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Supplementary Data from AZD6244 (ARRY-142886) enhances the therapeutic efficacy of sorafenib in mouse models of gastric cancer

Gastric cancer is a deadly disease for which current therapeutic options are extremely limited. Vascular endothelial growth factor receptors and platelet-derived growth factor receptors regulate gastric cancer cell proliferation, invasion, and tumor angiogenesis. In the present study, we report that sorafenib therapy effectively inhibited tumor growth and angiogenesis in tumor xenografts. These were associated with reduction in the phosphorylation of vascular endothelial growth factor receptor-2 Tyr951, c-Kit Tyr568/570, platelet-derived growth factor receptor-β Tyr1021, and Akt Ser473 and Thr308, down-regulation of positive cell cycle regulators, increased apoptosis, and up-regulation of p27. Sorafenib treatment also caused up-regulation of p-c-Raf Ser338 and p-extracellular signal-regulated kinase (ERK) Thr202/Tyr204 in gastric cancer xenografts. The combination of sorafenib and MAP/ERK kinase inhibitor AZD6244 enhances the effectiveness of each compound alone. Potential effect of sorafenib/AZD6244 included increase in proapoptotic Bim. Our data show that MAP/ERK kinase inhibition enhances the antitumor activity of sorafenib in vivo, supporting a rationale for multitargeted suppression of the angiogenesis and ERK signaling network in gastric cancer therapy. [Mol Cancer Ther 2009;8(9):2537–45]

Summary Background Therapeutic synergism between radiotherapy and immune checkpoint blockade has been observed in preclinical models of hepatocellular carcinoma. We aimed to study the safety and efficacy of sequential radioembolisation with yttrium-90-resin microspheres (Y90-radioembolisation) followed by nivolumab in patients with advanced hepatocellular carcinoma. Methods Patients with Child-Pugh A cirrhosis and advanced hepatocellular carcinoma not suitable for curative surgery were treated with Y90-radioembolisation followed by intravenous nivolumab 240 mg 21 days after Y90-radioembolisation and every 2 weeks thereafter. The primary endpoint, assessed in the per-protocol population, was the objective response rate, determined by RECIST version 1.1, defined as the proportion of patients with a confirmed complete or partial response observed for lesions both within and outside the Y90-radioembolisation field. This study is registered with ClinicalTrials.gov , NCT03033446 and has been completed. Findings 40 patients were enrolled, of whom 36 received Y90-radioembolisation followed by nivolumab. One (3%) patient had a complete response and ten (28%) had a partial response; the objective response rate was 30·6% (95% CI 16·4–48·1). The most common treatment-related adverse events of any grade were pruritus (18 [50%] of 36 patients) and maculopapular rash (13 [36%]). Two (6%) patients experienced grade 3–4 treatment-related adverse events: one patient had a grade 3 increase in alanine aminotransferase levels, grade 3 bilirubin increase, and grade 4 increase in aspartate aminotransferase levels, while the other had a grade 3 maculopapular rash. Five (14%) patients had a treatment-related serious adverse event (Steven-Johnson syndrome, hepatitis E infection, fever, liver abscesses, and ascites). Interpretation Y90-radioembolisation followed by nivolumab resulted in an encouraging objective response rate in patients with advanced hepatocellular carcinoma, although the activity observed was not as high as the study was powered for. This strategy should be further evaluated in patients with Barcelona Clinic Liver Clinic (BCLC) stage B hepatocellular carcinoma that is ineligible or refractory to transarterial chemoembolisation and patients with BCLC C disease without extrahepatic spread. Funding National Medical Research Council Singapore, Bristol-Myers Squibb, Sirtex.

Purpose To develop a Natural Language Processing (NLP) pipeline with the ability to determine the histological subtype and site of a patient’s cancer from pathology reports. Methods A Spark NLP-based deep learning model pipeline was developed to perform named entity recognition (NER) and assertion status detection for histological subtypes before extracting key relations of interest to determine the site of a patient’s cancer from pathology reports. We assessed the ability of this NLP pipeline to extract histological subtypes and site of a patient’s cancer against manual curation of pathology reports. Results A total of 1358 reports from 474 patients seen at a single tertiary cancer centre were used in the development and validation of the pipeline. The NLP pipeline achieved a mean accuracy of 99.79% and an F1 score of 84.08% for NER of histological subtypes. The relation extraction (RE) model also achieved an average accuracy of 91.96% and an F1-score of 92.45% for key entity relations relevant to histological subtypes entities. Conclusion We developed an NLP pipeline that can extract the histological subtypes and relate them to the site of a patient’s cancer from free-text pathology reports with high accuracy. This has the potential to be deployed for both research and clinical quality processes.

Background: The performance of MRI versus CT in the detection and evaluation of peritoneal surface malignancies (PSM) remains unclear in the current literature. Our study is the first prospective study in an Asian center comparing the two imaging modalities, validated against intra-operative findings. Methods: A total of 36 patients with PSM eligible for CRS-HIPEC underwent both MRI and CT scans up to 6 weeks before the operation. The scans were assessed for the presence and distribution of PSM and scored using the peritoneal cancer index (PCI), which were compared against PCI determined at surgery. Results: Both MRI and CT were 100% sensitive and specific in detecting the overall presence of PSM. Across all peritoneal regions, the sensitivity and specificity for PSM detection was 49.1% and 93.0% for MRI, compared to 47.8% and 95.1% for CT (p = 0.76). MRI was more sensitive than CT for small bowel disease, although the difference did not reach statistical significance. Comparing PCI on imaging with intra-operative PCI, the mean difference was found to be −3.4 ± 5.4 (p < 0.01) for MRI, and −3.9 ± 4.1 (p < 0.01) for CT. The correlation between imaging and intra-operative PCI was poor, with a concordance coefficient of 0.76 and 0.79 for MRI and CT, respectively. Within individual peritoneal regions, there was also poor agreement between imaging and intra-operative PCI for both modalities, other than in regions 1 and 3. Conclusion: MRI and CT are comparable in the detection and evaluation of PSM. While sensitive in the overall detection of PSM, they are likely to underestimate the true disease burden.

