Safety and efficacy of thermal ablation of adrenal metastases secondary to lung cancer.

OBJECTIVES: Assess safety and efficacy of thermal ablation for adrenal metastases (AM) secondary to non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: This retrospective study included patients with NSCLC AM treated with thermal ablation between 2/2010-11/2021. Local tumor progression free survival (LTPFS) and overall survival (OS) were calculated using Kaplan-Meier method. Adverse events were graded using Common Terminology Criteria for Adverse Events v5. RESULTS: Seven patients (mean age ± SD, 63.9 ± 12.5 years; 6 males) with seven AM were treated in eight sessions. Retreatment was performed in one patient with residual disease. Five sessions were with microwave ablation and 3 with radiofrequency ablation. Mean tumor size was 20.1 ± 7.0 mm. Median number of ablation probes used was 1 (range, 1-5), with a median of 3 activations (range, 1-3), and average ablation time of 14.4 ± 15.0 minutes. Response based on RECIST v 1.1 or PERCIST criteria revealed stable disease in 1 tumor, progression of disease in 3 tumors (one was re-ablated), and partial response in 3 tumors. Median LTPFS was not reached (NR) [95 % CI: 1- NR]. Median OS was 47.97 months (95 % CI: 18.63- NR). Intraprocedural hypertension (blood pressure ≥180 mmHg) occurred during 5/8 (62.5 %) sessions and intraoperative tachycardia occurred during 2/8 (25 %) sessions. Complications within one month of ablation occurred in 3/8 (37.5 %) sessions: grade 2 pneumothorax, grade 1 hematuria, and grade 2 adrenal insufficiency. CONCLUSIONS: In this small series, thermal ablation for NSCLC AM resulted in prolonged local control and OS with no major complications.

Outcomes of Y90 Radioembolization for Hepatocellular Carcinoma in Patients Previously Treated with Transarterial Embolization.

The aim of this study was to evaluate outcomes of transarterial radioembolization (TARE) for hepatocellular carcinoma (HCC) in patients previously treated with transarterial embolization (TAE). In this retrospective study, all HCC patients who received TARE from 1/2012 to 12/2022 for treatment of residual or recurrent disease after TAE were identified. Overall survival (OS) was estimated using the Kaplan-Meier method. Univariate Cox regression was performed to determine significant predictors of OS after TARE. Twenty-one patients (median age 73.4 years, 18 male, 3 female) were included. Median dose to the perfused liver volume was 121 Gy (112-444, range), and 18/21 (85.7%) patients received 112-140 Gy. Median OS from time of HCC diagnosis was 32.9 months (19.4-61.4, 95% CI). Median OS after first TAE was 29.3 months (15.3-58.9, 95% CI). Median OS after first TARE was 10.6 months (6.8-27.0, 95% CI). ECOG performance status of 0 (p = 0.038), index tumor diameter < 4 cm (p = 0.022), and hepatic tumor burden < 25% (p = 0.018) were significant predictors of longer OS after TARE. TARE may provide a survival benefit for appropriately selected patients with HCC who have been previously treated with TAE.

Percutaneous Lung Biopsies With Robotic Systems: A Systematic Review of Available Clinical Solutions.

Objectives: This systematic review aims to assess existing research concerning the use of robotic systems to execute percutaneous lung biopsy. Methods: A systematic review was performed and identified 4 studies involving robotic systems used for lung biopsy. Outcomes assessed were operation time, radiation dose to patients and operators, technical success rate, diagnostic yield, and complication rate. Results: One hundred and thirteen robot-guided percutaneous lung biopsies were included. Technical success and diagnostic yield were close to 100%, comparable to manual procedures. Technical accuracy, illustrated by needle positioning, showed less frequent needle adjustments in robotic guidance than in manual guidance (P < .001): 2.7 ± 2.6 (range 1-4) versus 6 ± 4 (range 2-12). Procedure time ranged from comparable to reduced by 35% on average (20.1 ± 11.3 minutes vs 31.4 ± 10.2 minutes, P = .001) compared to manual procedures. Patient irradiation ranged from comparable to reduced by an average of 40% (324 ± 114.5 mGy vs 541.2 ± 446.8 mGy, P = .001). There was no significant difference in reported complications between manual biopsy and biopsies that utilized robotic guidance. Conclusion: Robotic systems demonstrate promising results for percutaneous lung biopsy. These devices provide adequate accuracy in probe placement and could both reduce procedural duration and mitigate radiation exposure to patients and practitioners. However, this review underscores the need for larger, controlled trials to validate and extend these findings.

