Tumor Response Criteria Research Articles

Resisting RECIST-Uniformity Versus Clinical Validity.

The Response Evaluation Criteria in Solid Tumors (RECIST) International Working Group developed criteria for tumor response and progression to standardize radiological assessment in patients receiving chemotherapy in phase 2 trials. However, it is unclear whether the defined percentage change in tumor size and volume reflects true clinical benefit for the patient. The RECIST criteria were designed to improve objectivity in trials, but not to replace clinical decision making. The aim of this study was to understand clinicians' opinions about RECIST in current oncology practice. Using Web-based questionnaires, we investigated attitudes to the use of RECIST at a large comprehensive cancer center and in an international group of gynecologic cancer specialists through the Gynecologic Cancer InterGroup. The results reported here relate to the survey focusing on gynecologic cancer. Sixty medical professionals from 13 countries responded to the survey. The majority of respondents worked at a tertiary or specialist cancer center (51; 86%). Overall, 66% of respondents felt RECIST increased trial objectivity and was a good measure of response. The majority of respondents (81%) reported that they infrequently challenged RECIST evaluation. Overall, 60% felt more than 10% of patients came off trial for clinical rather than radiological progression. In the context of a new small lesion, only 35% felt that should always be considered disease progression. The importance of both clinician and radiologist input was highlighted with nontarget progression. Nontarget progression and target progression were recognized as equally important for clinical decision making (72%). RECIST is a key criterion for endpoint assessment in clinical trials with its value recognized by clinicians. However, this survey also highlights the practical limitations of RECIST. Disconnect can be seen between the radiological result and the clinical picture-learning from these patients is critical. Continued efforts to improve metrics assessing patient benefit in trials remains a priority.

Advanced Renal Cell Carcinoma: Role of the Radiologist in the Era of Precision Medicine.

For the past decade, advanced renal cell carcinoma (RCC) has been at the forefront of oncologic innovation. Our rapidly evolving understanding of the molecular and genetic basis of RCC has revolutionized the management of advanced RCC; 10 novel molecular targeted agents and immune checkpoint inhibitor have received U.S. Food and Drug Administration approval for treatment of advanced RCC in a little over a decade. Amid this progress, imaging has assumed a central role in metastatic surveillance and follow-up of advanced RCC. State-of-the-art knowledge of the molecular basis of RCC and its treatment and imaging will help ensure that the radiology community remains relevant and central in the care of patients with advanced RCC. This article will review developments in management of advanced RCC from a radiologist's perspective to highlight our clinical role. It will describe how the underlying molecular mechanisms of RCC provide specific targets for novel anticancer agents. The relationship between the mechanisms of action of these novel anticancer agents and the imaging appearance of tumor response will be discussed, along with the available tumor response criteria and their strengths and weaknesses, thus assisting radiologists in response assessment in the setting of clinical trials or routine practice. The class- and drug-specific toxicities and complications associated with the novel anticancer agents will be summarized, since these are frequently missed or misinterpreted and require the radiologist's input in prompt detection and management. The potential role of radiogenomics and texture analysis in the management of advanced RCC will also be discussed. © RSNA, 2017.

Abstract NTOC-104: BEYOND RECIST1.1 : THE NEED FOR ALTERNATIVE DISEASE MEASUREMENT CRITERIA FOR CLINICAL TRIALS IN OVARIAN CANCER

