18F-FDG PET independently predicts survival in patients with cholangiocellular carcinoma treated with 90Y microspheres

Prognostic significance of 18F-Fluorodeoxyglucose positron-emission tomography parameters in patients with biliary tract cancers: a meta-analysis

BACKGROUND AND OBJECTIVE

Numerous previous studies have assessed the prognostic role of 18F-fluorodeoxyglucose positron-emission tomography (18F FDG PET) in patients with biliary tract cancer (BTC), but those results were inconsistent. The present study aims to determine the predictive value of 18F FDG PET in BTC patients via a meta-analysis.

METHODS

The underlying studies related to 18F FDG PET and BTC patients` outcomes were searched and identified in the online databases. The interested parameters include total lesion glycolysis (TLG), metabolic tumor volume (MTV), primary tumor and metastatic lymph node (LN) maximum standardized uptake value (SUVmax), as well as change of SUVmax (ΔSUVmax) during treatment. Overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS) were considered as the primary endpoints. Hazard ratio (HR) and corresponding 95% confidence intervals (CIs) were defined as the effective measure and calculated by a pooled analysis. Publication bias was assessed by funnel plot, Bagg's and Egger's tests.

RESULTS

Totally, 23 studies involving 1478 patients were included in the present meta-analysis. After a pooled analysis, it revealed that a high SUVmax was significantly associated with a poor OS (HR:2.07, 95%CI: 1.74-2.46, P = 0.000) and DFS (HR: 2.28, 95%CI: 1.53-3.41, P = 0.000). In addition, an increased TLG level contributed to a shorter OS (HR:1.91, 95%CI: 1.26-2.90, P = 0.002) and DFS (HR: 4.34, 95%CI: 1.42-13.27, P = 0.01). Moreover, we confirmed that an elevated MTV was significantly associated with increased mortality (HR:2.04, 95%CI:1.26-3.31, P = 0.004) and disease relapse (HR: 3.88, 95%CI:1.25-12.09, P = 0.019) risks. Besides, the present study uncovered that increased ΔSUVmax could predict poor OS (HR:1.26, 95%CI:1.06-1.50, P = 0.008) instead of PFS (HR: 1.96, 95%CI: 0.82-4.72, P = 0.280). Lastly, we found that LN SUVmax did not link to OS (HR: 1.49, 95%CI: 0.83-2.68, P = 0.178). No obvious publication bias was detected in the present study.

CONCLUSION

18F FDG PET parameters, including SUVmax, TLG, MTV, and ΔSUVmax, could be applied as convenient and reliable factors for predicting BTC patients` outcomes.

Selective Internal Radiation Therapy with Yttrium-90 for Intrahepatic Cholangiocarcinoma: A Systematic Review on Post-Treatment Dosimetry and Concomitant Chemotherapy

Selective internal radiation therapy (SIRT) with yttrium-90 (90Y)-loaded microspheres is increasingly used for the treatment of Intrahepatic Cholangiocarcinoma (ICC). Dosimetry verifications post-treatment are required for a valid assessment of any dose-response relationship. We performed a systematic review of the literature to determine how often clinics conducted post-treatment dosimetry verification to measure the actual radiation doses delivered to the tumor and to the normal liver in patients who underwent SIRT for ICC, and also to explore the corresponding dose-response relationship. We also investigated other factors that potentially affect treatment outcomes, including the type of microspheres used and concomitant chemotherapy. Out of the final 47 studies that entered our study, only four papers included post-treatment dosimetry studies after SIRT to quantitatively assess the radiation doses delivered. No study showed that one microsphere type provided a benefit over another, one study demonstrated better imaging-based response rates associated with the use of glass-based TheraSpheres, and two studies found similar toxicity profiles for different types of microspheres. Gemcitabine and cisplatin were the most common chemotherapeutic drugs for concomitant administration with SIRT. Future studies of SIRT for ICC should include dosimetry to optimize treatment planning and post-treatment radiation dosage measurements in order to reliably predict patient responses and liver toxicity.

Transarterial yrittrium-90 radioembolization for unresectable intrahepatic cholangiocarcinoma: a systematic review and meta-analysis

PURPOSE

To investigate the overall efficacy and survival profile of Yrittrium-90 (Y-90) radioembolization for unresectable intrahepatic cholangiocarcinoma (ICC).

MATERIALS AND METHODS

A systematic literature review and meta-analysis was completed using a random effects model. Studies describing the use of Y-90 for unresectable ICC were included. Disease control rate (DCR), downstaged to resectable rate, CA19-9 response rate, pooled overall median survival (OS), pooled median progression free survival (PFS), and mean reported survival rates ranging from 3 to 36 months (mo) were evaluated.

RESULTS

Twenty-one studies detailing a total of 921 patients were included. The overall DCR was 82.3% [95% Confidence Interval (CI): 76.7% to 87.8%, I² = 81%). In 11% of cases, patients were downstaged to being surgically resectable (CI: 6.1% to 15.9%, I² = 78%). The CA19-9 response rate was 67.2% (CI: 54.5% to 79,8%, I² = 60%). From point of radioembolization, PFS was 7.8 months (CI: 4.2 mo to 11.3 mo, I² = 94%), and overall median survival was 12.7 months (CI: 10.6 mo to 14.8 mo, I² = 62%). Lastly, the overall mean reported survival proportions were at 3 mo (84% survival, SD: 10%), 6 mo (69%, SD:16%), 12 mo (47%, SD: 19%), 18 mo (31%, SD: 21%), 24 mo (30%, SD 19%), 30 mo (21% (SD: 27%), and at 36 mo (5%, SD 7%).

CONCLUSIONS

Radioembolization with Y-90 for unresectable ICC remains beneficial for both disease control and survival. Data from ongoing projects will continue to help optimize treatment and patient selection resulting in improved patient outcomes.

Current State of Multidisciplinary Treatment in Cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is a highly aggressive malignancy, and its incidence seems to be increasing over the last years. Given the high rate of irresectability at the time of initial diagnosis, new treatment approaches are important to achieve better patient outcomes. Our review provides an overview of current multimodal therapy options across different specialties of gastroenterology/oncology, surgery, and interventional radiology.

SUMMARY

CCA is subdivided into clinically and molecularly distinct phenotypes. Surgical treatment currently is the only potentially curative therapy, but unfortunately, the majority of all patients are not eligible for resection at the time of initial diagnosis due to anatomic location, inadequate hepatic reserve, metastatic disease, or limiting comorbidities. However, multimodal treatment options are available to prolong survival, relieve symptoms, and maintain life quality.

KEY MESSAGES

The treatment of CCA is complex and requires close interdisciplinary collaboration and individualized treatment planning to ensure optimal patient care at specialized centers. Molecular profiling of patients and inclusion into clinical trials is highly recommended.

Assessment of radiation sensitivity of unresectable intrahepatic cholangiocarcinoma in a series of patients submitted to radioembolization with yttrium-90 resin microspheres

Radioembolization is a valuable therapeutic option in patients with unresectable intrahepatic cholangiocarcinoma. The essential implementation of the absorbed dose calculation methods should take into account also the specific tumor radiosensitivity, expressed by the α parameter. Purpose of this study was to retrospectively calculate it in a series of patients with unresectable intrahepatic cholangiocarcinoma submitted to radioembolization. Twenty-one therapeutic procedures in 15 patients were analysed. Tumor absorbed doses were calculated processing the post-therapeutic ⁹⁰Y-PET/CT images and the pre-treatment contrast-enhanced CT scans. Tumor absorbed dose and pre- and post-treatment tumor volumes were used to calculate α and α_3D parameters (dividing targeted liver in n voxels of the same volume with specific voxel absorbed dose). A tumor volume reduction was observed after treatment. The median of tumor average absorbed dose was 93 Gy (95% CI 81–119) and its correlation with the residual tumor mass was statistically significant. The median of α and α_3D parameters was 0.005 Gy⁻¹ (95% CI 0.004–0.008) and 0.007 Gy⁻¹ (95% CI 0.005–0.015), respectively. Multivariate analysis showed tumor volume and tumor absorbed dose as significant predictors of the time to tumor progression. The knowledge of radiobiological parameters gives the possibility to decide the administered activity in order to improve the outcome of the treatment.