Imaging Considerations before and after Liver-Directed Locoregional Treatments for Metastatic Colorectal Cancer.

Colorectal cancer is a leading cause of cancer-related death. Liver metastases will develop in over one-third of patients with colorectal cancer and are a major cause of morbidity and mortality. Even though surgical resection has been considered the mainstay of treatment, only approximately 20% of the patients are surgical candidates. Liver-directed locoregional therapies such as thermal ablation, Yttrium-90 transarterial radioembolization, and stereotactic body radiation therapy are pivotal in managing colorectal liver metastatic disease. Comprehensive pre- and post-intervention imaging, encompassing both anatomic and metabolic assessments, is invaluable for precise treatment planning, staging, treatment response assessment, and the prompt identification of local or distant tumor progression. This review outlines the value of imaging for colorectal liver metastatic disease and offers insights into imaging follow-up after locoregional liver-directed therapy.

Safety and efficacy of percutaneous cryoablation for primary and metastatic pleural based tumors.

PURPOSE: Assess safety and local tumor progression-free survival (LTPFS) of percutaneous cryoablation for pleural-based thoracic malignancies. MATERIALS AND METHODS: Retrospective study of 46 patients (17 treated for palliation; 9 for oligoprogression; 20 for curative intent), with 62 pleural-based thoracic lesions, treated in 59 cryoablation sessions. Patients were treated from 9/2005-11/2021 with CryoCare CS (Varian, Irvine, CA) or IceFORCE (Boston Scientific, Marlborough, MA) systems. For tumors treated with curative intent and/or oligoprogression, LTPFS of the treated tumor(s) and overall survival (OS) were estimated using Kaplan-Meier method. Post-operative complications were reported for all sessions, including those with palliative intent; univariate analyses were used to calculate factors associated with increased complication risk. RESULTS: Median number of tumors treated in a single treatment session was 1 (range 1-4). Largest dimension of the treated tumor was 2.1 cm [IQR:0.9-5 cm]. Of the 59 treatments, 98.3 % were technically successful. Median LTPFS was 14.4 (95 % CI: 9.4-25.6) months. Tumor size was a significant predictor of LTPFS (HR: 1.21, 95 % CI: 1.03-1.44, p = 0.023). Median OS was 52.4 (28.1-NR) months. Complications occurred in 28/59 sessions (47.5 %); 2/59 (3.4 %) were ≥ grade D by Society of Interventional Radiology adverse event criteria (death; hypoxia requiring supplemental oxygen upon discharge). Pain and pneumothorax were the most common complications. The length of lung parenchyma traversed was a significant predictor of pneumothorax: HR 0.48 (95 %CI: 0.14-0.83), p = 0.0024. CONCLUSION: Percutaneous cryoablation for pleural lesions is associated with a long duration of local control and most complications were minor and self-limited.

Comparison of periprocedural and procedure room times between moderate sedation and monitored anesthesia care in interventional radiology.

Objectives: In recent years, there has been increased utilization of monitored anesthesia care (MAC) in interventional radiology (IR) departments. The purpose of this study was to compare pre-procedure bed, procedure room, and post-procedure bed times for IR procedures performed with either nurse-administered moderate sedation (MOSED) or MAC. Material and Methods: An institutional review board-approved single institution retrospective review of IR procedures between January 2010 and September 2022 was performed. Procedures performed with general anesthesia or local anesthetic only, missing time stamps, or where <50 cases were performed for both MAC and MOSED were excluded from the study. Pre-procedure bed, procedure room, post-procedure bed, and total IR encounter times were compared between MAC and MOSED using the t-test. The effect size was estimated using Cohen's d statistic. Results: 97,480 cases spanning 69 procedure codes were examined. Mean time in pre-procedure bed was 27 min longer for MAC procedures (69 vs. 42 min, P < 0.001, d = 0.95). Mean procedure room time was 11 min shorter for MAC (60 vs. 71 min, P < 0.001, d = 0.48), and mean time in post-procedure bed was 10 min longer for MAC (102 vs. 92 min, P < 0.001, d = 0.22). Total IR encounter times were on average 27 min longer for MAC cases (231 vs. 204 min, P < 0.001, d = 0.41). Conclusion: MAC improves the utilization of IR procedure rooms, but at the cost of increased patient time in the pre- and post-procedure areas.

