Safety and effectiveness of transsplenic access for portal venous interventions: a single-center retrospective study.

PURPOSE: To assess the safety and effectiveness of percutaneous transsplenic access (PTSA) for portal vein (PV) interventions among patients with PV disease. MATERIALS AND METHODS: Adult patients with PV disease were enrolled if they required percutaneous catheterization for PV angioplasty, embolization, thrombectomy, variceal embolization, or transjugular intrahepatic portosystemic shunt (TIPS) placement for a difficult TIPS or recanalization of a chronically occluded PV. The procedures were performed between January 2018 and January 2023. Patients were excluded if they had an active infection, had a chronically occluded splenic vein malignant infiltration of the needle tract, had undergone splenectomy, or were under age 18 years. RESULTS: Thirty patients (15 women, 15 men) were enrolled. Catheterization of the PV through PTSA succeeded for 29 of 30 patients (96.7%). The main adverse effect recorded was flank pain in 5 of 30 cases (16.7%). No bleeding events from the spleen, splenic vein, or percutaneous access point were recorded. Two cases (6.7%) each of hepatic bleeding and rethrombosis of the PV were reported, and a change in hemoglobin levels (mean [SD], - 0.5 [1.4] g/dL) was documented in 14 cases (46.7%). CONCLUSION: PTSA as an approach to accessing the PV is secure and achievable, with minimal risk of complications. Minimal to no bleeding is possible by using tract closure methods.

Single-arm prospective study comparing ablation zone volume between time zero and 24 h after microwave ablation of liver tumors.

PURPOSE: Percutaneous thermal ablation is an effective treatment for primary and metastatic liver tumors and is a recommended local therapy for early-stage hepatocellular carcinoma (HCC). Reported evidence shows an increase in the ablation zone volume over the first 24-h post-liver ablation. This report compares ablation zone volumes immediately at the completion (T = 0) of 26 microwave ablations of liver tumors to 24-h post-procedure (T = 24) volumes. MATERIALS AND METHODS: 20 patients, 13 (65%) males, underwent a total of 26 hepatic microwave ablations (MWA) under ultrasound guidance. Contrast-enhanced CT (CECT) or MRI was performed immediately and another CECT 24 h post operatively. Evaluation of the ablation zone and comparison of the two post-operative scans were done using BioTrace software. The expansion of ablation zones on post-op CECTs was matched point by point per direction. The distance between each 2 points was measured and grouped by distance. The incidence of each specific distance was then converted into a percentage, first for each case separately, then for all cases altogether. Data were tested by a matched paired one-sided t test. RESULTS: The median lesion diameter was 1.5 cm (range 0.5-3.3) with 16 (62%) HCC cases and 9 hepatic metastases (4 neuroendocrine carcinoma, 4 colorectal carcinomas, 1 breast carcinoma, 1 pancreatic cancer). The data show a consistent volume expansion greater than 30% (p = 7.7e-5) 24-h post-ablation, where the median expansion is 57%. Distances between T = 0 and T = 24 equal to 3-7 mm occur in over 35% of the cases. CONCLUSION: The ablation zone expansion at 24-h post-op was not uniform. The final ablation zone is difficult to predict at the time of the procedure. The awareness of the ablation zone expansion is important when treating near-critical structures, managing the heat sink effect, and preserving liver parenchyma.

Percutaneous Transesophageal Gastrostomy: Procedural Technique and Outcomes.

PURPOSE: To demonstrate the safety and effectiveness of percutaneous transesophageal gastrostomy (PTEG) as a palliative option in patients with malignant bowel obstructions (MBOs), and provide a comprehensive review of PTEG indications, placement technique, and short- and long-term outcomes. MATERIALS AND METHODS: Thirty-eight consecutive patients who underwent a PTEG procedure attempt from 2014 to 2022 were included in this analysis. Clinical indications, method of placement, technical and clinical success, adverse events, including procedure-related mortality, and effectiveness were assessed. Technical success was defined as placement of a PTEG. Clinical success was defined as improvement in clinical symptoms following PTEG placement. RESULTS: Of the 38 patients who underwent PTEG, 19 (50%) were men and 19 (50%) were women (median age, 58 years; range, 21-75 years). Three (8%) PTEG placements were performed with the patients under moderate sedation, whereas the remainder (92%) were performed with the patients under general anesthesia. Technical success was achieved in 35 of the 38 (92%) patients. The mean catheter duration was 61 days (median, 29 days; range, 1-562 days), with 5 of the 35 patients requiring tube exchanges after initial placement. Moreover, 7 of the 35 patients with successful PTEG placement experienced an adverse event, including 1 case of non-procedure-related mortality. All patients with successful PTEG placement experienced improvement in clinical symptoms. CONCLUSIONS: PTEG is an effective and safe option for patients with contraindications to traditional percutaneous gastrostomy tube placement in the setting of MBO. PTEG is an effective means of providing palliation and improving the quality of life.

