Survival outcomes of a salvage patient population after radioembolization of hepatic metastases with yttrium-90 microspheres

Interventional radiological therapies in colorectal hepatic metastases

Colorectal malignancy is the third most common cancer and one of the prevalent causes of death globally. Around 20-25% of patients present with metastases at the time of diagnosis, and 50-60% of patients develop metastases in due course of the disease. Liver, followed by lung and lymph nodes, are the most common sites of colorectal cancer metastases. In such patients, the 5-year survival rate is approximately 19.2%. Although surgical resection is the primary mode of managing colorectal cancer metastases, only 10-25% of patients are competent for curative therapy. Hepatic insufficiency may be the aftermath of extensive surgical hepatectomy. Hence formal assessment of future liver remnant volume (FLR) is imperative prior to surgery to prevent hepatic failure. The evolution of minimally invasive interventional radiological techniques has enhanced the treatment algorithm of patients with colorectal cancer metastases. Studies have demonstrated that these techniques may address the limitations of curative resection, such as insufficient FLR, bi-lobar disease, and patients at higher risk for surgery. This review focuses on curative and palliative role through procedures including portal vein embolization, radioembolization, and ablation. Alongside, we deliberate various studies on conventional chemoembolization and chemoembolization with irinotecan-loaded drug-eluting beads. The radioembolization with Yttrium-90 microspheres has evolved as salvage therapy in surgically unresectable and chemo-resistant metastases.

An update on locoregional percutaneous treatment technologies in colorectal cancer liver metastatic disease

INTRODUCTION

Liver-dominant metastatic colorectal cancer is noted in approximately 20%-35% of the patients. Systemic chemotherapy remains the first-line treatment for mCRC, but the prognosis is poor due to liver failure. Novel minimally invasive technologies have enabled the optimization of locoregional treatment options.

AREAS COVERED

This is a comprehensive review of novel locoregional treatment technologies, both percutaneous ablation and transcatheter arterial treatments, which can be used to decrease hepatic disease progression in patients with mCRC. Trans-arterial radioembolization is the most recently developed locoregional treatment for metastatic liver disease, and robust evidence has been accumulated over the past years.

EXPERT OPINION

Image-guided techniques, endovascular and ablative, have gained wide acceptance for the treatment of liver malignancies, in selected patients with non-resectable disease. The optimization of dosimetry and microsphere technological advancement will certainly upgrade the role of liver radioembolization segmentectomy or lobectomy in the upcoming years, due to its curative intent. Also, ablative interventions provide local curative intent, offering significant and sustained local tumor control. Standardization protocols in terms of predictability and reliability using immediate treatment assessment and ablation zone software could further ameliorate clinical outcomes.

Radioembolization of Secondary Hepatic Malignancies

Cancer has become the leading cause of mortality in America, and the majority of patients eventually develop hepatic metastasis. As liver metastases are frequently unresectable, the value of liver-directed therapies, such as transarterial radioembolization (TARE), has become increasingly recognized as an integral component of patient management. Outcomes after radioembolization of hepatic malignancies vary not only by location of primary malignancy but also by tumor histopathology. This article reviews the outcomes of TARE for the treatment of metastatic colorectal cancer, metastatic breast cancer, and metastatic neuroendocrine tumors, as well as special considerations when treating metastatic disease with TARE.

Bi-Centric Independent Validation of Outcome Prediction after Radioembolization of Primary and Secondary Liver Cancer

BACKGROUND

Yttrium-90 radioembolization (RE) plays an important role in the treatment of liver malignancies. Optimal patient selection is crucial for an effective and safe treatment. In this study, we aim to validate the prognostic performance of a previously established random survival forest (RSF) with an external validation cohort from a different national center. Furthermore, we compare outcome prediction models with different established metrics.

