Radioembolization with 90Y glass microspheres for the treatment of unresectable metastatic liver disease from chemotherapy-refractory gastrointestinal cancers: final report of a prospective pilot study

Is There a Role for Locoregional Therapies for Non-colorectal Gastrointestinal Malignancies?

The liver is the most common site of metastases from solid gastrointestinal tract tumors. Over the past few decades, the role of locoregional therapies, resection and thermal ablation, for neuroendocrine and colorectal liver metastases has been widely studied. However, for liver metastases originating from other gastrointestinal organs, the role of locoregional treatment remains unclear. This review summarizes and discusses the available evidence regarding benefits, risks, and indications for locoregional therapies for non-colorectal and non-neuroendocrine gastrointestinal liver metastases, highlighting the importance of multidisciplinary approach and patient selection.

Optimal patient selection for yttrium-90 glass plus chemotherapy in the treatment of colorectal liver metastases: additional quality of life, efficacy, and safety analyses from the EPOCH study

BACKGROUND

Evaluating transarterial radioembolization (TARE) in patients with metastatic colorectal carcinoma of the liver who have progressed on first-line chemotherapy (EPOCH) demonstrated superior outcomes using yttrium-90 glass microspheres plus chemotherapy (TARE/Chemo) vs chemotherapy (Chemo) to treat colorectal liver metastases. Additional exploratory analyses were undertaken to assess the impact of TARE/Chemo on efficacy, safety, time to subsequent therapy, time to deterioration in quality of life (QoL), and identify criteria for improved patient selection.

METHODS

Time to deterioration in QoL was analyzed for the primary study population. Subsequently, a post hoc analysis was undertaken to identify subgroups for which time to deterioration in QoL was improved with TARE/Chemo vs Chemo. Progression-free survival (PFS), hepatic (h)PFS, time to subsequent therapy, and safety outcomes were compared between treatments.

RESULTS

The primary population showed no significant difference in time to deterioration in QoL between treatment arms; however, significance was seen in 2 identified subgroups, namely: Subgroup A (N = 303) which excluded patients with both Eastern Cooperative Oncology Group (ECOG) 1 and baseline CEA ≥ 35 ng/mL from both treatment arms; subgroup B (N = 168) additionally excluded patients with KRAS (Kirsten rat sarcoma) mutation. In subgroup A, TARE/Chemo patients (N = 143) demonstrated superior outcomes vs Chemo (N = 160): PFS (9.4 vs. 7.6 months, hazard ratio (HR): 0.64; 1-sided P = .0020), hPFS (10.8 vs. 7.6 months, HR: 0.53; 1-sided P < .0001), time to deterioration in QoL (5.7 vs. 3.9 months, HR: 0.65; 1-sided P = .0063), and time to subsequent therapy (21.2 vs. 10.5 months, HR: 0.52; 1-sided P < .0001). Subgroup B patients showed similar but larger significant differences between treatment arms. Median PFS, hPFS, and time to deterioration in QoL were numerically greater for TARE/Chemo in both subgroups vs the primary population, with the greatest magnitude of difference in subgroup B. Both subgroups exhibited higher percentage of CEA responders and improved ORR with TARE/Chemo vs chemo alone. Safety (reported as event rate/100 patient-years) was higher with Chemo in all populations. Additional efficacy analyses in the primary population are also reported.

CONCLUSIONS

Careful patient selection, including consideration of the prognostic factors ECOG, baseline CEA, and KRAS status, sets outcome expectations in patients with colorectal liver metastases suitable for TARE/Chemo as second-line treatment (Trial Registry Number: NCT01483027).