Introduction The impact on clinical practice of the international guidelines including the Sendai Guidelines (SG06) and Fukuoka Guidelines (FG12) on the management of cystic lesions of the pancreas (CLP) has not been well-studied. The primary aim was to examine the changing trends and outcomes in the surgical management of CLP in our institution over time and to determine the impact of these guidelines on our institution practice. Methods 462 patients with surgically-treated CLP were retrospectively reviewed and classified under the 2 guidelines. The cohort was divided into 3 time periods: 1998–2006, 2007–2012 and 2013 to 2018. Results Comparison across the 3 time periods demonstrated significantly increasing frequency of older patients, asymptomatic CLP, male gender, smaller tumor size, elevated Ca 19-9, use of magnetic resonance imaging (MRI) and use of endoscopic ultrasound (EUS) prior to surgery. There was also significantly increasing frequency of adherence to the international guidelines as evidenced by the increasing proportion of HRSG06 and HRFG12 CLP with a corresponding lower proportion of LRSG06 and LRFG12 being resected. This resulted in a significantly higher proportion of resected CLP whereby the final pathology confirmed that a surgery was actually indicated. Conclusions Over time, there was increasing adherence to the international guidelines for the selection of patients for surgical resection as evidenced by the significantly increasing proportion of HRSG06 and HRFG06 CLPs undergoing surgery. This was associated with a significantly higher proportion of patients with a definitive indication for surgery. These suggested that over time, there was a continuous improvement in our selection of appropriate CLP for surgical treatment.

This article explores new acquisition methods in magnetic resonance (MR) imaging to provide high spatial and temporal resolution imaging for a wide spectrum of clinical applications in the abdomen and pelvis. We present an overview of some of these advanced MR techniques, such as non-cartesian image acquisition, fast sampling and compressed sensing, diffusion quantification and quantitative MR that can improve data sampling, enhance image quality, yield quantitative measurements, and/or optimize diagnostic performance in the body.

Immune checkpoint inhibitors (ICIs) have demonstrated promising results in a variety of advanced cancer types. The phenomenon of hyperprogressive disease (HPD) has only been documented in recent years, however, there have been no reports of HPD in hepatocellular carcinoma. We present a case series of six patients with advanced hepatocellular carcinoma treated with ICIs who demonstrated rapid radiological progression, this was confirmed by comparing tumor growth rates before and during treatment with HPD defined as tumor growth rateratio ≥2. Although ICIs have demonstrated profound efficacy in advanced cancer, they might also be responsible for HPD in a small subset of patients. The ability to predict treatment response to ICI is thus of importance in protecting patients from the deleterious effects of HPD.

Sarcomas are rare tumours, accounting for 1% of all malignancies. They are histologically diverse, presenting with more than 50 different subtypes. Sarcoma can be broadly divided into two categories—soft tissue sarcoma and bone sarcoma. Extraskeletal osteosarcoma is a unique subtype which is histologically similar to bone osteosarcoma but resides within soft tissue and has no attachments to bone. We present a rare case of a patient who initially presented with an extraskeletal osteosarcoma that was complicated by a chronic chest wall sinus and lymphedema of the left arm. He later developed enlarging left chest wall nodules at the same region that were proven to be dedifferentiated liposarcoma on biopsy 20 years later. We examine the occurrence of both extremely rare diseases of differing pathologies over the same site but separated by an extraordinarily long interval, and possible new associations to account for this phenomenon.

Simple Summary Breast cancer screening by mammography suffers from high rates of false positivity, resulting in unnecessary investigative imaging and biopsies. There is an unmet need for biomarkers that can distinguish between malignant and benign breast lesions. We performed miRNA profiling on 638 patients with abnormal mammograms and 100 healthy controls. A six-miRNA panel was identified and validated in an independent cohort that had an AUC of 0.881 when differentiating between cases versus those with benign lesions or healthy individuals with normal mammograms. In addition, biomarker panel scores increased with tumor size, stage and number of lymph nodes involved. This study demonstrates that circulating miRNAs can potentially be used in conjunction with mammography to differentiate between patients with malignant and benign breast lesions. Abstract Mammography is extensively used for breast cancer screening but has high false-positive rates. Here, prospectively collected blood samples were used to identify circulating microRNA (miRNA) biomarkers to discriminate between malignant and benign breast lesions among women with abnormal mammograms. The Discovery cohort comprised 72 patients with breast cancer and 197 patients with benign breast lesions, while the Validation cohort had 73 and 196 cancer and benign cases, respectively. Absolute expression levels of 324 miRNAs were determined using RT-qPCR. miRNA biomarker panels were identified by: (1) determining differential expression between malignant and benign breast lesions, (2) focusing on top differentially expressed miRNAs, and (3) building panels from an unbiased search among all expressed miRNAs. Two-fold cross-validation incorporating a feature selection algorithm and logistic regression was performed. A six-miRNA biomarker panel identified by the third strategy, had an area under the curve (AUC) of 0.785 and 0.774 in the Discovery and Validation cohorts, respectively, and an AUC of 0.881 when differentiating between cases versus those with benign lesions or healthy individuals with normal mammograms. Biomarker panel scores increased with tumor size, stage and number of lymph nodes involved. Our work demonstrates that circulating miRNA signatures can potentially be used with mammography to differentiate between patients with malignant and benign breast lesions.