METHODS

A previously established RSF model, trained on a consecutive cohort of 366 patients who had received RE due to primary or secondary liver tumor at a national center (center 1), was used to predict the outcome of an independent consecutive cohort of 202 patients from a different national center (center 2) and vice versa. Prognostic performance was evaluated using the concordance index (C-index) and the integrated Brier score (IBS). The prognostic importance of designated baseline parameters was measured with the minimal depth concept, and the influence on the predicted outcome was analyzed with accumulated local effects plots. RSF values were compared to conventional cox proportional hazards models in terms of C-index and IBS.

RESULTS

The established RSF model achieved a C-index of 0.67 for center 2, comparable to the results obtained for center 1, which it was trained on (0.66). The RSF model trained on center 2 achieved a C-index of 0.68 on center 2 data and 0.66 on center 1 data. CPH models showed comparable results on both cohorts, with C-index ranging from 0.68 to 0.72. IBS validation showed more differentiated results depending on which cohort was trained on and which cohort was predicted (range: 0.08 to 0.20). Baseline cholinesterase was the most important variable for survival prediction.

CONCLUSION

The previously developed predictive RSF model was successfully validated with an independent external cohort. C-index and IBS are suitable metrics to compare outcome prediction models, with IBS showing more differentiated results. The findings corroborate that survival after RE is critically determined by functional hepatic reserve and thus baseline liver function should play a key role in patient selection.

Yttrium-90 Hepatic Radioembolization for Advanced Chemorefractory Metastatic Colorectal Cancer: Survival Outcomes Based on Right- Versus Left-Sided Primary Tumor Location

BACKGROUND. Primary colon cancer location affects survival of patients with metastatic colorectal cancer (mCRC). Outcomes based on primary tumor location after salvage hepatic radioembolization with ⁹⁰Y resin microspheres are not well studied. OBJECTIVE. The objectives of this study are to assess the survival outcomes of patients with advanced chemorefractory mCRC treated with ⁹⁰Y radioembolization, as stratified by primary tumor location, and to explore potential factors that are predictive of survival. METHODS. A total of 99 patients who had progressive mCRC liver metastases while receiving systemic therapy and who were treated with ⁹⁰Y radioembolization at a single center were retrospectively analyzed. For 89 patients, tumor response on the first imaging follow-up examination (CT or MRI performed at a mean [± SD] of 1.9 ± 0.9 months after ⁹⁰Y radioembolization) was evaluated using RECIST. Overall survival (OS), OS after ⁹⁰Y radioembolization, and hepatic progression-free survival (PFS) were calculated using the Kaplan-Meier method. Outcomes and associations of outcomes with tumor response were compared between patients with left- and right-sided tumors. RESULTS. A total of 74 patients had left-sided colon cancer, and 25 patients had right-sided colon cancer. Median OS from the time of mCRC diagnosis was 37.2 months, median OS after ⁹⁰Y radioembolization was 5.8 months, and median hepatic PFS was 3.3 months. Based on RECIST, progressive disease on first imaging follow-up was observed in 38 patients (43%) after ⁹⁰Y radioembolization and was associated with shorter OS after ⁹⁰Y radioembolization compared with observation of disease control on first imaging follow-up (4.0 vs 10.5 months; p < .001). Patients with right-sided primary tumors showed decreased median OS after ⁹⁰Y radioembolization compared with patients with left-sided primary tumors (5.4 vs 6.2 months; p = .03). Right- and left-sided primary tumors showed no significant difference in RECIST tumor response, hepatic PFS, or extrahepatic disease progression (p > .05). Median survival after ⁹⁰Y radioembolization was significantly lower among patients with progressive disease than among those with disease control in the group with left-sided primary tumors (4.2 vs 13.9 months; p < .001); however, this finding was not observed in the group with right-sided primary tumors (3.3 vs 7.2 months; p = .05). CONCLUSION. Right-sided primary tumors were independently associated with decreased survival among patients with chemorefractory mCRC after ⁹⁰Y radioembolization, despite these patients having a similar RECIST tumor response, hepatic PFS, and extrahepatic disease progression compared with patients with left-sided primary tumors. CLINICAL IMPACT. Primary colon cancer location impacts outcomes after salvage ⁹⁰Y radioembolization and may help guide patient selection.