Detection of Shortwave-Infrared Cerenkov Luminescence from Medical Isotopes

Medical radioisotopes produce Cerenkov luminescence (CL) from charged subatomic particles (β+/-) traveling faster than light in dielectric media (e.g., tissue). CL is a blue-weighted and continuous emission, decreasing proportionally to increasing wavelength. CL imaging (CLI) provides an economic PET alternative with the advantage of also being able to image β- and α emitters. Like any optical modality, CLI is limited by the optical properties of tissue (scattering, absorption, and ambient photon removal). Shortwave-infrared (SWIR, 900-1700 nm) CL has been detected from MeV linear accelerators but not yet from keV medical radioisotopes. Methods: Indium-gallium-arsenide sensors and SWIR lenses were mounted onto an ambient light-excluding preclinical enclosure. An exposure and processing pipeline was developed for SWIR CLI and then performed across 6 radioisotopes at in vitro and in vivo conditions. Results: SWIR CL was detected from the clinical radioisotopes 90Y, 68Ga, 18F, 89Zr, 131I, and 32P (biomedical research). SWIR CLI's advantage over visible-wavelength (VIS) CLI (400-900 nm) was shown via increased light penetration and decreased scattering at depth. The SWIR CLI radioisotope sensitivity limit (8.51 kBq/μL for 68Ga), emission spectrum, and ex vivo and in vivo examples are reported. Conclusion: This work shows that radioisotope SWIR CLI can be performed with unmodified commercially available components. SWIR CLI has significant advantages over VIS CLI, with preserved VIS CLI features such as radioisotope radiance levels and dose response linearity. Further improvements in SWIR optics and technology are required to enable widespread adoption.

Phase I prospective trial of TAS-102 (trifluridine and tipiracil) and radioembolization with 90Y resin microspheres for chemo-refractory colorectal liver metastases

BACKGROUND

Extrahepatic disease progression limits clinical efficacy of Yttrium-90 (⁹⁰Y) radioembolization (TARE) for patients with chemotherapy-refractory metastatic colorectal cancer (mCRC). Trifluridine and tipiracil (TAS-102) has overall survival benefit for patients with refractory mCRC and may be a radiosensitizer.

METHODS

Sequential lobar TARE using ⁹⁰Y resin microspheres in combination with TAS-102 in 28-day cycles were used to treat adult patients with bilobar liver-dominant chemo-refractory mCRC according to 3 + 3 dose escalation design with a 12-patient dose expansion cohort. Study objectives were to establish safety and determine maximum tolerated dose (MTD) of TAS-102 in combination with TARE.

RESULTS

A total of 21 patients (14 women, 7 men) with median age of 60 years were enrolled. No dose limiting toxicities were observed. Treatment related severe adverse events included cytopenias (10 patients, 48%) and radioembolization-induced liver disease (2 patients, 10%). Disease control rate in the liver lobes treated with TARE was 100%. Best observed radiographic responses were partial response for 4 patients (19%) and stable disease for 12 patients (57%).

CONCLUSIONS

The combination of TAS-102 and TARE for patients with liver-dominant mCRC is safe and consistently achieves disease control within the liver.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02602327 (first posted 11/11/2015).

Predictive Factors for Resistant Disease with Medical/Radiologic/Liver-Directed Anti-Tumor Treatments in Patients with Advanced Pancreatic Neuroendocrine Neoplasms: Recent Advances and Controversies

Simple Summary

Tumor resistance, both primary and acquired, is leading to increased complexity in the nonsurgical treatment of patients with advanced panNENs, which would be greatly helped by reliable prognostic/predictive factors. The importance in identifying resistance is being contributed to by the increased array of possible treatments available for treating resistant advanced disease; the variable clinical course as well as response to any given treatment approach of patients within one staging or grading system, the advances in imaging which are providing increasing promising results/parameters that correlate with grading/outcome/resistance, the increased understanding of the molecular pathogenesis providing promising prognostic markers, all of which can contribute to selecting the best treatment to overcome resistance disease. Several factors have been identified that have prognostic/predictive value for identifying development resistant disease and affecting overall survival (OS)/PFS with various nonsurgical treatments of patients with advanced panNENs. Prognostic factors identified for patients with advanced panNENs for both OS/PFSs include various clinically-related factors (clinical, laboratory/biological markers, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors. Particularly important prognostic factors for the different treatment modalities studies are the recent grading systems. Most prognostic factors for each treatment modality for OS/PFS are not specific for a given treatment option. These advances have generated several controversies and new unanswered questions, particularly those related to their possible role in predicting the possible sequence of different anti-tumor treatments in patients with different presentations. Each of these areas is reviewed in this paper.