Proposed short titleY90-Resin Microspheres Radioembolization Followed by Nivolumab in Advanced Hepatocellular CarcinomaBackground : Nivolumab (N) and Y90-resin microspheres radioembolization (Y90-RE) aretherapeutic options in advanced hepatocellular carcinoma (aHCC). Emerging evidence suggests synergy between radiotherapy and immune checkpoint inhibitors. Methods : Eligible Child-Pugh A aHCC patients were treated with Y90-RE followed by N 240mg, 21 days after Y90-RE and every 2 weeks thereafter. Pre- and on-treatment tumor biopsies were obtained. Primary end-point was overall response rate (ORR) (RECIST v1·1), defined as the composite overall response observed for lesions both within and outside Y90-RE field. Secondary end points included progression free survival (PFS), overall survival (OS), and safety. This study is registered with ClinicalTrials.gov, NCT03033446 .Findings : Forty patients were enrolled, 36 received Y90-RE followed by N. At baseline: 61·1% had hepatitis B; 66·7% BCLC stage C; 50·0% had AFP > 400ng/mL; median number of liver lesions was 5 (range 1- >20); median size of largest liver lesion was 78·5 mm (range 14-177mm); 38·9% had prior TACE/RFA/MWA; and 12·5% had prior systemic therapy. ORR was 30·6% (16·4% to 48·1%). ORR was 43·5% in patients with no extra-hepatic spread (EHS) (n=23). 81% of target lesions within Y90-RE field regressed. Median PFS and OS were 5·6 months (95% CI 2·1 to 8·8 months) and 16.9 months (95% CI 8·1 to 27·6 months). Treatment was well tolerated with only 13·8% experiencing grade (G) 3/4 treatment related adverse events (TRAEs). Immune activation predicted response to Y90-RE followed by N. Interpretation : Y90-RE followed by N resulted in an encouraging ORR of 30·6% in aHCC and of 43·5% in subjects with no EHS. 81% of target lesions within Y90-RE field regressed suggesting synergy. Importantly, this combination is safe and tolerable with low G 3/4 TRAEs of 13·8%. Trial Registration: NCT number: NCT03033446 Funding: Funding for this study was acquired from National Medical Research Council Singapore (NMRC/CIRG/1454/2016), Bristol-Myers Squibb (BMS), and SIRTEX Declaration of Interest: David Tai All support for the present manuscript (e.g., funding, provision of study materials, medical writing, article processing charges, etc.): BMS, SIRTEX, NMRC Singapore (CIRG/1470/2017) Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events: IPSEN, Eisai, BMS Consulting fees: Novartis, BMS, MSD Choo Su Pin Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events: Roche, BMS, Ipsen, Lilly, AZ, Roche. Consulting fees: BMS, Roche, Ipsen, Servier, Eisai, AstraZeneca. Leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid: MOH Medishield Life Cancer Drug committee Stock or stock options: BMS David Ng All support for the present manuscript (e.g., funding, provision of study materials, medical writing, article processing charges, etc.): SIRTEX Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events: SIRTEX Joycelyn Lee Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events: BMS, IPSEN, Bayer Research Funding: Bayer Pierce K.H. Chow Grants or contracts from any entity: Sirtex Medical, Ipsen, IQVIA, New B Innovation, Perspectum, AMiLi, MiRXES, Genentech, Engine Biosciences. Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events: Sirtex Medical, Ipsen, Oncosil, Bayer, Roche, New B Innovation, MSD, BTG PLC, Eisai, Abbott, AZ, IQVIA, Genentech, Worrell Guerbet, LEK Consulting, COR2ED. Leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid: AVATAMED Stock or stock options: AVATAMED Too Chow Wei Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events: SIRTEX Consulting fees: SIRTEX Ethical Approval: All patients provided written informed consent and the institutional review board committee approved the protocol (Singhealth IRB Ref No. 2016/2613). The study was done in accordance with the Declaration of Helsinki and Good Clinical Practice.

Overexpression of fibroblast growth factor receptor (FGFR) contributes to tumorigenesis, metastasis, and poor prognosis of hepatocellular carcinoma (HCC). Infigratinib—a pan-FGFR inhibitor—potently suppresses the growth of high-FGFR-expressing HCCs in part via alteration of the tumor microenvironment and vessel normalization. In this study, we aim to assess the utility of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) as a non-invasive imaging technique to detect microenvironment changes associated with infigratinib and sorafenib treatment in high-FGFR-expressing HCC xenografts. Serial DCE-MRIs were performed on 12 nude mice bearing high-FGFR-expressing patient-derived HCC xenografts to quantify tumor microenvironment pre- (day 0) and post-treatment (days 3, 6, 9, and 15) of vehicle, sorafenib, and infigratinib. DCE-MRI data were analyzed using extended generalized kinetic model and two-compartment distributed parameter model. After treatment, immunohistochemistry stains were performed on the harvested tumors to confirm DCE-MRI findings. By treatment day 15, infigratinib induced tumor regression (70 % volume reduction from baseline) while sorafenib induced relative growth arrest (185 % volume increase from baseline versus 694 % volume increase from baseline of control). DCE-MRI analysis revealed different changes in microcirculatory parameters upon exposure to sorafenib versus infigratinib. While sorafenib induced microenvironment changes similar to those of rapidly growing tumors, such as a decrease in blood flow (F), fractional intravascular volume (vp), and permeability surface area product (PS), infigratinib induced the exact opposite changes as early as day 3 after treatment: increase in F, vp, and PS. Our study demonstrated that DCE-MRI is a reliable non-invasive imaging technique to monitor tumor microcirculatory response to FGFR inhibition and VEGF inhibition in high-FGFR-expressing HCC xenografts. Furthermore, the microcirculatory changes from FGFR inhibition manifested early upon treatment initiation and were reliably detected by DCE-MRI, creating possibilities of combinatorial therapy for synergistic effect.

BackgroundWe hypothesized that spatial heterogeneity exists between recurrent and non-recurrent regions within a tumor. The aim of this study was to determine if there is a difference between radiomics features derived from recurrent versus non recurrent regions within the tumor based on pre-treatment MRI.MethodsA total of 14 T4NxM0 NPC patients with histologically proven "in field" recurrence in the post nasal space following curative intent IMRT were included in this study. Pretreatment MRI were co-registered with MRI at the time of recurrence for the delineation of gross tumor volume at diagnosis(GTV) and at recurrence(GTVr). A total of 7 histogram features and 40 texture features were computed from the recurrent(GTVr) and non-recurrent region(GTV-GTVr). Paired t-tests and Wilcoxon signed-rank tests were carried out on the 47 quantified radiomics features.ResultsA total of 7 features were significantly different between recurrent and non-recurrent regions. Other than the variance from intensity-based histogram, the remaining six significant features were either from the gray-level size zone matrix (GLSZM) or the neighbourhood gray-tone difference matrix (NGTDM).ConclusionsThe radiomic features extracted from pre-treatment MRI can potentially reflect the difference between recurrent and non-recurrent regions within a tumor and has a potential role in pre-treatment identification of intra-tumoral radio-resistance for selective dose escalation.