Twenty Years of Radiation Therapy of Unresectable Intrahepatic Cholangiocarinoma: Internal or External? A Systematic Review and Meta-Analysis

PURPOSE

Both external beam radiation therapy (EBRT) and selective-internal radiation therapy (SIRT) are implemented to treat unresectable intrahepatic cholangiocarcinoma (iCCA). The present study aimed to evaluate the efficacy of EBRT and SIRT in managing iCCA through a systematic review and meta-analysis.

METHODS

PubMed and Cochrane database were queried to search for studies published from January 2000 toJune 2020 without language restrictions. Median survival time, overall survival, and radiological response were extracted. Secondary outcomes such as complication rates, predictors of survival, and downstage to surgery were pooled. Patient-level survival data were obtained to generate Kaplan-Meier survival graph. Pooled outcomes were analyzed with a random-effect model.

RESULTS

Twenty-nine and 20 studies including 732 and 443 patients from the SIRT and EBRT groups were included in the present study. From initial radiation treatment, the median survival time for patients who underwent SIRT and EBRT were 12.0 (95% confidence interval [CI]: 10.8-14.6) and 13.6 (95% CI: 11.1-16.0) months, respectively. As first-line therapy, the median survival time was 36.1 (95% CI: 20.6-39.5) months for SIRT and 11.0 (95% CI: 9.3-13.6) months for EBRT. Both radiation modalities were effective in downstaging initially unresectable iCCA to surgery (SIRT: 30.5%; EBRT: 18.3%). Patients in the SIRT group encountered more post-embolization abdominal pain (6.9 vs. 2.2%), ulcer (1.0 vs. 0.5%), nausea (1.6 vs. 0.7%), anorexia (5.9 vs. 0%), thrombocytopenia (7.3 vs. 6.0%), hyperbilirubinemia (5.2 vs. 2.1%), and hypoalbuminemia (13.2 vs. 3.3%), whereas EBRT was associated with higher rates of anemia (0.6 vs. 7.5%) and neutropenia (6.5 vs. 11.0%).

CONCLUSIONS

Both EBRT and SIRT were safe and effective in treating unresectable iCCA. However, available evidence was highly heterogeneous regarding patient population, limiting fair comparison between 2 radiation modalities. Future high-quality comparative studies are warranted.

Transarterial Chemoembolization and Radioembolization for Unresectable Intrahepatic Cholangiocarcinoma-a Systemic Review and Meta-Analysis

PURPOSE

Intrahepatic cholangiocarcinoma (ICC) has a poor prognosis, when unresectable; therefore, intra-arterial therapies (IAT) such as trans-arterial chemoembolization (TACE) and trans-arterial radioembolization (TARE) have been employed. With the present systematic review and meta-analysis, we aimed to analyse published studies to understand if one IAT can be superior to the alternative.

MATERIALS AND METHODS

A systematic search of PubMed and Web of Science databases was performed for articles published until 1 March 2020 relevant to IAT for ICC. Overall survival was the primary end point. Occurrence of clinical adverse events and tumour overall response were secondary outcome measures.

RESULTS

A total of 31 articles (of 793, n.1695 patients) were selected for data extraction, 13 were on TACE (906 patients) and 18 were on TARE (789 patients). Clinical and tumour characteristics showed moderate heterogeneity between the two groups. The median survival after TACE was 14.2 months while after TARE was 13.5 months (95%C.I.: 11.4-16.1). The survival difference was small (d = 0.112) at 1 year and negligible at 2 years (d = 0.028) and at 3 years (d = 0.049). The radiological objective response after TACE was 20.6% and after TARE was 19.3% (d = 0.032). Clinical adverse events occurred in 58.5% after TACE, more frequently than after TARE (43.0%, d = 0.314).

CONCLUSION

In conclusion, IATs are promising treatments for improving outcomes for patients with unresectable ICC. To date, TACE and TARE provide similar good outcomes, except for adverse events. Therefore, the decision about techniques is determined by ability to utilize these resources and patient specific factors (liver function or lesion dimension).

Factors affecting the response to Y-90 microsphere therapy in the cholangiocarcinoma patients

OBJECTIVE

The aim of this study was to assess the early therapy response in patients with unresectable CCA who received Y-90 microsphere therapy for CCA and define the factors related to therapy response.

MATERIALS AND METHODS

Data of 19 patients [extrahepatic (n: 6) and intrahepatic (n: 13)] who received 24 sessions of Y-90 microsphere therapy [glass (n: 13) and resin (n: 11)] were retrospectively evaluated. Tumor load, tumor size, therapy response evaluation by RECIST1.1 criteria (n: 13), tumor lesion glycolysis (TLG), metabolic tumor volume (MTV), and metabolic therapy responses were evaluated (n: 8) using PERCIST1.0 criteria.

RESULTS

No significant relation was found between therapy response and tumor localization, treated liver lobe, type of Y90 microspheres, the presence of previous therapies, perfusion pattern on hepatic artery perfusion scintigraphy, or patient demographics. The mean overall survival (OS) was 11.9 ± 2.3 months and was similar after both resin and glass Y90 microspheres; however, it was longer RECIST responders (p: 0.005). MTV and TLG values significantly decreased after therapy, and ΔMTV (- 45.4% ± 12.1) was found to be positively correlated with OS. No statistical difference was found between iCCA and eCCA, in terms of OS and response to therapy. Although not quantitatively displayed, better-perfused areas on HAPS images had a better metabolic response and less perfused areas were prone to local recurrences.

CONCLUSIONS

Both resin and glass microsphere therapy can be applied safely to iCCA and eCCA patients. Early therapy response can be evaluated with both RECIST and PERCIST criteria. Both anatomical and metabolic therapy response evaluations give complementary information.

Personalised radioembolization improves outcomes in refractory intra-hepatic cholangiocarcinoma: a multicenter study

PURPOSE

Reported outcomes of patients with intra-hepatic cholangiocarcinoma (IH-CCA) treated with radioembolization are highly variable, which indicates differences in included patients' characteristics and/or procedure-related variables. This study aimed to identify patient- and treatment-related variables predictive for radioembolization outcome.

METHODS

This retrospective multicenter study enrolled 58 patients with unresectable and chemorefractory IH-CCA treated with resin ⁹⁰Y-microspheres. Clinicopathologic data were collected from patient records. Metabolic parameters of liver tumor(s) and presence of lymph node metastasis were measured on baseline ¹⁸F-FDG-PET/CT. ^99mTc-MAA tumor to liver uptake ratio (TLR_MAA) was computed for each lesion on the SPECT-CT. Activity prescription using body-surface-area (BSA) or more personalized partition-model was recorded. The study endpoint was overall survival (OS) starting from date of radioembolization. Statistical analysis was performed by the log-rank test and multivariate Cox's proportional hazards model.

RESULTS

Median OS (mOS) post-radioembolization of the entire cohort was 10.3 months. Variables associated with significant differences in terms of OS were serum albumin (hazard ratio (HR) = 2.78, 95%CI:1.29-5.98, p = 0.002), total bilirubin (HR = 2.17, 95%CI:1.14-4.12, p = 0.009), aspartate aminotransferase (HR = 2.96, 95%CI:1.50-5.84, p < 0.001), alanine aminotransferase (HR = 2.02, 95%CI:1.05-3.90, p = 0.01) and γ-GT (HR = 2.61, 95%CI:1.31-5.22, p < 0.001). The presence of lymph node metastasis as well as a TLR_MAA < 1.9 were associated with shorter mOS: HR = 2.35, 95%CI:1.08-5.11, p = 0.008 and HR = 2.92, 95%CI:1.01-8.44, p = 0.009, respectively. Finally, mOS was significantly shorter in patients treated according to the BSA method compared to the partition-model: mOS of 5.5 vs 14.9 months (HR = 2.52, 95%CI:1.23-5.16, p < 0.001). Multivariate analysis indicated that the only variable that increased outcome prediction above the clinical variables was the activity prescription method with HR of 2.26 (95%CI:1.09-4.70, p = 0.03). The average mean radiation dose to tumors was significantly higher with the partition-model (86Gy) versus BSA (38Gy).

