Purpose To develop a lung-specific deformable image registration algorithm optimized for lung thermal ablation and evaluate whether three-dimensional (3D) margin assessment predicts time to local recurrence. Materials and Methods This institutional review board-approved, single-institution retrospective study evaluated patients who underwent lung thermal ablation with available pre- and postprocedural CT scans suitable for deformable registration. Images were preprocessed with segmentation of tumor, ablation zone, and lung. A four-stage deformable image registration framework was applied: (a) affine registration, (b) deformable image registration to the cropped lung, (c) lung mask-guided deformable image registration, and (d) local deformable image registration focused on the neighborhood adjacent to the ablation zone. Registrations were performed using free-form B-spline transformations with cost function masking of the ablation zone. Registration accuracy was assessed using target registration error (TRE). The 3D ablation margins were quantified using a distance-transform-based analysis of the spatial relationship between the tumor surface and ablation zone boundary. Associations between margin size and time to local recurrence were evaluated using competing-risks regression, and time-dependent receiver operating characteristic analysis was performed. Results A total of 69 patients (median age, 59 years [IQR, 50-69 years]; 38 female) with 108 ablated lung tumors were included. Mean TRE ± SD was 0.4 mm ± 0.3 and mean ablation margin was 1.6 mm ± 2.1. Larger margins were associated with longer time to local recurrence (subdistribution hazard ratio, 0.5 per millimeter increase [95% CI: 0.4, 0.6]; P < .001) and remained independently associated on multivariate analysis. Using a 2-mm margin threshold, the 2-year local recurrence rate was 3% (95% CI: 1, 8). The area under the receiver operating characteristic curve for predicting 2-year local recurrence was 0.86. Conclusion The four-step lung-optimized deformable image registration framework enabled accurate automated 3D tumor ablation margin quantification, and margin size was associated with time to local recurrence. Keywords: Ablation Techniques, Interventional-Oncology, Percutaneous, Thorax, Lung, Computer Applications-3D, Computational Studies, CT © RSNA, 2026.

We quantified volume and shape variability in lung microwave ablation (LMWA) zones, comparing them with expected ablation zones, exploring the correlation with tissue contraction. After Institutional Review Board approval, we retrospectively included patients who underwent LMWA between January 2015 and January 2019. Exclusion criteria were ablations with multiple burns/probes, overlapping ablation zones, or indistinguishable background lung parenchyma. Ablation zones were oriented along an applicator-centric coordinate system. We used Pyradiomics to generate volumes and the Euler characteristic transform for three-dimensional shape space analysis. Wilcoxon paired signed-rank tests compared the expected versus the actual ablation zone. Tissue contraction was quantified using paired anatomical landmarks before and after computed tomography scans. We included 111 ablations in 72 patients (31 male, 41 female; median age 59). Median ablation power was 65 watts (range 20‒65), median ablation time 5 min (range 1‒10). Total energy correlated with volume and width (p = 0.007, p = 0.003, respectively). Ablation volume did not differ from vendor predictions (p = 0.452), whereas length (p < 0.001) and maximum width (p < 0.001) were greater than predicted. Ablation shapes were more elongated (p < 0.001), less spherical (p < 0.001), asymmetric (wider in back than in front, p = 0.007), and diverged from expected ellipsoids. There was no correlation between tissue contraction and volume, power, or time. The provided vendor model offers a reasonable estimate of mean ablation volume, but wide variability in volume and shape necessitates a more bespoke method of ablation zone prediction. Tissue contraction did not correlate with ablation zone variability. High variability in actual ablation volume, shape, length, width, and position along the needle and divergence from ellipsoids necessitates the development of improved ablation zone prediction models.