Abstract BACKGROUND AND PURPOSE: The majority of ovarian cancer patients respond initially to platinum combination chemo therapy, however at least 70% will relapse and eventually die from recurrent platinum-resistant disease. Thus upon relapse, there is a high degree of interest in participation in clinical trials of novel treatments. However, the pattern of presentation of recurrent disease skews toward “non-measurable” by RECIST solid tumor response criteria, with a majority of patients presenting with diffuse, non-nodular disease and hence being excluded from participating in most trials. Yet these excluded patients may be the ones who would see most benefit from the tested drugs since drug efficacy would not be confounded with issues of penetration into bulky tumors. In addition, in cases where patients present with apparently isolated tumors that are amenable to measurement, the patient is currently forced to choose between surgical excision of the tumor, which retrospective studies suggest extends survival in appropriately selected cases, and keeping the tumor as measurable disease required for entry into a clinical trial. Finally, the current rapid development of targeted therapies, immunotherapies, and combinations means there are potentially many more trial opportunities than can be filled by the relatively small number of ovarian cancer patients, potentially slowing the translation from preclinical findings to actual patient treatment. Here we review the salient facts demonstrating the need for greater clinical trial access for patients with non-RECIST tumor presentation, issues of measuring tumor response, as well as some potential solutions. METHODS: We used a literature search and an online patient survey to assess the impact that the RECIST requirements have on clinical trial participation by ovarian cancer patients. We also reviewed the literature for potential alternative approaches to tumor assessment that would be novel to either solid tumor trials as a whole or ovarian cancer specifically. CONCLUSIONS: Expanding clinical trial access to ovarian cancer patients whose tumors do not meet RECIST requirements should accelerate progress in a way that benefits all stakeholders: patients, pharmaceutical companies, and researchers. Viable alternatives exist and more are under development. Ovarian cancer patients are eager to see these put into practice and are willing to help move this effort forward by participating in relevant validation trials. Adapting clinical trial structure and response criteria to accommodate non-measurable disease in ovarian cancer should be a high priority. Citation Format: Shirley Pepke and Trudy Rucker. BEYOND RECIST1.1 : THE NEED FOR ALTERNATIVE DISEASE MEASUREMENT CRITERIA FOR CLINICAL TRIALS IN OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr NTOC-104.

Health-Related Quality of Life in Patients with Hepatocellular Carcinoma Treated with Initial Transarterial Chemoembolization.

To investigate the impact of the first transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) on health-related quality of life (HRQoL) and identify predictors for low HRQoL following TACE. HRQoL was prospectively evaluated in 79 patients with standardized questionnaires (QlQ-C30 and HCC18) pre- and 2weeks post-TACE. Treatment response was evaluated using common tumour response criteria. Clinical parameters [e.g. Eastern Cooperative Oncology Group (ECOG) performance status, Model of End Stage Liver Disease (MELD) score], tumour load and pre-TACE HRQoL scores were tested for predicting HRQoL after TACE. Patients showed a 12.1% decrease in global health score (GHS). Major decreases were observed for physical (-21.4%), role (-23.4%), and social (-21.5%) functioning and increases in symptom severity for fatigue (+30.1%), loss of appetite (+25.3%), pain (+19.4%) after TACE. ECOG performance status >1 was associated with increased nausea/vomiting (p=0.002) and decreased GHS (p=0.01). MELD score >10 was associated with increased fatigue (p=0.021) and abdominal swelling (p<0.001). Our study showed an increase in symptom severity in patients with no symptoms before TACE for pain (p=0.005) and abdominal swelling (p<0.001). The first TACE for treatment of HCC does not result in a major loss of HRQoL in general. For TACE as a palliative therapy maintaining HRQoL is of critical importance and standardized HRQoL assessment can help to detect HRQoL problems.

How to assess response to immune therapy

Immunotherapy is already a mainstay in treating melanoma, lung cancer and renal cancer and shows compelling promise in many different tumors. However, responses to immunotherapy may be present despite apparent initial progression of the tumor. This underlines the importance of defining accurate tumor assessments and response criteria for immunotherapy. The RECIST criteria have therefore been modified to adhere to requirements of immunotherapy. In line with that, this review will focus on the current imaging tools, the statistical evaluations in clinical trials and the biological analysis of the tumor microenvironment that will in the future effectively guide treatment decisions in everyday clinical practice.

Connecting cancer biology and clinical outcomes to imaging in KRAS mutant and wild-type colorectal cancer liver tumors following selective internal radiation therapy with yttrium-90.

To determine whether pathologic colorectal tumor KRAS mutation status is correlated with progression-free survival (PFS) by imaging after selective internal radiation therapy with Yttrium-90 (SIRT Y90) for metastatic colorectal cancer in the liver (mCRC). This was an IRB approved, HIPAA compliant retrospective cohort study. Consecutive patients with unresectable mCRC with documented KRAS mutation status treated at a single center from 2002 to 2013 with SIRT Y90 were investigated. Treatment response was compared between KRAS wild-type (wt) and mutant (mut) using an anatomic tumor response criteria based on RECIST 1.0. Kaplan-Meier estimation and Cox regression analysis were used to measure progression-free survival (PFS) and to assess independent prognostic factors for PFS. 82 of 186 patients met review criteria. 33 (40.2%) patients were identified as KRAS mut. PFS was longer in KRAS wt (median 166days [95% CI 96-258days]) vs. mut (median 91days [95% CI 79-104days], p=0.002). KRAS mut patients were 1.48 times more likely to progress at first follow-up imaging than wt (95% CI 1.06-2.08, p=0.024). Univariate analysis identified high pre-SIRT Y90 INR, KRAS wt, any use of anti-EGFR therapy, and post-SIRT Y90 chemotherapy as prognostic factors for longer PFS. In multivariate analysis, only KRAS wt was an independent prognostic factor for longer PFS (RR: 1.80 [95% CI 1.08-2.99], p=0.024). Longer PFS is associated with KRAS wt vs. mut following SIRT Y90.

