Radioembolization with Yttrium-90 Microspheres for the Treatment of Liver Metastases of Pancreatic Adenocarcinoma: A Multicenter Analysis

Transarterial Radioembolization for Hepatic Metastases of Pancreatic Adenocarcinoma: A Systematic Review

PURPOSE

To assess the safety and effectiveness of transarterial radioembolization (TARE) in the treatment of hepatic metastases from pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

A systematic search of the Embase and MEDLINE databases was conducted using keywords and Medical Subject Headings terms related to TARE and hepatic metastases from PDAC. Observational studies and clinical trials reporting overall survival (OS), hepatic progression-free survival (hPFS), or tumor response after TARE were included.

RESULTS

Eight studies, comprising 145 patients with metastatic PDAC, met the inclusion criteria. No randomized controlled trials were identified, and 4 studies were prospective. Forty-four (30.3%) patients underwent previous pancreatic resection, and 66 (45.5%) had extrahepatic metastases at the time of TARE. Most studies (n = 6) used resin microspheres for TARE. The pooled disease control rate was 69.4% at a median of 3 months. The median OS from the time of TARE ranged from 3.7 to 9 months. The median hPFS ranged from 2.4 to 5.2 months. There were 31 Grade 3-4 biochemical toxicities and 4 treatment-related deaths.

CONCLUSIONS

The role of TARE in patients with hepatic metastases from PDAC remains unclear owing to low patient numbers, limited prospective data, and heterogeneity in the study design. Further prospective studies are required to evaluate the role of TARE in carefully selected patients with liver-only metastatic disease.

Ytrrium-90 transarterial radioembolization in patients with gastrointestinal malignancies

Transarterial radioembolization (TARE) with yttrium-90 (Y90) is a promising alternative strategy to treat liver tumors and liver metastasis from colorectal cancer (CRC), as it selectively delivers radioactive isotopes to the tumor via the hepatic artery, sparring surrounding liver tissue. The landscape of TARE indications is constantly evolving. This strategy is considered for patients with hepatocellular carcinoma (HCC) with liver-confined disease and preserved liver function in whom neither TACE nor systemic therapy is possible. In patients with liver metastases from CRC, TARE is advised when other chemotherapeutic options have failed. Recent phase III trials have not succeeded to prove benefit in overall survival; however, it has helped to better understand the patients that may benefit from TARE based on subgroup analysis. New strategies and treatment combinations are being investigated in ongoing clinical trials. The aim of this review is to summarize the clinical applications of TARE in patients with gastrointestinal malignancies.

A deep-learning-based prediction model for the biodistribution of 90 Y microspheres in liver radioembolization

BACKGROUND

Radioembolization with ⁹⁰ Y microspheres is a treatment approach for liver cancer. Currently, employed dosimetric calculations exhibit low accuracy, lacking consideration of individual patient, and tissue characteristics.

PURPOSE

The purpose of the present study was to employ deep learning (DL) algorithms to differentiate patterns of pretreatment distribution of ^99m Tc-macroaggregated albumin on SPECT/CT and post-treatment distribution of ⁹⁰ Y microspheres on PET/CT and to accurately predict how the ⁹⁰ Y-microspheres will be distributed in the liver tissue by radioembolization therapy.

METHODS

Data for 19 patients with liver cancer (10 with hepatocellular carcinoma, 5 with intrahepatic cholangiocarcinoma, 4 with liver metastases) who underwent radioembolization with ⁹⁰ Y microspheres were used for the DL training. We developed a 3D voxel-based variation of the Pix2Pix model, which is a special type of conditional GANs designed to perform image-to-image translation. SPECT and CT scans along with the clinical target volume for each patient were used as inputs, as were their corresponding post-treatment PET scans. The real and predicted absorbed PET doses for the tumor and the whole liver area were compared. Our model was evaluated using the leave-one-out method, and the dose calculations were measured using a tissue-specific dose voxel kernel.

RESULTS

The comparison of the real and predicted PET/CT scans showed an average absorbed dose difference of 5.42% ± 19.31% and 0.44% ± 1.64% for the tumor and the liver area, respectively. The average absorbed dose differences were 7.98 ± 31.39 Gy and 0.03 ± 0.25 Gy for the tumor and the non-tumor liver parenchyma, respectively. Our model had a general tendency to underpredict the dosimetric results; the largest differences were noticed in one case, where the model underestimated the dose to the tumor area by 56.75% or 72.82 Gy.