Abstract

Purpose: Recent advances in the diagnosis, management and nonsurgical treatment of patients with advanced pancreatic neuroendocrine neoplasms (panNENs) have led to an emerging need for sensitive and useful prognostic factors for predicting responses/survival. Areas covered: The predictive value of a number of reported prognostic factors including clinically-related factors (clinical/laboratory/imaging/treatment-related factors), pathological factors (histological/classification/grading), and molecular factors, on therapeutic outcomes of anti-tumor medical therapies with molecular targeting agents (everolimus/sunitinib/somatostatin analogues), chemotherapy, radiological therapy with peptide receptor radionuclide therapy, or liver-directed therapies (embolization/chemoembolization/radio-embolization (SIRTs)) are reviewed. Recent findings in each of these areas, as well as remaining controversies and uncertainties, are discussed in detail, particularly from the viewpoint of treatment sequencing. Conclusions: The recent increase in the number of available therapeutic agents for the nonsurgical treatment of patients with advanced panNENs have raised the importance of prognostic factors predictive for therapeutic outcomes of each treatment option. The establishment of sensitive and useful prognostic markers will have a significant impact on optimal treatment selection, as well as in tailoring the therapeutic sequence, and for maximizing the survival benefit of each individual patient. In the paper, the progress in this area, as well as the controversies/uncertainties, are reviewed.

Preparation of Rhenium-188-Lipiodol Using Freeze-Dried Kits for Transarterial Radioembolization: An Overview and Experience in a Hospital Radiopharmacy

Background: Rhenium-188-lipiodol is a clinically effective, economically viable radiopharmaceutical for Selective Internal Radiation Therapy of liver cancer. Present study evaluates the performance of three freeze-dried kits with respect to the radiochemistry, quality control, and overall "ease of preparation" aspects in a hospital radiopharmacy. Materials and Methods: Freeze-dried kits of acetylated 4-hexadecyl-4,7-diaza-1,10-decanedithiol (AHDD), super six sulfur (SSS), and diethyl dithiocarbamate (DEDC), obtained commercially or received as gift, were used for the preparation of Rhenium-188-lipiodol using freshly eluted ¹⁸⁸Re-sodium perrhenate from commercial Tungsten-188/Rhenium-188 generator following recommended procedures. Results: The overall yield of Rhenium-188-lipiodol prepared using AHDD Kit, SSS Kit, and DEDC Kit was 74.82% ± 3.3%, 87.55% ± 4.8%, and 76.38% ± 4.6%, respectively. Observed radiochemical purity (RCP) of Rhenium-188-lipiodol prepared using these kits was 88.65% ± 2.8%, 92.92% ± 3.0%, and 91.38% ± 3.0%, respectively. Using a modified version of the DEDC Kits, overall yield of 87.17% ± 2.7% and RCP of 95.43% ± 2.3% could be achieved. Conclusions: While all three freeze-dried kits can be used for the preparation of Rhenium-188-lipiodol in >70% overall yield, the modified version of DEDC Kits has some advantages in terms of preparation time and volume of Rhenium-188 activity that can be added to the kit vial. The latter feature of the DEDC Kit is particularly useful for patient dose preparation with Rhenium-188 activity of low radioactive concentration.