CONCLUSION

Radioembolization efficacy in patients with unresectable recurrent and/or chemorefractory IH-CCA strongly depends on the tumor radiation dose. Personalized activity prescription should be performed.

18F-fluorodeoxyglucose positron emission tomography (18FDG-PET) for patients with biliary tract cancer: Systematic review and meta-analysis

BACKGROUND & AIMS

The role of ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) in the diagnosis and staging of patients with biliary tract cancers (BTCs) remains controversial, so we aimed to provide robust information on the utility of ¹⁸FDG-PET in the diagnosis and management of BTC.

METHODS

This systematic review and meta-analysis explored the diagnostic test accuracy of ¹⁸FDG-PET as a diagnostic tool for diagnosis of primary tumour, lymph node invasion, distant metastases and relapsed disease. Subgroup analysis by study quality and BTC subtype were performed. Changes in management based on ¹⁸FDG-PET and impact of maximum standardised uptake values (SUVmax) on prognosis were also assessed. A random effects model was used for meta-analyses.

RESULTS

A total of 2,125 patients were included from 47 eligible studies. The sensitivity (Se) and specificity (Sp) of ¹⁸FDG-PET for the diagnosis of primary tumour were 91.7% (95% CI 89.8-93.2) and 51.3% (95% CI 46.4-56.2), respectively, with an area under the curve (AUC) of 0.8668. For lymph node invasion, Se was 88.4% (95% CI82.6-92.8) and Sp was 69.1% (95% CI 63.8-74.1); AUC 0.8519. For distant metastases, Se was 85.4% (95% CI 79.5-90.2) and Sp was 89.7% (95% CI86.0-92.7); AUC 0.9253. For relapse, Se was 90.1% (95% CI 84.4-94.3) and Sp was 83.5% (95% CI 74.4-90.4); AUC 0.9592. No diagnostic threshold effect was identified. Meta-regression did not identify significant sources of heterogeneity. Sensitivity analysis revealed no change in results when analyses were limited to studies with low risk of bias/concern. The pooled proportion of change in management was 15% (95% CI 11-20); the majority (78%) due to disease upstaging. Baseline high SUVmax was associated with worse survival (pooled hazard ratio of 1.79; 95% CI 1.37-2.33; p <0.001).

CONCLUSIONS

There is evidence to support the incorporation of ¹⁸FDG-PET into the current standard of care for the staging (lymph node and distant metastases) and identification of relapse in patients with BTC to guide treatment selection; especially if the identification of occult sites of disease would change management, or if diagnosis of relapse remains unclear following standard of care imaging. The role for diagnosis of the primary tumour remains controversial due to low sensitivity and ¹⁸FDG-PET should not be considered as a replacement for pathological confirmation in this setting.

LAY SUMMARY

A positron emission tomography (PET scan), using ¹⁸F-fluorodeoxyglucose (¹⁸FDG), can help doctors identify areas of cancer in the body by highlighting "hot spots". These hotspots may be cancerous (true positive) but may also be non-cancerous, like inflammation (false positive). We show that PET scans are useful to assess how far advanced the cancer is (by assessing spread to lymph glands and to other organs) and also to identify if the cancer has recurred (for example after surgery), thus helping doctors to make treatment decisions. However, a biopsy is still needed for the initial diagnosis of a biliary tract cancer, because of the high chance of a "false positive" with PET scans.

A pooled analysis of transarterial radioembolization with yttrium-90 microspheres for the treatment of unresectable intrahepatic cholangiocarcinoma

Purpose: The aim of this pooled analysis was to evaluate the clinical efficacy and safety of transarterial radioembolization (TARE) with yttrium-90 (⁹⁰Y) microspheres for the treatment of unresectable intrahepatic cholangiocarcinoma (ICC). Methods: We searched the Cochrane Library, Embase, PubMed, SCI with the English language from inception to October 2018. A pooled analysis was conducted using Stata software. Results: There were 16 eligible studies included in this pooled analysis. The pooled median overall survival (OS) from 12 studies was 14.3 (95% CI: 11.9-17.1) months. Based on Response Evaluation Criteria in Solid Tumors (RECIST), no complete response was reported, and the median of partial response, stable disease and progressive disease were 11.5% (range: 4.8-35.3%), 61.5% (range: 42.9-81.3%) and 22.7% (range: 12.5-52.4%) respectively. The pooled disease control rate (DCR) from nine studies was 77.2% (95% CI: 70.2-84.2%). According to the type of microspheres, subgroup analysis was performed, the median OS in the glass microspheres group was 14.0 (95% CI: 9.1-21.4) months, and 14.3 (95% CI: 11.5-17.8) months in the resin microspheres group. The DCR was 77.3% (95% CI: 63.5-91.1%) and 77.4% (95% CI: 66.8-87.9%) in the glass and resin microspheres groups respectively. Most of the side effects reported in the included studies were mild and did not require intervention. Conclusion: TARE with ⁹⁰Y microspheres is safe and effective for patients with unresectable ICC with acceptable side effects. And it seems that the type of microsphere has no influence on therapeutic efficacy.

Intrahepatic Cholangiocarcinoma Treated with Transarterial Yttrium-90 Glass Microsphere Radioembolization: Results of a Single Institution Retrospective Study

PURPOSE

To evaluate the efficacy and safety of transarterial yttrium-90 glass microsphere radioembolization in patients with unresectable intrahepatic cholangiocarcinoma (ICC).

MATERIALS AND METHODS

Retrospective review of 85 consecutive patients (41 men and 44 women; age, 73.4 ± 9.3 years) was performed. Survival data were analyzed by the Kaplan-Meier method, Cox regression models, and the log-rank test.

RESULTS

Median overall survival (OS) from diagnosis was 21.4 months (95% confidence interval [CI]: 16.6-28.4); median OS from radioembolization was 12.0 months (95% CI: 8.0-15.2). Seven episodes of severe toxicity occurred. At 3 months, 6.2% of patients had partial response, 64.2% had stable disease, and 29.6% had progressive disease. Median OS from radioembolization was significantly longer in patients with Eastern Cooperative Oncology Group (ECOG) scores of 0 and 1 than patients with an ECOG score of 2 (18.5 vs 5.5 months, P = .0012), and median OS from radioembolization was significantly longer in patients with well-differentiated histology than patients with poorly differentiated histology (18.6 vs 9.7 months, P = .012). Patients with solitary tumors had significantly longer median OS from radioembolization than patients with multifocal disease (25 vs. 6.1 months, P = .006). The absence of extrahepatic metastasis was associated with significantly increased median OS (15.2 vs. 6.8 months, P = .003). Increased time from diagnosis to radioembolization was a negative predictor of OS. The morphology of the tumor (mass-forming or infiltrative, hyper- or hypo-enhancing) had no effect on survival. Post-treatment increased cancer antigen 19-9 level, increased international normalized ratio, decreased albumin, increased bilirubin, increased aspartate aminotransferase, and increased Model for End-Stage Liver Disease score were significant predictors of decreased OS.

CONCLUSIONS

These data support the therapeutic role of radioembolization for the treatment of unresectable ICC with good efficacy and an acceptable safety profile.

Liver-Directed Therapies for Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC) are primary liver cancers where all or most of the tumor burden is usually confined to the liver. Therefore, locoregional liver-directed therapies can provide an opportunity to control intrahepatic disease with minimal systemic side effects. The English medical literature and clinical trials were reviewed to provide a synopsis on the available liver-directed percutaneous therapies for HCC and IHC. Locoregional liver-directed therapies provide survival benefit for patients with HCC and IHC compared to best medical treatment and have lower comorbid risks compared to surgical resection. These treatment options should be considered, especially in patients with unresectable disease.

