate trainees on quality and patient safety topics to meet board requirements and prepare residents to become effective physician leaders. A quality curriculum should encompass process improvement methodology as well as instruction about crucial patient safety subjects. The authors have developed a standardized and structured approach to fulfill this need using didactic and experiential learning. The educational format includes short lectures, peer-to-peer instruction, and self-study, with the value of presented information reinforced by physician leaders and process improvement specialists. Equally important is a structured experience in departmental quality improvement wherein trainees learn the collaborative nature of effective durable process change in areas of interest to them. This curriculum is implemented during the 3rd year of radiology residency to leverage residents' knowledge and experience with radiology workflows and proximity to the American Board of Radiology Core Exam. Feedback from educators and trainees as well as objective examination data support this approach. This article shares guidance and lessons learned from the authors' radiology residency educational efforts and offers a framework for successful implementation of a comprehensive quality curriculum at any residency training program. This curriculum serves the dual purpose of developing skilled future physician leaders and promoting value for patients. ©RSNA, 2020.

Effectiveness and Safety of Percutaneous CT-Guided Rib Biopsy.

PURPOSE: To retrospectively evaluate effectiveness and safety of percutaneous CT-guided rib biopsy. MATERIALS AND METHODS: CT-guided core rib biopsies were performed in 249 consecutive patients between January 2002 and June 2016. Mean patient age was 64.8 years ± 13.8. Additional patient demographics, rib lesion characteristics, and procedural techniques were reviewed. Diagnostic yield was assessed, and complications were classified using SIR criteria. RESULTS: Mean maximal diameter of 249 rib lesions was 2.7 cm ± 1.8, and 107 (43%) rib lesions had an associated extraosseous soft tissue component. Of rib lesions, 172 (69%) were lytic, 75 (30%) were sclerotic, and 2 (1%) were identifiable only with positron emission tomography/CT correlation. Specimens from 241 (96.8%) biopsies were adequate for pathologic diagnosis, whereas 8 (3.2%) were nondiagnostic. Of diagnostic biopsies, 168 (69.7%) were positive for malignancy; 73 (30.3%) revealed benign etiologies. There was a significant difference in diagnostic biopsy rate depending on size of the rib lesion (mean 2.8 cm ± 1.8 for diagnostic biopsies vs mean 1.3 cm ± 0.5 for nondiagnostic biopsies; P = .007). Of rib lesions, 170 (99%) lytic lesions and 69 (92%) sclerotic lesions yielded diagnostic biopsies; diagnostic biopsy rate was significantly higher for lytic lesions than sclerotic lesions (P = .01). There were 14 (5.6%) minor complications and no major complications. CONCLUSIONS: Percutaneous CT-guided core rib biopsy resulted in high diagnostic yield and low complications. Diagnostic biopsy rates were higher with larger lesion size and lytic rib lesions.

Procedure-Related Pain During Image-Guided Percutaneous Biopsies: A Retrospective Study of Prevalence and Predictive Factors.

OBJECTIVE. The purpose of this study was to evaluate the prevalence and severity of pain reported during image-guided percutaneous biopsies and to identify factors associated with increased reported pain. MATERIALS AND METHODS. In this retrospective study, a database of adult patients who underwent CT- or ultrasound-guided percutaneous core needle biopsy between July 22, 2013, and February 1, 2018, was reviewed. Data collected included patient age and sex, biopsy site, biopsy type (lesion or parenchymal), needle gauge, number of passes, use of sedation, and whether it was the patient's first recorded biopsy. The maximum procedure-related pain reported on a 0-10 numeric rating scale was recorded. Multivariable logistic regression with generalized estimating equations was used to assess the association between covariates and patient-reported pain. RESULTS. A total of 13,344 biopsy procedures were performed in 10,474 patients. Patients reported no pain (0 of 10 scale) during 9765 (73.2%) procedures. Female sex, younger age at biopsy, undergoing IV sedation, and larger needle diameter were all associated with increases in patient-reported pain. Biopsies of renal allografts were the least likely to be painful, followed by hepatic allografts. CONCLUSION. Patients typically report mild or no pain from image-guided biopsy performed by radiologists. Younger patients and women report greater pain. This information can assist preprocedural counseling and reassurance of patients and may help them predict procedure-related patient needs.