Comparison of a Patient-Mounted Needle-Driving Robotic System versus Single-Rotation CT Fluoroscopy to Perform CT-Guided Percutaneous Lung Biopsies.

PURPOSE: To compare the effectiveness of percutaneous lung biopsy using a patient-mounted needle-driving robotic system with that using a manual insertion of needles under computed tomography (CT) fluoroscopy guidance. MATERIALS AND METHODS: In this institutional review board approved study, the cohort consisted of a series of patients who underwent lung biopsies following the intention-to-treat protocol from September 2022 to September 2023 using robot (n = 15) or manual insertion under single-rotation CT fluoroscopy (n = 66). Patient and procedure characteristics were recorded as well as outcomes. RESULTS: Although age, body mass index, and skin-to-target distance were not statistically different, target size varied (median, 8 mm [interquartile range, 6.5-9.5 mm] for robot vs 12 mm [8-18 mm] for single-rotation CT fluoroscopy; P = .001). No statistical differences were observed in technical success (86.7% [13/15] vs 89.4% [59/66], P = .673), Grade 3 adverse event (AE) (6.7% [1/15] vs 12.1% [8/66], P = .298), procedural time (28 minutes [22-32 minutes] vs 19 minutes [14.3-30.5 minutes], P = .086), and patient radiation dose (3.9 mSv [3.2-5.6 mSv] vs 4.6 mSv [3.3-7.5 mSv], P = .398). In robot-assisted cases, the median angle out of gantry plane was 10° (6.5°-16°), although it was null (0°-5°) for single-rotation CT fluoroscopy (P = .001). CONCLUSIONS: Robot-assisted and single-rotation CT fluoroscopy-guided percutaneous lung biopsies were similar in terms of technical success, diagnostic yield, procedural time, AEs, and radiation dose, although robot allowed for out-of-gantry plane navigation along the needle axis.

Yttrium-90 Transarterial Radioembolization of Primary Lung Cancer Metastases to the Liver.

PURPOSE: To assess whether yttrium-90 transarterial radioembolization (TARE) is safe and effective in the treatment of primary lung cancer metastases to the liver (LCML). METHODS AND METHODS: This retrospective study included 57 patients with LCML who were treated with 79 TARE treatments. Histology included non-small cell lung cancer (NSCLC) (n = 27), small cell lung cancer (SCLC) (n = 17), and lung carcinoid (LC) (n = 13). Survival was calculated using Kaplan-Meier method; differences between groups were estimated using log rank test. Cox proportional hazards model was used to determine factors influencing survival. Adverse events were graded using the Society of Interventional Radiology Adverse Events Classification. RESULTS: Median overall survival (OS) was as follows: NSCLC, 8.3 months (95% confidence interval [CI], 6.3-16.4 months); SCLC, 4.1 months (95% CI, 1.9-6.6 months); and LC, 43.5 months (95% CI, 7.8-61.4 months). For NSCLC, presence of bilobar vs unilobar disease (hazard ratio [HR], 5.24; 95% CI, 1.64-16.79; P = .002); more tumors, 2-5 vs 1 (HR, 4.88; 95% CI, 1.17-20.37; P = .003) and >5 vs 1 (HR, 3.75; 95% CI, 0.95-6.92; P = .05); and lobar vs segmental treatment (HR, 2.56; 95% CI, 0-NA; P = .002) were negative predictors of OS. For SCLC, receipt of >2 lines of chemotherapy vs ≤2 lines (HR, 3.16; 95% CI, 0.95-10.47; P = .05) was a negative predictor of OS. For LC, tumor involvement of >50% was a negative predictor of OS (HR, 3.77 × 1015; 95% CI, 0-NA; P = .002). There were 11 of 79 severe or life-threatening adverse events within 30 days (abdominal pain, altered mental status, nausea/vomiting, acalculous/aseptic cholecystitis, hyponatremia, pancreatitis, renal failure, and death from pneumonia). CONCLUSIONS: TARE has an acceptable safety profile for the treatment of LCML, with survival benefits best seen in LC tumors.