Currently available treatment options for neuroendocrine liver metastases

Neuroendocrine neoplasms (NEN) are frequently characterized by a high propensity for metastasis to the liver, which appears to be a dominant site of distant-stage disease, affecting quality of life and overall survival. Liver surgery with the intention to cure is the treatment of choice for resectable neuroendocrine liver metastases (NELM), aiming to potentially prolong survival and ameliorate hormonal symptoms refractory to medical control. Surgical resection is indicated for patients with NELM from well-differentiated NEN, while its feasibility and complexity are largely dictated by the degree of liver involvement. As a result of advances in surgical techniques over the past decades, complex 1- and 2-stage, or repeat liver resections are performed safely and effectively by experienced surgeons. Furthermore, liver transplantation for the treatment of NELM should be anchored in a multimodal and multidisciplinary therapeutic strategy and restricted only to highly selected individual cases. A broad spectrum of interventional radiology treatments for NELM have recently been available, with expanding indications that are more applicable, as they are less limited by patient- and tumor-related parameters, being therefore important adjuncts or alternatives to surgery. Overall, liver-targeted treatment modalities may precede the administration of systemic molecular targeted agents and chemotherapy for patients with liver-dominant metastatic disease; these appear to be a crucial component of multimodal management of patients with NEN. In the present review, we discuss surgical and non-surgical liver-targeted treatment approaches for NELM, each complementing the other, with a view to assisting physicians in optimizing multimodal NEN patient care.

Is There a Role for Locoregional Therapies for Non-colorectal Gastrointestinal Malignancies?

The liver is the most common site of metastases from solid gastrointestinal tract tumors. Over the past few decades, the role of locoregional therapies, resection and thermal ablation, for neuroendocrine and colorectal liver metastases has been widely studied. However, for liver metastases originating from other gastrointestinal organs, the role of locoregional treatment remains unclear. This review summarizes and discusses the available evidence regarding benefits, risks, and indications for locoregional therapies for non-colorectal and non-neuroendocrine gastrointestinal liver metastases, highlighting the importance of multidisciplinary approach and patient selection.

Association between objective response rate and overall survival in metastatic neuroendocrine tumors treated with radioembolization: a systematic literature review and regression analysis

OBJECTIVES

Neuroendocrine tumors (NETs) are a heterogeneous group of cancers arising from neuroendocrine cells. The aim was to evaluate objective response rate (ORR) as a predictor of overall survival (OS) in patients with metastatic NETs (mNETs) treated with radioembolization (RE).

METHODS

Randomized controlled trials and observational studies of RE treatment of mNETs were identified by systematic literature review (SLR). Pooled ORR and OS estimates were calculated and a weighted generalized linear model (GLM) of ORR as a predictor of OS was derived, stratified by ORR assessment criteria and RE type (Yttrium-90 resin or glass microspheres).

RESULTS

The SLR identified 32 observational studies. Mean ORR was 41% (95% confidence interval 38-45%). The Yttrium-90 resin and glass microsphere GLMs accounted for 59% and 57% of OS deviance, respectively. ORR was a significant predictor of OS in the resin microspheres model (p < 0.001), but not the glass microspheres model (p = 0.11).

CONCLUSIONS

A weighted GLM showed a significant relationship between ORR and OS in patients with mNETs treated with Yttrium-90 resin microspheres. ORR could therefore potentially be an OS surrogate in future trials of Yttrium-90 resin microspheres. Further research is needed to confirm the relationship between ORR and OS and the difference between resin and glass microspheres.

Transarterial Radioembolization for Hepatocellular Carcinoma and Hepatic Metastases: Clinical Aspects and Dosimetry Models

Transarterial radioembolization (TARE) with Yttrium-90 (⁹⁰Y) microspheres is a liver-directed therapy for primary and metastatic disease. This manuscript provides a review of the clinical literature on TARE indications and efficacy with overviews of patient-selection and toxicity. Current dosimetry models used in practice are safe, relatively simple, and easy for clinicians to use. Planning currently relies on the imperfect surrogate, ^99mTc macroaggregated albumin. Post-therapy quantitative imaging (⁹⁰Y SPECT/CT or ⁹⁰Y PET/CT) of microspheres can be used to calculate the macroscopic in vivo absorbed dose distribution. Similar to the evolution of other brachytherapy dose calculations, TARE is moving toward more patient-specific dosimetry that includes calculating and reporting nonuniform dose distributions throughout tumors and normal uninvolved liver.