Immune-related response evaluations during immune-checkpoint inhibitor therapy: establishing a “common language” for the new arena of cancer treatment

The recent study by Hodi et al. published in the Journal of Clinical Oncology has evaluated unconventional response patterns during PD-1 inhibitor therapy using immune-related response criteria (irRC) in comparison...

Comparison of performance of various tumor response criteria in assessment of sunitinib activity in advanced gastrointestinal stromal tumors

PurposeTo compare the performance of various tumor response criteria (TRC) in the assessment of patients with advanced gastrointestinal stromal tumor (GIST) treated with sunitinib after failure of imatinib. MethodsSixty-two participants with advanced GIST in two clinical trials received oral sunitinib after prior failure of imatinib (median duration 24 weeks; interquartile range 14–56) and were followed with contrast-enhanced computed tomography at baseline and thereafter at median intervals of 6 weeks (IRQ 6–9). Tumor response was prospectively determined using Response Evaluation Criteria in Solid Tumors (RECIST) 1.0, and retrospectively reassessed for comparison using RECIST 1.1, Choi criteria, and modified Choi (mChoi) criteria using the original target lesions. For mChoi criteria, progressive disease was defined as 20% increase in sum of the longest dimension, similar to RECIST 1.1. Clinical benefit rate (CBR; complete response, partial response, or stable disease ≥12 weeks) and progression-free survival were compared between various TRCs using kappa statistics. ResultsWhile partial response as the best response was more frequent by Choi and mChoi criteria (50% each) than RECIST 1.1 (15%) and RECIST 1.0 (13%), CBR was similar between various TRCs (overall CBR 60%–77%, 77%–94% agreement between all TRC pairs). Time to best response was shorter for Choi and mChoi criteria (median 11 weeks each) compared to RECIST 1.1 and RECIST 1.0 (median 25 and 24 weeks, respectively). PFS was similar for RECIST 1.1, RECIST 1.0, and mChoi (median 35 weeks each), and shortest for Choi criteria (median 23 weeks). ConclusionsCBR was similar among the various TRCs, although Choi criteria led to earlier determination of disease progression. Therefore, RECIST 1.1 and mChoi criteria may be preferred for response assessment in patients with advanced GIST.

WHO, RECIST, and immune-related response criteria: is it time to revisit pembrolizumab results?

In recent years, with the rise of immunotherapeutic agents for cancer treatment, we have observed a paradigm shift in oncology drug development. One common problem accompanying such paradigm shifts is how to build research strategies to fit the mechanism of action of the newer compounds. Developing immunotherapy in oncology requires us to address the unique characteristics of immunotherapeutic agents and to provide adequate tools for their evaluation, including the adjustment of clinical trial endpoints. Immunotherapy creates patterns of response different from those of chemotherapy, and thus they are not captured by the traditional World Health Organisation (WHO) tumour response criteria or the RECIST. Revisiting the results of pembrolizumab in patients with melanoma can help to evaluate the efficacy of the immune-related response criteria (irRC) as the gold standard for evaluating the clinical response of immunologic agents in oncology.

Real-time monitoring efficiency and toxicity of chemotherapy in patients with advanced lung cancer.

BackgroundThe Response Evaluation Criteria in Solid Tumors (RECIST) guideline and Common Terminology Criteria for Adverse Events (CTCAE) criteria are used to assess chemotherapy efficiency and toxicity in patients with advanced lung cancer. However, no real-time, synchronous indicators that can evaluate chemotherapy outcomes are available. We wanted to evaluate tumor response and toxicity in advanced lung cancer chemotherapy by using a novel synchronous strategy.ResultsWe enrolled 316 patients with advanced lung cancer who were treated with cisplatin-based therapy and followed up them for 3 years. Plasma was obtained before and after every chemotherapy cycle. We quantitative assayed total plasma DNA and methylation of the APC/RASSF1A genes. Four parameters were assessed: methylation level before chemotherapy (meth0 h), methylation level 24 h after chemotherapy (meth24 h), total plasma DNA concentration before chemotherapy (DNA0 h), and total plasma DNA concentration 24 h after chemotherapy (DNA24 h). When meth24 h > meth0 h of at least one gene was used to predict tumor response, the correct prediction rate was 82.4 %. Additionally, patients for whom DNA24 h/DNA0 h ≤ 2 had mild toxicities. Therefore, meth24 h > meth0 h and DNA24 h/DNA0 h ≤ 2 were defined as criteria for better tumor response and fewer adverse events with a high correct prediction rate (84.7 %).ConclusionsQuantitative analysis of total plasma DNA and plasma APC/RASSF1A methylation provide a real-time synchronous rapid monitoring indicator for therapeutic outcomes of advanced lung cancer, which could be a reference or supplementary guidelines in evaluating chemotherapy effects.Electronic supplementary materialThe online version of this article (doi:10.1186/s13148-015-0150-9) contains supplementary material, which is available to authorized users.