CONCLUSIONS

The proposed deep-learning-based pretreatment planning method for liver radioembolization accurately predicted ⁹⁰ Y microsphere biodistribution. Its combination with a rapid and accurate 3D dosimetry method will render it clinically suitable and could improve patient-specific pretreatment planning.

Minimally invasive image-guided therapy of primary and metastatic pancreatic cancer

Pancreatic cancer is a challenging malignancy with limited treatment options and poor life expectancy. The only curative option is surgical resection, but only 15%-20% of patients are resectable at presentation because more than 50% of patients has distant metastasis at diagnosis and the rest of them has locally advanced pancreatic cancer (LAPC). The standard of care first line treatment for LAPC patients is chemotherapy with or without radiation therapy. Recent developments in minimally invasive ablative techniques may add to the treatment armamentarium of LAPC. There are increasing number of studies evaluating these novel ablative techniques, including radiofrequency ablation, microwave ablation, cryoablation and irreversible electroporation. Most studies which included pancreatic tumor ablation, demonstrated improved overall survival in LAPC patients. However, the exact protocols are yet to set up to which stage of the treatment algorithm ablative techniques can be added and in what kind of treatment combinations. Patients with metastatic pancreatic cancer has dismal prognosis with 5-year survival is only 3%. The most common metastatic site is the liver as 90% of pancreatic cancer patients develop liver metastasis. Chemotherapy is the primary treatment option for patients with metastatic pancreatic cancer. However, when the tumor is not responding to chemotherapy or severe drug toxicity develops, locoregional liver-directed therapies can provide an opportunity to control intrahepatic disease progression and improve survival in selected patients. During the last decade new therapeutic options arose with the advancement of minimally invasive technologies to treat pancreatic cancer patients. These new therapies have been a topic of increasing interest due to the severe prognostic implications of locally advanced and metastatic pancreatic cancer and the low comorbid risk of these procedures. This review summarizes new ablative options for patients with LAPC and percutaneous liver-directed therapies for patients with liver-dominant metastatic disease.

Surgical and survival outcomes after robotic and open pancreaticoduodenectomy with positive margins

BACKGROUND

Though nowadays a palliative pancreaticoduodenectomy (PD) can be performed safely with relatively low mortality and acceptable morbidity rates in experienced centers, there have been no studies on the routine use of a palliative PD or on the advantages of performing surgical resection as a debulking procedure. Furthermore, the impact of resection margins on survival outcomes has been a matter of controversy. Therefore, this study aimed to clarify the role of robotic PD (RPD) in pancreatic and periampullary adenocarcinomas with positive resection margins.

METHODS

Patients undergoing RPDs and open PDs (OPDs) were included in this study. Based on the resection margins, the patients were divided into the R0, R1, and R2 PD groups. Surgical risks and survival outcomes were analyzed.

RESULTS

There were 348 PDs, including 29 (8.3%) palliative and 319 (91.7%) curative. Primary tumor origin, tumor sizes, perineural invasions, and abnormal serum carcinoembryonic antigen (CEA) levels were factors leading to palliative resection. The multivariate analysis showed that only pancreatic head adenocarcinomas and abnormal serum CEA levels (>5 ng/mL) were independent predictors. The surgical risks between curative and palliative PD were similar. There were no significant differences in the surgical risks and other surgical parameters between palliative RPDs and OPDs. For curative resection, RPDs resulted in less blood loss, greater harvested lymph nodes yield, less postoperative complications, less delayed gastric emptying, and shorter hospital stays than OPDs. The survival outcome was significantly better following R0 resection in overall periampullary adenocarcinomas, whereas a significant survival difference was shown only between the R0 and R2 resections for pancreatic head adenocarcinomas.

CONCLUSION

Compared with R0 PDs, palliative R1 PDs could benefit patients with pancreatic head adenocarcinomas when considering survival outcomes without increasing surgical risks. RPD can be considered for curative purposes and as an alternative for palliative management.

