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42 result(s) for "Shyn, Paul B"
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CT-guided percutaneous cryoablation of central lung tumors
Cryoablation has been successfully used to treat lung tumors. However, the safety and effectiveness of treating tumors adjacent to critical structures has not been fully established. We describe our experience with computed tomography (CT)-guided percutaneous cryoablation of central lung tumors and the role of ice ball monitoring. Eight patients with 11 malignant central lung tumors (nine metastatic, two primary; mean, 2.6 cm; range, 1.0-4.5 cm) located adjacent to mediastinal or hilar structures were treated using CT-guided cryoablation in 10 procedures. Technical success and effectiveness rates were calculated, complications were tabulated and intraprocedural imaging features of ice balls were described. All procedures were technically successful; imaging after 24 hours demonstrated no residual tumor. Five tumors recurred, three of which were re-ablated successfully. A hypodense ice ball with well-defined margin was visible during the first (n=6, 55%) or second (n=11, 100%) freeze, encompassing the entire tumor in all patients, and abutting (n=7) or minimally involving (n=4) adjacent mediastinal and hilar structures. Pneumothorax developed following six procedures (60%); percutaneous treatment was applied in three of them. All patients developed pleural effusions, with one patient requiring percutaneous drainage. Transient hemoptysis occurred after six procedures (60%), but all cases improved within a week. No injury occurred to mediastinal or hilar structures. CT-guided percutaneous cryoablation can be used to treat central lung tumors successfully. Although complications were common, they were self-limited, treatable, and not related to tumor location. Ice ball monitoring helped maximize the amount of tumor treated, while avoiding critical mediastinal and hilar structures.
Assessing ablation margins of FDG-avid liver tumors during PET/CT-guided thermal ablation procedures: a retrospective study
BackgroundTo retrospectively assess liver tumor ablation margins using intraprocedural PET/CT images from FDG PET/CT-guided microwave or cryoablation procedures and to correlate minimum margin measurements with local progression outcomes.MethodsFifty-six patients (ages 36 to 85, median 62; 32 females) with 77 FDG-avid liver tumors underwent 60 FDG PET/CT guided, percutaneous microwave, or cryoablation procedures. Single breath-hold PET/CT images were used for intraprocedural assessment of the tumor ablation margin: liver tumors remained visible on PET immediately following ablation; microwave ablation zones were visible using contrast-enhanced CT; cryoablation zones (ice balls) were visible using unenhanced CT. Two readers retrospectively determined ablation margin assessability and measured the minimum ablation margin on intraprocedural PET/CT (n = 77) and postprocedural MRI (n = 56). Local tumor progression was assessed on all available follow-up imaging (1–49 months, mean 15). Local tumor progression was correlated with PET/CT minimum margin measurements using clustered survival models for 61 tumors.ResultsMinimum ablation margins were more often assessable using intraprocedural PET/CT (≥ 73/77 tumors, 95%) than postprocedural MRI (≤ 35/56 tumors, 63%). In 61 tumors with PET/CT-assessable margins (excluding tumors with overlapping ablations after PET/CT), there was a 6-fold increased risk of local tumor progression [hazard ratio (HR) 6.05; P = 0.004] for minimum ablation margins < 5 mm.ConclusionBreath-hold PET/CT scans, during PET/CT-guided microwave or cryoablation procedures for FDG-avid liver tumors, enable reliable intraprocedural assessment of the entire tumor ablation margin; a minimum PET/CT ablation margin threshold of 5 mm correlates well with local tumor progression outcomes.
Image-guided percutaneous ablation of hepatic epithelioid hemangioendothelioma
PurposeDisease control and survival following percutaneous ablation of hepatic epithelioid hemangioendothelioma (EHE) was studied retrospectively.MethodsSix patients underwent 16 image-guided ablation procedures to treat 35 liver tumors from 2015 to 2022 (17 microwave ablation, 9 irreversible electroporation, 8 cryoablation, and 1 radiofrequency ablation). Technical success, local progression, intrahepatic progression, distant progression, overall survival, and adverse events were assessed.ResultsFour of six (67%) patients were treatment naïve prior to ablation. The mean length of imaging follow-up from first ablation procedure was 43.0 ± 31.2 months. Thirty-three of 35 (94.3%) ablated tumors did not progress locally. Three of 6 patients (50%) had new intrahepatic progression and underwent repeat ablation or systemic treatment. No extrahepatic progression was observed. One patient died from EHE 2.7 years after initial diagnosis. No severe adverse events occurred.ConclusionPercutaneous ablation is feasible, often in a staged fashion, and may provide favorable intermediate to long-term disease control for patients with hepatic EHE.