Background Real-time methods are needed for intraprocedural detection of residual tumors and incomplete thermal ablation (TA) to allow immediate retreatment and tumor eradication. Purpose To validate a TA workflow for detecting and immediately ablating residual viable colorectal liver metastases (CLMs). Materials and Methods This prospective single-center trial enrolled participants who underwent PET/CT-guided microwave CLM ablation from November 2019 to February 2023. The minimal ablation margin (MM) was calculated in all directions. Biopsies were obtained from the ablation zone (AZ) center and margin, with rapid tissue assessment for viable tumor (VT) cells using imprint cytology and fluorescent viability staining. Immediate reablation was performed if any of the following criteria were met: MM less than 5 mm at contrast-enhanced CT, residual PET-avid tumor, and/or VT cells at rapid tissue assessment. Gray-model statistics quantified the MM and VT impact on local tumor progression subdistribution hazard amid the competing risk of death. Results Seventy-seven participants (median age, 56 years [IQR, 47-64.5 years]; 39 male participants) underwent ablation in 104 CLMs. Overall, 15 of 104 (14%) CLMs underwent immediate reablation per the criteria (12 of 15, VT; seven of 15, MM <5 mm; and four of 15, residual fluorodeoxyglucose avidity). After reablation, all 12 initially VT-positive AZs underwent repeat biopsies with negative findings. Five of seven MMs less than 5 mm in AZs increased to greater than 5 mm after reablation. All four CLMs that underwent reablation due to PET/CT findings had AZs positive for VT, and one had MM less than 5 mm. MM greater than 5 mm protected against local tumor progression (LTP) (subdistribution hazard ratio, 0.12; 95% CI: 0.05, 0.30; P < .001). There was no LTP for MMs greater than 10 mm. The cumulative LTP incidence at 1, 2, and 3 years for participants with biopsy-proven completely ablated CLMs with MM greater than 5 mm was 7%, 12%, and 12%, respectively. Conclusion MM remained a critical technical factor affecting tumor control; the proposed multimodal comprehensive AZ assessment enabled immediate onsite reablation of 14% of CLMs with initially insufficient ablation treatment and improved local tumor control after thermal ablation. ClinicalTrials.gov identifier: NCT04143516 © RSNA, 2026 Supplemental material is available for this article. See also the editorial by Georgiades in this issue.

Objective:To compare the safety and efficacy of transarterial embolization (TAE) and transarterial radioembolization (TARE) in the treatment of lung carcinoid liver metastasis. Method:This retrospective, single-institution study included 30 patients with lung carcinoid liver metastasis treated with 53 primary embolization procedures (24 TARE; 29 TAE) between 2009 and 2022. Survival analyses were performed using the Kaplan-Meier method. Adverse events were assessed using the Common Terminology Criteria of Adverse Events Version 5.0. Results:The local tumor progression-free survival (LTPFS) for the entire cohort was 16.2 (95% confidence interval [CI]: 12.6-22.2) months. Factors associated with poor LTFPS for all patients included chromogranin A positivity (hazard ratio [HR]: 10.13, 95% CI: 2.32-44.31, p = 0.002), previous octreotide treatment (HR: 2.37, 95% CI: 1.12-5.01, p = 0.01), and previous everolimus treatment (HR: 2.4, 95% CI: 1.12-5.01, p = 0.02).TARE was associated with significantly improved LTPFS; 30.57 (95% CI: 12.4-33.4) months compared with TAE 13.9 (95% CI: 10.87-20.13) months, (p = 0.01). Patients on concurrent everolimus at the time of TARE had a significant improvement in LTPFS (HR: 0.25, 95% CI: 0.16-0.41, p < 0.001).The median overall survival of the entire cohort was 43.5 (95% CI: 20.5-55.9) months; 40.6 (95% CI: 20-49.0) months for TAE versus 43.5 (95% CI: 12.3-61.4) months for TARE (p = 0.49).Postprocedure adverse events occurred in 28 out of 74 (38%) treatments, most being grade 1 and 2 (n = 24). Severe adverse events (Common Terminology Criteria of Adverse Events grade ≥3) included severe vomiting after TARE (2), acute kidney injury after TAE (1), and bacteremia after TAE (1). Conclusion:TARE exhibited better local tumor control compared with TAE in patients with lung carcinoid, with no significant difference in overall survival. Both hepatic arterially directed therapies exhibited acceptable safety profiles.

This multisociety, multidisciplinary consensus—formally endorsed by the European Society of Surgical Oncology, the Cardiovascular and Interventional Radiological Society of Europe, and the Society of Interventional Oncology—was developed to standardise the assessment of ablation margins in liver tumour thermal ablation. A modified Delphi process, consisting of two online surveys and a hybrid (online and in-person meeting in Innsbruk) consensus meeting of 72 experts from North America, South America, Europe, and Asia. Formal consensus was reached for 150 (75%) of 199 statements. Strong agreement was observed between interventional and surgical oncologists, with only 12 (6%) of 199 statements showing significantly different ratings. Participants agreed that ablation margins should be assessed and documented for every treated tumour. Margins should be assessed quantitatively in three dimensions, with contrast-enhanced CT or MRI, preferably intraprocedurally with ablation confirmation software. Ablation margins should be categorised as A0 (tumour completely covered with sufficient margin), A1 (tumour completely covered but insufficient margin), or A2 (portion of tumour remains unablated). This effort is, to our knowledge, the first international consensus initiative to define best-practice recommendations for margin assessment in liver tumour thermal ablation to standardise practices, aiming to improve and promote uniform outcomes.