Frequency of Bleeding Complications After Percutaneous Core Needle Biopsy and the Association With Aspirin Usage and Length of Aspirin Discontinuation.

OBJECTIVE. The purpose of this study is to report the frequency of major bleeding after percutaneous image-guided core biopsy and its association with aspirin usage and duration of prebiopsy aspirin abstinence. MATERIALS AND METHODS. A retrospective review of percutaneous image-guided core biopsies performed at our institution between September 1, 2005, and September 1, 2016, was performed (n = 30,966). Patients were excluded if aspirin usage data were missing (n = 633). Bleeding complications were defined using the Common Terminology Criteria for Adverse Events and were considered significant if they were grade 3 or higher. Multivariate models were adjusted for age, sex, platelet count, international normalized ratio, and biopsy target. Three categorizations of aspirin use were examined: any use within 10 days before biopsy, duration of abstinence (> 10 days or no aspirin, 8-10 days, 4-7 days, and 0-3 days before biopsy), and use on the day of biopsy. Associations with bleeding complications were modeled using logistic regression models. A p < 0.05 was considered significant. RESULTS. The study included 30,333 biopsies in 21,938 subjects (57% male; median age, 60 years; interquartile range, 49-70 years). Of the biopsies, 7921 (26.1%) were performed in patients who received aspirin within 10 days of biopsy, and 3761 (47.5%) of those biopsies were performed in patients who took aspirin within 3 days. Ninety-eight (0.32%) significant bleeding complications occurred overall, including 34 (0.43%) in patients who used aspirin within 10 days before biopsy (odds ratio, 1.5; 95% CI, 0.96-2.3; p = 0.08). Duration of abstinence was associated with a significantly increased bleeding risk only between 0-3 days versus more than 10 days or no aspirin (odds ratio, 2.1; 95% CI, 1.3-3.6; p = 0.004). Aspirin use on the day of biopsy showed the greatest increase in risk (1.9%; odds ratio, 6.6; 95% CI, 3.8-11.5; p < 0.001). CONCLUSION. Significant bleeding complications after biopsy remain rare even among patients with recent aspirin usage, although shorter duration of prebiopsy abstinence increases bleeding risk, most significantly if aspirin is taken the day of biopsy.

Patient-Reported Outcomes After Percutaneous Renal Ablation: Initial Experience.

OBJECTIVE: The purpose of this study is to assess patient-reported outcomes after renal tumor ablation. MATERIALS AND METHODS: A retrospective review of a pilot quality initiative from February 2016 to April 2016 in our renal ablation practice was performed to assess outcomes after treatment. This included a total of 38 patients (mean age, 63 years; range, 39-83 years) undergoing renal ablation procedures. This pilot included the quantification of recovery, pain, physical well-being, interference with social activities, and physical function as reported by the patient, including measures obtained from the National Institutes of Health's Patient-Reported Outcome Measurement Information System (PROMIS). Such measures were obtained within 24 hours before ablation and days 1-7 and 30 after ablation. RESULTS: The mean numeric rating (0-10) pain scores at 1 and 2 days after treatment were 1.8 (SD, 2.3) and 2.6 (SD, 2.5). Similarly, mean scores for both overall physical well-being and social activities declined by less than 2 points in the days after ablation. PROMIS scales for physical function and social activities showed very little change from baseline. Nearly 50% of patients thought that they had completely recovered from the ablation on the day after treatment; this perception of recovery declined at days 3-5 and then increased to 89% at 30 days after ablation. CONCLUSION: This pilot study shows the feasibility of capturing patient-reported outcomes after renal ablation. Such information, particularly when collected from a broader patient population, will be valuable in providing a means to measure quality in the ablation practice and in improving patient education regarding treatment.