Hepatic Hilar Block as an Adjunct to Transarterial Embolization of Neuroendocrine Tumors: A Retrospective Review of Safety and Efficacy.

PURPOSE: This study investigates whether hepatic hilar nerve blocks (HHNB) provide safe, effective analgesia in patients with neuroendocrine tumors (NET) treated with transarterial embolization (TAE). METHODS: The retrospective study included all NETs treated with TAE or TAE + HHNB from 1/2020 to 8/2022. Eighty-five patients (45 men), mean age 62 years, were treated in 165 sessions (TAE, n = 153; TAE + HHNB, n = 12). For HHNBs, ≤10 mL bupivacaine HCl 0.25% ± 2 mg methylprednisolone were injected under ultrasound guidance. The aims were to assess safety of HHNB and reduction in pain. Groups were compared with Pearson's chi-squared and Wilcoxon rank sum tests. Logistic regression assessed independent risk factors for pain. RESULTS: No immediate complications from HHNBs were reported. No difference in incidence of major complications between TAE and TAE + HHNB one month post-embolization was observed (7.19% vs. 8.33%, p = 0.895). No differences in mean length of hospital stay after treatment were observed (TAE 2.2 days [95%CI: 1.74-2.56] vs. TAE + HHNB 2.8 days [95%CI: 1.43-4.26]; p = 0.174). Post-procedure pain was reported in 88.2% of TAE and 75.0% of TAE + HHNB patients (p = 0.185). HHNB recipients were more likely to use analgesic patches (25.0% vs. 5.88%; p = 0.014). No other differences in analgesic use were observed. CONCLUSIONS: HHNBs can safely be performed in patients with NETs. No difference in hospital stays or analgesic drug use was observed. Managing pain after TAE is an important goal; further study is warranted.

Endovascular management of incidentally discovered splenic arteriovenous fistula resulting from ruptured splenic aneurysm: Case report and review of the literature.

Splenic arteriovenous fistulas (SAVFs) are rare vascular anomalies, which have a described association with splenic artery aneurysms. Treatment options include surgical fistula excision, splenectomy, or percutaneous embolization. Here we present a unique case of endovascular repair of a splenic arteriovenous fistula (SAVFs) associated with a splenic aneurysm. A patient with past medical history of early-stage invasive lobular carcinoma was referred to our interventional radiology practice to discuss an incidentally discovered splenic "vascular malformation" discovered during magnetic resonance imaging of the abdomen and pelvis. Arteriography demonstrated smooth dilatation of the splenic artery, with a fusiform aneurysm which had fistulized to the splenic vein. There were high flows and early filling of the portal venous system. The splenic artery, immediately proximal to the aneurysm sac, was catheterized using a microsystem and embolized using coils and N-butyl cyanoacrylate. Complete occlusion of the aneurysm and resolution of the fistulous connection was achieved. The patient was discharged home the following day, without complication. Associated splenic artery aneurysms and SAVFs are rare occurrences. Timely management is necessary to prevent adverse sequelae such as aneurysm rupture, further enlargement of the aneurysmal sac, or portal hypertension. Endovascular treatment, including n-Butyl Cyanoacrylate glue and coils, offers a minimally invasive treatment option, with facile recovery and low morbidity.

Neuroendocrine Tumors: Genomics and Molecular Biomarkers with a Focus on Metastatic Disease.