Combined [18F]-Fluoroethylcholine PET/CT and 99mTc-Macroaggregated Albumin SPECT/CT Predict Survival in Patients With Intermediate-Stage Hepatocellular Carcinoma

AIM

The aim of this study was to retrospectively analyze the prognostic value of combined Tc-macroaggregated albumin (MAA) SPECT/CT and [F]-fluoroethylcholine (FEC) PET/CT before radioembolization for survival of patients with intermediate-stage hepatocellular carcinoma.

METHODS

Twenty-four patients with known hepatocellular carcinoma Barcelona Clinic Liver Cancer stage B were eligible for this analysis. All patients were scheduled for radioembolization and received a pretherapeutic [F]FEC PET/CT scan as well as Tc-MAA SPECT/CT for hepatopulmonary shunting. Laboratory and semiquantitative PET parameters and morphologic and metabolic (intersection) volumes of MAA and FEC were evaluated. Spearman correlation with overall survival, receiver operating curve analyses, univariate and multivariate Cox regression, and Kaplan-Meier-analysis was applied.

RESULTS

All patients (5 female/19 male) are deceased within the observational period. Median survival was 395 days (±51 days; range, 23-1122 days). The percentage of hypervascularized metabolically active tumor volume (vascularized tumor ratio; defined as high MAA and FEC uptake) correlated significantly with survival. Vascularized tumor ratio was a significant predictor in univariate and multivariate analyses (P = 0.026; hazard ratio, 11.65; 95% confidence interval, 1.62-83.73; P = 0.015). Statistical significance was not reached by all other variables in multivariate analysis. Receiver operating curve analysis for 1-year survival revealed an area under the curve of 0.77 (P = 0.024) for vascularized tumor ratio. At a cutoff value of 9%, sensitivity, specificity, and positive and negative prediction were 83%, 67%, and 71% and 80% (P = 0.036). Patients with a higher tumor vascularization had a median survival of 274 ± 80 versus 585 ± 284 days (P = 0.015).

CONCLUSIONS

Hepatocellular carcinoma with high vascularization in metabolic active areas as assessed by combined FEC PET/CT and Tc-MAA SPECT/CT represents an unfavorable subgroup with reduced overall survival after radioembolization.

Yttrium-90 resin microspheres and their use in the treatment of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a severe and rapidly progressive hepatic tumor. Surgery is often impracticable due to locally advanced presentation. On the other hand, chemotherapy has demonstrated only limited effectiveness. For these reasons, liver-directed therapies have been successfully applied for treating ICC. In particular, radioembolization with Yttrium-90 (90Y)-labeled spheres has been reported to be a promising therapeutic approach for this neoplasia. Two commercial forms of 90Y-labeled spheres are available: glass (TheraSphere®) and resin (SIR-Spheres®) microspheres. The aim of the present paper is to review the existing literature on the use of the resin microspheres for the treatment of unresectable and chemorefractory ICC, focusing on the methodology, clinical applications and side effects.

Safety of selective internal radiation therapy (SIRT) with yttrium-90 microspheres combined with systemic anticancer agents: expert consensus

Selective internal radiation therapy (SIRT) with microspheres labelled with the β-emitter yttrium-90 (Y-90) enables targeted delivery of radiation to hepatic tumors. SIRT is primarily used to treat inoperable primary or metastatic liver tumors. Eligible patients have usually been exposed to a variety of systemic anticancer therapies, including cytotoxic agents, targeted biologics, immunotherapy and peptide receptor radionuclide therapy (PRRT). All these treatments have potential interactions with SIRT; however, robust evidence on the safety of these potential combinations is lacking. This paper provides current clinical experiences and expert consensus guidelines for the use of SIRT in combination with the anticancer treatment agents likely to be encountered in clinical practice. It was agreed by the expert panel that precautions need to be taken with certain drugs, but that, in general, systemic therapies do not necessarily have to be stopped to perform SIRT. The authors recommend stopping vascular endothelial growth factor inhibitors 4-6 weeks before SIRT, and restart after the patient has recovered from the procedure. It may also be prudent to stop potent radiosensitizers such as gemcitabine therapy 4 weeks before SIRT, and restart treatment at least 2‒4 weeks later. Data from phase III studies combining SIRT with fluorouracil (5FU) or folinic acid/5FU/oxaliplatin (FOLFOX) suggest that hematological toxicity is more common from the combination than it is from chemotherapy without SIRT. There is no evidence to suggest that chemotherapy increases SIRT-specific gastro-intestinal or liver toxicities.

Improving patient selection for selective internal radiation therapy of intra-hepatic cholangiocarcinoma: A meta-regression study

BACKGROUND & AIMS

Selective internal radiation therapy (SIRT) is emerging as a potential therapy for unresectable intra-hepatic cholangiocarcinoma (iCCA) able to prolong life-expectancy. Aim of this study was to collect available literature meta-analyse data and results and investigate sources of heterogeneity through a meta-regression approach before suggesting SIRT as a valuable option.

METHODS

A systematic review of studies published until 1 September 2016 in PubMed and Scopus databases was performed. Patient survival was the primary outcome measure. Meta-analysis was performed using a random-effects model. Meta-regression was applied to investigate relationships existing between clinical and tumour features and the primary outcome.

RESULTS

Nine observational studies were included in the analysis involving 224 patients. The 1-, 2- and 3-year pooled survival estimates were 55.7%, 33.1% and 20.2%. Clinical and tumour characteristics showed medium-to-considerable heterogeneity (I² >50%). Meta-regression analysis showed that determinants of best survivals were the presence of mass-forming iCCA type (median survival=19.9 months vs 8.1 months for the infiltrative type; P=.002) that also accounted for most of the heterogeneity between included studies (residual I² =0); SIRT as first-line therapy (median survival=24 months vs 11.5 months for non-naïve patients; P=.048) and the adoption of concomitant chemotherapy (median survival 19.5 months vs 5.5 months in patients not receiving chemotherapy; P=.042).

CONCLUSIONS

There is considerable heterogeneity between studies highlighting that indications for SIRT are extremely varied. To ameliorate SIRT results naïve patients with mass-forming iCCA should be selected as the best candidates with the possibility of adding concomitant standard chemotherapy.

Selective internal radiation therapy with SIR-Spheres in hepatocellular carcinoma and cholangiocarcinoma

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) often present at stages where patients have limited treatment options. Use of selective internal radiation therapy (SIRT) with yttrium-90 (Y-90) resin microspheres has progressed as data increasingly speak to its utility in patients with both intermediate and late stage disease in these cancers. In anticipation of the pending completion of several prospective randomized controlled multicenter studies exploring the use of Y-90 resin microspheres in primary liver cancers, this article outlines mechanisms involved in SIRT administration and reviews key efficacy and safety data that are currently available in the literature involving use of this therapy in both HCC and ICC.

18F-FDG PET/CT predicts survival after 90Y transarterial radioembolization in unresectable hepatocellular carcinoma

PURPOSE

To compare the value of pretreatment functional and morphological imaging parameters for predicting survival in patients undergoing transarterial radioembolization using yttrium-90 (⁹⁰Y-TARE) for unresectable hepatocellular carcinoma (uHCC).

METHODS

We analysed data from 48 patients in our prospective database undergoing ⁹⁰Y-TARE treatment for uHCC (31 resin, 17 glass). All patients underwent ¹⁸F-FDG PET/CT and morphological imaging (CT and MRI scans) as part of a pretherapeutic work-up. Patients did not receive any treatment between these imaging procedures and ⁹⁰Y-TARE. Kaplan-Meier estimates of progression-free survival (PFS) and overall survival (OS) were used to assess the prognostic value of ¹⁸F-FDG PET/CT metabolic parameters, including SUV_max, tumour-to-liver (T/L) uptake ratio and SUV_mean of healthy liver, and morphological data, including number and size of lesions, portal-venous infiltration (PVI). Relevant prognostic factors for HCC including Child-Pugh class, Barcelona Clinic Liver Cancer (BCLC) stage, tumour size, PVI and serum AFP level were compared with metabolic parameters in univariate and multivariate analyses.