A Comparison of Bleeding Complications in Patients Undergoing Percutaneous Renal Cryoablation Using Cryoprobes with and without Heat-Based Track Ablation.

PURPOSE: To determine if the use of heat-based track ablation with new-generation cryoprobes is associated with decreased renal cryoablation bleeding complications. MATERIALS AND METHODS: Eighty-nine patients who underwent percutaneous cryoablation for treatment of a solitary renal mass with the use of cryoprobes with track ablation (CwTA) from October 29, 2015, to May 18, 2017, were compared with a propensity score-matched control group of 178 patients who underwent treatment with the use of cryoprobes without track ablation (Cw/oTA) from January 5, 2012, to October 28, 2015. Bleeding complications were assessed with the use of the Clavien-Dindo classification system and compared between the matched patient groups by means of conditional logistic regression, both univariately and in a multivariate model to adjust for imbalanced covariates. Change in patient hemoglobin was evaluated as a secondary measure of periprocedural bleeding. RESULTS: Seven of the 89 patients (7.9%) who underwent percutaneous renal cryoablation with the use of CwTA developed major (grade ≥3) bleeding complications, versus 13 of the 178 patients (7.3%) treated with the use of Cw/oTA. Conditional logistic regression analysis adjusted for potential confounders showed that major, minor, and overall bleeding complications were not associated with the type of cryoprobes used for treatment (P values .727, .370, and .733, respectively). There was also no significant difference in postprocedural change in hemoglobin for patients treated with the use of CwTA compared with Cw/oTA (P = .909). Furthermore, total duration of track ablation in patients with bleeding complications (mean 169 seconds, SD 68, range 60-240) was not significantly different than in patients without bleeding complications (mean 171 seconds, SD 86, range 30-360; P = .940). CONCLUSIONS: The use of cryoprobes with heat-based track ablation did not decrease the incidence of bleeding complications after renal cryoablation compared with procedures performed without track ablation.

Percutaneous Cryoablation of Solitary, Sporadic Renal Cell Carcinoma: Outcome Analysis Based on Clear-Cell versus Papillary Subtypes.

PURPOSE: To evaluate treatment outcomes with percutaneous cryoablation (PCA) based on renal cell carcinoma (RCC) histology. METHODS AND MATERIALS: Patients treated with PCA for a solitary, sporadic stage T1a RCC from 2003 to 2016 were identified from a single institution's renal ablation registry. Patients with multiple tumors, history of RCC, or genetic syndromes associated with RCC (n = 60); no specific RCC subtype determined from core biopsy (n = 66); RCC subtype other than clear-cell or papillary (n = 7); or less than 3 mo of follow-up imaging (n = 5) were excluded. In total, 173 patients met study inclusion criteria. Oncologic outcomes, clinical outcomes, and complications were evaluated based on tumor subtype. RESULTS: Of the 173 patients who underwent PCA for a stage T1a RCC, 130 (75%) had clear-cell RCC (ccRCC) and 43 (25%) had papillary RCC (pRCC). Median tumor size was 2.9 cm (range, 1.3-4.0 cm). Technically successful cryoablation was achieved in all 173 patients. Local tumor recurrence developed in 6 patients with ccRCC (4.6%), new renal tumors developed in 1 patient (0.8%), and metastatic RCC developed in 1 patient (0.8%) who also had local tumor recurrence. No patients with pRCC showed local tumor recurrence, new renal tumors, or metastatic disease. The 5-year disease-free survival rate in patients with ccRCC was 88%, compared with 100% in patients with pRCC (P = .48). Nine patients (5.2%), all with ccRCC, experienced major complications (P = .11). CONCLUSIONS: Percutaneous ablation is a viable treatment option for patients with clinical stage T1a pRCC and ccRCC. Percutaneous ablation may be a very favorable treatment strategy particularly for pRCC.

