Outcomes of Percutaneous Thermal Ablation for Biopsy-Proven T1a Renal Cell Carcinoma in Patients With Other Primary Malignancies.

OBJECTIVE. The purpose of this article is to investigate the oncologic effectiveness and survival outcomes of percutaneous image-guided thermal ablation for clinical T1a renal cell carcinoma (RCC) in patients with other primary nonrenal malignancies. MATERIALS AND METHODS. We reviewed records of patients with histologically proven T1a RCC (< 4.0 cm) treated with thermal ablation over a period of 10 years between January 2005 and December 2014. We recorded past or current history of primary malignancy other than RCC, status of the primary malignancy, tumor histology (in remission or under therapy), and whether patient was currently alive or not, and if not, the date and reason of death. Three cohorts were studied: patients with RCC only (group A), patients with RCC and other primary malignancy in remission (group B), and patients with RCC and other primary malignancy under treatment (group C). The Kaplan-Meier product-limit estimator was used to estimate the survival rates. RESULTS. One hundred nine patients met the inclusion criteria (109 lesions, 110 ablation procedures). There were 46, 45, and 18 patients in the A, B, and C groups, respectively. The 5-year survival was 87%, 63%, and 40% for groups A, B, and C, respectively. The local recurrence-free survival for the whole sample was 95% at 3, 5, and 10 years. The disease-free survival was 96%, 93%, and 91% at 3, 5, and 10 years. Although a significant difference is noted between the three cohorts in overall survival (p = .02); for RCC, there were no significance differences in the local recurrence-free, disease-free, metastasis-free, and cancer-specific survivals. In addition, there was no difference in outcomes for patients in group B (in remission) when compared with those in group C (under treatment). CONCLUSION. Thermal ablation is an effective and safe modality of treatment of T1a RCC in patients with other primary malignancies that are in remission or under treatment.

Risk factors for recurrent percutaneous nephrostomy catheter-related infections.

PURPOSE: Percutaneous nephrostomy (PCN) catheters are mainly indicated for urinary tract obstructions. Unfortunately, the rate for infection and recurrence remains elevated. Our objective was to identify the risk factors leading to recurrent PCN-related infections (PCNI) in cancer patients. METHODS: We retrospectively reviewed 571 patients who underwent initial PCN catheter placement at our institution. Of these, we identified patients with a definite PCNI and catheter exchange, with a minimum 30-day follow-up. We defined PCNI as presence of a urine culture positive for bacteria (≥ 104 CFU/mL) plus symptoms of urinary tract infection. A PCNI was considered recurrent if the same organism was isolated. Antibiotics were considered concordant if they were active against all identified organisms. RESULTS: A total of 81 patients (14%) developed an initial PCNI. Of 47 patients with 30-day follow-up, 10 patients (21%) were identified as having a recurrent PCNI. In terms of demographic characteristics, clinical manifestations, and microbiological data, there was no statistically significant difference between the recurrent and non-recurrent groups. However, in multivariate logistic regression analysis, two factors were independently associated with a decrease in recurrent PCNI: concordant antibiotic use (OR 0.04; p = 0.008) and PCN catheter exchange within 4 days of infection (OR 0.1; p = 0.048). CONCLUSIONS: To decrease the high rate of recurrent infections, associated costs, and potential delay in further chemotherapy, we recommend that once antimicrobial susceptibility test results are available and the patient is known to be receiving concordant antimicrobials, clinicians proceed with immediate PCN catheter exchange, ideally within the first 4 days of the infection.

MRI-Guided Interventions in Musculoskeletal System.

Image-guided interventions in the musculoskeletal system require accurate detection and characterization of lesions involving bone and soft tissues. Magnetic resonance imaging (MRI) has superior soft tissue contrast resolution particularly in bone and soft tissues where computed tomography and ultrasonography have significant limitations. In addition, the multiplanar imaging capabilities of MRI facilitate targeting lesions and tracking interventional devices. Although conventional diagnostic MRI sequences suffer from motion sensitivity and prolonged imaging time, recently developed fast imaging sequences allow for rapid acquisition of high-quality images, rendering MRI more suitable for image-guided interventions. Although computed tomography and ultrasonography still dominate the spectrum of image-guided interventions in the musculoskeletal system, many MRI-guided procedures have been developed and are well established in routine clinical work. In addition, new techniques and novel MRI-guided applications are being developed to address complex clinical problems in a minimally invasive fashion.