CBM-15DYNAMICS OF CIRCULATING HYPOXIA MEDIATED miRNAs AND TUMOR RESPONSE IN HIGH-GRADE GLIOMA PATIENTS TREATED WITH BEVACIZUMAB

BACKGROUND: Bevacizumab is an antiangiogenic agent which is approved for recurrent glioblastoma and is still under investigation in high-grade gliomas. It produces a high rate of radiologic response but this response should be interpreted with caution because it is related to normalization of permeable tumor vessels and not necessarily to a true anti-tumor effect. We previously demonstrated that four of the hypoxia-mediated-miRNAs (miR-210, miR-21, miR-10b and miR-196b), are up-regulated in gliomas as compared to normal brain. We hypothesized that the regulation and expression of these miRNAs will be altered in response to bevacizumab treatment and tested it prospectively. OBJECTIVES: To perform a longitudinal monitoring of the circulating miRNAs in patients exposed to bevacizumab treatment and to correlate it with tumor response. METHODS: 55 serum samples were prospectively collected from 15 high-grade glioma patients prior to bevacizumab treatment and longitudinally during treatment. The quantification of the 4 miRNAs was evaluated by real-time-RT-PCR using total RNA that was extracted from the serum. At each time point tumor response was assessed on MRI using FLAIR and contrast enhanced images as well as RANO criteria for tumor response. RESULTS: Serum quantification level of miR-210 and miR-196b did not differ in high-grade glioma patients from healthy controls while levels of miR-10b and miR-21 were significantly increased in untreated brain tumor patients. Throughout the period of bevacizumab treatment higher quantification levels were displayed for both miR-10b and miR-21 in the majority of patients when compared to pre-bevacizumab levels. Their quantification correlated negatively and significantly with changes in enhancing tumor diameters (R= -0.648, p < 0.0001). FLAIR images and RANO assessment did not correlate with the sum quantification of these miRNAs. CONCLUSIONS: Circulating miR-10b and miR-21 probably reflect the anti-angiogenic effect of therapy but their role as biomarkers for tumor response remains uncertain and requires further investigation.

Évaluation de la réponse à la chimiothérapie, aux thérapies ciblées et à l'immunothérapie

Designing tumor response criteria is a critical step for treating cancer patients in daily practice as long as in clinical trials since it provides a homogeneous way to analyze radiological results. The first criteria to be proposed were made for evaluating cytotoxic chemotherapy. They included the WHO criteria, further replaced by RECIST criteria, for which a new version has been released in 2009. However, these criteria have shown some limitations, especially for evaluating treatments with different mechanisms of action such as targeted therapies or immunotherapy. This review will address the WHO and RECIST criteria and then the specificities of evaluating targeted therapies and immunotherapy.

Objective tumor response to denosumab in patients with giant cell tumor of bone: a multicenter phase II trial

BackgroundGiant cell tumor of bone (GCTB) is a rare primary bone tumor, characterized by osteoclast-like giant cells that express receptor activator of nuclear factor-kappa B (RANK), and stromal cells that express RANK ligand (RANKL), a key mediator of osteoclast activation. A RANKL-specific inhibitor, denosumab, was predicted to reduce osteolysis and control disease progression in patients with GCTB. Patients and methodsSeventeen patients with GCTB were enrolled. Patients were treated with denosumab at 120 mg every 4 weeks, with a loading dose of 120 mg on days 8 and 15. To evaluate efficacy, objective tumor response was evaluated prospectively by an independent imaging facility on the basis of prespecified criteria. ResultsThe proportion of patients with an objective tumor response was 88% based on best response using any tumor response criteria. The proportion of patients with an objective tumor response using individual response criteria was 35% based on the modified Response Evaluation Criteria in Solid Tumors (RECIST) criteria, 82% based on the modified European Organization for Research and Treatment of Cancer (EORTC) criteria, and 71% based on inverse Choi criteria. The median time of study treatment was 13.1 months. ConclusionThe findings demonstrate that denosumab has robust clinical efficacy in the treatment of GCTB.