Liver Embolisation for Patients with Neuroendocrine Neoplasms: Systematic Review

BACKGROUND

Liver embolisation is one of the treatment options available for patients diagnosed with neuro-endocrine neoplasms (NEN). It is still uncertain whether the benefits of the various types of embolisation treatments truly outweigh the complications in NENs. This systematic review assesses the available data relating to liver embolisation in patients with NENs.

METHODS

Eligible studies (identified using MEDLINE-PubMed) were those reporting data on NEN patients who had undergone any type of liver embolisation. The primary end points were best radiological response and symptomatic response; secondary end-points included progression-free survival (PFS), overall survival (OS) and toxicity.

RESULTS

Of 598 studies screened, 101 were eligible: 16 were prospective (15.8%). The eligible studies included a total of 5,545 NEN patients, with a median of 39 patients per study (range 5-214). Pooled rate of partial response was 36.6% (38.9% achieved stable disease) and 55.2% of patients had a symptomatic response to therapy when pooled data were analysed. The median PFS and OS were 18.4 months (95% CI 15.5-21.2) and 40.7 months (95% CI 35.2-46.2) respectively. The most common toxicities were found to be abdominal pain (48.8%) and nausea (48.1%). Outcome did not significantly vary depending on the type of embolisation performed.

CONCLUSION

Liver embolisation provides adequate symptom relief for patients with carcinoid syndrome and is also able to reach partial response in a significant proportion of patients and a reasonable PFS. Quality of studies was limited, highlighting the need of further prospective studies to confirm the most suitable form of liver embolisation in NENs.

Shanghai international consensus on diagnosis and comprehensive treatment of colorectal liver metastases (version 2019)

The liver is the most common anatomical site for hematogenous metastases from colorectal cancer. Therefore effective treatment of liver metastases is one of the most challenging elements in the management of colorectal cancer. However, there is rare available clinical consensus or guideline only focusing on colorectal liver metastases. After six rounds of discussion by 195 clinical experts of the Shanghai International Consensus Expert Group on Colorectal Liver Metastases (SINCE) from 29 countries or regions, the Shanghai Consensus has been finally completed, based on current research and expert experience. The consensus emphasized the principle of multidisciplinary team, provided detailed diagnosis approaches, and guided precise local and systemic treatments. This Shanghai Consensus might be of great significance to standardized diagnosis and treatment of colorectal liver metastases all over the world.

Prognostic factors in patients treated with transarterial radioembolization for unresectable and chemorefractory colorectal cancer with liver metastases

Background: Transarterial radioembolization (TARE) is used to treat unresectable colorectal cancer with liver metastases (CRCLM). This study aimed to assess survival after TARE and to identify potential prognostic factors in this patient population. Methods: Patients with unresectable and chemorefractory CRCLM treated with TARE at our institution between February 2006 and September 2015 were included in the study. Survival rate, hepatic tumor response, and potential prognostic factors were analyzed. Results: In the 43 study patients, the mean follow-up was 15.0 ± 14.2 months, with a median survival of 13.0 months and 1-, 2-, 3-, 4-, and 5-year survival rates of 52.1%, 24.9%, 21.4%, 21.4%, and 7.1%, respectively. The mean activity of yttrium-90 administered was 1.55 ± 0.28 GBq for the disease-controlled group and 1.19 ± 0.27 GBq for the progressive disease group (p= 0.031). Survival was correlated with Child-Pugh class (p< 0.001), hepatic tumor response (p= 0.001), and baseline carcinoembryonic antigen (CEA) level (p= 0.013). Conclusion: Child-Pugh class B, low degree of hepatic tumor response, and normal baseline CEA levels are prognostic factors for poorer survival after TARE in patients with unresectable and chemorefractory CRCLM. Hepatic tumor response is related to radiation activity delivered to the liver.