Investigation of tissue cellularity at the tip of the core biopsy needle with optical coherence tomography.

We report the development and the pre-clinical testing of a new technology based on optical coherence tomography (OCT) for investigating tissue composition at the tip of the core biopsy needle. While ultrasound, computed tomography, and magnetic resonance imaging are routinely used to guide needle placement within a tumor, they still do not provide the resolution needed to investigate tissue cellularity (ratio between viable tumor and benign stroma) at the needle tip prior to taking a biopsy core. High resolution OCT imaging, however, can be used to investigate tissue morphology at the micron scale, and thus to determine if the biopsy core would likely have the expected composition. Therefore, we implemented this capability within a custom-made biopsy gun and evaluated its capability for a correct estimation of tumor tissue cellularity. A pilot study on a rabbit model of soft tissue cancer has shown the capability of this technique to provide correct evaluation of tumor tissue cellularity in over 85% of the cases. These initial results indicate the potential benefit of the OCT-based approach for improving the success of the core biopsy procedures.

Portomesenteric Venous Stenting for Palliation of Ascites and Variceal Bleeding Caused by Prehepatic Portal Hypertension.

BACKGROUND: The purpose of this study was to evaluate percutaneous transhepatic portal vein stenting (PVS) for palliation of refractory ascites and/or variceal bleeding caused by extrahepatic portomesenteric venous stenosis in patients with pancreaticobiliary cancer. MATERIALS AND METHODS: A single-institution, retrospective review of patients who underwent PVS between January 2007 and July 2015 was performed. A total of 38 patients were identified, of whom 28 met the inclusion criterion of PVS performed primarily for refractory ascites or variceal bleeding. In addition to technical success and overall survival, clinical success was measured by fraction of remaining life palliated. The palliative effect of PVS was also quantified by measuring changes in liver and ascites volumes after the procedure. RESULTS: Technical success was 93% (26/28). Stent deployment involved more than one portomesenteric vessel in most patients (20/26). The cumulative probability of symptom recurrence at 6, 12, 18, and 24 months was 12%, 16%, 26%, and 40%, respectively. There was a significant difference (p < .001) in the probability of symptom recurrence, recurrence of abdominal ascites, and increase in liver volume between patients whose stents remained patent and those whose stents demonstrated partial or complete occlusion. The mean fraction of remaining life palliated was 87%. All but two patients were found to have improvement in clinical symptoms for the majority of their lives after the procedure. There were no major or minor complications. CONCLUSION: As a low-risk procedure with a high clinical success rate, PVS can play a substantial role in improving quality of life in patients with portomesenteric stenoses. IMPLICATIONS FOR PRACTICE: Portomesenteric venous stenosis is a challenging complication of pancreaticobiliary malignancy. Portomesenteric stenoses can lead to esophageal, gastric, and mesenteric variceal bleeding, as well as abdominal ascites. The purpose of this study was to evaluate the safety and efficacy of portal vein stenting (PVS) in patients with cancer who have symptomatic portal hypertension caused by portomesenteric venous compression. As a low-risk procedure with a high clinical success rate, PVS can play a substantial role in improving quality of life in patients with portomesenteric stenoses.

Characteristics of percutaneous core biopsies adequate for next generation genomic sequencing.

PURPOSE: Determine the characteristics of percutaneous core biopsies that are adequate for a next generation sequencing (NGS) genomic panel. MATERIALS AND METHODS: All patients undergoing percutaneous core biopsies in interventional radiology (IR) with samples evaluated for a 46-gene NGS panel during 1-year were included in this retrospective study. Patient and procedure variables were collected. An imaging-based likelihood of adequacy score incorporating targeting and sampling factors was assigned to each biopsied lesion. Univariate and multivariate logistic regression was performed. RESULTS: 153 patients were included (58.2% female, average age 59.5 years). The most common malignancy was lung cancer (40.5%), most common biopsied site was lung (36%), and average size of biopsied lesions was 3.8 cm (+/- 2.7). Adequacy for NGS was 69.9%. Univariate analysis showed higher likelihood of adequacy score (p = 0.004), primary malignancy type (p = 0.03), and absence of prior systemic therapy (p = 0.018) were associated with adequacy for NGS. Multivariate analysis showed higher adequacy for lesions with likelihood of adequacy scored 3 (high) versus lesions scored 1 (low) (OR, 7.82; p = 0.002). Melanoma lesions had higher adequacy for NGS versus breast cancer lesions (OR 9.5; p = 0.01). Absence of prior systemic therapy (OR, 6.1; p = 0.02) and systemic therapy 3 months before biopsy yielded greater adequacy for NGS. Lesions <3 cm had greater adequacy for NGS than larger lesions (OR 2.72, p = 0.02). CONCLUSION: As targeted therapy becomes standard for more cancers, percutaneous biopsy specimens adequate for NGS genomic testing will be needed. An imaging-based likelihood of adequacy score assigned by IR physicians and other pre-procedure variables can help predict the likelihood of biopsy adequacy for NGS.