Interventional Liver-Directed Therapy for Neuroendocrine Metastases: Current Status and Future Directions

OPINION STATEMENT

Liver-directed therapy should be considered for patients with unresectable liver metastases from neuroendocrine tumor if symptomatic or progressing despite medical management. Our experience and current literature shows that the bland embolization, chemoembolization, and radioembolization are very effective in controlling symptoms and disease burden in the liver, and that these embolization modalities are similar in terms of efficacy and radiologic response. Their safety profiles differ, however, with recent studies suggesting an increase in biliary toxicity with drug-eluting bead chemoembolization over conventional chemoembolization, and a risk of long-term hepatotoxicity with radioembolization. For this reason, we tailor the type of embolotherapy to each patient according to their clinical status, symptoms, degree of tumor burden, histologic grade, and life expectancy. We do not recommend a "one-size-fits-all" approach. Our general strategy is to use bland embolization as first-line embolotherapy, and radioembolization for patients with high-grade tumors or who have failed other embolotherapy.

Prognostic and predictive factors on overall survival and surgical outcomes in pancreatic neuroendocrine tumors: recent advances and controversies

Introduction: Recent advances in diagnostic modalities and therapeutic agents have raised the importance of prognostic factors in predicting overall survival, as well as predictive factors for surgical outcomes, in tailoring therapeutic strategies of patients with pancreatic neuroendocrine neoplasms (panNENs).Areas covered: Numerous recent studies of panNEN patients report the prognostic values of a number of clinically related factors (clinical, laboratory, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors on long-term survival. In addition, an increasing number of studies showed the usefulness of various factors, specifically biomarkers and molecular makers, in predicting recurrence and mortality related to surgical treatment. Recent findings (from the last 3 years) in each of these areas, as well as recent controversies, are reviewed.Expert commentary: The clinical importance of prognostic and predictive factors for panNENs is markedly increased for both overall outcome and post resection, as a result of recent advances in all aspects of the diagnosis, management and treatment of panNENs. Despite the proven prognostic utility of routinely used tumor grading/classification and staging systems, further studies are required to establish these novel prognostic factors to support their routine clinical use.

Non-Pharmacological Therapeutic Options for Liver Metastases in Advanced Neuroendocrine Tumors

The incidence of liver metastasis in digestive neuroendocrine tumors is high. Their presence appears as an important prognostic factor in terms of quality of life and survival. These tumors may be symptomatic because of the tumor burden itself and/or the hormonal hyper-secretion induced by the tumor. Surgery is the treatment of choice for resectable tumors and metastasis. Nevertheless, surgery is only possible in a small number of cases. The management of non-resectable liver metastasis is a challenge. The literature is rich but consists predominantly in small retrospective series with a low level of proof. Thus, the choice of one technique over another could be difficult. Local ablative techniques (radiofrequency) or trans-catheter intra-arterial liver-directed treatments (hepatic artery embolization, chemo-embolization, and radio-embolization) are frequently considered for liver metastasis. In the present review, we focus on these different therapeutic approaches in advanced neuroendocrine tumors, results (clinical and radiological), and overall efficacy, and summarize recommendations to help physicians in their clinical practice.

Radioembolisation with 90Y microspheres for neuroendocrine liver metastases: an institutional case series, systematic review and meta-analysis

BACKGROUND

Neuroendocrine liver metastases are clinically challenging due to their frequent disseminated distribution. This study aims to present a British experience with an emerging modality, radioembolisation with yttrium-90 labelled microspheres, and embed this within a meta-analysis of response and survival outcomes.

METHODS

A retrospective case series of patients treated with SIR-Spheres (radiolabelled resin microspheres) was performed. Results were included in a systematic review and meta-analysis of published results with glass or resin microspheres. Objective response rate (ORR) was defined as complete or partial response. Disease control rate (DCR) was defined as complete/partial response or stable disease.