Wall suction-assisted image-guided therapeutic paracentesis: a safe and less expensive alternative to evacuated bottles
Objective To assess the safety and cost savings of using wall suction and plastic canisters instead of evacuated bottles, currently in short supply, to drain, and collect large amounts of fluid during image-guided paracentesis procedures. Materials and methods In a hospital-based practice, 551 image-guided paracenteses were performed in 191 consecutive patients over a 10-month period, using wall suction to facilitate drainage. Total volume of fluid removed and complications were recorded. Complications were graded using Common Terminology Criteria for Adverse Events. The pressure generated from the wall suction at our institution was measured using a manometer and compared to that of an empty evacuated bottle. Cost savings per procedure were estimated by calculating the difference in the price of supplies used to collect the average volume of fluid removed per procedure for each method. Results The mean volume of fluid removed per procedure was 3541 mL. Four (0.72%) complications occurred in 551 procedures. One grade I complication consisted of a prolonged puncture site leak of ascites. Three Grade III complications included infection, hypotension, and atrial fibrillation. All four complications appeared unrelated to the use of wall suction and were treated successfully. Maximum pressure generated from the wall suction at our institution was less than the initial pressure generated from an empty evacuated bottle. Estimated cost savings per procedure was $33.92. Conclusion The use of wall suction and plastic canisters to drain and collect fluid during image-guided therapeutic paracenteses is a safe alternative to using evacuated glass bottles and reduces per-procedure costs.
Liver tumor F-18 FDG-PET before and immediately after microwave ablation enables imaging and quantification of tumor tissue contraction
PurposePoor liver tumor visibility after microwave ablation (MWA) limits direct tumor ablation margin assessments using contrast-enhanced CT or ultrasound (US). Positron emission tomography (PET) or PET/CT may offer improved intraprocedural assessment of liver tumor ablation margins versus current imaging techniques, as 18F-fluorodeoxyglucose (18F-FDG)-avid tumors remain visible on PET immediately following ablation. The purpose of this study was to assess intraprocedural 18F-FDG PET scans before and immediately after PET/CT-guided MWA for visualization and quantification of metabolic liver tumor tissue contraction resulting from MWA.MethodsThis retrospective study, conducted at a large academic medical center after Institutional Review Board approval, included 36 patients (20 men; mean age 63 [range 37–85]) who underwent PET/CT-guided MWA of 42 18F-FDG-avid liver tumors from May 2013 to March 2018. Tumor metabolic diameters (short/long axes) were measured for each tumor on pre- and post-ablation PET images. Tumor metabolic volumes were calculated using tumor diameter measurements and compared with automated volumes using an SUV threshold algorithm. A two-tailed paired t test was used for the analyses.ResultsComparing intraprocedural pre- and post-ablation PET images, mean metabolic tumor short- and long-axis diameters decreased from 21.4 to 14.9 mm [− 29%, p < 0.001, standard deviation (SD) 18%] and from 24.0 to 18.0 mm (− 24%, p < 0.001, SD 16%), respectively. The mean calculated tumor metabolic volume decreased from 10.5 to 4.6 mm3 (− 55%, p < 0.001, SD 26%). The mean automated tumor metabolic volume decreased from 10.6 to 5.8 mm3 (− 45%, p < 0.001, SD 30%).ConclusionIntraprocedural PET images of 18F-FDG-avid liver tumors allow visualization and quantification of MWA-induced metabolic tumor tissue contraction during 18F-FDG PET/CT-guided procedures. The ability to visualize contracted tumor immediately post-MWA may facilitate emerging intraprocedural PET and PET/CT imaging techniques that address a clinical gap in directly assessing the ablation margin.
Can MRI features predict clinically relevant hepatocellular carcinoma genetic subtypes?
