State of the art: radiolabeled microspheres treatment for liver malignancies

Cryotherapy for liver metastases

BACKGROUND

The liver is affected by two of the most common groups of malignant tumours: primary liver tumours and liver metastases from colorectal carcinoma. Liver metastases are significantly more common than primary liver cancer and long-term survival rates reported for patients after radical surgical treatment is approximately 50%. However, R0 resection (resection for cure) is not feasible in the majority of patients. Cryotherapy is performed with the use of an image-guided cryoprobe which delivers liquid nitrogen or argon gas to the tumour tissue. The subsequent process of freezing is associated with formation of ice crystals, which directly damage exposed tissue, including cancer cells.

OBJECTIVES

To assess the beneficial and harmful effects of cryotherapy compared with no intervention, other ablation methods, or systemic treatments in people with liver metastases.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid, Embase Ovid, and six other databases up to June 2018.

SELECTION CRITERIA

Randomised clinical trials assessing beneficial and harmful effects of cryotherapy and its comparators for liver metastases, irrespective of the location of the primary tumour.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We extracted information on participant characteristics, interventions, study outcomes, and data on the outcomes important for our review, as well as information on the design and methodology of the trials. Two review authors independently assessed risk of bias in each study. One review author performed data extraction and a second review author checked entries.

MAIN RESULTS

We found no randomised clinical trials comparing cryotherapy versus no intervention or versus systemic treatments; however, we identified one randomised clinical trial comparing cryotherapy with conventional surgery. The trial was conducted in Ukraine. The trial included 123 participants with solitary, or multiple unilobar or bilobar liver metastases; 63 participants received cryotherapy and 60 received conventional surgery. There were 36 women and 87 men. The primary sites for the metastases were colon and rectum (66.6%), stomach (7.3%), breast (6.5%), skin (4.9%), ovaries (4.1%), uterus (3.3%), kidney (3.3%), intestines (1.6%), pancreas (1.6%), and unknown (0.8%). The trial was not reported sufficiently enough to assess the risk of bias of the randomisation process, allocation concealment, or presence of blinding. It was also not possible to assess incomplete outcome data and selective outcome reporting bias. The certainty of evidence was low because of risk of bias and imprecision.The participants were followed for up to 10 years (minimum five months). The trial reported that the mortality at 10 years was 81% (51/63) in the cryotherapy group and 92% (55/60) in the conventional surgery group. The calculated by us relative risk (RR) with 95% Confidence Interval (CI) was: RR 0.88, 95% CI 0.77 to 1.02. We judged the evidence as low-certainty evidence. Regarding adverse events and complications, separately and in total, our calculation showed no evidence of a difference in recurrence of the malignancy in the liver: 86% (54/63) of the participants in the cryotherapy group and 95% (57/60) of the participants in the conventional surgery group developed a new malignancy (RR 0.90, 95% CI 0.80 to 1.01; low-certainty evidence). The frequency of reported complications was similar between the cryotherapy group and the conventional surgery group, except for postoperative pain. Both insignificant and pronounced pain were reported to be more common in the cryotherapy group while intense pain was reported to be more common in the conventional surgery group. However, the authors did not report whether there was any evidence of a difference. There were no intervention-related mortality or bile leakages.We identified no evidence for health-related quality of life, cancer mortality, or time to progression of liver metastases. The study reported tumour response in terms of the carcinoembryonic antigen level in 69% of participants, and reported results in the form of a graph for 30% of participants. The carcinoembryonic antigen level was lower in the cryotherapy group, and decreased to normal values faster in comparison with the control group (P < 0.05).

FUNDING

the trial did not provide information on funding.

AUTHORS' CONCLUSIONS

The evidence for the effectiveness of cryotherapy versus conventional surgery in people with liver metastases is of low certainty. We are uncertain about our estimate and cannot determine whether cryotherapy compared with conventional surgery is beneficial or harmful. We found no evidence for the benefits or harms of cryotherapy compared with no intervention, or versus systemic treatments.

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.

Perfusion CT best predicts outcome after radioembolization of liver metastases: a comparison of radionuclide and CT imaging techniques

OBJECTIVE

To determine the best predictor for the response to and survival with transarterial radioembolisation (RE) with (90)yttrium microspheres in patients with liver metastases.