RESULTS

The median follow-up in living patients was 16.2 months (range 11.4-50.1 months). Relapse occurred in 34 patients (70.8%) at a median of 7.4 months (range 1.4-27.9 months) after ⁹⁰Y-TARE, and relapse occurred in 24 of 34 patients (70.8%) who died from their disease at a median of 8.1 months (range 2.2-35.2 months). Significant prognostic markers for PFS were the mean and median lesion SUV_max (both P = 0.01; median PFS 10.2 vs. 7.4 months), and significant prognostic markers for OS were the first quarter (Q1) cut-off values for lesion SUV_max and T/L uptake ratio (both P = 0.02; median OS 30.9 vs. 9 months). The multivariate analysis confirmed that lesion SUV_max and T/L uptake ratio were independent negative predictors of PFS (hazard ratio, HR, 2.7, 95% CI 1.2-6.1, P = 0.02, for mean SUV_max; HR 2.6, 95% CI 1.1-5.9, P = 0.02, for median SUV_max:) and OS (HR 3.2, 95% CI 1-10.9, P = 0.04 for Q1 SUV_max; HR 3.7, 95% CI 1.1-12.2, P = 0.03, for Q1 T/L uptake ratio), respectively, when testing with either the BCLC staging system or serum AFP level.

CONCLUSION

Lesion SUV_max and T/L uptake ratio as assessed by ¹⁸F-FDG PET/CT, but not morphological imaging, were predictive markers of survival in patients undergoing ⁹⁰Y-TARE for uHCC.

Intra-arterial embolotherapy for intrahepatic cholangiocarcinoma: update and future prospects

Intrahepatic cholangiocarcinoma (ICC) is a rare disease and carries a poor prognosis with surgery remaining the only curative treatment option. However, due to the late presentation of symptoms and close proximity of the tumors to central hepatic structures, only about 30% of patients are classified eligible to resection. As for palliative approaches, ICC constitutes a possible indication for loco-regional therapies (LRT). As such, intra-arterial therapies (IAT) are reported to be feasible, safe and effective in inducing tumor response in unresectable ICC. The paradigm of IAT is premised on the selective delivery of embolic, chemotherapeutic agents to the tumor via its feeding arteries, thus allowing dose escalation within the carcinoma and reduction of systemic toxicity. Conventional transcatheter arterial chemoembolization (cTACE) so far remains the most commonly used IAT modality. However, drug-eluting beads (DEB)-TACE was initiated with the idea of more selective targeting of the tumor owing to the combined embolizing as well as drug-eluting properties of the microspheres used in this setting. Moreover, radioembolization is performed by intra-arterial administration of very small spheres containing β-emitting yttrium-90 (Y90-RE) to the site of the tumor. Clinical evidence exists in support of survival benefits for IAT in the palliative treatment of ICC compared to surgery and systemic chemotherapy. As for combination regimens, cTACE, DEB-TACE and Y90-RE are reported to achieve conversion of patients to surgery in a sequential treatment planning and simultaneous IAT combinations may provide a therapeutic option for treatment escalation. Regarding the current status of literature, controlled randomized prospective trials to compare different IAT techniques and combination therapies as well as treatment recommendations for different IAT modalities are needed.

Locoregional Therapies of Cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CC) is the second most primary liver malignancy with increasing incidence in Western countries. Currently, surgical R0 resection is regarded as the only potentially curative treatment. The results of systemic chemotherapy and best supportive care (BSC) in patients with metastatic disease are often disappointing in regard to toxicity, oncologic efficacy, and overall survival. In current practice, the use of different locoregional therapies is increasingly more accepted.

METHODS

A review of the literature on locoregional therapies for intrahepatic cholangiocarcinoma (ICC) was undertaken.

RESULTS

There are no prospective randomized controlled trials. For localized ICC, either primary or recurrent, radiofrequency ablation (RFA) is by far the most commonly used thermal ablation modality. Thereby, a systematic review and meta-analysis reports major complication in 3.8% as well as 1-, 3-, and 5-year overall survival rates of 82, 47, and 24%, respectively. In selected patients (e.g. with a tumor diameter of ≤3 cm), oncologic efficacy and survival after RFA are comparable with surgical resection. For diffuse ICC, different transarterial therapies, either chemotherapy-based (hepatic artery infusion (HAI), transarterial chemoembolization (TACE)) or radiotherapy-based (transarterial radioembolization (TARE)), show extremely promising results. With regard to controlled trials (transarterial therapy versus systemic chemotherapy, BSC or no treatment), tumor control is virtually always better for transarterial therapies and very often accompanied by a dramatic survival benefit and improvement of quality of life. Of note, the latter is the case not only for patients without extrahepatic metastatic disease but also for those with liver-dominant extrahepatic metastatic disease. There are other locoregional therapies such as microwave ablation, irreversible electroporation, and chemosaturation; however, the current data support their use only in controlled trials or as last-line therapy.

CONCLUSION

Dedicated locoregional therapies are commonly used for primary and recurrent ICC as well as liver-only and liver-dominant extrahepatic metastatic disease. Currently, the best evidence and most promising results are available for RFA, HAI, TACE, and TARE. In cohort studies, the overall survival rates are similar to those obtained with surgery or systemic therapies. Prospective randomized controlled trials are warranted to compare safety and efficacy between different surgical, interventional, and systemic therapies, as well as their combinations.

Selective Internal Radiation Therapy (SIRT) as Conversion Therapy for Unresectable Primary Liver Malignancies

BACKGROUND

Many patients with primary liver cancers are not candidates for surgery, and systemic therapies are seldom effective. Selective internal radiation therapy (SIRT) has been shown to obtain partial and even complete response in unresectable primary tumors. As a "side effect", SIRT can induce contra-lateral liver hypertrophy. Tumor response to SIRT can be sufficient to allow disengagement from normal vital structures whose involvement is the cause of the initial unresectability. The contra-lateral hypertrophy can thereby increase the future liver remnant (FLR) volume to over the safe threshold so that extended hepatectomy can be performed.

SUMMARY

A review of the available literature was performed to assess the tumor response and liver hypertrophy that can be expected after SIRT, in order to delineate whether SIRTcan play a role in conversion therapy for resectability of primary liver malignancies.

KEY MESSAGE

Available data suggest that SIRT in unresectable hepatocellular and cholangiocellular carcinomas can provide a considerable down-sizing of the tumors to possibly allow resection. Hypertrophy of the contra-lateral lobe represents a favorable collateral effect that can help in achieving safer subsequent major hepatectomy. In patients whose FLR volume represents the only surgical concern, portal vein embolization remains the treatment of choice.

Yttrium-90 Microsphere Brachytherapy for Liver Metastases From Uveal Melanoma: Clinical Outcomes and the Predictive Value of Fluorodeoxyglucose Positron Emission Tomography

OBJECTIVES

To report outcomes after yttrium-90 microsphere brachytherapy for unresectable liver metastases from uveal melanoma and to evaluate factors predictive for overall survival (OS) and hepatic progression-free survival (PFS).

METHODS

A total of 71 patients were consecutively treated with microsphere brachytherapy for unresectable liver metastases from uveal melanoma between 2007 and 2012. Clinical, radiographic, and positron emission tomography-derived, functional tumor parameters were evaluated by log-rank test in univariate analysis and backwards stepwise multivariate Cox proportional hazards regression. OS and hepatic PFS were estimated by Kaplan-Meier analysis.

RESULTS

A total of 134 procedures were performed in 71 patients with a median age of 63 years (range, 23 to 91 y). Fifty-eight patients (82%) received microsphere brachytherapy as a salvage therapy. Median hepatic PFS and OS after microsphere brachytherapy were 5.9 months (range, 1.3 to 19.1 mo) and 12.3 months (range, 1.9 to 49.3 mo), respectively. Median OS times after diagnosis of liver metastases was 23.9 months (range, 6.2 to 69.0 mo). In univariate analysis, female sex, pretreatment metabolic tumor volume, and total glycolic activity (TGA) were significantly correlated with hepatic PFS and OS. In multivariate analysis, female sex and TGA retained significance as independent predictors of hepatic PFS and OS. A low pretreatment TGA (<225 g) was associated with a significantly longer median OS than was a TGA≥225 g (17.2 vs. 9.7 mo, P=0.01).

