Hepatic yttrium-90 radioembolotherapy in metastatic colorectal cancer treated with cetuximab or bevacizumab

Interventional Treatment of Hepatic Metastases from Colorectal Cancer

Modern systemic therapies provide a significant survival benefit in metastatic colorectal cancer. Despite these advances, the durability of response remains limited and nearly all patients progress on systemic treatment. Colorectal liver metastases (CLM) develop in approximately half of patients with metastatic disease and contribute to mortality in most patients. In selected patients, surgical resection of hepatic metastases prolongs survival, indicating the benefits of the targeted treatment of CLM through alternate means. Minimally invasive interventional treatments offer the promise of treating CLM in a wider range of patients than those eligible for surgical resection. Thermal ablation and intra-arterial therapies, including chemoembolization and radioembolization, are commonly used in the treatment of CLM. Each of these treatment modalities will be discussed in detail with an emphasis on the available clinical data for each interventional treatment for CLM.

Red Flags, Pitfalls, and Cautions in Y90 Radiotherapy

Radioembolization with yttrium-90 (Y90) microspheres is increasingly used to palliate patients with liver-dominant malignancy. With appropriate patient selection, this outpatient treatment is efficacious with limited toxicity profile. This article reviews common scenarios that can present in daily practice including evaluation of liver functions, evaluation of previous therapies, integrating Y90 into ongoing systemic therapy, determining performance status, and considering retreatment for patients who have already undergone Y90 who have hepatic dominant progression. Finally, we address the importance of evaluating tumors in potential watershed zones to maximize treatment response by using c-arm computed tomography. Many of these potential variables can overlap in an individual patient. By considering these factors individually, the consulting Interventional Radiologist can present a thorough treatment plan with a full description of expected outcomes and toxicities to clinic patients.

Assessing Intra-arterial Complications of Planning and Treatment Angiograms for Y-90 Radioembolization

PURPOSE

To report hepatic arterial-related complications encountered during planning and treatment angiograms for radioembolization and understand any potential-associated risk factors.

MATERIALS AND METHODS

518 mapping or treatment angiograms for 180 patients with primary or metastatic disease to the liver treated by Yttrium-90 radioembolization between 2/2010 and 12/2015 were retrospectively reviewed. Intra-procedural complications were recorded per SIR guidelines. Patient demographics, indication for treatment, prior exposure to chemotherapeutic agents, operator experience, and disease burden were reviewed. Technical variables including type of radioembolic (glass vs. resin microspheres), indication for angiography (mapping vs. treatment), variant anatomy, and attempts at coil embolization were also assessed.

RESULTS

Thirteen (13/518, 2.5%) arterial-related complications occurred in 13 patients. All but two complications resulted during transcatheter coil embolization to prevent non-target embolization. Complications included coil migration (n = 6), arterial dissection (n = 2), focal vessel perforation (n = 2), arterial thrombus (n = 2), and vasospasm prohibiting further arterial sub-selection (n = 1). Transarterial coiling was identified as a significant risk factor of complications on both univariate and multivariate regression analysis (odds ratio 7.8, P = 0.004). Usage of resin microspheres was also a significant risk factor (odds ratio 9.5, P = 0.042). No other technical parameters or pre-procedural variables were significant after adjusting for confounding on multivariate analysis (P > 0.05).

CONCLUSION

Intra-procedural hepatic arterial complications encountered during radioembolization were infrequent but occurred mainly during coil embolization to prevent non-target delivery to extra-hepatic arteries.

Transarterial Therapy for Colorectal Liver Metastases

Until recently, hepatic arterial therapies (HAT) had been used for colorectal liver metastases after failure of first-, second-, and third-line chemotherapies. HAT has gained greater acceptance in patients with liver-dominant colorectal metastases after failure of surgery or systemic chemotherapy. The current data demonstrate that HAT is a safe and effective option for preoperative downsizing, optimizing the time to surgery, limiting non-tumor-bearing liver toxicity, and improving overall survival after surgery in patients with colorectal liver-only metastases. The aim of this review is to present the current data for HAT in liver-only and liver-dominant colorectal liver metastases.

Locoregional Therapies for Primary and Secondary Hepatic Malignancies

Management of hepatic malignancies is a multidisciplinary task with the involvement of hepatologists, medical/surgical oncologists, transplant surgeons, and interventional radiologists. The patients should be selected for a specific targeted therapy after multidisciplinary consensus. Interventional oncology has established its role in the management of hepatic malignancies. Image-guided locoregional therapies decrease the rate of systemic toxicity without compromising tumoricidal effect.