METHODS

Forty consecutive patients with liver metastases undergoing RE were evaluated with multiphase CT, perfusion CT and (99m)Tc-MAA SPECT. Arterial perfusion (AP) from perfusion CT, HU values from the arterial (aHU) and portal venous phase (pvHU) CT, and (99m)Tc-MAA uptake ratio of metastases were determined. Morphologic response was evaluated after 4 months and available in 30 patients. One-year survival was calculated with Kaplan-Meier curves.

RESULTS

We found significant differences between responders and non-responders for AP (P < 0.001) and aHU (P = 0.001) of metastases, while no differences were found for pvHU (P = 0.07) and the (99m)Tc-MAA uptake ratio (P = 0.40). AP had a significantly higher specificity than aHU (P = 0.003) for determining responders to RE. Patients with an AP >20 ml/100 ml/min had a significantly (P = 0.01) higher 1-year survival, whereas an aHU value >55 HU did not discriminate survival (P = 0.12). The Cox proportional hazard model revealed AP as the only significant (P = 0.02) independent predictor of survival.

CONCLUSION

Compared to arterial and portal venous enhancement and the (99m)Tc-MAA uptake ratio of liver metastases, the AP from perfusion CT is the best predictor of morphologic response to and 1-year survival with RE.

KEY POINTS

• Perfusion CT allows for calculation of the liver arterial perfusion. • Arterial perfusion of liver metastases differs between responders and non-responders to RE. • Arterial perfusion can be used to select patients responding to RE.

Superiority of proximal embolization of the gastroduodenal artery with the Amplatzer vascular plug 4 before yttrium-90 radioembolization: a retrospective comparison with coils in 134 patients

PURPOSE

To evaluate the effectiveness of proximal embolization of the gastroduodenal artery (GDA) using the Amplatzer Vascular Plug 4 (AVP 4) compared with pushable coils to avoid hepaticoenteric collaterals of the GDA stump, which may serve as pathways for nontarget embolization.

MATERIALS AND METHODS

One hundred thirty-four patients scheduled for 90-yttrium radioembolization (Y-90 RE) using either plugs (n = 67) or standard coils (n = 67) for GDA occlusion were retrospectively analyzed. Parameters recorded were length of the perfused GDA stump, distance device to the GDA origin, perfused proximal side branches after embolization, and durability of vessel occlusion at Y-90 RE.

RESULTS

Length of the residually perfused GDA stump was 3.89 ± 2.86 mm for the AVP 4, which was significantly shorter compared with 5.78 ± 3.85 mm for coils (p = 0.005). Distance of the plug to the GDA origin was 1.41 ± 2.60 mm, which was also significantly shorter than 4.73 ± 3.44 mm for coils (p < 0.001). This resulted in significantly fewer patients with residually perfused side branches in the AVP 4 group (n = 2; 3.0%) compared with the coil group (n = 18; 26.9%; p < 0.001). At Y-90 RE, no GDA reperfusion was found after plug embolization compared with 2 cases after coil embolization (3.0%; p = 0.156). Only one patient had a radiation-induced duodenal ulcer after coil embolization, whereas no Y-90-related toxicity was identified after plug embolization.

CONCLUSION

Use of the AVP 4 for embolization of the GDA allowed an optimal proximal and more effective target vessel occlusion compared with coil embolization, which can avoid complications caused by extrahepatic gastrointestinal deposition of Y-90 microspheres by way of residually perfused proximal side branches.

Intra-arterial therapies for metastatic colorectal cancer

Intra-arterial therapies for unresectable hepatic metastases from colorectal cancer include radioembolization (RE) with yttrium-90 microspheres, transarterial chemoembolization (TACE), hepatic arterial infusion, and percutaneous hepatic perfusion using an organ isolation system. In this article, we discuss our approach toward treatment selection, followed by details of how RE and TACE are performed at our institution.

Pharmacotherapy of Zollinger-Ellison syndrome

INTRODUCTION

The role of pharmacotherapy in the management of patients with Zollinger-Ellison syndrome (ZES) is often equated with the medical management of acid hypersecretion. However, pharmacotherapy is also increasingly involved in the other management areas of these patients.