The role of interventional oncology in the treatment of colorectal cancer liver metastases

Colorectal cancer is a leading cause of death both in Europe and worldwide. Unfortunately, 20-25% of patients with colorectal cancer already have metastases at the time of diagnosis, while 50-60% of the remainder will develop metastases later during the course of the disease. Although hepatic excision is the first-line treatment for patients with liver-limited colorectal metastases and is reported to prolong the survival of these patients, few patients are candidates. Locoregional therapy encompasses minimally invasive techniques practiced by interventional radiology. Most widely used locoregional therapies include ablative treatments (radiofrequency ablation, microwave ablation) and transcatheter intra-arterial therapies (transarterial chemoembolization, and radioembolization with yttrium-90).

The role of interventional oncology in the treatment of colorectal cancer liver metastases

Colorectal cancer is a leading cause of death both in Europe and worldwide. Unfortunately, 20-25% of patients with colorectal cancer already have metastases at the time of diagnosis, while 50-60% of the remainder will develop metastases later during the course of the disease. Although hepatic excision is the first-line treatment for patients with liver-limited colorectal metastases and is reported to prolong the survival of these patients, few patients are candidates. Locoregional therapy encompasses minimally invasive techniques practiced by interventional radiology. Most widely used locoregional therapies include ablative treatments (radiofrequency ablation, microwave ablation) and transcatheter intra-arterial therapies (transarterial chemoembolization, and radioembolization with yttrium-90).

Radioembolization as a Treatment Strategy for Metastatic Colorectal Cancer to the Liver: What Can We Learn from the SIRFLOX Trial?

OPINION STATEMENT

In the setting of liver metastases from colorectal cancer (CRC), radioembolization with yttrium-90 has been used to treat chemotherapy refractory disease with a growing interest to establish its efficacy in prospective trials combined with first- and second-line chemotherapy. SIRFLOX is an ongoing, multi-center, phase 3 randomized trial comparing first-line chemotherapy alone or in combination with yttrium-90 radioembolization in patients with CRC who have isolated liver metastases or liver-dominant metastases. Preliminary results from SIRFLOX demonstrate that radioembolization combined with first-line chemotherapy is safe and feasible. There was no significant difference in median overall progression-free survival (PFS) between the combined radioembolization-chemotherapy and chemotherapy-only arms (10.7 versus 10.2 months). Although the trial did not meet its primary endpoint of improved median PFS, there was a significant increase in the median hepatic PFS (20.5 versus 12.6 months; p = 0.02) favoring the combination arm. Thus, combining radioembolization with chemotherapy in the first-line setting may be most effective for liver-limited metastatic CRC. Since radioembolization targets liver disease, it is plausible that the trial failed to achieve an improvement in PFS given that 40 % of the SIRFLOX population had extra-hepatic disease. It is also possible that the overall median PFS may be a poor surrogate endpoint, and other endpoints like overall survival still needs to be delineated in this setting. In addition, it is crucial to document improvement or delay in time to deterioration in quality of life symptom endpoints in this population. SIRFLOX is the first of three prospective studies that assess the efficacy of adding radioembolization to first-line chemotherapy, and the combined data from these trials will provide the necessary power for an overall survival analysis. The final results of SIRFLOX will be eagerly awaited to determine if the increased hepatic PFS in preliminary data will translate to increased overall survival benefit.

Metastatic Liver Disease: Indications for Locoregional Therapy and Supporting Data

Metastatic liver disease is a major cause of cancer-related morbidity and mortality. Surgical resection is considered the only curative treatment, yet only a minority is eligible. Patients who present with unresectable disease are treated with systemic agents and/or locoregional therapies. The latter include thermal ablation and catheter-based transarterial interventions. Thermal ablation is reserved for those with limited tumor burden. It is used to downstage the disease to enable curative surgical resection, as an adjunct to surgery, or in select patients it is potentially curative. Transarterial therapies are indicated in those with more diffuse disease. The goals of care are to palliate symptoms and prolong survival. The indications and supporting data for thermal ablation and transarterial interventions are reviewed, technical and tumor factors that need to be considered prior to intervention are outlined, and finally several cases are presented.