Side effects of yttrium-90 radioembolization

Limited therapeutic options are available for hepatic malignancies. Image guided targeted therapies have established their role in management of primary and secondary hepatic malignancies. Radioembolization with yttrium-90 ((90)Y) microspheres is safe and efficacious for treatment of hepatic malignancies. The tumoricidal effect of radioembolization is predominantly due to radioactivity and not ischemia. This article will present a comprehensive review of the side effects that have been associated with radioembolization using (90)Y microspheres. Some of the described side effects are associated with all transarterial procedures. Side effects specific to radioembolization will also be discussed in detail. Methods to decrease the incidence of these potential side effects will also be discussed.

A systematic review on the safety and efficacy of yttrium-90 radioembolization for unresectable, chemorefractory colorectal cancer liver metastases

INTRODUCTION

The management of unresectable, chemorefractory colorectal cancer liver metastases (CRCLM) is a clinical dilemma. Yttrium-90 (Y90) radioembolization is a potentially safe and effective treatment for patients with CRCLM who have failed conventional chemotherapy regimens.

METHODS

A systematic review of clinical studies before November 2012 was performed to examine the radiological response, overall survival and progression-free survival of patients who underwent Y90 radioembolization of unresectable CRCLM refractory to systemic therapy. The secondary objectives were to evaluate the safety profile of this treatment and identify prognostic factors for overall survival.

RESULTS

Twenty studies comprising 979 patients were examined. Patients had failed a median of 3 lines of chemotherapy (range 2-5). After treatment, the average reported value of patients with complete radiological response, partial response and stable disease was 0% (range 0-6%), 31% (range 0-73%) and 40.5% (range 17-76%), respectively. The median time to intra-hepatic progression was 9 months (range 6-16). The median overall survival was 12 months (range 8.3-36). The overall acute toxicity rate ranged from 11 to 100% (median 40.5 %). Most cases of acute toxicity were mild (Grade I or II) (median 39%; range 7-100%) which resolved without intervention. The number of previous lines of chemotherapy (≥ 3), poor radiological response to treatment, extra-hepatic disease and extensive liver disease (≥ 25%) were the factors most commonly associated with poorer overall survival.

CONCLUSION

Y90 radioembolization is a safe and effective treatment of CRCLM in the salvage setting and should be more widely utilized.

Yttrium 90 microspheres for the treatment of hepatocellular carcinoma

Yttrium-90 microspheres are radioactive particles which are increasingly being employed for treating patients with unresectable hepatocellular carcinoma (HCC). The procedure is called radioembolization. It involves the injection of micron-sized embolic particles loaded with a radioisotope by use of transarterial techniques. Because of the sensitivity of liver parenchyma and relative insensitivity of tumor, external radiation has played a limited role in treating HCC. (90)Y administered via arterial route directs the highly concentrated radiation to the tumor while healthy liver parenchyma is relatively spared due to its preferential blood supply from portal venous blood. This technique has proven useful for the majority of patients with HCC as most of them present in advanced stage, beyond potentially curative options (resection/liver transplantation). (90)Y microspheres can be used in downstaging large tumors to bring within transplantable criteria, in patients with portal venous thrombosis due to tumor invasion and as palliative therapy. There are two available devices for (90)Y administration; TheraSphere® (glass based) and SIR-Spheres® (resin based). The procedure is performed on an outpatient basis. The incidence of complications is comparatively less and may include nausea, fatigue, abdominal pain, hepatic dysfunction, biliary injury, fibrosis, radiation pneumonitis, GI ulcers, and vascular injury; however, these can be avoided by meticulous pretreatment assessment, careful patient selection, and adequate dosimetry. This article explores the technical and clinical aspects of (90)Y radioembolization with keeping emphasis on patient selection, uses, and complications.

Pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pancreatic NETs) are rare, low- to intermediate-grade neoplasms thought to arise from the pancreatic islets. Recent advances in pathology and our understanding of the biological behavior of this group of tumors has resulted in changes in their nomenclature and how we treat them. This review puts into perspective our current understanding of pancreatic NETs in terms of their incidence, pathology, and management.