Thermal ablation offers a safer, less invasive, and more cost-effective curative-intent treatment for selected patients with primary and metastatic liver tumours than surgery; when done with appropriate technique, ablation can deliver similar oncological outcomes. However, effectiveness in routine practice varies because structured training, planning, and procedural governance remain scarce. These international multidisciplinary, multi-society guidelines—formally endorsed by the European Society of Surgical Oncology, the Cardiovascular and Interventional Radiological Society of Europe, and the Society of Interventional Oncology—define key domains contributing to procedural difficulty and practice variation in liver tumour thermal ablation. A Delphi consensus initiative held in Innsbruck, Austria, engaged 72 experts across three iterative rounds of scoring across 135 statements grouped into five domains: credentialing, indications, approach, procedural factors, and safety measures. Consensus was achieved for 94 (70%) of 135 statements. The least invasive route—typically percutaneous—should be prioritised, and margin adequacy was reaffirmed as the principal technical goal. Procedural difficulty was considered context-dependent, shaped by tumour factors, institutional infrastructure, and operator experience. Organ displacement techniques were endorsed to maintain safety and expand treatable indications. Complex ablations should be done by experienced operators (more than 100 previous cases), with programmes underpinned by structured training, multidisciplinary team participation, and routine audit. Future efforts should develop and validate practical tools such as difficulty scoring systems, standardised procedural reporting templates, and comprehensive training curricula to improve consistency, standardisation, and clinical outcomes globally.

Interventional radiologists are key members of the multidisciplinary team involved in the care of patients with primary or metastatic neoplastic disease in the thorax. Percutaneous ablation is a safe and efficacious treatment of lung tumors, especially for patients with medical comorbidities or oligometastatic disease. Endovascular approaches can benefit patients with thoracic oncologic disease by allowing for primary arterial treatment, preoperative embolization, or embolization for tumor-related hemoptysis. Drainage and shunt procedures can help alleviate symptoms in patients with malignant pleural effusions, chylothoraces, and pericardial effusions. The authors summarize several available minimally invasive interventions to the thorax for tumor treatment and symptom palliation. ©RSNA, 2025.

Purpose: To characterize the current state of interventional radiology (IR) practice and education worldwide and to identify factors impacting access to IR services. Materials and Methods: A Society of Interventional Radiology (SIR)-approved, anonymous survey was created to gather data on demographics, regional IR practice and education characteristics, and challenges impacting local IR development. The survey was distributed to members of global IR societies and shared on social media from June 2022 to September 2023. Results: Of 1,263 respondents, 987 provided specialty affiliations, including 811 interventional radiologists, 85 diagnostic radiologists (DRs), and 91 interventional radiologists/DRs. Two hundred sixty identified as attending/consultants, 185 as residents/fellows, 12 as medical students, and 7 as technologists/nurses. IR awareness was the greatest reported need globally. Education, patient referrals, and training were also common needs. When compared with North American training programs, there were significant shortages of dedicated IR training programs in Africa (odds ratio [OR], 0.06; P < .001), Asia (OR, 0.50; P = .004), Europe (OR, 0.12; P < .001), and Oceania (OR, 0.12; P < .001). Significant shortage of any IR exposure during radiology training was observed in Africa (OR, 0.31; P < .001), Asia (OR, 0.16; P < .001), and South America (OR, 0.14; P < .001). Additional challenges included awareness and support in the hospital setting and competition with other specialties. Compared with respondents from North America, the top 3 actions recommended to provide the most significant relative impact included establishing IR training programs, providing access to online education, and holding multidisciplinary conferences. Conclusions: This survey established the universal needs to increase patient awareness about IR and improve dedicated IR training programs. The results can help guide organizational and societal efforts to improve access to IR services worldwide.