Percutaneous Cryoablation of the Horseshoe Kidney: An Initial Experience.

Between June 2006 and January 2016, 6 renal cryoablation procedures were performed in 5 patients with horseshoe kidneys. Renal cell carcinoma (RCC) accounted for 5 of the tumors, and the sixth was a carcinoid tumor. All 6 procedures were technically successful. The patient with the carcinoid tumor developed local tumor progression 38 months after ablation. Technique effectiveness was achieved in all 5 patients with RCC. Two complications occurred: obstructive hematuria and transient inguinal neuralgia after ablation. In this small initial experience, percutaneous cryoablation appears feasible in treatment of primary tumors in horseshoe kidneys.

Retrospective Review of Percutaneous Image-Guided Ablation of Oligometastatic Prostate Cancer: A Single-Institution Experience.

PURPOSE: To retrospectively review and report the efficacy and safety of percutaneous image-guided ablation (cryoablation or radiofrequency ablation) in the treatment of oligometastatic prostate cancer. MATERIALS AND METHODS: An institutional registry was retrospectively reviewed and revealed 16 patients with oligometastatic prostate cancer (median age, 67 y; range, 50-86 y) who underwent percutaneous image-guided ablation to treat 18 metastatic sites. A subgroup of 7 patients with 8 metastases were androgen-deprivation therapy (ADT)-naïve and underwent ablation to delay initiation of ADT. Local tumor control, progression-free survival (PFS), ADT-free survival, and procedural complications were analyzed. RESULTS: Local tumor control was achieved in 15 of 18 metastases (83%) at a median follow-up of 27 months (range, 5-56 mo). Local tumor recurrence was found in 3 of 18 metastases (17%), with a median time to local recurrence of 3.5 months (range, 3-38 mo). Estimated PFS rates at 12 and 24 months were 56% (95% confidence interval [CI], 30%-76%) and 43% (95% CI, 19%-65%), respectively. In the 7 ADT-naïve patients, local tumor control was achieved in all metastases, and the median ADT-free survival period was 29 months. There were no major procedural complications. CONCLUSIONS: In this cohort of patients with oligometastatic prostate cancer, percutaneous image-guided ablation was feasible and well tolerated and achieved acceptable local tumor control rates. Percutaneous ablation may be of particular utility in patients who wish to delay initiation of ADT.

Percutaneous Cryoablation of Renal Cell Carcinoma with Sinus Vein Involvement Based on Preprocedural Imaging.

PURPOSE: To assess feasibility, safety, and oncologic outcomes of cryoablation in treatment of renal cell carcinoma (RCC) with extension into adjacent renal sinus vein. MATERIALS AND METHODS: Review of an internally maintained renal ablation registry identified 7 patients (4 men and 3 women; median age 62 y; age range, 45-91 y) who underwent percutaneous cryoablation of RCC with imaging consistent with extension of tumor into an immediately adjacent renal sinus vein. Four of 7 (57%) patients had recurrent tumors following prior partial nephrectomy. Three of 7 patients (43%) had solitary kidneys. RESULTS: Median tumor size was 4.3 cm (range, 1.9-5.0 cm). Biopsy showed RCC in 6 of 7 patients. Technical success was achieved in 6 of 7 tumors (86%) There was a single Clavien grade 3 major complication. Median hospital stay was 1 night (range, 1-3 nights). Follow-up imaging performed in the 6 successfully treated patients at median 11 months (range, 2-101 months) showed no local tumor progression. In 2 patients with solitary kidneys, estimated glomerular filtration rate declined from 63 mL/min/1.73 m2 to 45 mL/min/1.73 m2 and 67 mL/min/1.73 m2 to 40 mL/min/1.73 m2 at 101 months and 12 months following treatment, respectively. Estimated glomerular filtration rate remained > 60 mL/min/1.73 m2 in the remaining patients. CONCLUSIONS: In this small select group of patients, percutaneous cryoablation afforded a safe and, based on early outcomes, effective means of providing local control of locally invasive RCC. Percutaneous cryoablation may obviate the need for nephrectomy in similar patients.