Radioembolization for primary and metastatic liver cancer

The incidence of hepatocellular carcinoma is increasing. Most patients present beyond potentially curative options and are usually affected by underlying cirrhosis. In this scenario, transarterial therapies, such as radioembolization, are rapidly gaining acceptance as a potential therapy for hepatocellular carcinoma and liver metastases. Radioembolization is a catheter-based liver-directed therapy that involves the injection of micron-sized embolic particles loaded with a radioisotope by use of percutaneous transarterial techniques. Cancer cells are preferentially supplied by arterial blood and normal hepatocytes by portal venous blood; therefore, radioembolization specifically targets tumor cells with a high dose of lethal radiation and spares healthy hepatocytes. The antitumor effect mostly comes from radiation rather than embolization. The most commonly used radioisotope is yttrium-90. The commercially available devices are TheraSphere (glass based; MDS Nordion, Ottawa, Canada) and SIR-Sphere (resin based; Sirtex, Lane Cove, Australia). The procedure is performed on an outpatient basis. The incidence of complications is comparatively less than other locoregional therapies and may include nausea, fatigue, abdominal pain, hepatic dysfunction, biliary injury, fibrosis, radiation pneumonitis, gastrointestinal ulcers, and vascular injury. However, these complications can be avoided by meticulous pretreatment assessment, careful patient selection, and adequate dosimetry. This article focuses on both the technical and clinical aspects of radioembolization with emphasis on patient selection, uses and complications.

Radioembolization for hepatocellular carcinoma using TheraSphere®

BACKGROUND/AIM

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver. Radioembolization with yttrium-90 (Y90) microspheres is a new concept in radiation therapy for HCC. This review focuses on the indications, efficacy, side effects, and future direction of Y90 therapy, using TheraSphere® , in HCC patients.

RESULTS

Comprehensive literature reviews have described the clinical and scientific evidence of Y90 therapy. The Radioembolization Brachytherapy Oncology Consortium has concluded that there is sufficient evidence to support the safe and effective use of this locoregional therapy in HCC patients, including those with portal vein thrombosis.

CONCLUSIONS

There are currently no randomized clinical trials done on TheraSphere® and none of the studies so far have shown a survival benefit. Thus, although it represents a very promising therapy with excellent initial results, it cannot be fully recommended yet, till well-designed, large, randomized clinical studies are conducted showing survival benefits.

Radioembolization (yttrium-90 microspheres) for primary and metastatic hepatic malignancies

Radioembolization using radioactive yttrium-90-labeled microspheres is gaining a stronger foothold in the management of primary and metastatic hepatic cancers. The expanding literature reveals good and encouraging results in both retrospective and prospective reports as demonstrated by low acute or late toxicity and high response rates. This treatment modality, which is most beneficial in patients with good liver reserve and low Eastern Cooperative Oncology Group performance status, has led to improved time to liver progression and extended overall patient survival. Although the phase III trials of radioembolization are ongoing as a first-line treatment of patients with metastatic colorectal cancer, there are sufficient phase II and retrospective clinical data supporting its use in salvage therapy for most patients. Patients with hepatocellular cancer, neuroendocrine tumors, and other primary sites, including breast and lung, have also shown promising response and survival increases in multi-institutional experiences.

Yttrium-90 radioembolization in the management of liver malignancies

Primary and secondary liver tumors are common. Locoregional therapies are establishing a role in the management of liver tumors due to the limited roles of surgical and systemic therapies. Our review presents some general concepts associated with yttrium-90 radioembolization and its specific utilization in various primary and secondary liver malignancies.

Liver metastases from colorectal cancer: radioembolization with systemic therapy

The majority of patients with advanced colorectal cancer die from hepatic metastases caused by disease progression; therefore, several novel technologies are in clinical development to potentially improve local control of liver disease. Radioembolization is a technique for administering radiotherapy internally to unresectable primary or secondary hepatic malignancies in a single procedure. This technique involves the injection of resin or glass microspheres that contain (90)Y into the arterial supply of the liver. Clinical trials of radioembolization used with concomitant radiosensitizing chemotherapy have shown promising results in patients with metastatic colorectal cancer. Several reports suggest that radioembolization is associated with significant downsizing of liver metastases to permit subsequent surgical resection. In this article, the rationale for combining radioembolization with the cytotoxic and molecularly targeted agents licensed for the systemic treatment of colorectal cancer is outlined. Clinical data from trials of radioembolization with concomitant systemic treatment are reviewed, with an emphasis on the appropriateness of primary end points in large-scale trials and the practical aspects of surgical resection in patients whose tumors are successfully downsized by this chemoradiation approach.

Complications following radioembolization with yttrium-90 microspheres: a comprehensive literature review

The past decade has seen significant advancement in the locoregional management of liver tumors; novel and promising therapies such as transarterial chemoembolization, radioembolization, and radiofrequency ablation are now available. The development of new techniques and devices has led to the improved safety and efficacy profiles of external-beam radiation. Radioembolization with yttrium-90 ((90)Y) microspheres has emerged as a safe and efficacious treatment modality for liver malignancies. The purpose of this article is to present a comprehensive evidence-based review of the complications and adverse events that may be associated with radioembolization with (90)Y microspheres. Strategies to mitigate these adverse events are also discussed.