Pretreatment tumor volume as a prognostic factor in metastatic colorectal cancer treated with selective internal radiation to the liver using yttrium-90 resin microspheres

BACKGROUND

Yttrium-90 (⁹⁰Y)-resin microspheres can prolong intrahepatic disease control and improve overall survival (OS) in patients with metastatic colorectal cancer (CRC). Prognostic factors for improved outcomes in patients undergoing selective internal radiation therapy (SIRT) have been studied, but the relationship between pre-SIRT liver tumor volume and outcomes has not well described.

METHODS

We retrospectively reviewed the records of patients with metastatic CRC who were treated at our institution with ⁹⁰Y-resin microspheres. Each patient underwent either MR or CT imaging of the liver with intravenous (IV) contrast before and within ~2-3 months after SIRT. Imaging data were transferred into our treatment planning system. Each metastatic liver lesion was contoured, and the volume of each lesion was summed to determine the total liver tumor volume at a given time point. We evaluated whether pretreatment liver tumor volume was related to OS. We also evaluated the relationship between pre-SIRT tumor volume and radiographic treatment response by either unidimensional Response Evaluation Criteria in Solid Tumors (RECIST) or three-dimensional volumetric criteria.

RESULTS

We included 60 patients with a median age of 59 years (range, 38-97 years); 60% of patients received sequential lobar treatment. The median number of chemotherapy cycles received prior to SIRT was 2. Median follow-up from first SIRT was 8.9 months. Pre- and post-SIRT tumor volumes were primarily calculated on CT (87%). The median pre-SIRT tumor volume was 77 cc (range, 4.5-2,170.4 cc). The median intervals between the first SIRT and the first, second, and third follow-up scans were 2.2, 4.4, and 7.7 months, respectively. No patient experienced a radiographic complete response. Pretreatment volume was a significant predictor for estimating the odds of a patient having stable disease or partial response using volumetric response criteria at first (P=0.016), second (P=0.023), and third (P=0.015) follow-ups. For each unit increase in log volume, a patient's odds of having a stable or partial response were 0.57, 0.63, and 0.61 times as likely at first, second, and third follow-up, respectively. OS was not significantly associated with pretreatment tumor volume.

CONCLUSIONS

Patients with metastatic CRC with larger overall pretreatment liver tumor volumes, regardless of number of individual liver lesions, are less likely to have radiographic evidence of stable disease or partial response following SIRT using volumetric response criteria. However, pretreatment volume was not significantly associated with OS, and thus SIRT should be considered for patients with larger pretreatment volumetric tumor burden.

Yttrium-90 radioembolization for the treatment of chemorefractory colorectal liver metastases: Technical results, clinical outcome and factors potentially influencing survival

BACKGROUND

The purpose of this study was to retrospectively assess the technical and clinical outcomes, overall survival and prognostic factors for prolonged survival after yttrium-90 ((90)Y) radioembolization as a salvage therapy for patients with chemorefractory liver-only or liver-dominant colorectal metastases.

MATERIAL AND METHODS

From January 2005 to January 2014, all the patients selected for (90)Y radioembolization to treat chemorefractory colorectal liver metastases were identified. Demographic, laboratory, imaging and dosimetry data were collected. Post-treatment technical and clinical outcomes were analyzed as well as overall survival; finally several factors potentially influencing survival were analyzed.

RESULTS

In total 88 patients were selected for angiographic workup; 71 patients (81%) finally underwent catheter-directed (90)Y microsphere infusion into the hepatic artery 25 days (standard deviation 13 days) after angiographic workup. Median infused activity was 1809 MBq; 30-day toxicity included: fatigue (n = 39; 55%), abdominal discomfort (n = 33; 47%), nausea (n = 5; 7%), fever (n = 14; 20%), diarrhea (n = 6; 9%), liver function abnormalities and elevated bilirubin (transient) (n = 3; 4%). Gastric ulcer was found in five patients (7%). A late complication was radioembolization-induced portal hypertension (REIPH) in three patients (4%). Median time to progression in the liver was 4.4 months. Estimated survival at six and 12 months was 65% and 30%, respectively, with a 50% estimated survival after 8.0 months in this group of chemorefractory patients. Prognostic factors for worse survival were high preprocedural bilirubin, alkaline phosphatase and tumor volume levels.