The use of collimator angle optimization and jaw tracking for VMAT-based single-isocenter multiple-target stereotactic radiosurgery for up to six targets in the Varian Eclipse treatment planning system.

PURPOSE: Island blocking occurs in single-isocenter multiple-target (SIMT) stereotactic radiotherapy (SRS) whenever targets share multi-leaf collimator (MLC) leaf pairs. This study investigated the effect on plan quality and delivery, of reducing island blocking through collimator angle optimization (CAO). In addition, the effect of jaw tracking in this context was also investigated. METHODS: For CAO, an algorithm was created that selects the collimator angle resulting in the lowest level of island blocking, for each beam in any given plan. Then, four volume-modulated arc therapy (VMAT) SIMT SRS plans each were generated for 10 retrospective patients: two CAO plans, with and without jaw tracking, and two plans with manually selected collimator angles, with and without jaw tracking. Plans were then assessed and compared using typical quality assurance procedures. RESULTS: There were no substantial differences between plans with and without CAO. Jaw tracking produced statistically significant reduction in low-dose level parameters; healthy brain V10% and mean dose were reduced by 9.66% and 15.58%, respectively. However, quantitative values (108 cc for V10% and 0.35 Gy for mean dose) were relatively small in relation to clinical relevance. Though there were no statistically significant changes in plan deliverability, there was a notable trend of plans with jaw tracking having lower gamma analysis pass rates. CONCLUSION: These findings suggest that CAO has limited benefit in VMAT SIMT SRS of 2-6 targets when using a low-dose penalty to the healthy brain during plan optimization in Eclipse. As clinical benefits of jaw tracking were found to be minimal and plan deliverability was potentially reduced, a cautious approach would be to exclude jaw tracking in SIMT SRS plans.

History and Evolution of Yttrium-90 Radioembolization for Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer and affects millions worldwide. Due to the lack of effective systemic therapies for HCC, researchers have been investigating the use of locoregional tumor control with Yttrium-90 (Y90) radioembolization since the 1960s. Following the development of glass and resin Y90 microspheres in the early 1990s, Y90 radioembolization has been shown to be a safe and efficacious treatment for patients with HCC across Barcelona Clinic Liver Cancer (BCLC) stages. By demonstrating durable local control, good long term outcomes, and equivalent if not superior tumor responses and tolerability when compared to alternative therapies including transarterial chemoembolization (TACE) and sorafenib, Y90 radioembolization is being increasingly used in HCC treatment. More recently, investigations into variations in Y90 radioembolization technique including radiation segmentectomy and radiation lobectomy have further expanded its clinical utility. Here, we discuss the history and evolution of Y90 use in HCC. We outline key clinical trials that have established the safety and efficacy of Y90 radioembolization, and also summarize trials comparing its efficacy to existing HCC treatments. We conclude by reviewing the techniques of radiation segmentectomy and lobectomy, and by discussing dosimetry.

Computed tomography angiography evaluation of acute limb ischemia.