Purpose Selective internal radiation therapy or radioembolization (RE) shows efficacy in unresectable hepatocellular carcinoma (HCC) limited to the liver. This study compared the safety and efficacy of RE and sorafenib in patients with locally advanced HCC. Patients and Methods SIRveNIB (selective internal radiation therapy v sorafenib), an open-label, investigator-initiated, phase III trial, compared yttrium-90 (90Y) resin microspheres RE with sorafenib 800 mg/d in patients with locally advanced HCC in a two-tailed study designed for superiority/detriment. Patients were randomly assigned 1:1 and stratified by center and presence of portal vein thrombosis. Primary end point was overall survival (OS). Efficacy analyses were performed in the intention-to-treat population and safety analyses in the treated population. Results A total of 360 patients were randomly assigned (RE, 182; sorafenib, 178) from 11 countries in the Asia-Pacific region. In the RE and sorafenib groups, 28.6% and 9.0%, respectively, failed to receive assigned therapy without significant cross-over to either group. Median OS was 8.8 and 10.0 months with RE and sorafenib, respectively (hazard ratio, 1.1; 95% CI, 0.9 to 1.4; P = .36). A total of 1,468 treatment-emergent adverse events (AEs) were reported (RE, 437; sorafenib, 1,031). Significantly fewer patients in the RE than sorafenib group had grade ≥ 3 AEs (36 of 130 [27.7%]) v 82 of 162 [50.6%]; P < .001). The most common grade ≥ 3 AEs were ascites (five of 130 [3.8%] v four of 162 [2.5%] patients), abdominal pain (three [2.3%] v two [1.2%] patients), anemia (zero v four [2.5%] patients), and radiation hepatitis (two [1.5%] v zero [0%] patients). Fewer patients in the RE group (27 of 130 [20.8%]) than in the sorafenib group (57 of 162 [35.2%]) had serious AEs. Conclusion In patients with locally advanced HCC, OS did not differ significantly between RE and sorafenib. The improved toxicity profile of RE may inform treatment choice in selected patients.

Background This systematic review was performed to assess the clinical utility of the Sendai Consensus Guidelines (SCG) and Fukuoka Consensus Guidelines (FCG) for intraductal papillary mucinous neoplasm (IPMN). Methods A computerized search of PubMed was performed to identify all the studies which evaluated the SCG and FCG in surgically resected, histologically confirmed IPMNs. Results Ten studies evaluating the FCG, 8 evaluating the SCG and 4 evaluating both guidelines were included. In 14 studies evaluating the FCG, out of a total of 2498 neoplasms, 849 were malignant and 1649 were benign neoplasms. Pooled analysis showed that 751 of 1801 (42%) FCG+ve neoplasms were malignant and 599 neoplasms of 697 (86%) FCG−ve neoplasms were benign. PPV of the high risk and worrisome risk groups were 465/986 (47%) and 239/520 (46%) respectively. In 12 studies evaluating the SCG, 1234 neoplasms were analyzed of which 388 (31%) were malignant and 846 (69%) were benign. Pooled analysis demonstrated that 265 of 802 (33%) SCG+ve neoplasms were malignant and 238 of 266 SCG−ve (90%) neoplasms were benign. Conclusion The FCG had a higher positive predictive value (PPV) compared to the SCG. However, the negative predictive value (NPV) of the FCG was slightly lower than that of the SCG. Malignant and even invasive IPMN may be missed according to both guidelines.

Purpose To report the safety profile and 2-year functional outcomes of in-bore magnetic resonance (MR)-guided focused ultrasound on single cancer foci in men with prostate cancer. Materials and Methods Ethics approval was obtained from the centralized institutional review board for this prospective single-arm study, and patients provided informed consent. Patients with untreated low-volume low-grade prostate cancer (clinical stage T2a or lower; Gleason score, 3+3; index tumor ≤10 mm

The transfer constant K trans is commonly employed in dynamic contrast-enhanced MRI studies, but the utility and interpretation of K trans as a potential biomarker of tumor vasculature remains unclear. In this study, computer simulations based on a comprehensive tracer kinetic model with multiple pathways was used to provide clarification on the interpretation and application of K trans. Tissue concentration-time curves pertaining to a wide range of transport conditions were simulated using the multiple-pathway (MP) model and fitted using the generalized kinetic (GK) and extended GK models. Relationships between K trans and plasma flow F p, vessel permeability PS and extraction rate EF p under various transport conditions were assessed by correlation and regression analysis. Results show that the MP model provides an alternative two-tier interpretation of K trans based on the vascular transit time. K trans is primarily associated with F p and EF p respectively, in the slow and rapid vascular transit states, independent of the magnitude of PS. The relative magnitudes of PS and F p only serve as secondary constraints for which K trans can be further associated with EF p and PS in the slow and rapid transit states, respectively.

Although mammography is the gold standard for breast cancer screening, the high rates of false-positive mammograms remain a concern. Thus, there is an unmet clinical need for a non-invasive and reliable test to differentiate between malignant and benign breast lesions in order to avoid subjecting patients with abnormal mammograms to unnecessary follow-up diagnostic procedures. Serum samples from 116 malignant breast lesions and 64 benign breast lesions were comprehensively profiled for 2,083 microRNAs (miRNAs) using next-generation sequencing. Of the 180 samples profiled, three outliers were removed based on the principal component analysis (PCA), and the remaining samples were divided into training (n = 125) and test (n = 52) sets at a 70:30 ratio for further analysis. In the training set, significantly differentially expressed miRNAs (adjusted p &lt, 0.01) were identified after correcting for multiple testing using a false discovery rate. Subsequently, a predictive classification model using an eight-miRNA signature and a Bayesian logistic regression algorithm was developed. Based on the receiver operating characteristic (ROC) curve analysis in the test set, the model could achieve an area under the curve (AUC) of 0.9542. Together, this study demonstrates the potential use of circulating miRNAs as an adjunct test to stratify breast lesions in patients with abnormal screening mammograms.

Hepatocellular carcinoma (HCC) is the 6th most common cancer in the world, but the second most common cause of cancer death. There is no universally accepted consensus practice guidelines for HCC owing to rapid developments in new treatment modalities, the heterogeneous epidemiology and clinical presentation of HCC worldwide. However, a number of regional and national guidelines currently exist which reflect practice relevant to the epidemiology and collective experience of the consensus group. In 2014, clinicians at the multidisciplinary Comprehensive Liver Cancer Clinic (CLCC) at the National Cancer Centre Singapore (NCCS) reviewed the latest published scientific data and existing international and regional practice guidelines, such as those of the National Comprehensive Cancer Network, American Association for the Study of Liver Diseases and the Asian Pacific Association for the Study of the Liver, and modified them to reflect local practice. These would serve as a template by which treatment outcomes can be collated and benchmarked against international data. The NCCS Consensus Guidelines for HCC have been successfully implemented in the CLCC since their publication online on 26th September 2014, and the guidelines allow outcomes of treatment to be compared to international data. These guidelines will be reviewed periodically to incorporate new data.