The aim of this study was to evaluate associations between TP53 status and outcomes after transarterial embolization (TAE) for the treatment of patients with hepatocellular carcinoma (HCC). This single-institution study included patients from 1/2014 to 6/2022 who underwent TAE of HCC and genomic analysis of tumoral tissue. The primary outcome was overall survival (OS) with relation to TP53 status, and the secondary outcome was the time to progression. Survival analysis was performed using the Kaplan–Meier method. The time to progression with death or the last patient contact without progression as competing risks were used to obtain a cumulative incidence function, and the association with TP53 status was evaluated using the Gray test. In total, 75 patients (63 men) with a median age of 70.0 (IQR 62.0–76.3) years were included. Of these, 26/75 (34.7%) patients had TP53-mutant HCC. Patients with TP53-mutant HCC had a significantly worse median OS of 15.2 (95% CI, 9.5–29.3) months, versus 31.2 (95% CI, 21.2–52.4) months as the median OS (p = 0.023) for TP53 wild-type HCC. Competing risk analysis showed a shorter time to local hepatic progression (at the site of the previously treated tumor) after TAE in patients with TP53-mutant HCC. The cumulative incidences of local progression at 6 and 12 months for TP53-mutant HCC were 65.4% and 84.6%, versus 40.8% and 55.1% for TP53 wild-type HCC (p = 0.0072). A TP53 mutation may predict a worse overall survival and a shorter time to local progression in HCC patients treated with TAE.

BACKGROUND:Radiation segmentectomy (RS) is an alternative potential local curative treatment for selected colorectal liver metastases (CLMs) not amenable to ablation or limited resection. PURPOSE:The aim of this study was to evaluate the dosimetric response of low volume CLMs to RS in heavily pretreated patients who are not candidates for resection or percutaneous ablation. PATIENTS AND METHODS:This single-center retrospective study evaluated CLMs patients treated with RS (prescribed tumor dose >190 Gy) from 2015 to 2023. RS doses to tumor(s) and margins were calculated from SPECT/CT and PET/CT images. Response and local tumor progression (LTP) were assessed using anatomic (RECIST 1.1) and metabolic (PERCIST) criteria. LTP-free survival (LTPFS) and overall survival were estimated with Kaplan-Meier methodology. Variables were assessed as predictors of LTPFS using the Cox proportional hazards model. RESULTS:Thirty-six patients underwent 38 RS procedures to treat 57 tumors. Median time from initial diagnosis to detection of liver metastases and RS were 16.4 (interquartile range: 6.5-32.2) and 26.8 (interquartile range: 12.5-40.0) months, respectively. Median overall survival after RS was 14.3 (95% confidence interval [CI]: 10.8-30.7) months. Predictors of LTPFS included tumor number(s), mean tumor dose (MTD), and margin mean absorbed dose (MMAD). Complete radiographic (hazards ratio [HR]: 1.29e-16, 95% CI: 4.06e-17-4.07e-16, P < 0.001) and metabolic response (HR: 0.38, 95% CI: 0.15-0.95, P = 0.038) correlated with prolonged LTPFS. One-year LTPFS rate was 83.3% for tumors receiving MTD ≥400 Gy and a 5-mm surrounding MMAD ≥350 Gy ( P = 0.006). No instances of LTP were observed when tumors received stereotactic irradiation over 300 Gy (at least 95% of the tumor volume received ≥300 Gy). One-year LTPFS rate for tumors receiving MTD ≥400 Gy was 68.6% versus 14.3% for those that did not reach this threshold ( P = 0.013). In multivariate analysis, MTD ≥400 Gy and 5-mm MMAD ≥350 Gy were independent predictors of LTPFS (HR: 0.11; 95% CI: 0.01-0.81; P = 0.03). CONCLUSIONS:MTD ≥400 Gy, MMAD ≥350 Gy, and stereotactic tumor irradiation ≥300 Gy are associated with prolonged LTPFS after RS for CLMs.