Cryoablation of Bone Metastases from Renal Cell Carcinoma for Local Tumor Control.

BACKGROUND: Patients with bone metastases from renal cell carcinoma often are not surgical candidates and have a poor prognosis. There are limited data on the use of cryoablation as a locoregional therapy for bone metastases. Our objective was to assess the local tumor-control rate following cryoablation of bone metastases in the setting of renal cell carcinoma. METHODS: We retrospectively reviewed the medical records of patients with metastatic renal cell carcinoma who underwent cryoablation for bone metastases between 2007 and 2014. We excluded patients if the intent of treatment was for pain palliation only, if cryoablation was performed without an attempt for complete tumor control (cytoreduction), or if the patient had no further follow-up beyond the cryoablation procedure. We recorded patient demographics, procedural variables, and complications. Cross-sectional imaging and clinical follow-up were reviewed to determine disease recurrence. The median overall survival and recurrence-free survival were determined using the Kaplan-Meier method. RESULTS: Forty patients (30 male and 10 female) with 50 bone metastases were included for analysis. The mean patient age was 62 years (range, 47 to 82 years). The median follow-up was 35 months (95% confidence interval [CI], 22.7 to 74.4 months). Twenty-five (62.5%) of the 40 patients had oligometastatic disease, defined as ≤5 metastases at the time of ablation. The mean tumor size was 3.4 ± 1.5 cm. Metastases in the pelvic region represented 68% of the treated tumors (34 of 50). The overall local tumor-control rate per lesion was 82% (41 of 50). Patients with oligometastatic disease experienced better local tumor control (96% [24 of 25]) compared with patients who had >5 metastases (53.3% [8 of 15]) (p = 0.001). The local tumor-control rate was better for lesions for which a larger mean difference between maximum ice-ball diameter and maximum lesion diameter was achieved (2.2 ± 0.9 cm for those without recurrence versus 1.35 ± 1.2 cm for those with recurrence; p = 0.005). There were 3 grade-3 complications and 1 grade-4 complication. CONCLUSIONS: Cryoablation can be effective for achieving local oncologic control in bone metastases from renal cell carcinoma and may represent a valuable alternative to surgical metastasectomy in select patients. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Impact of an inferior vena cava filter retrieval algorithm on filter retrieval rates in a cancer population.

OBJECTIVE: Our primary purpose was to assess the impact of an inferior vena cava filter retrieval algorithm in a cancer population. Because cancer patients are at persistently elevated risk for development of venous thromboembolism (VTE), our secondary purpose was to assess the incidence of recurrent VTE in patients who underwent filter retrieval. METHODS: Patients with malignant disease who had retrievable filters placed at a tertiary care cancer hospital from August 2010 to July 2014 were retrospectively studied. A filter retrieval algorithm was established in August 2012. Patients and referring physicians were contacted in the postintervention period when review of the medical record indicated that filter retrieval was clinically appropriate. Patients were classified into preintervention (August 2010-July 2012) and postintervention (August 2012-July 2014) study cohorts. Retrieval rates and clinical pathologic records were reviewed. RESULTS: Filter retrieval was attempted in 34 (17.4%) of 195 patients in the preintervention cohort and 66 (32.8%) of 201 patients in the postintervention cohort (P < .01). The median time to filter retrieval in the preintervention and postintervention cohorts was 60 days (range, 20-428 days) and 107 days (range, 9-600 days), respectively (P = .16). In the preintervention cohort, 49 of 195 (25.1%) patients were lost to follow-up compared with 24 of 201 (11.9%) patients in the postintervention cohort (P < .01). Survival was calculated from the date of filter placement to death, when available. The overall survival for patients whose filters were retrieved was longer compared with the overall survival for patients whose filters were not retrieved (P < .0001). Of the 80 patients who underwent successful filter retrieval, two patients (2.5%) suffered from recurrent VTE (n = 1 nonfatal pulmonary embolism; n = 1 deep venous thrombosis). Both patients were treated with anticoagulation without filter replacement. CONCLUSIONS: Inferior vena cava filter retrieval rates can be significantly increased in patients with malignant disease with a low rate (2.5%) of recurrent VTE after filter retrieval.

