Imaging in staging, treatment planning, and monitoring of hepatocellular carcinoma for local and locoregional therapies: consensus recommendations from EORTC and ESGAR Öcal O, Zech CJ, Bali MA, et al; on behalf of the study group Eur Radiol. 2026;36(1):597–606. DOI: 10.1007/s00330-025-11699-7.
Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and remains a leading cause of cancer-related mortality worldwide [1]. Local ablative and locoregional therapies—thermal ablation, transarterial chemoembolization (TACE), transarterial radioembolization (TARE), and stereotactic body radiation therapy (SBRT)—are standard-of-care treatments across multiple disease stages. Imaging informs staging, treatment planning, procedural guidance, and response assessment throughout this pathway, yet timing, modality, and protocol design remain highly heterogeneous in clinical practice despite well-established guidance for individual therapies [2,3]. To address this gap, the European Organisation for Research and Treatment of Cancer (EORTC) Imaging and Gastrointestinal Tract Cancer Groups, together with the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), conducted a multidisciplinary Delphi consensus survey to standardize periinterventional imaging for HCC patients undergoing these therapies [4]. The survey followed a prospective, multistep, modified, non-anonymous Delphi design. Fifty-one participants from 15 countries—predominantly interventional radiologists (35%), followed by gastroenterologists/hepatologists, radiologists, radiation oncologists, nuclear medicine physicians, and medical oncologists, among others—completed the first round, mapping current practice patterns. A targeted literature review then informed 37 candidate statements for a second, dichotomous voting round, with a 70% consensus threshold; a discussion meeting addressed statements failing to reach consensus, refining a single item for a third round. Imaging work-up. Both CT and MRI were endorsed for evaluating local disease burden (83.8%), with gadoxetic acid recommended as the MRI contrast agent and diffusion-weighted imaging deemed mandatory—each reaching 89.2% agreement. Abdominal CT should include arterial, portal, and venous phases with a 180-second venous phase delay (77.8%); the authors did not reach a consensus on whether unenhanced images should always be obtained. Baseline thorax CT was endorsed in all patients (86.5%), while PET-CT was not considered mandatory for the diagnostic work-up (83.8%), reflecting the low FDG-avidity of HCC. Liver imaging older than one month, or thoracic imaging older than three months, should be repeated before locoregional treatment. Diagnosis. The LI-RADS reporting system was recommended for HCC diagnosis (88.9%). Biopsy is not required to confirm the diagnosis in lesions with typical imaging characteristics before locoregional treatment, given imaging's high specificity (89.2%). It remains advisable, however, when no prior histopathological confirmation exists (75.7%), since it provides prognostically relevant tumor grading and helps exclude mixed tumors or cholangiocarcinoma. The panel reached similar agreement (73%) that biopsy should be obtained for additional hypovascular hepatobiliary-phase hypointense lesions larger than 1 cm, given their recognized malignant potential even at intermediate LI-RADS categories. Follow-up after locoregional therapy. Recommended surveillance intervals converged on imaging every three months across all four therapies, though the timing of the first post-treatment scan varied: no consensus emerged for thermal ablation (proposals ranged from day 1 to month 1), while month 1 was endorsed for TACE and month 3 for both TARE and SBRT. MRI is the preferred imaging modality for follow-up after thermal ablation, TARE, and SBRT. For TACE, opinions remain split, likely due to CT's value in tracking lipiodol retention. Response assessment and AI. Perfusion-based criteria (mRECIST, EASL, or LI-RADS-TRA) were preferred over anatomic RECIST for assessing response after locoregional therapy (97.3%), consistent with HCC's characteristic vascular behavior. The panel also agreed that AI has not yet been established for treatment decision-making (97.3%) or follow-up (100%)—a pragmatic reflection of the current evidence gap despite growing research interest. Intraprocedural imaging. All modalities (US/CT/MRI) were considered acceptable for thermal ablation guidance depending on institutional expertise (100%), and lipiodol-based TACE was endorsed as a tool to improve lesion conspicuity before thermal ablation (85%). Cone-beam CT was strongly recommended during both TACE (88.6%) and TARE (94.3%) to confirm tumor vascular supply, since more selective delivery is linked to better outcomes. The authors acknowledge that several recommendations rest on expert opinion rather than prospective trial data, and that some statements failed to reach consensus, partly attributable to question phrasing. Nonetheless, this EORTC–ESGAR consensus addresses the periinterventional imaging pathway for HCC local and locoregional therapies, complementing guidelines such as EASL and LI-RADS. It offers a structured, practical framework spanning pretreatment work-up, intraprocedural guidance, and follow-up scheduling. For ESGAR members, it provides a ready-to-adopt protocol that can reduce inter-center variability in daily reporting practice, as well as a common backbone for future prospective trials evaluating locoregional and combined locoregional–systemic strategies in HCC. | References
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