AREAS COVERED

This paper reviews the role of pharmacotherapy in all aspects of the management of patients with ZES. Newer aspects are emphasized. This includes the difficulty of diagnosing ZES in patients taking proton pump inhibitors. Also covered is the role of pharmacotherapy in controlling acid hypersecretion and other hormonal hypersecretory states these patients may develop, including hyperparathyroidism in patients with multiple endocrine neoplasia type 1 and ZES; tumor localization; and the treatment of advanced metastatic disease. The last includes chemotherapy, liver-directed therapies, biotherapy (somatostatin/interferon), peptide radio-receptor therapy and molecular-targeted therapies including the use of mTor inhibitors (everolimus) and tyrosine kinase inhibitors (sunitinib).

EXPERT OPINION

Pharmacotherapy is now involved in all aspects of the management of patients with ZES, with the result that ZES has progressed from being considered an entirely surgical disease initially to the present where medical treatment plays a major role in almost all aspects of the management of these patients.

Availability of yttrium-90 from strontium-90: a nuclear medicine perspective

Yttrium-90 (T(½) 64.1 hours, E(βmax)=2.28 MeV) is a pure β⁻ particle emitting radionuclide with well-established applications in targeted therapy. There are several advantages of ⁹⁰Y as a therapeutic radionuclide. It has a suitable physical half-life (∼64 hours) and decays to a stable daughter product ⁹⁰Zr by emission of high-energy β⁻ particles. Yttrium has a relatively simple chemistry and its suitability for forming complexes with a variety of chelating agents is well established. The ⁹⁰Sr/⁹⁰Y generator is an ideal source for the long-term continuous availability of no-carrier-added ⁹⁰Y suitable for the preparation of radiopharmaceuticals for radionuclide therapy. The parent radionuclide ⁹⁰Sr, which is a long-lived fission product, is available in large quantities from spent fuel. Several useful technologies have been developed for the preparation of ⁹⁰Sr/⁹⁰Y generators. There are several well-established radiopharmaceuticals based on monoclonal antibodies, peptides, and particulates labeled with ⁹⁰Y, that are in regular use for the treatment of some forms of primary cancers and arthritis. At present, there are no generators for the elution of ⁹⁰Y that can be set up in a hospital radiopharmacy. The radionuclide is procured from manufacturers and the radiopharmaceuticals are formulated on site. This article reviews the development of ⁹⁰Sr/⁹⁰Y generator and the development of ⁹⁰Y radiopharmaceuticals.

Therapy of metastatic pancreatic neuroendocrine tumors (pNETs): recent insights and advances

Neuroendocrine tumors (NETs) [carcinoids, pancreatic neuroendocrine tumors (pNETs)] are becoming an increasing clinical problem because not only are they increasing in frequency, but they can frequently present with advanced disease that requires diagnostic and treatment approaches different from those used in the neoplasms that most physicians are used to seeing and treating. In the past few years there have been numerous advances in all aspects of NETs including: an understanding of their unique pathogenesis; specific classification systems developed which have prognostic value; novel methods of tumor localization developed; and novel treatment approaches described. In patients with advanced metastatic disease these include the use of newer chemotherapeutic approaches, an increased understanding of the role of surgery and cytoreductive methods, the development of methods for targeted delivery of cytotoxic agents, and the development of targeted medical therapies (everolimus, sunitinib) based on an increased understanding of the disease biology. Although pNETs and gastrointestinal NETs share many features, recent studies show they differ in pathogenesis and in many aspects of diagnosis and treatment, including their responsiveness to different therapies. Because of limited space, this review will be limited to the advances made in the management and treatment of patients with advanced metastatic pNETs over the past 5 years.

The role of early ¹⁸F-FDG PET/CT in prediction of progression-free survival after ⁹⁰Y radioembolization: comparison with RECIST and tumour density criteria

PURPOSE

This study evaluated the ability of (18)F-FDG PET/CT imaging to predict early response to (90)Y-radioembolization in comparison with contrast-enhanced CT (CECT) using RECIST and lesion density (Choi) criteria. Progression-free survival (PFS) in patients with liver metastases at 2 years and decline in tumour markers were the primary end-points of the study.