Acute limb ischemia (ALI), a subclass of critical limb ischemia, is a medical emergency. The cause of ALI is usually thrombotic or embolic in nature, and the specific etiology often dictates the appropriate therapy. While the diagnosis is a clinical with common presenting symptoms, advances in ultrasound, computed tomography, and magnetic resonance technology have impacted the diagnosis and subsequent therapy. In ALI, the time to revascularization is critical and computed tomography angiography (CTA) provides a highly sensitive and specific technique for rapidly identifying occlusions and precisely defining vascular anatomy prior to interventions. In patients with significant renal disease, magnetic resonance angiography with or without contrast provides effective alternatives at the expense of imaging time. Treatment can include a variety of endovascular or surgical interventions, including thromboembolectomy, angioplasty, or bypass. Proper evaluation of the etiology of the ischemia, affected vasculature, and medical history is critical to select appropriate treatment and improve patient outcomes. Here, we examine the presentation, evaluation, and treatment of ALI and the role of CTA in diagnosis and therapy.

Using Naïve Bayesian Analysis to Determine Imaging Characteristics of KRAS Mutations in Metastatic Colon Cancer.

Genotype, particularly Ras status, greatly affects prognosis and treatment of liver metastasis in colon cancer patients. This pilot aimed to apply word frequency analysis and a naive Bayes classifier on radiology reports to extract distinguishing imaging descriptors of wild-type colon cancer patients and those with v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations. In this institutional-review-board-approved study, we compiled a SNaPshot mutation analysis dataset from 457 colon adenocarcinoma patients. From this cohort of patients, we analyzed radiology reports of 299 patients (> 32,000 reports) who either were wild-type (147 patients) or had a KRAS (152 patients) mutation. Our algorithm determined word frequency within the wild-type and mutant radiology reports and used a naive Bayes classifier to determine the probability of a given word belonging to either group. The classifier determined that words with a greater than 50% chance of being in the KRAS mutation group and which had the highest absolute probability difference compared to the wild-type group included: "several", "innumerable", "confluent", and "numerous" (p < 0.01). In contrast, words with a greater than 50% chance of being in the wild type group and with the highest absolute probability difference included: "few", "discrete", and "[no] recurrent" (p = 0.03). Words used in radiology reports, which have direct implications on disease course, tumor burden, and therapy, appear with differing frequency in patients with KRAS mutations versus wild-type colon adenocarcinoma. Moreover, likely characteristic imaging traits of mutant tumors make probabilistic word analysis useful in identifying unique characteristics and disease course, with applications ranging from radiology and pathology reports to clinical notes.

Below-knee deep vein thrombosis (DVT): diagnostic and treatment patterns.

BACKGROUND: Guidelines are lacking for isolated below-knee deep vein thrombosis (BKDVT). The American College of Chest Physicians (ACCP) suggests anticoagulation only if symptoms are severe, otherwise surveillance with follow-up ultrasound in 2 weeks is recommended. Yet clinical practice remains highly variable. Little is known about the natural history of BKDVT and how to best manage these patients. METHODS: A retrospective analysis was conducted of medical records from 2014-2016. Risk factors were assessed such as age, gender, malignancy, recent surgery, and history of DVT. Treatment decisions and outcomes were identified. Radiology reports were graded for clarity. Chi-square and logistic regression were used to correlate risk factors with outcomes and determine odds of treatment. RESULTS: New isolated BKDVT was identified in 102 patients. Patients were symptomatic or had previous pulmonary embolism (PE) or DVT in all cases. Eighteen were positive for PE at diagnosis (17.6% of all patients or 62.1% with chest CT). Malignancy was independently associated with PE (P=0.015); no other risk factors were significant. Treatment was not associated with clinical risk factors. The language used for radiology reports was highly variable and was associated with the decision to treat with anticoagulation. One hundred percent were treated (n=24) when the report stated "positive DVT" and 89.2% (n=58) were treated after an objective description without the word "DVT" (P=0.01). Treatment was much less likely if the report described BKDVT anatomically but was said to be "negative for DVT" (P<0.001). A total of 86.3% (n=88) of all patients were treated, compared to 46.2% (n=6) of patients in this group (n=13). IVC filters were placed in 3 patients. Of the 14 untreated patients, 5 received surveillance, 3 developed new proximal DVT, and none developed PE. CONCLUSIONS: About 90% of patients diagnosed with BKDVT received anticoagulation after the initial diagnosis. Surveillance was not commonly recommended and is likely underutilized. Radiology reporting was highly variable and correlated with clinical treatment decisions, whereas other clinical risk factors did not. Describing BKDVT findings only in terms of being "positive" or "negative" for DVT may be inadequate.