CONCLUSION

(90)Y microsphere radioembolization for chemorefractory colorectal liver metastases has an acceptable safety profile with a 50% estimated survival after 8.0 months. Pretreatment high bilirubin, alkaline phosphatase and tumor volume levels were associated with early death.

Cerenkov Luminescence Imaging for Radiation Dose Calculation of a ⁹⁰Y-Labeled Gastrin-Releasing Peptide Receptor Antagonist

(90)Y has been used to label various new therapeutic radiopharmaceuticals. However, measuring the radiation dose delivered by (90)Y is challenging because of the absence of suitable γ emissions and its low abundance of positron emissions. For the treatment of prostate cancer, radiolabeled gastrin-releasing peptide receptor (GRPr) antagonists have yielded promising results in mouse models. In this study, we evaluated whether Cerenkov luminescence imaging (CLI) could be used to determine radiation doses of a (90)Y-labeled GRPr antagonist in nude mice.

METHODS

Mice bearing subcutaneous prostate cancer xenografts were injected with 0.74-18.5 MBq of the (90)Y-labeled GRPr antagonist DOTA-AR and underwent in vivo and ex vivo CLI at 1-48 h after injection. After imaging, animals were sacrificed, their tumors and organs were harvested, and the activity concentration was measured by liquid scintillation counting. In a second set of experiments, Cerenkov photon counts for tumor and kidney on in vivo CLI were converted to activity concentrations using conversion factors determined from the first set of experiments.

RESULTS

(90)Y-DOTA-AR concentration in the 3 tumor models ranged from 0.5% to 4.8% of the injected activity per gram at 1 h after injection and decreased to 0.05%-0.15 injected activity per gram by 48 h after injection. A positive correlation was found between tumor activity concentrations and in vivo CLI signal (r(2) = 0.94). A similar correlation was found for the renal activity concentration and in vivo Cerenkov luminescence (r(2) = 0.98). Other organs were not distinctly visualized on the in vivo images, but ex vivo CLI was also correlated with the radioactivity concentration (r(2) = 0.35-0.94). Using the time-activity curves from the second experiment, we calculated radiation doses to tumor and kidney of 0.33 ± 0.12 (range, 0.21-0.66) and 0.06 ± 0.01 (range, 0.05-0.08) Gy/MBq, respectively.

CONCLUSION

CLI is a promising, low-cost modality to measure individual radiation doses of (90)Y-labeled compounds noninvasively. The use of Cerenkov imaging is expected to facilitate the development and comparison of (90)Y-labeled compounds for targeted radiotherapy.

SIR-Spheres yttrium-90 radioembolization for the treatment of unresectable liver cancers

Transarterial radioembolization with yttrium-90 resin microspheres (SIR-Spheres; Sirtex Medical Limited, Sydney, Australia) is a liver-directed therapy that is gaining recognition as a treatment option for liver-dominant primary and metastatic cancers. The incidence of complications is low and can be further reduced by patient selection and rigorous pretreatment assessment. Ideal candidates for radioembolization have preserved liver function without ascites or encephalopathy, Child-Pugh score <7 and limited lung shunting. Phase III randomized controlled trials (RCTs) against other liver-directed therapies are lacking for intermediate-stage hepatocellular carcinoma. However, preliminary data from a recent RCT has suggested that radioembolization has a similar time-to-progression and comparable toxicity to selective chemoembolization. Phase II/III RCTs are now ongoing to evaluate the combination of radioembolization with systemic therapies in advanced-stage hepatocellular carcinoma and metastatic liver-dominant colorectal cancer in order to expand the treatment opportunities for patients with cancers in the liver.