METHODS

A total of 121 liver lesions were evaluated in 25 patients (14 men, 11 women) with liver-dominant metastatic colorectal cancer who underwent (18)F-FDG PET/CT and CECT before and 6-8 weeks after treatment. Changes in SUV(max), tumour density measured in terms of Hounsfield units and the sum of the longest diameters (LD) were calculated for the target liver lesions in each patient. The patient responses to treatment were categorized using EORTC PET criteria, tumour density criteria (Hounsfield units) and RECIST, and were correlated with the responses of tumour markers and 2-year PFS using Kaplan-Meier plots and the log-rank test for comparison. Multivariate proportional hazards (Cox) regression analysis was performed to assess the effect of relevant prognostic factors on PFS.

RESULTS

Using (18)F-FDG PET/CT response criteria, 15 patients had a partial response (PR) and 10 patients had stable disease (SD), while using RECIST only 2 patients had a PR and 23 had SD. Two patients had a PR, 21 SD and 2 progressive disease using tumour density criteria. The mean changes in SUV(max), sum of the LDs and tumour density after treatment were 2.9 ± 2.6, 7.3 ± 14.4 mm and 1.9 ± 13.18 HU, respectively. Patients who had a PR on (18)F-FDG PET/CT had a mean decrease of 44.5 % in SUV(max) compared to those with SD who had a decrease of only 10.3 %. The decreases in SUV(max) and sum of the LDs were significant (p < 0.0001, p < 0.05, respectively) while the decrease in tumour density was not (p > 0.1065). The responses on the (18)F-FDG PET/CT studies were highly correlated with the responses of tumour markers (p < 0.0001 for LDH, p = 0.01 for CEA and p = 0.02 for Ca19-9), while the responses on the CECT studies using both RECIST and tumour density criteria were not significantly correlated with the responses of tumour markers. The responses on (18)F-FDG PET/CT studies also significantly predicted PFS (the median PFS in those with a PR was 12.0 months and in those with SD was 5 months, p < 0.0001), while RECIST and tumour density did not significantly predict PFS. Multivariate analysis demonstrated that responses on (18)F-FDG PET/CT studies and decreases in SUV(max) of ≤ 2.0 were the strongest predictors of PFS.

CONCLUSION

Early response assessment to (90)Y-radioembolization using (18)F-FDG PET/CT is superior to RECIST and tumour density, demonstrating a correlation with tumour markers and significantly predicting PFS in patients with liver metastases. This could enable early response-adapted treatment strategies to be employed.

In vivo distribution of (131)I and (125)I dual-labeled gelatin microspheres after implantation into rabbit liver

OBJECTIVE

The purpose of this study was to explore the radionuclide distribution and metabolism of (131)I and (125)I dual-labeled gelatin microspheres ((131)I-(125)I-GMSs) implanted in rabbit liver.

METHODS

The simultaneous radiolabeling of (131)I and (125)I into GMSs was performed by a chloramine-T method to prepare biodegradable dual-labeled radionuclide microspheres. The microspheres were injected into rabbit liver. Radionuclide distribution and metabolism in vivo were examined using single photon emission computed tomography (SPECT) and by blood and urine radioactivity counting.

RESULTS

(131)I and (125)I were labeled into the biodegradable GMSs in accordance with the mixture ratio of batch feeding. After (131)I-(125)I-GMSs had been implanted in rabbit liver, small amounts of (131)I and (125)I were released into the blood along with the degradation of microspheres and excreted via the urine within 24 days. The radionuclides in the rabbit liver injection site could be detected by SPECT until day 48. The microspheres could be observed by histological methods on day 32. No signs of thyroid damage were observed throughout the entire experimental period.

CONCLUSION

(131)I-(125)I-GMS can be retained long term in the injection site. Due to the advantages of combining two radionuclides, (131)I-(125)I-GMS may be a safe and effective choice for cancer brachytherapy.