RESULTS

Twenty-four patients were identified. ORR and DCR in the institutional series was 14/24 and 21/24 at 3 months. Overall survival and progression-free survival at 3-years was 77.6% and 50.4%, respectively. There were no grade 3/4 toxicities post-procedure. A fixed-effects pooled estimate of ORR of 51% (95% CI: 47%-54%) was identified from meta-analysis of 27 studies. The fixed-effects weighted average DCR was 88% (95% CI: 85%-90%, 27 studies).

CONCLUSION

Current data demonstrate evidence of the clinical effectiveness and safety of radioembolisation for neuroendocrine liver metastases. Prospective randomised studies to compare radioembolisation with other liver directed treatment modalities are needed.

Radioembolization Versus Bland Embolization for Hepatic Metastases from Small Intestinal Neuroendocrine Tumors: Short-Term Results of a Randomized Clinical Trial

Background

Radioembolization (RE) with intra-arterial administration of ⁹⁰Y microspheres is a promising technique for the treatment of liver metastases from small intestinal neuroendocrine tumors (SI-NET) not amenable to surgery or local ablation. However, studies comparing RE to other loco-regional therapies are lacking. The aim of this randomized study was to compare the therapeutic response and safety after RE and bland hepatic arterial embolization (HAE), and to investigate early therapy-induced changes with diffusion-weighted MRI (DWI-MRI).

Methods

Eleven patients were included in a prospective randomized controlled pilot study, six assigned to RE and five to HAE. Response according to RECIST 1.1 using MRI or CT at 3 and 6 months post-treatment was recorded as well as changes in DWI-MRI parameters after 1 month. Data on biochemical tumor response, toxicity, and side effects were also collected.

Results

Three months after treatment, all patients in the HAE group showed partial response according to RECIST while none in the RE group did (p = 0.0022). After 6 months, the response rates were 4/5 (80%) and 2/6 (33%) in the HAE and RE groups, respectively (NS). DWI-MRI metrics could not predict RECIST response, but lower pretreatment ADC_(120–800) and larger ADC_(0–800) increase at 1 month were related to larger decrease in tumor diameter when all tumors were counted.

Conclusion

HAE resulted in significantly higher RECIST response after 3 months, but no difference compared to RE remained after 6 months. These preliminary findings indicate that HAE remains a safe option for the treatment of liver metastases from SI-NET, and further studies are needed to establish the role of RE and the predictive value of MR-DWI.

Electronic supplementary material

The online version of this article (10.1007/s00268-017-4324-9) contains supplementary material, which is available to authorized users.

Everolimus in the treatment of neuroendocrine tumors: efficacy, side-effects, resistance, and factors affecting its place in the treatment sequence

INTRODUCTION

Since the initial approval of everolimus in 2011, there have been a number of important changes in therapeutic/diagnostic modalities as well as classification/staging systems of neuroendocrine tumors (NETs), which can significantly impact the use of everolimus in patients with advanced NETs. Areas covered: The efficacy of everolimus monotherapy and combination therapy demonstrated in clinical studies involving patients with advanced NETs are reviewed. Several factors affecting everolimus use are described including: the development and routine use of NET classification/staging systems; widespread use of molecular imaging modalities; side effects; drug resistance; and the availability of other treatment options. Furthermore, the current position of everolimus in the treatment approach is discussed, taking into account the recommendations from the recent guidelines. Expert opinion: Although everolimus demonstrated its high efficacy and tolerability in the RADIANT trials and other clinical studies, there still remain a number of controversies related to everolimus treatment in the management of NETs. The synergistic anti-growth effect of other agents in combination with everolimus or its effect on overall survival have not been established. The appropriate order of the use of everolimus in the treatment of advanced NETs still remains unclear, which needs to be defined in further studies and will be addressed in the new guidelines.