Yttrium-90 radioembolization of hepatic metastases from colorectal cancer

Liver metastases from colorectal cancer (CRC) result in substantial morbidity and mortality. The primary treatment is systemic chemotherapy, and in selected patients, surgical resection; however, for patients who are not surgical candidates and/or fail systemic chemotherapy, liver-directed therapies are increasingly being utilized. Yttrium-90 (Y-90) microsphere therapy, also known as selective internal radiation therapy (SIRT) or radioembolization, has proven to be effective in terms of extending time to progression of disease and also providing survival benefit. This review focuses on the use of Y-90 microsphere therapy in the treatment of liver metastases from CRC, including a comprehensive review of published clinical trials and prospective studies conducted thus far. We review the methodology, outcomes, and side effects of Y-90 microsphere therapy for metastatic CRC.

Twelve-year experience of radioembolization for colorectal hepatic metastases in 214 patients: survival by era and chemotherapy

PURPOSE

The aim of this study was to analyze the safety, treatment characteristics and survival outcomes of Yttrium-90 (Y90) radioembolization for unresectable colorectal carcinoma (CRC) liver metastases refractory to standard of care therapy.

METHODS

A total of 214 patients with CRC metastases were treated with Y90 radioembolization over 12 years. Toxicity was assessed using National Cancer Institute common terminology criteria. Overall survival was analyzed from date of diagnosis of primary cancer, hepatic metastases and from the first Y90. Uni/multivariate analyses were performed. Substratification by era of chemotherapeutics was performed.

RESULTS

Most patients were male (60 %) and <65 years old (61 %). Of them, 98 % had been exposed to chemotherapy. Grade 3 lymphocyte, bilirubin, albumin, ALP and AST toxicities were observed in 39 %, 11 %, 10 %, 8 % and 4 % of patients, respectively. Grade 4 lymphocyte and ALP toxicities were observed in 5 % and 3 % of patients, respectively. Median overall survival was 43.0, 34.6, and 10.6 months from date of diagnosis of primary cancer, hepatic metastases and first Y90, respectively. Survival was significantly longer in patients: (1) who received ≤2 cytotoxic drugs (n = 104) than those who received 3 (n = 110) (15.2 vs. 7.5 months, p = 0.0001); and (2) who received no biologic agents (n = 52) compared with those that did (n = 162) (18.6 vs. 9.4 months, p = 0.0001). Multivariate analyses identified ≤2 cytotoxic agents, no exposure to biologics, ECOG 0, tumor burden <25 %, lack of extrahepatic disease and albumin >3 g/dL as independent predictors of survival.

CONCLUSION

In this largest metastatic CRC series published to date, Y90 radioembolization was found to be safe; survival varied by prior therapy. Further studies are required to further refine the role of Y90 in metastatic CRC.

Early arterial stasis during resin-based yttrium-90 radioembolization: incidence and preliminary outcomes

OBJECTIVES

This study was conducted to determine the incidence of early stasis in radioembolization using resin yttrium-90 (Y-90) microspheres, to evaluate potential contributing factors, and to review initial imaging outcomes.

METHODS

Patients in whom early stasis occurred were compared with those in whom complete delivery was achieved for tumour type and vascularity, tumour : normal liver ratio (T : N ratio) at technetium-99m-macroaggregated albumin (Tc-99m-MAA) angiography, previous intra-arterial therapy, and infusion site (left, right or whole liver). Tumour response was evaluated at 3 months and defined according to whether a partial response and stable disease versus progressive disease were demonstrated.

RESULTS

A total of 71 patients underwent 128 Y-90 infusions in which 26 (20.3%) stasis events occurred. Hypervascular and hypovascular tumours had similar rates of stasis (17.4% versus 27.8%; P = NS). The mean ± standard deviation T : N ratio was 3.03 ± 1.54 and 3.66 ± 2.79 in patients with and without stasis, respectively (P = NS). Stasis occurred in 14 of 81 (17.3%) and 12 of 47 (25.5%) infusions following previous intra-arterial therapy and in therapy-naïve territories, respectively (P = NS). Early stasis occurred in 15 of 41 (36.6%) left, 10 of 65 (15.4%) right and one of 22 (4.5%) whole liver infusions (P < 0.001). Rates of partial response and stable disease were similar in the stasis (88.3%) and non-stasis (76.0%) groups (P = NS).