Outcomes of Ultrasound-Guided Thrombin Injection of Nongroin Arterial Pseudoaneurysms.

PURPOSE: To evaluate success and complication rates of percutaneous ultrasound-guided thrombin injection of nongroin pseudoaneurysms (PSAs). MATERIALS AND METHODS: Retrospective review of a prospectively maintained institutional database yielded 39 cases of arterial PSAs occurring at nongroin sites that were treated with percutaneous ultrasound-guided thrombin injection between 2000 and 2016 (average patient age 69.2 y ± 14.0). Of PSAs, 74.4% (29/39) arose in the upper extremities, and 92.3% (36/39) were iatrogenic. The brachial artery was the most commonly affected vessel (51.3% [20/39]), and arterial access was the most common cause (56.4% [22/39]). Average overall PSA size was 2.4 cm (range, 0.5-7.2 cm); average amount of thrombin injected was 320 IU (range, 50-2,000 IU). Technical success was defined as absence of flow within the PSA immediately after thrombin injection. Treatment success was defined as sustained thrombosis on follow-up imaging obtained at 1-3 days after treatment. RESULTS: Technical and treatment success rates of thrombin injections were 100% (39/39) and 84.8% (28/33), respectively. Longer term follow-up imaging (average 71 d; range, 12-201 d) was available for 7 of the treatment successes with 100% (7/7) showing sustained thrombosis. Comparing treatment successes and failures, there was no significant difference in average PSA size (2.3 cm vs 2.0 cm, P = .51) or average amount of thrombin injected (360 IU vs 180 IU, P = .14). There were no complications. CONCLUSIONS: Ultrasound-guided thrombin injection is a safe, efficacious treatment option for PSAs arising in nongroin locations.

Effects of Aspirin Therapy on Ultrasound-Guided Renal Allograft Biopsy Bleeding Complications.

PURPOSE: To determine if patient aspirin exposure and timing affect bleeding risk after renal allograft biopsy. MATERIALS AND METHODS: Review of 6,700 renal allograft biopsies (in 2,362 unique patients) was performed. Median patient age was 53.0 years [interquartile range 43.0, 62.0]; 56.2% of patients were male. Of biopsies, 4,706 (70.2%) were performed in patients with no aspirin exposure within 10 days of biopsy; 664 (9.9%), were performed within 8-10 days of aspirin exposure; 855 (12.8%), within 4-7 days; and 475 (7.1%), within 0-3 days. Follow-up to 3 months after the procedure was completed in all patients. Biopsies were categorized as protocol or indication; 19.7% were indication biopsies. Bleeding complications were graded based on SIR criteria. Logistic regression models examined the association between aspirin use and bleeding events. RESULTS: Rate [95% confidence interval] of major bleeding complications was 0.24% [0.14, 0.39], and rate of any bleeding complication was 0.66% [0.46, 0.90]. Bleeding events were significantly associated with patients undergoing indication biopsies compared with protocol biopsies (odds ratio [OR] 2.27, P = .012). Patient factors associated with major bleeding complications in multivariate models included estimated glomerular filtration rate (OR 0.61, P = .016) and platelet count (OR 0.64, P = .033). Aspirin use was not significantly associated with increased risk of bleeding complication except for use of 325 mg of aspirin within 3 days of biopsy (any complication OR 3.87 [1.12, 13.4], P = .032; major complication OR 6.30 [1.27, 31.3], P = .024). CONCLUSIONS: Renal allograft biopsy bleeding complications are very rare, particularly for protocol biopsies. Use of 325 mg of aspirin within 3 days of renal allograft biopsy was associated with increased bleeding complications.