Purpose: To evaluate non-invasive imaging biomarkers for assessing renal fibrosis. DWI is used to assess renal function; intravoxel incoherent motion (IVIM) provides additional measures of perfusion-related diffusion (D*, blood flow; f, perfusion fraction). We aim to determine if reduced ADC seen in renal fibrosis is attributable to perfusion-related diffusion changes or to known reduction in tissue diffusivity (D). Materials and methods: Unilateral ureteral obstruction (UUO) was created in six mice to induce renal fibrosis. DWI was performed the day before and 7 days post-UUO. A range of b-values from 0 to 1200 s/mm(2) were used. IVIM parameters were obtained using region of interests drawn over the renal parenchyma. Histopathological analysis of both kidneys was performed in all mice. Results were analyzed using the paired t-test with P

4590 Background: Nivolumab (N) and Y90-radioembolization (RE) are both therapeutic options in advanced hepatocellular carcinoma (aHCC). Increasing evidence suggests that radiotherapy synergizes with immune checkpoint inhibitors to augment anti-tumour effects. Methods: Eligible Child-Pugh A aHCC patients (pts) were treated with Y90-RE followed by N 240mg, 21 days after Y90-RE and every 2 weeks thereafter. Pre- and on-treatment tumor biopsies together with circulating biomarkers were obtained. Primary end-point was overall response rate (ORR) (per RECIST v 1.1). Overall response was defined as the composite overall response observed for the lesions within Y90-RE field and outside Y90-RE field. Key secondary end points included disease control rate (DCR), progression free survival (PFS), overall survival (OS), and safety. 36 evaluable pts were needed to assess whether the addition of N improved the ORR of Y90-RE from 21% to 41% as determined by Simon two-stage optimal design with 80% power and one sided significance level of 0.05. Results: Forty pts were enrolled of which 36 were evaluable. At baseline: 63.9% were HepB in aetiology; 63.9% BCLC stage C; 47.2% had AFP > 400ng/mL; number of liver lesions – median 5 (range 1- 20); size of largest liver lesion – median 80mm (range 14-177mm); 27.8% had prior TACE; and 13.9% had prior systemic therapy. ORR was 31% (95% CI 16.4 - 48.1%). Eight out of 11 responders had not progressed at study cut-off. DCR was 58.3%. 81% of target lesions within Y90-RE field regressed. With a median follow up of 16.4 months, median PFS and OS were 4.6 months (95% CI 2.3m - 8.4m) and 15.1 months (95% CI 7.8m - NE) respectively. Six- and 12-month PFS rates were 44.2% (95% CI 27.3% - 59.9%) and 26.1% (95% CI 11.2% - 43.8%) respectively. Overall, N+ Y90-RE was well tolerated and safe; only 11% had grade 3/4 treatment related adverse events (AEs). Responders demonstrated significant alterations of LIF, MIG and Eotaxin3 levels in the pre-treatment cytokine analyses. Conclusions: Combination N+Y90-RE resulted in an encouraging ORR of 31% (95% CI 16.4 - 48.1%) in aHCC. 81% of target lesions within Y90-RE field regressed suggesting synergy in combining Y90-RE with nivolumab. This combination is safe and tolerable with low G3/4 treatment related AEs of 11%. Further biomarker analyses will be presented at the meeting. Clinical trial information: NCT03033446 .

Background International consensus guidelines to guide management of intraductal papillary mucinous neoplasms (IPMN) were revised in Fukuoka and published in 2012. However, despite widespread acceptance of the Fukuoka Consensus Guidelines (FCG), the utility of these guidelines have not been well-validated. This systematic review was performed to evaluate the clinical utility of the FCG. Design A computerized search of the PubMed and Scopus databases was performed to identify all studies evaluating the utility of the FCG in surgically resected IPMN. IPMN were stratified according to the FCG as high risk (HR), worrisome risk (WR), and low risk (LR). HR and WR IPMN were termed FCG+ve and LR IPMN were termed FCG-ve. Results Seven studies analyzing 1,382 patients were included. There were 402 malignant neoplasms (29%), including 242 invasive IPMNs. There were 1,000 IPMN classified as FCG+ve. The FCG+ve group had a positive predictive value (PPV) ranging from 27 to 62% and the FCG-ve group had negative predictive value ranging from 82 to 100%. Pooled analysis demonstrated that there was 362 of 1,000 (36%) malignant FCG+ve IPMN and 342 of 382 (90%) benign FCG-ve IPMN. PPV of the HR group and the WR groups alone were 104 of 158 (66%) and 75 of 261 (29%), respectively. Forty of 382 (11%), including 22 (6%) invasive FCG-ve IPMN, were malignant. Twenty-six malignant including 18 invasive FCG-ve IPMN were reported from a single study. When the results from this study were excluded, there were only 14 of 241 malignant neoplasms (6%), including 4 of 241 (2%) invasive FCG-ve IPMN in the remaining 6 studies. Conclusion The FCG+ve criteria had a similarly low PPV compared with the 2006 consensus criteria. Stratification of IPMN into HR and WR groups resulted in a higher PPV in the HR group. Some malignant and even invasive IPMN may be missed by the FCG criteria.

Introduction The aim of this study was to determine if neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were predictive of malignancy in mucin-producing pancreatic cystic neoplasms (MpPCN). Methods One hundred and twenty patients with MpPCN were retrospectively reviewed. Malignant neoplasms were defined as neoplasms harbouring invasive carcinoma or high grade dysplasia. A high NLR and PLR were defined as ≥2.551 and ≥208.1, respectively. Results High NLR was significantly associated with symptomatic tumors, larger tumors, solid component, main-duct IPMN, and Sendai high risk category. High PLR was significantly associated with jaundice and Sendai high risk category. On univariate analyses, symptomatic tumors, jaundice, solid component, dilated pancreatic duct, and both a high NLR and PLR were significant predictors of malignant and invasive MpPCN. On multivariate analyses, solid component and dilated pancreatic duct were independent predictors of malignant and invasive MpPCN. PLR was an independent predictor for invasive MpPCN. When MpPCN were stratified by the Fukuoka and Sendai Guidelines, both a high NLR and PLR were significantly associated with malignant neoplasms within the high risk categories. Conclusions PLR is an independent predictor of invasive carcinoma. The addition of PLR as a criterion to the FCG and SCG significantly improved the predictive value of these guidelines in detecting invasive neoplasms. J. Surg. Oncol. 2015; 112:366–371. © 2015 Wiley Periodicals, Inc.