Response evaluation in mesothelioma: Beyond RECIST.

Malignant pleural mesothelioma (MPM) typically demonstrates a non-spherical growth pattern, so it is often difficult to accurately categorize change in tumour burden using size-based tumour response criteria (e.g., WHO (World Health Organisation), RECIST (Response Evaluation Criteria in Solid Tumours) and modified RECIST). Functional imaging techniques are applied to derive quantitative measurements of tumours, which reflect particular aspects of the tumour pathophysiology. By quantifying how these measurements change with treatment, it is possible to observe treatment effects. In this review, we survey the existing roles of CT and MRI for the management of MPM, including the currently applied size measurement criteria for the assessment of treatment response. New functional imaging techniques, such as positron emission tomography (PET), diffusion-weighted MRI (DWI) and dynamic contrast-enhanced MRI (DCE-MRI) that may potentially improve the assessment of treatment response will be highlighted and discussed.

Imaging in pleural mesothelioma: A review of the 12th International Conference of the International Mesothelioma Interest Group.

Imaging of malignant pleural mesothelioma is essential to patient management, prognostication, and response assessment. From animal models to clinical trials, the gamut of research activities and clinical standards relies on imaging to provide information on lesion morphology and the growing number of physiologic characteristics amenable to capture through imaging techniques. The complex morphology, growth pattern, and biological mechanisms of mesothelioma, however, present challenges for image acquisition and interpretation. Nevertheless, novel approaches to image acquisition and subsequent image analysis have expanded the opportunities for (as well as the need for) imaging in this disease. This paper summarizes the imaging-based research presented orally at the 2014 International Conference of the International Mesothelioma Interest Group (iMig) in Cape Town, South Africa, October 2014. Presented topics include the imaging of hypoxia in a murine model through positron emission tomography (PET), the use of diffusion-weighted magnetic resonance imaging (MRI) to assess the histologic composition of biphasic mesothelioma and to assess early response to chemotherapy, the correlation of CT-based tumor volume with the volume of the post-surgical tumor specimen, the development of volumetric tumor response criteria, and pre-treatment tumor volume growth considerations for tumor response assessment.

3:57 PM, Abstract No. 139 - The role of Lipiodol as an imaging biomarker of metastatic tumor necrosis after TACE: preliminary results of a longitudinal multimodality investigation

3:57 PM, Abstract No. 139 - The role of Lipiodol as an imaging biomarker of metastatic tumor necrosis after TACE: preliminary results of a longitudinal multimodality investigation

Role of positron emission tomography for the monitoring of response to therapy in breast cancer.

This review considers the potential utility of positron emission tomography (PET) tracers in the setting of response monitoring in breast cancer, with a special emphasis on glucose metabolic changes assessed with (18)F-fluorodeoxyglucose (FDG). In the neoadjuvant setting of breast cancer, the metabolic response can predict the final complete pathologic response after the first cycles of chemotherapy. Because tumor metabolic behavior highly depends on cancer subtype, studies are ongoing to define the optimal metabolic criteria of tumor response in each subtype. The recent multicentric randomized AVATAXHER trial has suggested, in the human epidermal growth factor 2-positive subtype, a clinical benefit of early tailoring the neoadjuvant treatment in women with poor metabolic response after the first course of treatment. In the bone-dominant metastatic setting, there is increasing clinical evidence that FDG-PET/computed tomography (CT) is the most accurate imaging modality for assessment of the tumor response to treatment when both metabolic information and morphologic information are considered. Nevertheless, there is a need to define standardized metabolic criteria of response, including the heterogeneity of response among metastases, and to evaluate the costs and health outcome of FDG-PET/CT compared with conventional imaging. New non-FDG radiotracers highlighting specific molecular hallmarks of breast cancer cells have recently emerged in preclinical and clinical studies. These biomarkers can take into account the heterogeneity of tumor biology in metastatic lesions. They may provide valuable clinical information for physicians to select and monitor the effectiveness of novel therapeutics targeting the same molecular pathways of breast tumor.