Interventional radiology and the care of the oncology patient

Interventional Radiology (IR) is occupying an increasingly prominent role in the care of patients with cancer, with involvement from initial diagnosis, right through to minimally invasive treatment of the malignancy and its complications. Adequate diagnostic samples can be obtained under image guidance by percutaneous biopsy and needle aspiration in an accurate and minimally invasive manner. IR techniques may be used to place central venous access devices with well-established safety and efficacy. Therapeutic applications of IR in the oncology patient include local tumour treatments such as transarterial chemo-embolisation and radiofrequency ablation, as well as management of complications of malignancy such as pain, organ obstruction, and venous thrombosis.

Hepatic toxicity after radioembolization of the liver using (90)Y-microspheres: sequential lobar versus whole liver approach

PURPOSE

(90)Y-radioembolization (RE) is a promising technique for delivering high doses of radiation to liver tumors but may result in compromise of liver function. To gain further perspective, we evaluated the toxicity rates of sequential lobar versus "whole liver" (90)Y-radioembolization.

METHODS

Thirty-four patients with liver malignancy in noncirrhotic livers were included; (90)Y-radioembolization was performed as either whole liver or sequential lobar treatment in 17 patients each. Standard clinical and liver specific laboratory parameters as well as MR imaging before treatment and at follow-up (6 and 12 weeks) after radioembolization were evaluated for toxicity using the Common Terminology Criteria for Adverse Events (CTCAE). Volumetry of the liver, tumor, and spleen and measurement of portal vein diameter also were performed.

RESULTS

Three months after whole liver RE, 14 liver-related grade 3/4 events were recorded versus 2 events after sequential lobar treatment (P < 0.05). Three patients treated with whole liver RE suffered from radioembolization-induced liver disease (REILD). Pathological increases in bilirubin at 3 months were observed for the whole liver group only (52.3 vs. 18.7 μmol/l, P = 0.012). Total liver volume did not change significantly in either group, but shrinkage of the initially treated hepatic lobe with compensatory hypertrophy of the subsequently treated lobe was observed in the sequential lobar group (P < 0.05). Portal vein diameter increased significantly in whole liver-treated patients only (+17% vs. +6.6%, P = 0.043).

CONCLUSIONS

Noncirrhotic patients undergoing sequential lobar radioembolization had less hepatic toxicity compared to whole liver embolization. The sequential approach should be the preferred strategy.

Effectiveness of repeat angiographic assessment in patients designated for radioembolization using yttrium-90 microspheres with initial extrahepatic accumulation of technitium-99m macroaggregated albumin: a single center's experience

PURPOSE

To evaluate the efficacy of a workflow consisting of repeat assessment in patients planned for yttrium-90 ((90)Y) radioembolization in case of nontarget visceral technetium-99m ((99m)Tc)-macroaggregated albumin (MAA) accumulation despite initial prophylactic coil embolization of nonhepatic arteries.

MATERIALS AND METHODS

In 341 patients with primary and secondary liver cancer, pretreatment hepatic angiograms, as well as single-photon emission computed tomography coregistered with magnetic resonance imaging scans, were obtained. Extrahepatic tracer deposition was identified in 33 patients (9.7%) necessitating repeat assessment. Images were reviewed to correlate the site of MAA accumulation with causative gastrointestinal vessels, and repeat angiograms served as reference standard.

RESULTS

At repeat angiography, the source of extrahepatic flow was identified and eliminated in 31 of 33 patients (93.9%). In 20 patients (60.6%), successful embolization of nontarget vessels was achieved, in 13 patients (39.4%), MAA was administered more distally. Afterward, extrahepatic MAA deposition was eliminated in 30 patients (90.9%).

CONCLUSION

The algorithm of repeat assessment in case of extrahepatic MAA accumulation has proven highly effective to eliminate extrahepatic shunting, thus decreasing the risk of postradioembolization complications due to inadvertent visceral microsphere deposition.

Automation of labelling of Lipiodol with high-activity generator-produced 188Re

This work describes optimisation of the kit formulation for labelling of Lipiodol with high-activity generator-produced rhenium-188. Radiochemical purity (RCP) was 92.52±2.3% and extraction yield was 98.56±1.2%. The synthesis has been automated with a TADDEO module (Comecer) giving a mean final yield of 52.68±9.6%, and reducing radiation burden to the radiochemist by 80%. Radiolabelled Lipiodol ((188)Re-SSS/Lipiodol) is stable for at least 7 days (RCP=91.07±0.9%).