Background To date, biomarkers to predict benefit from anti-angiogenic therapy are still lacking. Sorafenib and metronomic oral vinorelbine combination was studied and changes in blood and DCE-MRI parameters were investigated as biomarkers for benefit. Material and methods Patients with advanced NSCLC were recruited to 3 successive cohorts. Each cohort was given a fixed metronomic (3 times a week) dose of oral vinorelbine at 60 mg/week, 90 mg/week, or 120 mg/week respectively. Within each cohort, patients received a starting dose of sorafenib at 200 mg bid for 4 weeks. In the absence of dose-limiting toxicities, each patient's dose of sorafenib was escalated to 400 mg bid for 4 weeks, 600 mg bid for 4 weeks and finally 800 mg bid. Biomarkers measured include DCE-MRI parameters, circulating endothelial cells (CECs), circulating endothelial progenitor cells (CEPs), and plasma thrombospondin (TSP-1). Results 48 evaluable patients were analyzed. There were 4 (8.9%) patients with partial response (PR) and 7 (15.2%) with cavitary response (CaR). Two subpopulations of CECs (CEChi, CEClo) were identified that trended in opposite directions during treatment, with CEChi demonstrating an upward trend in contrast to CEClo. Higher baseline CEChi and lower baseline blood flow (F) and fractional intravascular blood volume (V1) predicted for response. Multivariate analysis revealed a lower baseline V1, and dynamic changes of CEC during treatment (CEC increase, sum of CEChi and CEClo) predicted for improved survival. Conclusions Sorafenib and metronomic oral vinorelbine is active in advanced NSCLC. Baseline levels and changes in DCE parameters and CEC may be useful predictive biomarkers.

The purpose of this study was to validate DCE-MRI parameters such as blood flow (F), permeability surface area product (PS), fractional intravascular space (v1), and fractional extracellular extravascular space (v2), obtained using a standard two-compartment model against other established analysis methods and histological indices. DCE-MRI datasets of 28 mice implanted with various human cancer xenografts were acquired and analyzed. Statistically significant correlations were found between the parameters derived from the standard two-compartment model (v1, v2, F, and PS) with the histological markers of intravascular and interstitial space and with the corresponding flow and permeability estimates obtained by the initial slope method and Patlak plot, respectively.

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has been widely applied to evaluate microcirculatory parameters in clinical settings. However, pre-clinical studies involving DCE-MRI of small animals remain challenging with the requirement for high spatial and temporal resolution for quantitative tracer kinetic analysis. This study illustrates the feasibility of applying a high temporal resolution (2 s) protocol for liver imaging in mice by analyzing the DCE-MRI datasets of mice liver with a dual-input two-compartment tracer kinetic model. Phantom studies were performed to validate the T1 estimates derived by the proposed protocol before applying it in mice studies. The DCE-MRI datasets of mice liver were amendable to tracer kinetic analysis using a dual-input two-compartment model. Estimated micro-circulatory parameters were consistent with liver physiology, indicating viability of applying the technique for pre-clinical drug developments.

Angiogenesis and RAS/RAF/MEK/ERK pathway have been demonstrated to be relevant in hepatocellular carcinoma (HCC). Sorafenib, an oral multikinase inhibitor with activity against RAF kinase and vascular endothelial growth factor receptor-2, is approved for the treatment of advanced HCC. The therapeutic benefit however is modest. While displaying tumour growth inhibition and angiogenesis, sorafenib treatment in pre-clinical models exhibited up-regulation of pERK which may limit its anti-tumour activity. Inhibition of the MEK/ERK pathway by selumetinib enhanced the anti-tumour effect of sorafenib in pre-clinical models of HCC. In this phase I study, we investigated the maximum tolerated dose (MTD), safety and activity of combination sorafenib and selumetinib in patients with advanced HCC. The combination of selumetinib and sorafenib has manageable toxicity and showed encouraging anti-tumour activity. These findings support further evaluation in a phase II study. Background Treatment with sorafenib, although associated with inhibition of tumour growth and angiogenesis in in vivo studies, leads to up-regulation of pERK. The addition of MEK inhibition could potentially abrogate this effect and potentiate anti-tumour activity. This phase I study investigated the maximum tolerated dose (MTD), safety, tolerability, pharmacokinetics (PK) and biomarker correlates of selumetinib combined with sorafenib in patients with advanced hepatocellular carcinoma (HCC). Methods Patients with Child–Pugh (CP) score ≤7 were treated with 400 mg twice daily of sorafenib with escalating doses of selumetinib in a 3 + 3 study design. The dose-limiting toxicity (DLT) evaluation period was 28 days. PK of selumetinib was determined. Angiogenic effect was evaluated with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Results Twenty-seven patients of Asian ethnicity were enrolled. The MTD was selumetinib 75 mg daily with sorafenib 400 mg twice daily. DLT included grade 3 transaminitis, diarrhoea and fatigue. Most common treatment-related adverse events at MTD (all grades) were diarrhoea (85%), rash (59%), hypertension (44%), fatigue (30%), anorexia (22%) and hand–foot syndrome (22%). Four patients (15%) had PR and 13 (48%) had SD. PR or SD was observed for ≥6 months in seven patients. The median overall survival was 14.4 months. Selumetinib exposures in combination with sorafenib were comparable to other monotherapy studies. A reduction in permeability-surface area product noted in DCE-MRI with treatment correlated with worse survival outcomes. Conclusion The MTD of selumetinib was 75 mg daily when combined with sorafenib 400 mg twice a day in CP ≤7 HCC. Acceptable adverse events and encouraging anti-tumour activity warrant further evaluation. DCE-MRI findings deserve prospective evaluation. ClinicalTrials.gov identifier NCT01029418.