Neuroendocrine tumors (NETs) are considered rare tumors that originate from specialized endocrine cells. Patients often present with metastatic disease at the time of diagnosis, which negatively impacts their quality of life and overall survival. An understanding of the genetic mutations that drive these tumors and the biomarkers used to detect new NET cases is important to identify patients at an earlier disease stage. Elevations in CgA, synaptophysin, and 5-HIAA are most commonly used to identify NETs and assess prognosis; however, new advances in whole genome sequencing and multigenomic blood assays have allowed for a greater understanding of the drivers of NETs and more sensitive and specific tests to diagnose tumors and assess disease response. Treating NET liver metastases is important in managing hormonal or carcinoid symptoms and is imperative to improve patient survival. Treatment for liver-dominant disease is varied; delineating biomarkers that may predict response will allow for better patient stratification.

Factors affecting outcomes of Yttrium-90 radioembolization in heavily pretreated patients with intrahepatic cholangiocarcinoma.

PURPOSE: Transarterial radioembolization (TARE) is a liver-directed treatment for unresectable intrahepatic cholangiocarcinoma (ICC). The aim of this study is to evaluate factors affecting outcomes of TARE in heavily pretreated ICC patients. METHODS: We evaluated pretreated ICC patients who received TARE from January 2013 to December 2021. Prior treatments included systemic therapy, hepatic resection, and liver-directed therapies, including hepatic arterial infusion chemotherapy, external beam radiation, transarterial embolization, and thermal ablation. Patients were classified based on history of hepatic resection and genomic status based on next-generation sequencing (NGS). The primary endpoint was overall survival (OS) after TARE. RESULTS: Fourteen patients with median age 66.1 years (range, 52.4-87.5), 11 females and 3 males, were included. Prior therapies included systemic in 13/14 patients (93%), liver resection in 6/14 (43%), and liver-directed therapy in 6/14 (43%). Median OS was 11.9 months (range, 2.8-81.0). Resected patients had significantly longer median OS compared to unresected patients (16.6 versus 7.9 months; p = 0.038). Prior liver-directed therapy (p = 0.043), largest tumor diameter > 4 cm (p = 0.014), and > 2 hepatic segments involvement (p = 0.001) were associated with worse OS. Nine patients underwent NGS; 3/9 (33.3%) and had a high-risk gene signature (HRGS), defined as alterations in TP53, KRAS, or CDKN2A. Patients with a HRGS had worse median OS (10.0 versus 17.8 months; p = 0.024). CONCLUSIONS: TARE may be used as salvage therapy in heavily treated ICC patients. Presence of a HRGS may predict worse OS after TARE. Further investigation with more patients is recommended to validate these results.

Reducing Wait Times for Radiology Exams Around Holiday Periods: A Monte Carlo Simulation.

Reducing patient wait times is a key operational goal and impacts patient outcomes. The purpose of this study is to explore the effects of different radiology scheduling strategies on exam wait times before and after holiday periods at an outpatient imaging facility using computer simulation. An idealized Monte Carlo simulation of exam scheduling at an outpatient imaging facility was developed based on the actual distribution of scheduled exams at outpatient radiology sites at a tertiary care medical center. Using this simulation, we examined three scheduling strategies: (1) no scheduling modifications, (2) increase imaging capacity before or after the holiday (i.e. increase facility hours), and (3) use a novel rolling release scheduling paradigm. In the third scenario, a fraction of exam slots are blocked to long-term follow-up exams and made available only closer to the exam date, thereby preventing long-term follow-up exams from filling the schedule and ensuring slots are available for non-follow-up exams. We examined the effect of these three scenarios on utilization and wait times, which we defined as the time from order placement to exam completion, during and after the holiday period. The baseline mean wait time for non-follow-up exams was 5.4 days in our simulation. When no scheduling modifications were made, there was a significant increase in wait times in the week preceding the holiday when compared to baseline (10.0 days vs 5.4 days, p < 0.01). Wait times remained elevated for 4 weeks following the holiday. Increasing imaging capacity during the holiday and post-holiday period by 20% reduced wait times by only 6.2% (9.38 days vs 10.0 days, p < 0.01). Increasing capacity by 50% resulted in a 7.1% reduction in wait times (9.28 days, p < 0.01), and increasing capacity by 100% resulted in a 13% reduction in wait times (8.75 days, p < 0.01). In comparison, using a rolling release model produced a reduction in peak wait times equivalent to doubling capacity (8.76 days, p < 0.01) when 45% of slots were reserved. Improvements in wait times persisted even when rolling release was limited to the 3 weeks preceding or 1 week following the holiday period. Releasing slots on a rolling basis did not significantly decrease utilization or increase wait times for long-term follow-up exams except in extreme scenarios where 80% or more of slots were reserved for non-follow-up exams. A rolling release scheduling paradigm can significantly reduce wait time fluctuations around holiday periods without requiring additional capacity or impacting utilization.