Development of a predictive model for 6 month survival in patients with venous thromboembolism and solid malignancy requiring IVC filter placement.

PURPOSE: Our purpose was to develop a predictive model for short-term survival (i.e. <6 months) following inferior vena cava filter placement in patients with venous thromboembolism (VTE) and solid malignancy. METHODS: Clinical and laboratory parameters were retrospectively reviewed for patients with solid malignancy who received a filter between January 2009 and December 2011 at a tertiary care cancer center. Multivariate Cox proportional hazards modeling was used to assess variables associated with 6 month survival following filter placement in patients with VTE and solid malignancy. Significant variables were used to generate a predictive model. RESULTS: 397 patients with solid malignancy received a filter during the study period. Three variables were associated with 6 month survival: (1) serum albumin [hazard ratio (HR) 0.496, P < 0.0001], (2) recent or planned surgery (<30 days) (HR 0.409, P < 0.0001), (3) TNM staging (stage 1 or 2 vs. stage 4, HR 0.177, P = 0.0001; stage 3 vs. stage 4, HR 0.367, P = 0.0002). These variables were used to develop a predictive model to estimate 6 month survival with an area under the receiver operating characteristic curve of 0.815, sensitivity of 0.782, and specificity of 0.715. CONCLUSIONS: Six month survival in patients with VTE and solid malignancy requiring filter placement can be predicted from three patient variables. Our predictive model could be used to help physicians decide whether a permanent or retrievable filter may be more appropriate as well as to assess the risks and benefits for filter retrieval within the context of survival longevity in patients with cancer.

Efficacy of a Self-expanding Tract Sealant Device in the Reduction of Pneumothorax and Chest Tube Placement Rates After Percutaneous Lung Biopsy: A Matched Controlled Study Using Propensity Score Analysis.

PURPOSE: To evaluate the use of a self-expanding tract sealant device (BioSentry™) on the rates of pneumothorax and chest tube insertion after percutaneous lung biopsy. MATERIALS AND METHODS: In this retrospective study, we compared 318 patients who received BioSentry™ during percutaneous lung biopsy (treated group) with 1956 patients who did not (control group). Patient-, lesion-, and procedure-specific variables, and pneumothorax and chest tube insertion rates were recorded. To adjust for potential selection bias, patients in the treated group were matched 1:1 to patients in the control group using propensity score matching based on the above-mentioned variables. Patients were considered a match if the absolute difference in their propensity scores was ≤equal to 0.02. RESULTS: Before matching, the pneumothorax and chest tube rates were 24.5 and 13.1% in the control group, and 21.1 and 8.5% in the treated group, respectively. Using propensity scores, a match was found for 317 patients in the treatment group. Chi-square contingency matched pair analysis showed the treated group had significantly lower pneumothorax (20.8 vs. 32.8%; p = 0.001) and chest tube (8.2 vs. 20.8%; p < 0.0001) rates compared to the control group. Sub-analysis including only faculty who had >30 cases of both treatment and control cases demonstrated similar findings: the treated group had significantly lower pneumothorax (17.6 vs. 30.2%; p = 0.002) and chest tube (7.2 vs. 18%; p = 0.001) rates. CONCLUSIONS: The self-expanding tract sealant device significantly reduced the pneumothorax rate, and more importantly, the chest tube placement rate after percutaneous lung biopsy.

Radiation exposure from CT-guided ablation of renal masses: effects on life expectancy.