CONCLUSIONS

Yttrium-90 microsphere brachytherapy provided favorable survival times in patients with unresectable liver metastases from uveal melanoma. Metabolic tumor volume and TGA are predictive functional tumor parameters, which may aid patient selection and risk stratification.

Role of 18F-FDG PET/CT Imaging in Intrahepatic Cholangiocarcinoma

PURPOSE

Although intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy after hepatocellular carcinoma, there are limited data available on PET/CT imaging in ICC. This retrospective study analyzed the role of PET/CT imaging in the evaluation of ICC.

METHODS

FDG PET/CT findings were reviewed in 65 patients with histologically confirmed ICC. PET/CT was evaluated based on visual interpretation and the semiquantitative index of SUVmax and tumor-to-normal liver tissue ratio (TNR), which were consequently further analyzed and correlated with tumor localization, differentiation, size, and serum levels of tumor markers. Forty-five cases also underwent abdominal MRI examinations.

RESULTS

Nineteen patients had hilar ICC, whereas 46 patients had peripheral ICC. Sixty cases of ICC showed elevated FDG uptake with an average SUVmax of 8.3 ± 4.7 and TNR of 3.1 ± 1.7. Five cases located in the hilum were false negative on PET/CT imaging. Compared with hilar ICC, SUVmax and TNR of peripheral ICC were significantly higher (P < 0.05). FDG accumulation correlated with the degree of ICC differentiation. SUVmax and TNR correlated with tumor size, whereas there was no correlation observed with serum levels of carbohydrate antigen 19-9. The sensitivity, specificity, and accuracy of PET/CT and MRI in the diagnosis of regional lymph node metastases were 70.0% versus 50%, 91.7% versus 83.3%, and 81.8% versus 68.2%, respectively. PET/CT upstaged 12.3% and downstaged 3.1% of cases and had no impact on patient management in the remaining 84.6% of cases.

CONCLUSIONS

Combination of FDG PET/CT and abdominal MRI might improve the diagnostic accuracy for ICC.

Yttrium-90 hepatic radioembolization: clinical review and current techniques in interventional radiology and personalized dosimetry

In recent years, yttrium-90 ((90)Y) microsphere radioembolization has been establishing itself as a safe and efficacious treatment for both primary and metastatic liver cancers. This extends to both first-line therapies as well as in the salvage setting. In addition, radioembolization appears efficacious for patients with portal vein thrombosis, which is currently a contraindication for surgery, transplantation and transarterial chemoembolization. This article reviews the efficacy and expanding use of (90)Y microsphere radioembolization with an added emphasis on recent advances in personalized dosimetry and interventional radiology techniques. Directions for future research into combination therapies with radioembolization and expansion into sites other than the liver are also explored.

Trans-arterial embolisation therapies for unresectable intrahepatic cholangiocarcinoma: a systematic review

BACKGROUND

Unresectable intrahepatic cholangiocarcinoma (ICC) portends a poor prognosis despite standard systemic treatments which confer minimal survival benefits and significant adverse effects. This study aimed to assess clinical outcomes, complications and prognostic factors of TAE therapies using chemotherapeutic agents or radiation.

METHODS

A literature search and article acquisition was conducted on PubMed (MEDLINE), OVID (MEDLINE) and EBSCOhost (EMBASE). Original articles published after January 2000 on trans-arterial therapies for unresectable ICC were selected using strict eligibility criteria. Radiological response, overall survival, progression-free survival, safety profile, and prognostic factors for overall survival were assessed. Quality appraisal and data tabulation were performed using pre-determined forms. Results were synthesized by narrative review and quantitative analysis.

RESULTS

Twenty articles were included (n=929 patients). Thirty three percent of patients presented with extrahepatic metastases. After treatment, the average rate of complete and partial radiological response was 10% and 22.2%, respectively. Overall median survival time was 12.4 months with a median 30-day mortality and 1-year survival rate of 0.6% and 53%, respectively. Acute treatment toxicity (within 30 days) was reported in 34.9% of patients, of which 64.3% were mild to moderate in severity. The most common clinical toxicities were abdominal pain, nausea and vomiting, and fatigue. Multiplicity, localization and vascularity of the tumor may predict worse overall survival.

CONCLUSIONS

Trans-arterial therapies are safe and effective treatment options which should be considered routinely for unresectable ICC. Consistent and standardized methodology and data collection is required to facilitate a meta-analysis. Randomized controlled trials will be valuable in the future.

PET response criteria for solid tumors predict survival at three months after intra-arterial resin-based 90Yttrium radioembolization therapy for unresectable intrahepatic cholangiocarcinoma

PURPOSE

PET Response Criteria for Solid Tumors (PERCIST) were assessed and correlated with survival analysis after resin-based 90Yttrium (90Y) radioembolization therapy for intrahepatic cholangiocarcinoma (ICC).

PATIENTS AND METHODS

Target and overall PERCIST and Response Criteria for Solid Tumors (RECIST) treatment responses were assessed in consecutive patients treated with Y radioembolization for ICC refractory to standard chemotherapy. Significant measurable tumor was defined as 1 cm or greater in diameter and SUVpeak of 2.5 or greater in targeted and nontargeted lesions. The PERCIST defines complete response as resolution of 18F-FDG uptake within measurable lesions, and partial response as 30% reduction in 18F-FDG peak standardized uptake value in measurable lesions. Objective response included partial response and complete response. Survival analysis by Kaplan-Meier and log-rank proportional models was performed using SPSS software version 20.0 (IBM, Armonk, NY), and significance was set at P < 0.05.

RESULTS

Median overall survival (OS) of 9 consecutive patients (56% women; mean age, 58 years) from 90Y therapy was 21.7 months. At 3 months, PERCIST objective response rate of target lesions was 77.7%, and target objective response on PERCIST correlated significantly to prolonged OS (P = 0.022). Overall objective PERCIST response at 3 months had significant correlation with OS (P = 0.011). Probability of death was significantly higher in overall nonresponders by PERCIST (hazard ratio, 12.3). No objective response was seen with RECIST.

CONCLUSIONS

In patients with unresectable ICC refractory to standard chemotherapy, PERCIST at 3 months for assessment of imaging response after 90Y radioembolization therapy predict OS.

Effects of Yttrium-90 selective internal radiation therapy on non-conventional liver tumors

The liver is a common site of metastasis, with essentially all metastatic malignancies having been known to spread to the liver. Nearly half of all patients with extrahepatic primary cancer have hepatic metastases. The severe prognostic implications of hepatic metastases have made surgical resection an important first line treatment in management. However, limitations such as the presence of extrahepatic spread or poor functional hepatic reserve exclude the majority of patients as surgical candidates, leaving chemotherapy and locoregional therapies as next best options. Selective internal radiation therapy (SIRT) is a form of catheter-based locoregional cancer treatment modality for unresectable tumors, involving trans-arterial injection of microspheres embedded with a radio-isotope Yttrium-90. The therapeutic radiation dose is selectively delivered as the microspheres permanently embed themselves within the tumor vascular bed. Use of SIRT has been conventionally aimed at treating primary hepatic tumors (hepatocellular carcinoma) or colorectal and neuroendocrine metastases. Numerous reviews are available for these tumor types. However, little is known or reviewed on non-colorectal or non-neuroendocrine primaries. Therefore, the aim of this paper is to systematically review the current literature to evaluate the effects of Yttrium-90 radioembolization on non-conventional liver tumors including those secondary to breast cancer, cholangiocarcinoma, ocular and percutaneous melanoma, pancreatic cancer, renal cell carcinoma, and lung cancer.

Integration of chemoembolization and radioembolization into multimodal treatment of cholangiocarcinoma

Over the last decade radioembolization and transarterial chemoembolization have been shown to be effective in unresectable intrahepatic cholangiocellular carcinoma. Unfortunately, up to now the evidence is not high with most of the conclusions drawn from single center retrospective analyses with small sample sizes treated in the salvage situation. However, the results are promising and suggest a survival benefit in the treatment of unresectable cholangiocellular carcinoma, even in an advanced stage with extrahepatic disease. In the following, available results of the treatment of unresectable cholangiocellular carcinoma by radioembolization and transarterial chemoembolization will be summarized. Special attention will be given to prognostic factors and efficacy as measured by response criteria. The potential integration of these therapies into multimodal treatment concepts will be discussed with focus on the intensification of therapy and a staged concept of therapy.