The purpose of this study was to correlate intravoxel incoherent motion (IVIM) imaging with classical perfusion-weighted MRI metrics in human gliomas. Parametric images for slow diffusion coefficient (D), fast diffusion coefficient (D*), and fractional perfusion-related volume (f) in patients with high-grade gliomas were generated. Maps of Fp (plasma flow), vp (vascular plasma volume), PS (permeability surface–area product), ve (extravascular, extracellular volume), E (extraction ratio), ke (influx ratio into the interstitium), and tc (vascular transit time) from dynamic contrast-enhanced (DCE) and dynamic susceptibility contrast-enhanced (DSC) MRI were also generated. A region-of-interest analysis on the contralateral healthy white matter and on the tumor areas was performed and the extracted parameter values were tested for any significant differences among tumor grades or any correlations. Only f could be significantly correlated to DSC-derived vp and tc in healthy brain tissue. Concerning the tumor regions, Fp was significantly positively correlated with D* and inversely correlated with f in DSC measurements. The D*, f, and f × D* values in the WHO grade III gliomas were non-significantly different from those in the grade IV gliomas. There was a trend to significant negative correlations between f and PS as well as between f × D* and ke in DCE experiments. Presumably due to different theoretical background, tracer properties and modeling of the tumor vasculature in the IVIM theory, there is no clearly evident link between D*, f and DSC- and DCE-derived metrics. Copyright © 2014 John Wiley & Sons, Ltd.

Background The Sendai Consensus Guidelines (SCG) were formulated in 2006 to guide the management of mucinous cystic lesions of the pancreas (CLPs) and were updated in 2012 (International Consensus Guidelines, ICG 2012). This study aims to evaluate the clinical utility of the ICG 2012 with the SCG based on initial cross-sectional imaging findings. Methods One hundred fourteen patients with mucinous CLPs were reviewed and classified according to the ICG 2012 as high risk (HR ICG2012 ), worrisome (W ICG2012 ), and low risk (LR ICG2012 ), and according to the SCG as high risk (HR SCG ) and low risk (LR SCG ). Results On univariate analysis, the presence of symptoms, obstructive jaundice, elevated serum carcinoembryonic antigen (CEA)/carbohydrate antigen (CA)19-9, solid component, main pancreatic duct ≥10 mm, and main pancreatic duct ≥5 mm was associated with high grade dysplasia/invasive carcinoma in all mucinous CLPs. Increasing number of HR SCG or HR ICG2012 features was associated with a significantly increased likelihood of malignancy. The positive predictive value of HR SCG and HR ICG2012 for high grade dysplasia/invasive carcinoma was 46% and 62.5% respectively. The negative predictive value of both LR SCG and LR ICG2012 was 100%. Conclusion Both the guidelines were useful in the initial cross-sectional imaging evaluation of mucinous CLPs. The ICG 2012 guidelines were superior to the SCG guidelines.

Liver perfusion magnetic resonance (MR) imaging is currently being actively investigated as a functional imaging technique that provides physiologic information on the microcirculation and microenvironment of liver tumors and the underlying liver. It has gained importance in light of antiangiogenic therapy for hepatocellular carcinoma and colorectal liver metastases. This article explains the various model-free and model-based approaches for liver perfusion MR imaging and their relative clinical utility. Relevant published works are summarized for each approach so that the reader can understand their relative strengths and weaknesses, to make an informed choice when performing liver perfusion MR imaging studies.

Contrary to the common notion that tumor necrotic regions are non-enhancing after contrast administration, recent evidence has shown that necrotic regions exhibit delayed and slow uptake of gadolinium tracer on dynamic contrast-enhanced MRI (DCE MRI). The purpose of this study is to explore whether the mapping of tumor voxels with delayed and slow enhancement on DCE MRI can be used to derive estimates of tumor necrotic fraction. Patient-derived tumor xenograft lines of seven human cancers were implanted in 26 mice which were subjected to DCE MRI performed using a spoiled gradient recalled sequence. Gadolinium tracer concentration was estimated using the variable flip angle technique. To identify tumor voxels exhibiting delayed and slow uptake of contrast medium, clustering analysis was performed using a k-means clustering algorithm that classified tumor voxels according to their contrast enhancement patterns. Comparison of the percentage of tumor voxels exhibiting delayed and slow enhancement with the tumor necrotic fraction estimated on histology showed a strong correlation (r = 0.962, p

Introduction To determine if neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were predictive of malignancy in pancreatic cystic neoplasms (PCN) and if these improved the performance of the international consensus guidelines (ICG) in the initial triage of these patients. Methods 318 patients with surgically-treated suspected PCN were retrospectively reviewed. Malignant neoplasms were defined as neoplasms harbouring invasive carcinoma. The optimal cut-off for NLR and PLR were determined by plotting the receiver operating characteristics (ROC) curves of NLR/PLR in predicting malignant PCN and utilizing the Youden index. Results The optimal NLR and PLR cut-offs were determined to be 3.33 and 205, respectively. Univariate analyses demonstrated that symptomatic PCNs, age, obstructive jaundice, presence of solid component, dilatation of main pancreatic duct ≥10 mm, high NLR and high PLR were predictive of a malignant PCN. Multivariate analyses demonstrated that obstructive jaundice, presence of solid component, MPD ≥10 mm and high PLR but not NLR were independent predictors of a malignant PCN. A high PLR significantly predicted invasive carcinoma in patients classified within the ICG HR group. Comparison between the ROC curves of the ICG versus ICG plus high PLR in predicting malignant PCN demonstrated a significant improvement in the accuracy of the ICG when PLR was included [AUC 0.784 (95% CI: 0.740–0.829) vs AUC 0.822 (95% CI: 0.772–0.872) (p = 0.0032)]. Conclusions High PLR is an independent predictor of malignancy in PCN. The addition of PLR as a criterion to the ICG improved the accuracy of these guidelines in detecting invasive neoplasms.