OBJECTIVE. The purpose of this article is to project the effects of radiation exposure on life expectancy (LE) in patients who opt for CT-guided radiofrequency ablation (RFA) instead of surgery for renal cell carcinoma (RCC). MATERIALS AND METHODS. We developed a decision-analytic Markov model to compare LE losses attributable to radiation exposure in hypothetical 65-year-old patients who undergo CT-guided RFA versus surgery for small (≤ 4 cm) RCC. We incorporated mortality risks from RCC, radiation-induced cancers (for procedural and follow-up CT scans), and all other causes; institutional data informed the RFA procedural effective dose. Radiation-induced cancer risks were generated using an organ-specific approach. Effects of varying model parameters and of dose-reduction strategies were evaluated in sensitivity analysis. RESULTS. Cumulative RFA exposures (up to 305.2 mSv for one session plus surveillance) exceeded those from surgery (up to 87.2 mSv). In 65-year-old men, excess LE loss from radiation-induced cancers, comparing RFA to surgery, was 11.7 days (14.6 days for RFA vs 2.9 days for surgery). Results varied with sex and age; this difference increased to 14.6 days in 65-year-old women and to 21.5 days in 55-year-old men. Dose-reduction strategies that addressed follow-up rather than procedural exposure had a greater impact. In 65-year-old men, this difference decreased to 3.8 days if post-RFA follow-up scans were restricted to a single phase; even elimination of RFA procedural exposure could not achieve equivalent benefits. CONCLUSION. CT-guided RFA remains a safe alternative to surgery, but with decreasing age, the higher burden of radiation exposure merits explicit consideration. Dose-reduction strategies that target follow-up rather than procedural exposure will have a greater impact.

Early initiation of enteral feeding in cancer patients after outpatient percutaneous fluoroscopy-guided gastrostomy catheter placement.

PURPOSE: To report the results of early enteral feeding in patients with cancer after outpatient placement of a percutaneous fluoroscopy-guided gastrostomy (PFG). MATERIALS AND METHODS: From January 2008 through December 2008, 121 consecutive patients with cancer underwent outpatient placement of a PFG for nutrition. Of these patients, 118 patients met criteria for early feeding, and 113 were successfully fed early (after at least 3 hours). Of the patients fed early, 5 had insufficient follow-up for further analysis leaving 108 patients for outcomes analysis. After placement of the PFG, patients were put on low-wall suction via the PFG for 1 hour followed by feeding via the PFG at least 3 hours after placement. Follow-up evaluation was done the next business day. The medical records were reviewed for 30-day outcomes of early feeding, technical aspects of the procedures, and complications. RESULTS: After placement of the PFG, 98% (118 of 121) of patients met criteria for early feeding, and 93% (113 of 121) of patients were successfully fed early. The median time between the end of the procedure and initiation of feeding was 4 hours (interquartile range, 3.7-4.4 h). The 30-day minor complication rate was 14% (15 of 108), and the 30-day major complication rate was 1% (1 of 108). No complications were directly attributable to early feeding. CONCLUSIONS: Early initiation of tube feedings after outpatient placement of a PFG was well tolerated in patients with cancer and carried comparable risks to previously reported results using traditional delayed feeding protocols. Early feeding provided patients with prompt enteral nutrition and eliminated the need for routine hospital admission after the procedure.

Simulation-based training in radiology.

Although the apprenticeship model of medical training has been in use for centuries, there are several problems with its use. The fundamental ethical principle of nonmaleficence requires that no preventable harm come to patients involved in the training process. In addition, changing medical practice patterns with shorter hospital stays and duty-hour restrictions are making it difficult for trainees to be exposed to enough patients to prepare them to deal with the many possible scenarios they may face in practice. Despite these limitations, the apprenticeship model cannot be completely rejected because it is essential for trainees to perfect their technique by caring for real patients with the guidance of experienced practitioners. Simulation-based training can allow novices to learn from their mistakes in a safe environment and in accordance with the principles of deliberate practice, thus allowing simulation to be a bridge to help get trainees from the novice state, in which they have a higher risk of causing harm, to a more experienced state in which they are more likely to do what is needed for patients.

Diffusion tensor imaging of hemispheric asymmetries in the developing brain.

Diffusion tensor imaging (DTI) was performed in 39 right-handed children to examine structural hemispheric differences and the impact of age, socioeconomic status, and sex on these differences. Apparent diffusion coefficient (ADC) values were smaller in the left than in the right temporal, prefrontal, anterior internal capsular and the thalamic regions, and fractional anisotropy (FA) values were larger in the left than in the right internal capsule, thalamus, and cingulate. Significant region-by-sex interactions disclosed that the relation of DTI asymmetries to performance depended on sex including the relation of temporal lobes to reading comprehension and the relation of frontal lobes to solving applied mathematical problems.