Yttrium-90 microspheres: a review of its emerging clinical indications

BACKGROUND

Many patients with liver malignancies are not candidates for resection, and systemic therapies are often not effective. Radioembolization (RE) is an alternative treatment for this group of patients. The safety and efficacy of RE with yttrium 90 (Y90) in patients with hepatocellular carcinoma (HCC) or metastatic colon cancer to the liver have been proven in several studies. However, fewer studies have focussed on the safety and efficacy of RE with Y90 in other extrahepatic primary and secondary liver cancers. The effect on outcomes of concomitant use of Y90 with a systemic therapy is still currently under investigation.

SUMMARY

A review of the published data on the use of RE as stand-alone, concomitant or sequential with other treatment modalities in HCC and other primary and secondary liver cancer is reported here.

KEY MESSAGE

RE for the treatment of HCC and other extrahepatic, primary and secondary liver cancer has reasonable efficacy and acceptable toxicities. Definitive studies to establish the role of RE in the treatment of such malignancies are warranted.

Systematic evaluation of tumoral 99mTc-MAA uptake using SPECT and SPECT/CT in 502 patients before 90Y radioembolization

The aim of this study was to evaluate the (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) uptake of primary and secondary liver tumors in a large patient cohort before (90)Y radioembolization.

METHODS

We included 502 patients during the years 2005-2013 (55% male; mean age, 62 ± 11 y), who were examined with (99m)Tc-MAA SPECT or SPECT/CT before planned radioembolization. The patients had colorectal cancer (CRC; n = 195, 38.8%), neuroendocrine tumors (NET; n = 77, 15.3%), mammary cancer (MAM; n = 68, 13.5%), hepatocellular carcinoma (HCC; n = 59, 11.8%), cholangiocellular carcinoma (CCC; n = 40, 8.0%), or urologic tumors (URO; n = 14, 2.8%). SPECT with coregistered contrast-enhanced CT or MR imaging and SPECT/CT images of these patients were analyzed using dedicated software with regard to the (99m)Tc-MAA uptake of the liver tumors. Regions of interest were drawn around the lesions manually and quantified the uptake of up to 3 lesions per patient and also adjacent healthy liver tissue without evidence of tumor. We quantified maximum and mean counts per pixel and calculated tumor-to-background ratio (TBR). Data are reported as mean ± SD. Lesion uptake was classified as being homogeneously high (grade 1), heterogeneously high (grade 2), equal to that of the liver (grade 3), or low (grade 4).

RESULTS

Grade 1 uptake was seen in 230 of 1,008 lesions (with the highest rates in sarcoma [47%], MAM [37%], and NET [32%]), grade 2 in 706 lesions (with the highest rates in CRC [77%], HCC [75%], and CCC [74%]), grade 4 in 57 lesions (with the highest rates in pancreatic cancer [17%], sarcoma [SAR] [13%], and MAM [8%]), and grade 3 in only 15 lesions. In quantitative analysis, the mean TBRmax of all lesions was 4.8 ± 4.1 (range, 0.2-50.1), with the highest values in HCC (6.0 ± 4.7; range, 1.4-21.6), NET (5.4 ± 4.9; range, 0.8-43.0), pancreatic cancer (4.0 ± 2.8; range, 0.9-12.2), and CCC (4.7 ± 2.9; range, 0.9-11.6), and the lowest values in SAR (3.5 ± 1.8; range, 0.8-2.7) and MAM (3.6 ± 2.2; range, 0.9-11.6). The mean TBRmean was 1.9 ± 1.0 (range, 0.1-7.2), with the highest values in NET (2.2 ± 1.2; range, 0.2-7.2), HCC (2.1 ± 1.2; range, 0.3-6.3), and CCC (2.0 ± 1.0; range, 0.2-6.3) and the lowest values in MAM (1.7 ± 0.8; range, 0.2-4.1), CRC (1.8 ± 0.9; range, 0.4-6.6), and SAR (1.7 ± 1.1; range, 0.3-3.9).

CONCLUSION

The (99m)Tc-MAA uptake of different tumor entities shows a wide variation, with generally highest values for NET, HCC, and CCC and lowest values for MAM, CRC, and SAR. However, the variation of uptake within the different tumor entities is high.

Survival in patients with hepatocellular carcinoma treated with 90Y-microsphere radioembolization. Prediction by 18F-FDG PET

AIM

This retrospective study aims to evaluate the predictive value of FDG PET/CT in patients with unresectable hepatocellular carcinoma (HCC) undergoing radioembolization with yttrium-90 labeled microspheres (RE).

PATIENTS, METHODS

The study cohort comprised 33 patients who were treated with RE at our institution and underwent FDG PET/CT at baseline and four weeks after radioembolization. According to the baseline FDG metabolic status of the HCC lesions, patients were divided into two groups: FDG-negative (n = 12) and FDG-positive (n = 21) HCC. FDG-positive patients were further divided into early metabolic responders and non-responders according to the relative change in SUVmax of the treated lesions. Survival analyses were performed with the Kaplan-Meier method (log-rank test, p < 0.05). Multivariate analysis was performed to assess the influence of prognostic factors on overall survival (OS).

RESULTS

FDG-negative patients had a significantly longer OS (13 months, 95%CI 7-19) than FDG-positive patients (9 months, 95%CI 7-11; p = 0.010). Among FDG-positive patients, metabolic responders survived significantly longer than metabolic non-responders (10 months, 95%CI 8-12 vs. 5 months, 95%CI 4-6; p = 0.003). From the other baseline factors (including performance status, hepatic tumour burden, presence of extra-hepatic disease, administered activity) only the BCLC stage had a significant impact on OS (p = 0.028).

CONCLUSION

Pre- and post-therapeutic FDG PET independently predicts overall survival in patients with HCC undergoing radioembolization. Interestingly, early metabolic response seems to be assessable as early as four weeks post-treatment.

Early post-treatment FDG PET predicts survival after 90Y microsphere radioembolization in liver-dominant metastatic colorectal cancer

PURPOSE

The aim of this study was to evaluate the predictive value of early metabolic response 4 weeks post-treatment using (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in patients with unresectable hepatic metastases of colorectal cancer (CRC) undergoing radioembolization (RE) with (90)Y-labelled microspheres.

METHODS

A total of 51 consecutive patients with liver-dominant metastases of CRC were treated with RE and underwent (18)F-FDG PET/CT at baseline and 4 weeks after RE. In each patient, three hepatic metastases with the highest maximum standardized uptake value (SUVmax) were selected as target lesions. Metabolic response was defined as >50 % reduction of tumour to liver ratios. Survival analyses using Kaplan-Meier and multivariate analyses were performed to identify prognostic factors for overall survival (OS). Investigated baseline characteristics included age (>60 years), performance status (Eastern Cooperative Oncology Group >1), bilirubin (>1.0 mg/dl), hepatic tumour burden (>25 %) and presence of extrahepatic disease.

RESULTS

The median OS after RE was 7 months [95 % confidence interval (CI) 5-8]; early metabolic responders (n = 33) survived longer than non-responders (p < 0.001) with a median OS of 10 months (95 % CI 3-16) versus 4 months (95 % CI 2-6). Hepatic tumour burden also had significant impact on treatment outcome (p < 0.001) with a median OS of 5 months (95 % CI, 3-7) for patients with >25 % metastatic liver replacement vs 14 months (95 % CI 6-22) for the less advanced patients. Both factors (early metabolic response and low hepatic tumour burden) remained as independent predictors of improved survival on multivariate analysis.

CONCLUSION

These are the first findings to show that molecular response assessment in CRC using (18)F-FDG PET/CT appears feasible as early as 4 weeks post-RE, allowing risk stratification and potentially facilitating early response-adapted treatment strategies.