Percutaneous Image-Guided Biopsy for a Comprehensive Hybridization Capture-Based Next-Generation Sequencing in Primary Lung Cancer: Safety, Efficacy, and Predictors of Outcome.

Introduction: To evaluate factors associated with successful comprehensive genomic sequencing of image-guided percutaneous needle biopsies in patients with lung cancer using a broad hybrid capture-based next-generation sequencing assay (CHCA). Methods: We conducted a single-institution retrospective review of image-guided percutaneous transthoracic needle biopsies from January 2018 to December 2019. Samples with confirmed diagnosis of primary lung cancer and for which CHCA had been attempted were identified. Pathologic, clinical data and results of the CHCA were reviewed. Covariates associated with CHCA success were tested for using Fisher's exact test or Wilcoxon ranked sum test. Logistic regression was used to identify factors independently associated with likelihood of CHCA success. Results: CHCA was requested for 479 samples and was successful for 433 (91%), with a median coverage depth of 659X. Factors independently associated with lower likelihood of CHCA success included small tumor size (OR = 0.26 [95% confidence interval (CI): 0.11-0.62, p = 0.002]), intraoperative inadequacy on cytologic assessment (OR = 0.18 [95% CI: 0.06-0.63, p = 0.005]), small caliber needles (≥20-gauge) (OR = 0.22 [95% CI: 0.10-0.45, p < 0.001]), and presence of lung parenchymal abnormalities (OR = 0.12 [95% CI: 0.05-0.25, p < 0.001]). Pneumothorax requiring chest tube insertion occurred in 6% of the procedures. No grade IV complications or procedure-related deaths were reported. Conclusions: Percutaneous image-guided transthoracic needle biopsy is safe and has 91% success rate for CHCA in primary lung cancer. Intraoperative inadequacy, small caliber needle, presence of parenchymal abnormalities, and small tumor size (≤1 cm) are independently associated with likelihood of failure.

Augmented fluoroscopy guided transbronchial pulmonary microwave ablation using a steerable sheath.

Background: Transbronchial microwave ablation (MWA) is a promising novel therapy. Despite advances in bronchoscopy and virtual navigation, real time image guidance of probe delivery is lacking, and distal maneuverability is limited. Cone-beam computed tomography (CBCT) based augmented fluoroscopy guidance using steerable sheaths may help overcome these shortcomings. The aim of this study was to evaluate feasibility and accuracy of augmented fluoroscopy guided transbronchial MWA with a steerable sheath and without a bronchoscope. Methods: In this prospective study, procedures were performed under general anesthesia. Extra-bronchial lung synthetic targets were placed percutaneously. Target and airways extracted from CBCT, with planned bronchial parking point close to the target were overlaid on live fluoroscopy. Endobronchial navigation was solely performed under augmented fluoroscopy guidance. A 6.5 Fr steerable sheath was parked in the bronchus per plan, and a flexible MWA probe was inserted coaxially then advanced through the bronchus wall towards the target. Final in-target position was confirmed by CBCT. Only one ablation of 100 W-5 min was performed per target. Animals were euthanized and pathology analysis of the lungs was performed. Results: Eighteen targets with a median largest diameter of 9 mm (interquartile range, 7-11 mm) were ablated in 9 pigs. Median needle-target center distance was 2 mm (interquartile range, 0-4 mm), and was higher for lower/middle than for upper lobes [0 mm (interquartile range, 0-4 mm) vs. 4 mm (interquartile range, 3-8 mm), P=0.04]. No severe complications or pneumothorax occurred. Two cases of rib fractures in the ablation zone resolved after medical treatment. Median longest axis of the ablation zone on post-ablation computed tomography was 38 mm (interquartile range, 30-40 mm). Histology showed coagulation necrosis of ablated tissue. Conclusions: Transbronchial MWA under augmented fluoroscopy guidance using a steerable sheath is feasible and accurate.