Tumor response criteria for hepatocellular carcinoma treated by transarterial chemoembolization - a radiologist's point-of-view

Hepatocellular carcinoma is a common malignancy which, in specific stages, benefits from transarterial chemoembolization. The survival of treated patients depends on the accurate interpretation of follow-up studies after the procedure, with focus on the early detection of residual tumor or tumor recurrence. Dynamical contrast enhanced CT and MRI are sensitive methods in evaluating tumor response, although diffusion weighted imaging and other new modalities can improve the diagnostic role of these tests. A strong knowledge of common and rare imaging signs of neoplastic tissue in a chemoembolized nodule can lead to a prompt and effective complementary treatment. Some lesions related to the endovascular intervention mimic tumor behavior and should always be sought and correctly identified, in order to avoid unnecessary treatment and impacts in the patient’s quality of life.

Comparison of performance of various tumour response criteria in assessment of regorafenib activity in advanced gastrointestinal stromal tumours after failure of imatinib and sunitinib

PurposeTo compare performance of various tumour response criteria (TRCs) in assessment of regorafenib activity in patients with advanced gastrointestinal stromal tumour (GIST) with prior failure of imatinib and sunitinib. MethodsTwenty participants in a phase II trial received oral regorafenib (median duration 47weeks; interquartile range (IQR) 24–88) with computed tomography (CT) imaging at baseline and every two months thereafter. Tumour response was prospectively determined on using Response Evaluation Criteria in Solid Tumours (RECIST) 1.1, and retrospectively reassessed for comparison per RECIST 1.0, World Health Organization (WHO) and Choi criteria, using the same target lesions. Clinical benefit rate [CBR; complete or partial response (CR or PR) or stable disease (SD)⩾16weeks] and progression-free survival (PFS) were compared between various TRCs using kappa statistics. Performance of TRCs in predicting overall survival (OS) was compared by comparing OS in groups with progression-free intervals less than or greater than 20weeks by each TRC using c-statistics. ResultsPR was more frequent by Choi (90%) than RECIST 1.1, RECIST 1.0 and WHO (20% each), however, CBR was similar between various TRCs (overall CBR 85–90%, 95–100% agreement between all TRC pairs). PFS per RECIST 1.0 was similar to RECIST 1.1 (median 44weeks versus 58weeks), and shorter for WHO (median 34weeks) and Choi (median 24weeks). With RECIST 1.1, RECIST 1.0 and WHO, there was moderate concordance between PFS and OS (c-statistics 0.596–0.679). Choi criteria had less favourable concordance (c-statistic 0.506). ConclusionsRECIST 1.1 and WHO performed somewhat better than Choi criteria as TRC for response evaluation in patients with advanced GIST after prior failure on imatinib and sunitinib.

Diffusion-weighted MRI Before and After Robotic Radiosurgery (Cyberknife®) in Primary and Secondary Liver Malignancies

The purpose of this study was to evaluate the role of diffusion-weighted MR imaging (DW-MRI) in the assessment of treatment response of primary or secondary liver malignancies after stereotactic radiosurgery (SRS) using robotic radiosurgery. All patients who underwent SRS therapy for hepatic malignancies who had pre- and post-interventional MR examinations including DW-MRI at our hospital between 02/2010 and 02/2012 were included. A retrospective analysis of the institutional imaging database identified 13 patients (4 men, 9 women, mean age: 66 years) with a total of 14 primary or secondary liver malignancies. Criteria of tumor response to treatment were a decrease in size and/or loss of contrast enhancement as assessed with respect to RECIST criteria. Mean apparent diffusion coefficient (ADC) values for normal liver parenchyma and hepatic masses in each MR examination were calculated and compared using two-tailed, paired t-test with a significance level of 0.05. Mean ADC values of liver malignancies were 1.10 ± 0.30 x 10(-3) mm(2)/s, 1.48 ± 0.35 x 10(-3) mm(2)/s and 1.56 ± 0.40 x 10(-3) mm(2)/s on pre-interventional, the first post-interventional, and the second post-interventional DW-MRI. There was a significant increase of ADC values between the pre-interventional examination and the first and second post-interventional follow-up exams (p < 0.01 and p = 0.01, respectively). However, there was no statistical difference between the ADC values of the first and second post-interventional MRI. ADC values of normal liver parenchyma did not show significant changes in ADC values during pre- and post-interventional MRI. ADC measurements may allow the evaluation of response to treatment of hepatic malignancies by SRS. ADC values of liver malignancies increase significantly after SRS treatment.