PurposeRecent studies in cancer genomics have revealed core drivers for hepatocellular carcinoma (HCC) pathogenesis. We aim to study whether MRI features can serve as non-invasive markers for the prediction of common genetic subtypes of HCC.MethodsSequencing of 447 cancer-implicated genes was performed on 43 pathology proven HCC from 42 patients, who underwent contrast-enhanced MRI followed by biopsy or resection. MRI features were retrospectively evaluated including tumor size, infiltrative tumor margin, diffusion restriction, arterial phase hyperenhancement, non-peripheral washout, enhancing capsule, peritumoral enhancement, tumor in vein, fat in mass, blood products in mass, cirrhosis and tumor heterogeneity. Fisher’s exact test was used to correlate genetic subtypes with imaging features. Prediction performance using correlated MRI features for genetic subtype and inter-reader agreement were assessed.ResultsThe two most prevalent genetic mutations were TP53 (13/43, 30%) and CTNNB1 (17/43, 40%). Tumors with TP53 mutation more often demonstrated an infiltrative tumor margin on MRI (p = 0.01); inter-reader agreement was almost perfect (kappa = 0.95). The CTNNB1 mutation was associated with peritumoral enhancement on MRI (p = 0.04), inter-reader agreement was substantial (kappa = 0.74). The MRI feature of an infiltrative tumor margin correlated with the TP53 mutation with accuracy, sensitivity, and specificity of 74.4%, 61.5% and 80.0%, respectively. Peritumoral enhancement correlated with the CTNNB1 mutation with accuracy, sensitivity, and specificity of 69.8%, 47.0% and 84.6%, respectively.ConclusionAn infiltrative tumor margin on MRI correlated with TP53 mutation and peritumoral enhancement correlated with CTNNB1 mutation in HCC. Absence of these MRI features are potential negative predictors of the respective HCC genetic subtypes that have implications for prognosis and treatment response.
Risk of persistent air leaks following percutaneous cryoablation and microwave ablation of peripheral lung tumors
Objectives To compare the incidence of persistent air leak (PAL) following cryoablation vs MWA of lung tumors when the ablation zone includes the pleura. Methods This bi-institutional retrospective cohort study evaluated consecutive peripheral lung tumors treated with cryoablation or MWA from 2006 to 2021. PAL was defined as an air leak for more than 24 h after chest tube placement or an enlarging postprocedural pneumothorax requiring chest tube placement. The pleural area included by the ablation zone was quantified on CT using semi-automated segmentation. PAL incidence was compared between ablation modalities and a parsimonious multivariable model was developed to assess the odds of PAL using generalized estimating equations and purposeful selection of predefined covariates. Time-to-local tumor progression (LTP) was compared between ablation modalities using Fine-Gray models, with death as a competing risk. Results In total, 260 tumors (mean diameter, 13.1 mm ± 7.4; mean distance to pleura, 3.6 mm ± 5.2) in 116 patients (mean age, 61.1 years ± 15.3; 60 women) and 173 sessions (112 cryoablations, 61 MWA) were included. PAL occurred after 25/173 (15%) sessions. The incidence was significantly lower following cryoablation compared to MWA (10 [9%] vs 15 [25%]; p  = .006). The odds of PAL adjusted for the number of treated tumors per session were 67% lower following cryoablation (odds ratio = 0.33 [95% CI, 0.14–0.82]; p  = .02) vs MWA. There was no significant difference in time-to-LTP between ablation modalities ( p  = .36). Conclusions Cryoablation of peripheral lung tumors bears a lower risk of PAL compared to MWA when the ablation zone includes the pleura, without adversely affecting time-to-LTP. Key Points • The incidence of persistent air leaks after percutaneous ablation of peripheral lung tumors was lower following cryoablation compared to microwave ablation (9% vs 25%; p  =  .006). • The mean chest tube dwell time was 54% shorter following cryoablation compared to MWA (p  =  .04). • Local tumor progression did not differ between lung tumors treated with percutaneous cryoablation compared to microwave ablation (p  =  .36).