Prospective Study of Systemic Yttrium-90 Elution during Radioembolization of Hepatic Metastases.

PURPOSE: To evaluate total blood radioactivity (BR) after SIR-Spheres yttrium-90 (90Y) radioembolization and differences in BR based on delivery method. MATERIALS AND METHODS: Twenty participants with hepatic metastases undergoing first radioembolization were prospectively enrolled from December 2017 to June 2018. Blood samples were drawn at baseline and 0, 10, 20, 60, and 120 minutes after 90Y administration. BR was measured with a γ-counter and scaled by estimated blood volume. Percentage of instilled radioactivity in the bloodstream was calculated as area under the fitted curve, and differences between delivery methods were examined with nonparametric statistical tests. RESULTS: In 10 participants, resin microspheres were instilled with 50% Isovue 300 diluted in saline solution in the D line, and 10 others were treated with dextrose 5% in water (D5W) in the D line. Median administered activities were 944 MBq (range, 746-1,993 MBq) and 1,213 MBq (range, 519-2,066 MBq), respectively. Fraction of 90Y in blood was significantly higher with dilute contrast agent than with D5W (median, 0.5% of injected activity vs 0.2%; P = .001). Among all participants, the maximum activity delivered was 2,066 MBq, and a maximum of 1% of administered radioactivity was measured as free 90Y in blood. Assuming these highest-case values and complete decay of all free 90Y in bone, a dose to red marrow of 132.3 mGy was calculated by Organ Level INternal Dose Assessment/EXponential Modeling. CONCLUSIONS: Blood sampling after radioembolization allowed for estimation of the time-activity curve and BR. Delivery with 50% contrast agent in saline solution resulted in a significant increase in BR vs D5W, even though the total BR for both groups was nominal.

CT Densitometry and Morphology of Radiofrequency-Ablated Stage IA Non-Small Cell Lung Cancer: Results from the American College of Surgeons Oncology Group Z4033 (Alliance) Trial.

PURPOSE: To evaluate tumor and ablation zone morphology and densitometry related to tumor recurrence in participants with Stage IA non-small cell lung cancer undergoing radiofrequency ablation in a prospective, multicenter trial. MATERIALS AND METHODS: Forty-five participants (median 76 years old; 25 women; 20 men) from 16 sites were followed for 2 years (December 2006 to November 2010) with computed tomography (CT) densitometry. Imaging findings before and after ablation were recorded, including maximum CT attenuation (in Hounsfield units) at precontrast and 45-, 90-, 180-, and 300-s postcontrast. RESULTS: Every 1-cm increase in the largest axial diameter of the ablation zone at 3-months' follow-up compared to the index tumor reduced the odds of 2-year recurrence by 52% (P = .02). A 1-cm difference performed the best (sensitivity, 0.56; specificity, 0.93; positive likelihood ratio of 8). CT densitometry precontrast and at 45 seconds showed significantly different enhancement patterns in a comparison among pretreated lung cancer (delta = +61.2 HU), tumor recurrence (delta = +57 HU), and treated tumor/ablation zone (delta [change in attenuation] = +16.9 HU), (P < .0001). Densitometry from 45 to 300 s was also different among pretreated tumor (delta = -6.8 HU), recurrence (delta = -11.2 HU), and treated tumor (delta = +12.1 HU; P = .01). Untreated and residual tumor demonstrated washout, whereas treated tumor demonstrated increased attenuation. CONCLUSIONS: An ablation zone ≥1 cm larger than the initial tumor, based on 3-month follow-up imaging, is recommended to decrease odds of recurrence. CT densitometry can delineate tumor versus treatment zones.