Ablation of Musculoskeletal Metastases.

OBJECTIVE: The purpose of this article is to summarize the evidence supporting thermal ablation of musculoskeletal metastases on the basis of clinical application and to describe an approach to percutaneous ablative treatment, including patient workup, procedural strategy and techniques, and postablation follow-up. CONCLUSION: Percutaneous ablation of musculoskeletal metastases may result in significant pain palliation, prevention of morbidity from skeletal-related events, and local tumor control. This minimally invasive approach has unique advantages compared with surgery or radiation therapy.

Utility of PET/CT After Cryoablation for Early Identification of Local Tumor Progression in Osseous Metastatic Disease.

OBJECTIVE: The purpose of this study is to evaluate the utility of combined PET/CT for the detection of early local tumor progression after cryoablation of bone metastases. MATERIALS AND METHODS: A retrospective single-institution review revealed 61 consecutive patients with 80 separate bone metastases treated with cryoablation who were evaluated with a preablation PET/CT and at least two postablation PET/CT examinations between September 2007 and July 2015. Patients were excluded if they had local therapy or pathologic fracture after ablation. The patients were grouped according to postcryoablation disease status (i.e., local tumor progression or not) and PET radiotracer (i.e., 11C-choline or 18F-FDG) used. The maximum standardized uptake value (SUVmax) ratio (i.e., ratio of SUVmax to blood pool) was calculated within each osseous metastasis before and after cryoablation, and these were then compared between groups. RESULTS: Of the 61 patients and 80 ablations performed, 32 patients were imaged with FDG PET/CT and 29 were imaged with 11C-choline PET/CT. Twenty-three patients imaged with FDG and 13 patients imaged with 11C-choline had evidence of local tumor progression on all postablation PET/CT examinations. The SUVmax ratio was significantly higher in patients with local tumor progression on the first and most remote postcryoablation PET/CT examinations for both FDG and 11C-choline (p < 0.001 in all cases). There was no significant difference in the postablation systemic therapy between the groups with and without local tumor progression. CONCLUSION: Increased SUVmax ratio in patients after cryoablation for osseous metastatic disease should raise concern about local tumor progression independently of time after ablation.

Safety and Outcomes of Percutaneous Biopsy of 61 Hepatic Adenomas.

OBJECTIVE: Given the recent classification of hepatic adenoma (HA) into subtypes and recognition of imperfect specificity of MRI to differentiate HA from focal nodular hyperplasia (FNH), there is a resurgent interest in the role of biopsy to diagnose HA. The purpose of this study was to determine the safety and outcomes of biopsy of HAs. MATERIALS AND METHODS: A retrospective review of the electronic medical records of all patients who underwent hepatic mass biopsy revealing HA from 2000 through 2013 was performed. The biopsy procedure parameters were evaluated. Complications were graded using the Common Terminology Criteria for Adverse Events. Pathology-specific outcomes related to the diagnosis of HA were assessed. RESULTS: Sixty patients (52 women and eight men) were identified with a mean age of 42 ± 13 (SD) years and a mean follow-up of 2.3 ± 3.0 years after biopsy. One patient had two HAs biopsied during the same procedure, resulting in a total of 61 biopsy-proven HAs. Of the 60 patients, one patient (2%) had a single major complication, which involved bleeding that resulted in a blood transfusion, and six patients (10%) had a minor complication. A total of six (10%) discordant biopsy results were found: Four biopsy-proven HAs (7%) revealed FNH on surgical resection or repeat biopsy, one HA (2%) showed well-differentiated hepatocellular carcinoma (HCC) at subsequent biopsy, and one HA (2%) showed findings suggestive of HCC on follow-up imaging. CONCLUSION: Complications after biopsy of HAs are uncommon. Although uncommon, discordant pathology results between biopsy and surgical resection may occur.