Improved freeze-dried kit for the preparation of 188ReN-DEDC/lipiodol for the therapy of unresectable hepatocellular carcinoma

Rhenium-188-N-(DEDC)₂/lipiodol (abbreviated as ¹⁸⁸ReN-DEDC, where DEDC = monoanionic diethyldithiocarbamate) is a clinically proven radiopharmaceutical for the therapy of unresectable hepatocellular carcinoma (HCC) through trans arterial radioembolization (TARE). A two-vial freeze-dried kit for the preparation of [¹⁸⁸ReN(DEDC)₂] complex using sodium perrhenate (Na¹⁸⁸ReO₄) obtained from a commercial Tungsten-188/Rhenium-188 generator had been reported earlier. This method required addition of stipulated volume of glacial acetic acid into vial 1 by the user for efficient preparation of [¹⁸⁸ReN]²⁺ intermediate. An error in this step can result in low radiochemical yield of [¹⁸⁸ReN]²⁺ intermediate as well as sub-optimal pH of the reaction mixture for the second step, leading to poor radiochemical purity of ¹⁸⁸ReN-DEDC complex. In the present work, a solution to this problem was found by including an oxalate buffer of pH = 3 in vial 1, eliminating the need for the addition of glacial acetic acid by the user. This modification not only made the kits more user-friendly, it resulted in significant improvement in the kinetics of formation of [¹⁸⁸ReN]²⁺ intermediate, wherein > 95% radiochemical purity could be achieved within 5 min incubation at ambient temperature. Moreover, the novel route for the preparation of [¹⁸⁸ReN]²⁺ intermediate may be applied to any radiopharmaceutical based on ¹⁸⁸ReN-core.

Liver transarterial embolizations in metastatic neuroendocrine tumors

The management of patients with well-differentiated neuroendocrine tumors (NET) and non-resectable liver metastases is challenging. Liver-directed transarterial embolization (TAE), transarterial chemo-embolization (TACE) and selective internal radiation therapy (SIRT) have a place of choice among other treatment modalities. However, their utilization relies on a low level of proof, due to the lack of prospective data, the absence of comparative studies and considerable heterogeneity between local practices. TAE and TACE generally achieve average symptomatic, biological and radiological responses of 75%, 56% and 50%, with progression-free survival of 12-18 months, with acceptable tolerance. Although not clearly demonstrated, TACE may be more effective than TAE in pancreatic NET, but not in small-intestine NET. SIRT has been developed more recently and may achieve similar results, with improved tolerance, but decreased cost-effectiveness, although no prospective comparison has been published to date. There is currently no strong argument to choose between TAE, TACE and SIRT, and they have not been compared to other treatment modalities. The evaluation of their efficacy has mostly relied on criteria based on size variations, which do not take into account tumor viability and metabolism, and thus may not be relevant. These techniques may be especially effective when performed as first-line therapies, in patients with non-major liver involvement (<75%) and with hypervascular metastases. Finally, studies exploring their combination with systemic therapies are ongoing.

Liver Metastases in Pancreatic Acinar Cell Carcinoma Treated with Selective Internal Radiation Therapy with Y-90 Resin Microspheres

Background

Pancreatic acinar cell carcinoma (PACC) is a rare tumor. Surgical resection is the treatment of choice when feasible, but there are no clear recommendations for patients with advanced disease. Liver-directed therapy with Y-90 selective internal radiation therapy (SIRT) has been used to treat hepatic metastases from pancreatic tumors. We describe a case of PACC liver metastases treated with SIRT.

Case Report

59-year-old man was admitted with an infiltrative, solid lesion in pancreatic tail diagnosed as PACC. Lymph nodes in the hepatic hilum were enlarged, and many metastatic liver nodules were observed. After partial pancreatectomy, the left and right lobes of the liver were separately treated with Y-90 resin microspheres. Follow-up imaging revealed that all hepatic nodules shrank by at least 50%, and 3 nodules disappeared completely. Lipase concentration was 8407 U/L at baseline, rose to 12,705 U/L after pancreatectomy, and declined to 344 U/L after SIRT. Multiple rounds of chemotherapy in the subsequent year shrank the hepatic tumors further; disease then progressed, but a third line of chemotherapy shrank the tumors again, 16 months after SIRT treatment.

Conclusion

SIRT had a positive effect on liver metastases from PACC. In conjunction with systemic therapy, SIRT can achieve sustained disease control.