To evaluate predictors of outcomes in colorectal liver metastases (CLM) patients undergoing 90Y radioembolization (TARE), focusing on the impact of tumor absorbed dose. Patients’ characteristics and dosimetry assessments were analyzed in 231 patients undergoing 329 TARE sessions from 09/2009 to 07/2023. Response was assessed using RECIST1.1 and PERCIST criteria. Patients were predominantly male (137/231, 56.3

Cancer is a leading cause of cancer-related death. Liver metastases develop in over one-third of patients and are associated with worse prognosis. The evolution in the field of interventional oncology/radiology over the past two decades has expanded image-guided locoregional therapies for colorectal liver metastases (CLM). Historically, hepatic resection was considered the only possible cure for selected patients with CLM. Current evidence supports thermal ablation (TA) as another locally curative treatment modality for small CLM that can be ablated with adequate margins. Other non-thermal ablative treatment options include Yttrium-90 (90Y) radiation segmentectomy (RS), irreversible electroporation (IRE), and histotripsy, with an evolving role in the treatment of CLM. More extensive disease that is not amenable to resection or ablation can be treated with intra-arterial therapies (90Y trans-arterial radioembolization (TARE) and trans-arterial chemoembolization (TACE)). This comprehensive review describes the evolution of interventional oncology treatments for CLM and examines the appropriate indications for each treatment modality.

Purpose: This study examines the association between tumor volume doubling time (TVDT) and clinical outcomes for patients with hepatocellular carcinoma (HCC) treated with transarterial embolization (TAE) and evaluates the impact of tumor genotype on TVDT. Methods: This was a retrospective cohort study at a single tertiary care cancer center, including treatment-naïve patients with biopsy-proven HCC treated with TAE from 1/2014 to 6/2022. The patients underwent initial baseline contrast-enhanced cross-sectional imaging more than 30 days prior to embolization. Index tumors were defined as the largest HCC present on baseline imaging treated with TAE, and TVDT was calculated using Schwartz’s equation with perpendicular trans-axial measurements. Genetic mutation analysis was performed on HCC tissue specimens using next-generation sequencing. Survival analysis was performed using the Kaplan–Meier method, and Cox regression was used to assess prognostic factors for survival. Results: Patients with a TVDT ≤ 2.5 months had a worse overall survival (OS) after TAE (p = 0.011). On multivariate regression analysis, predictors of worse OS following TAE included TVDT ≤ 2.5 months (p = 0.036), Eastern Cooperative Oncology Group (ECOG) performance score of 1 or 2 (p = 0.006), and alpha fetoprotein > 200 ng/mL (p = 0.013). The presence of ≥5 HCC tumors on initial imaging was associated with a worse local tumor progression-free survival (LTPFS) on multivariate analysis (p = 0.002). No single genetic mutation was associated with shorter TVDT. Conclusion: Patients with HCC exhibiting rapid growth, defined as shorter TVDT, may be associated with worse overall survival following TAE. Rapid tumor growth does not seem to be correlated with a single genetic mutation.

Breast cryoablation is a minimally invasive procedure that has demonstrated feasibility, tolerability, and effectiveness in eradicating small breast cancers. The integration of multimodal imaging systems is crucial for optimal patient selection, precise tumor targeting, and complete tumor eradication. Expanding the use of cryoablation to larger tumors may be feasible by leveraging established ablation techniques, such as ablation margin confirmation and postablation biopsy.

Small cell lung cancer (SCLC) is a high-grade neuroendocrine carcinoma associated with early development of distant metastases, which portends a worse prognosis. The median survival of metastatic SCLC with standard treatment is only 9-11 months, with a 5-year survival of 1-2%. Patients with SCLC are often initially responsive to systemic therapies, but once they develop resistance to them, locoregional therapies like thermal ablation should be investigated for possible improvements in morbidity and mortality. This brief retrospective report evaluates six patients with SCLC liver metastases (LMs), treated in 11 thermal ablation sessions (radiofrequency ablation or microwave ablation). Technical success was achieved in all treatments (100%). After the first ablation, 3/7 ablated tumors had residual disease. Survival outcomes were determined using the Kaplan-Meier method. Median local tumor progression-free survival (LTPFS) was 2.9 [95% confidence interval (CI): 0.5-3.9] months. Median assisted LTPFS, defined as tumor control with subsequent retreatment, was 25.9 (95% CI: 8.3-not reported) months. Median overall survival (OS) was 14.3 months. There was one adverse event (1/11) of grade 1, according to the Common Terminology Criteria for Adverse Events version 5.0, fatigue within a month of ablation, which self-resolved. The results suggest that thermal ablation is safe for SCLC LMs. Although LTPFS was very modest, the long duration of assisted LTPFS and OS in this small, retrospective study suggests that thermal ablation may be a promising treatment option.