Outcomes Following Percutaneous Microwave and Cryoablation of Lung Metastases from Adenoid Cystic Carcinoma of the Head and Neck: A Bi-Institutional Retrospective Cohort Study
ObectiveThe aim of this study was to report outcomes following percutaneous microwave and cryoablation of lung metastases from adenoid cystic carcinoma (ACC) of the head and neck. Material and MethodsThis bi-institutional retrospective cohort study included 10 patients (6 females, median age 59 years [range 28–81]) who underwent 32 percutaneous ablation sessions (21 cryoablation, 11 microwave) of 60 lung metastases (median 3.5 tumors per patient [range 1–16]) from 2007 to 2019. Median tumor diameter was 16 mm [range 7–40], significantly larger for cryoablation (22 mm, p = 0.002). A median of two tumors were treated per session [range 1–7]. Technical success, local control, complications, and overall survival were assessed.ResultsPrimary technical success was achieved for 55/60 tumors (91.7%). Median follow-up was 40.6 months (clinical) and 32.5 months (imaging, per tumor). Local control at 1, 2, and 3 years was 94.7%, 80.8%, and 76.4%, respectively, and did not differ between ablation modalities. Five of fifteen recurrent tumors underwent repeat ablation, and secondary technical success was achieved in four (80%). Assisted local tumor control at 1, 2, and 3 years was 96.2%, 89.8%, and 84.9%, respectively. Complications occurred following 24/32 sessions (75.0%) and 63.2% Common Terminology Criteria for Adverse Events (CTCAE) lower than grade 3. Of 13 pneumothoraces, 7 required chest tube placements. Hemoptysis occurred after 7/21 cryoablation sessions, and bronchopleural fistula developed more frequently with microwave (p = 0.037). Median length of hospital stay was 1 day [range 0–10], and median overall survival was 81.5 months (IQR 40.4–93.1).ConclusionPercutaneous computed tomography-guided microwave and cryoablation can treat lung metastases from ACC of the head and neck. Complications are common but manageable, with full recovery expected.
Comparison of expected imaging findings following percutaneous microwave and cryoablation of pulmonary tumors: ablation zones and thoracic lymph nodes
Objective To compare temporal changes of ablation zones and lymph nodes following lung microwave ablation (MWA) and cryoablation. Methods This retrospective cohort study compared lung ablation zones and thoracic lymph nodes following MWA and cryoablation performed 2006–2020. In the ablation zone cohort, ablation zone volumes were measured on serial CT for 12 months. In the lymph node cohort, the sum of bidimensional products of lymph node diameters was measured before (baseline) and up to 6 months following ablation. Cumulative incidence curves estimated the time to 75% ablation zone reduction and linear mixed-effects regression models compared the temporal distribution of ablation zones and lymph node sizes between modalities. Results Ablation zones of 59 tumors treated in 45 sessions (16 MWA, 29 cryoablation) in 36 patients were evaluated. Differences in the time to 75% volume reduction between modalities were not detected. Following MWA, half of the ablation zones required an estimated time of 340 days to achieve a 75% volume reduction compared to 214 days following cryoablation ( p = .30). Thoracic lymph node sizes after 33 sessions (13 MWA, 20 cryoablation) differed between modalities (baseline–32 days, p = .01; 32–123 days, p = .001). Following MWA, lymph nodes increased on average by 38 mm 2 (95%CI, 5.0–70.7; p = .02) from baseline to 32 days, followed by an estimated decrease of 50 mm 2 (32–123 days; p = .001). Following cryoablation, changes in lymph nodes were not detected (baseline–32 days, p = .33). Conclusion The rate of ablation zone volume reduction did not differ between MWA and cryoablation. Thoracic lymph nodes enlarged transiently after MWA but not after cryoablation. Key Points • Contrary to current belief, the rate of lung ablation zone volume reduction did not differ between microwave and cryoablation. • Transient enlargement of thoracic lymph nodes after microwave ablation was not associated with regional tumor spread and decreased within six months following ablation. • No significant thoracic lymph node enlargement was observed following cryoablation.
Liver-Directed Therapies for Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma
Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC) are primary liver cancers where all or most of the tumor burden is usually confined to the liver. Therefore, locoregional liver-directed therapies can provide an opportunity to control intrahepatic disease with minimal systemic side effects. The English medical literature and clinical trials were reviewed to provide a synopsis on the available liver-directed percutaneous therapies for HCC and IHC. Locoregional liver-directed therapies provide survival benefit for patients with HCC and IHC compared to best medical treatment and have lower comorbid risks compared to surgical resection. These treatment options should be considered, especially in patients with unresectable disease.