// Andrea L.A. Wong 1, 2, 3 , Raghav Sundar 1, 2 , Ting-Ting Wang 3 , Thian-C Ng 4 , Bo Zhang 4 , Sing-Huang Tan 1, 2 , Thomas I.P. Soh 1, 2 , Angela S.L. Pang 1, 2 , Chee-Seng Tan 1, 2 , Samuel G.W. Ow 1, 2 , Lingzhi Wang 3, 5 , Jannet Mogro 2 , Jingshan Ho 1, 2 , Anand D. Jeyasekharan 1, 2, 3 , Yiqing Huang 1, 2 , Choon-Hua Thng 6 , Ching-Wan Chan 7 , Mikael Hartman 7 , Philip Iau 7 , Shaik A. Buhari 7 , Boon-Cher Goh 1, 2, 3, 5 , Soo-Chin Lee 1, 2, 3 1 Department of Haematology-Oncology, National University Cancer Institute, National University Health System, Singapore 2 Haematology Oncology Research Group, National University Cancer Institute, National University Health System, Singapore 3 Cancer Science Institute, National University of Singapore, Singapore 4 Clinical Imaging Research Centre, National University of Singapore, Singapore 5 Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, Singapore 6 Department of Diagnostic Imaging, National Cancer Centre, Singapore 7 Department of Surgical Oncology, National University Cancer Institute, National University Health System, Singapore Correspondence to: Soo-Chin Lee, email: csilsc@nus.edu.sg Keywords: vascular normalization, anti-angiogenic therapy, sunitinib, neoadjuvant chemotherapy, breast cancer Received: January 31, 2016 Accepted: August 08, 2016 Published: August 25, 2016 ABSTRACT Background: Prolonged anti-angiogenic therapy destroys tumor vasculature, whereas vascular-normalizing doses may enhance intra-tumoral drug delivery. We hypothesize that low-dose, short-course sunitinib normalizes vasculature, enhancing chemotherapy efficacy. Patients and Methods: In phase Ib, treatment-naive breast cancer patients received four cycles of pre-operative doxorubicin/cyclophosphamide, with sunitinib before each cycle. The optimal dose of sunitinib leading to tumor vessel normalization on immunohistochemistry was identified. In phase II, subjects were randomized to chemotherapy alone or chemotherapy plus sunitinib at the recommended phase II dose (RP2D). Primary endpoint was pathological complete response (pCR) rate. Tumor and functional imaging biomarkers were evaluated serially. Results: In phase Ib ( n =9), sunitinib 12.5 mg daily for 7 days before each chemotherapy was established as RP2D. In phase II, patients receiving chemotherapy plus sunitinib ( n =24) had similar pCR rates (5.0% versus 4.3%, p =1.00), but a higher incidence of chemotherapy dose delays (33.3% versus 8.7%, p =0.04), compared to those receiving chemotherapy alone ( n =25). The addition of sunitinib to chemotherapy significantly increased vascular normalization index (VNI) and decreased lymphatic vessel density (D2-40) on immunohistochemistry [VNI:25.50±27.94% versus 49.29±31.84%, p =0.034; D2-40:3.29±2.70 versus 1.29±1.54, p =0.014, baseline versus post-cycle 1], and improved perfusion on DCE-MRI ( K trans :12.6±9.6 mL/100 g/min versus 16.3±10.7 mL/100 g/min, baseline versus post-cycle 1, p =0.015). Conversely, immunohistochemical and DCE-MRI parameters were not significantly altered by chemotherapy alone. Conclusion: Low-dose, short-course sunitinib prior to anthracycline-based chemotherapy in breast cancer patients did not improve pCR and increased chemotherapy dose delays. However, the addition of sunitinib induced compelling pharmacodynamic evidence of vascular normalization. Further studies with alternative cytotoxic regimens should be explored.

Approximately 20 % of hepatocellular carcinoma (HCC) patients diagnosed in the early stages may benefit from potentially curative ablative therapies such as surgical resection, transplantation or radiofrequency ablation. For patients not eligible for such options, prognosis is poor. Sorafenib and Selective Internal Radiation Therapy (SIRT) are clinically proven treatment options in patients with unresectable HCC, and this study aims to assess overall survival following either SIRT or Sorafenib therapy for locally advanced HCC patients. This investigator-initiated, multi-centre, open-label, randomized, controlled trial will enrol 360 patients with locally advanced HCC, as defined by Barcelona Clinic Liver Cancer stage B or stage C, without distant metastases, and which is not amenable to immediate curative treatment. Exclusion criteria include previous systemic therapy, metastatic disease, complete occlusion of the main portal vein, or a Child-Pugh score of >7. Eligible patients will be randomised 1:1 and stratified by centre and presence or absence of portal vein thrombosis to receive either a single administration of SIRT using yttrium-90 resin microspheres (SIR-Spheres®, Sirtex Medical Limited, Sydney, Australia) targeted at HCC in the liver by the trans-arterial route or continuous oral Sorafenib (Nexavar®, Bayer Pharma AG, Berlin, Germany) at a dose of 400 mg twice daily until disease progression, no further response, complete regression or unacceptable toxicity. Patients for both the Sorafenib and SIRT arms will be followed-up every 4 weeks for the first 3 months and 12 weekly thereafter. Overall survival is the primary endpoint, assessed for the intention-to-treat population. Secondary endpoints are tumour response rate, time-to-tumour progression, progression free survival, quality of life and down-staging to receive potentially curative therapy. Definitive data comparing these two therapies will help to determine clinical practice in the large group of patients with locally advanced HCC and improve outcomes for such patients. ClinicalTrials.gov identifier, NCT01135056 , first received 24, May 2010.

Computer simulations based on a physiologically realistic tracer kinetic model with multiple pathways was used to provide insights on the applicability and interpretation of tissue enhancement metrics such as the maximum slope, peak enhancement and area under curve, commonly used in dynamic contrast-enhanced (DCE) MRI. Results show that physiological conditions of the tissue that could affect the accuracy of the maximal slope method include a high blood flow, increased variability of flow within the vasculature or a low vascular volume. Interestingly, changes in permeability and interstitial volume might not affect the accuracy of the maximal slope method. Time-to-peak and peak value of the tissue enhancement curve are not strictly properties of the tissue alone, and they cannot be linearly related to intrinsic tissue parameters such as blood flow, blood volume, capillary permeability, interstitial volume and mean transit time. Similar to the normalized initial area under tissue concentration curve, an alternative estimate of the total tracer distribution volume can be simply given by the ratio of tracer concentration in the tissue and artery sampled at the final DCE scan.