CONCLUSIONS

Early stasis occurred in approximately 20% of infusions with similar incidences in hyper- and hypovascular tumours. Whole-liver therapy reduced the incidence of stasis. Stasis did not appear to affect initial imaging outcomes.

Yttrium-90 radioembolization of liver tumors: what do the images tell us?

Transarterial radioembolization (TARE) with yttrium 90 microspheres is an increasingly popular therapy for both primary and secondary liver malignancies. TARE entails delivery of β-particle brachytherapy and embolization of the tumor vasculature. The consequent biological sequelae are distinct from those of other transarterial therapies for liver tumors, as reflected in the often baffling post-treatment imaging features. As the clinical use of TARE is increasing, more diverse post-treatment radiological findings are encountered with variable overlap among treatment response, residual disease, reactionary changes and complications. Thus, post-TARE image interpretation is challenging. This review provides a comprehensive description of the different findings seen in post-treatment scans, with the aim of facilitating appropriate radiological interpretation of post-TARE pathologic changes, notwithstanding their existing limitations.

Initial outcome after selective intraarterial radionuclide therapy with yttrium-90 microspheres as salvage therapy for unresectable metastatic liver disease

PURPOSE

The aim of the study was to retrospectively evaluate the potential benefit on survival outcomes of selective intraarterial radionuclide therapy (SIRT) with Yttrium-90 microspheres as a salvage therapy in liver metastasis of different tumors.

MATERIAL AND METHODS

Sixty-one patients who had unresectable liver metastases from colorectal carcinoma (n=23), neuroendocrine tumor (NET; n=12), cholangiocarcinoma (n=9), and others (n=17) received yttrium-90 microspheres. All patients were treated in a salvage setting with an 11-month mean follow-up. Early metabolic treatment response was evaluated by 18F-Fluorodeoxyglucose positron emission tomography (FDG PET-CT) in the sixth week after treatment.

RESULTS

Of the 61 patients, 32 were alive at the end of the study; median overall survival (OS) was 17.0 ± 2.5 months (95% confidence interval: 11.9-22.0). A subset analysis of colorectal and noncolorectal groups demonstrated median OS rates of 14.0 ± 5.8 and 17.0 ± 4.8 months, respectively (p=0.543). The mean OS for patients with NET and cholangiocarcinoma was 29.0 ± 3.1 months and 17.7 ± 3.2 months, respectively (p=0.010). According to the early metabolic treatment response, the mean OS of responder and nonresponder groups was 32.0 ± 5.6 months and 11.4 ± 2.1 months, respectively (p=0.054). Eastern Cooperative Oncology Group performance status <1 (p=0.018) and chemotherapy-naive patients (p=0.008) showed significant correlation with survival.

CONCLUSION

SIRT is an effective treatment option for patients with metastatic liver disease in a salvage setting with acceptable toxicity.

Interventional oncologic approaches to liver metastases

Metastatic liver disease is the most common cause of death in cancer patients. Complete surgical resection is currently considered the only curative treatment, with only about 25% of patients being amenable to surgery. Therefore, a variety of interventional oncologic techniques have been developed for treating secondary liver malignancies. The aim of these therapies is either to allow patients with unresectable tumors to become surgical candidates, provide curative treatment options in nonsurgical candidates, or improve survival in a palliative or even curative approach. Among these interventional therapies are transcatheter therapies such as portal vein embolization, hepatic artery infusion chemotherapy, transarterial chemoembolization, and radioembolization, as well as interstitial techniques, particularly radiofrequency ablation as the most commonly applied technique. The rationale, application and clinical results of each of these techniques are reviewed on the basis of the current literature. Future prospects such as gene therapy and immunotherapy are introduced.