Prognostic significance of standardized uptake value on preoperative ¹⁸F-FDG PET/CT in patients with ampullary adenocarcinoma

PURPOSE

The purpose of this study was to investigate the prognostic value of (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with ampullary adenocarcinoma (AAC) after curative surgical resection.

METHODS

Fifty-two patients with AAC who had undergone (18)F-FDG PET/CT and subsequent curative resections were retrospectively enrolled. The maximum standardized uptake value (SUVmax) and tumor to background ratio (TBR) were measured on (18)F-FDG PET/CT in all patients. The prognostic significances of PET/CT parameters and clinicopathologic factors for recurrence-free survival (RFS) and overall survival (OS) were evaluated by univariate and multivariate analyses.

RESULTS

Of the 52 patients, 19 (36.5%) experienced tumor recurrence during the follow-up period and 18 (35.8%) died. The 3-year RFS and OS were 62.3 and 61.5%, respectively. Preoperative CA19-9 level, tumor differentiation, presence of lymph node metastasis, SUVmax, and TBR were significant prognostic factors for both RFS and OS (p < 0.05) on univariate analyses, and patient age showed significance only for predicting RFS (p < 0.05). On multivariate analyses, SUVmax and TBR were independent prognostic factors for RFS, and tumor differentiation, SUVmax, and TBR were independent prognostic factors for OS.

CONCLUSION

SUVmax and TBR on preoperative (18)F-FDG PET/CT are independent prognostic factors for predicting RFS and OS in patients with AAC; patients with high SUVmax (>4.80) or TBR (>1.75) had poor survival outcomes. The role of and indications for adjuvant therapy after curative resection of AAC are still unclear. (18)F-FDG uptake in the primary tumor could provide additive prognostic information for the decision-making process regarding adjuvant therapy.

Comparative effectiveness of hepatic artery based therapies for unresectable intrahepatic cholangiocarcinoma

BACKGROUND

Hepatic artery based therapies (HAT) are offered for patients with unresectable intrahepatic cholangiocarcinoma (ICC). We aimed to evaluate the comparative effectiveness of HAT -hepatic arterial infusion (HAI), transcatheter arterial chemoembolization (TACE), drug-eluting bead TACE (DEB-TACE), and Yttrium(90) radioembolization (Y-90) for unresectable ICC.

METHODS

A meta-analysis was performed using a prospectively registered search strategy at PROSPERO (CRD42013004830) that utilized PubMed (2003-2013). Primary outcome was median overall survival (OS), and secondary outcomes were tumor response to therapy and toxicity.

RESULTS

A total of 20 articles (of 793, n=657 patients) were selected for data extraction. Highest Median OS was observed for HAI (22.8, 95% CI 9.8-35.8) months versus Y90 (13.9, 9.5-18.3) months versus TACE (12.4, 10.9-13.9) months versus DEB-TACE (12.3, 11-13.5) months. Response to therapy (complete and partial) was highest for HAI (56.9%, 95%CI 41.0-72.8) versus Y90 (27.4%, 17.4-37.5) versus TACE (17.3%, 6.8-27.8). The grade III/IV toxicity (Events per patient) was highest for HAI (0.35, 95% CI 0.22-0.48) versus TACE (0.26, 0.21-0.32) versus DEB-TACE (0.32, 0.17-0.48).

CONCLUSION

For patients with unresectable ICC treated with HAT, HAI offered the best outcomes in terms of tumor response and survival but may be limited by toxicity.

Change in total lesion glycolysis and clinical outcome after (90)Y radioembolization in intrahepatic cholangiocarcinoma

INTRODUCTION

Our aim was to assess the prognostic value of post-treatment decrease in total lesion glycolysis (ΔTLG) assessed by 2-[(18)F]-fluorodeoxyglucose ([(18)F] FDG) PET-CT performed 6weeks after (90)Y radioembolization ((90)Y RE) in patients affected by intrahepatic cholangiocarcinoma (ICC).

METHODS

A total of 18 patients were accepted into our department for (90)Y RE. Before the procedure, all patients underwent [(18)F] FDG PET-CT, and total lesion glycolysis was calculated. Six weeks after (90)Y administration, PET scan was performed, and ΔTLG was determined. Patients underwent follow up by imaging and laboratory at quarterly intervals until death or for at least 24 months from (90)Y RE. Furthermore, subjects were divided in 2 groups (group 1: 6 weeks ΔTLG>50%, group 2: ΔTLG<50%). Kaplan-Meier method was used to achieve time to progression (TTP) and overall survival (OS) curves for each group. TTP and OS curves were compared to demonstrate eventual relevant differences between the 2 groups.

RESULTS

Seventeen patients underwent (90)Y RE, and one subject was considered ineligible. According to PET Response Criteria in Solid Tumors, partial response was found in 14 patients (82.4%), stable disease in 3 (17.6%). No patient showed complete metabolic response. The mean OS for all patients was 64.5±5.0 weeks. Subjects with a ΔTLG>50% and ΔTLG<50% had a mean OS of 79.6±3.6 and 43.1±2.0 weeks, respectively (p<0.001). TTP resulted of 28.9±3.8 weeks for the whole cohort. Patients with ΔTLG>50% had a significantly longer TTP (mean 36.9±3.6 weeks) than those with ΔTLG<50% (mean 13.7±1.7 weeks, p=0.001).

CONCLUSION

Our results indicate that (90)Y RE can be an effective and safe therapy for ICC. ΔTLG calculated on post-treatment [(18)F] FDG PET-CT agrees with patients' final outcome.

Review to better understand the macroscopic subtypes and histogenesis of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma is macroscopically classified into three subtypes, mass-forming-type, periductal infiltrating-type, and intraductal growth-type. Each subtype should be preoperatively differentiated to perform the valid surgical resection. Recent researches have revealed the clinical, radiologic, pathobiological characteristics of each subtype. We reviewed recently published studies covering various aspects of intrahepatic cholangiocarcinoma (ICC), focusing especially on the macroscopic subtypes and stem cell features to better understand the pathophysiology of ICC and to establish the valid therapeutic strategy.

[18F]Fluorodeoxyglucose PET/Computed Tomography in Gastrointestinal Malignancies

This article discusses the current state-of-the-art application of 2-deoxy-2-[(18)F]fluoro-d-glucose (FDG)-PET and FDG-PET/computed tomography (CT) in the management of patients with gastrointestinal malignancies. Gastrointestinal malignancies include many different cell types, several common malignancies of which may be imaged by FDG-PET/CT. This review focuses on gastric carcinoma, pancreatic carcinoma, hepatocellular carcinoma, cholangiocarcinoma, colorectal carcinoma, and stroma cell tumors. The role of FDG-PET/CT in staging these malignancies is discussed, in addition to (re)staging, detection of recurrent disease, patient selection/prognostication, and response assessment, using the currently available literature.

Imaging tumor response following liver-directed intra-arterial therapy

Liver-directed intra-arterial therapies are palliative treatment options for patients with unresectable liver cancer; their use has also resulted in patients being downstaged leading to curative resection and transplantation. These intra-arterial therapies include transarterial embolization, conventional transarterial chemoembolization (TACE), drug-eluting bead TACE and radioembolization. Assessment of imaging response following these liver-directed intra-arterial therapies is challenging but pivotal for patient management. Size measurements based on computed tomography or magnetic resonance imaging (MRI) have been traditionally used to assess tumor response to therapy. However, these anatomic changes lag behind functional changes and may require months to occur. Further, these intra-arterial therapies cause acute tumor necrosis, which may result in a paradoxical increase in tumor size on early follow-up imaging despite complete cell death or necrosis. This concept is unique comparing to changes seen following systemic chemotherapy. The recent development of functional imaging techniques including diffusion-weighted MRI (DW MRI) and positron emission tomography (PET) allow for early assessment of treatment response and even prediction of overall tumor response to intra-arterial therapies. Although the results of DW MRI and PET studies are promising, the impact of these imaging modalities to assess treatment response has been limited without standardized protocols. The aim of this review article is to delineate the best practice for assessing tumor response in patients with primary or secondary hepatic malignancies undergoing intra-arterial therapies.