Locoregional Treatment of Metastatic Pancreatic Cancer Utilizing Resection, Ablation and Embolization: A Systematic Review

Simple Summary

Metastatic pancreatic ductal adenocarcinoma (mPDAC) has a dismal prognosis. In selected patients with limited metastatic disease, locoregional therapy, in addition to systemic chemotherapy, may improve survival. This systematic review sought to examine current evidence on the value of additional locoregional treatment, including resection, ablation and embolization, in patients with hepatic or pulmonary mPDAC. The results, although liable to substantial bias, demonstrated superior survival from metastatic diagnosis or treatment in a subset of patients after radical-intent local primary and metastatic treatment (hepatic mPDAC 7.8–19 months; pulmonary mPDAC 22.8–47 months) compared to chemotherapy or best supportive care (hepatic mPDAC 4.3–7.6 months; pulmonary mPDAC 11.8 months). However, as a consequence of the bias, definitive conclusions regarding the seemingly beneficial effect of locoregional treatment cannot be endorsed. Randomized controlled trials with strictly selected oligometastatic PDAC patients are required to deduce final recommendations on this notion.

Abstract

The prognosis of metastatic pancreatic ductal adenocarcinoma (mPDAC) remains universally poor, requiring new and innovative treatment approaches. In a subset of oligometastatic PDAC patients, locoregional therapy, in addition to systemic chemotherapy, may improve survival. The aim of this systematic review was to explore and evaluate the current evidence on locoregional treatments for mPDAC. A systematic literature search was conducted on locoregional techniques, including resection, ablation and embolization, for mPDAC with a focus on hepatic and pulmonary metastases. A total of 59 studies were identified, including 63,453 patients. Although subject to significant bias, radical-intent local therapy for both the primary and metastatic sites was associated with a superior median overall survival from metastatic diagnosis or treatment (hepatic mPDAC 7.8–19 months; pulmonary mPDAC 22.8–47 months) compared to control groups receiving chemotherapy or best supportive care (hepatic mPDAC 4.3–7.6 months; pulmonary mPDAC 11.8 months). To recruit patients that may benefit from these local treatments, selection appears essential. Most significant is the upfront possibility of local radical pancreatic and metastatic treatment. In addition, a patient’s response to neoadjuvant systemic chemotherapy, performance status, metastatic disease load and, to a lesser degree, histological differentiation grade and tumor marker CA19-9 serum levels, are powerful prognostic factors that help identify eligible subjects. Although the exact additive value of locoregional treatments for mPDAC patients cannot be distillated from the results, locoregional primary pancreatic and metastatic treatment seems beneficial for a highly selected group of oligometastatic PDAC patients. For definite recommendations, well-designed prospective randomized controlled trials with strict in- and exclusion criteria are needed to validate these results.

Clinical Evaluation of a Three-Dimensional Internal Dosimetry Technique for Liver Radioembolization with 90Y Microspheres Using Dose Voxel Kernels

Background: The purpose of this study was to develop a rapid, reliable, and efficient tool for three-dimensional (3D) dosimetry treatment planning and post-treatment evaluation of liver radioembolization with ⁹⁰Y microspheres, using tissue-specific dose voxel kernels (DVKs) that can be used in everyday clinical practice. Materials and Methods: Two tissue-specific DVKs for ⁹⁰Y were calculated through Monte Carlo (MC) simulations. DVKs for the liver and lungs were generated, and the dose distribution was compared with direct MC simulations. A method was developed to produce a 3D dose map by convolving the calculated DVKs with the activity biodistribution derived from clinical single-photon emission computed tomography (SPECT) or positron emission tomography (PET) images. Image registration for the SPECT or PET images with the corresponding computed tomography scans was performed before dosimetry calculation. The authors first compared the DVK convolution dosimetry with a direct full MC simulation on an XCAT anthropomorphic phantom. They then tested it in 25 individual clinical cases of patients who underwent ⁹⁰Y therapy. All MC simulations were carried out using the GATE MC toolkit. Results: Comparison of the measured absorbed dose using tissue-specific DVKs and direct MC simulation on 25 patients revealed a mean difference of 1.07% ± 1.43% for the liver and 1.03% ± 1.21% for the tumor tissue, respectively. The largest difference between DVK convolution and full MC dosimetry was observed for the lung tissue (10.16% ± 1.20%). The DVK statistical uncertainty was <0.75% for both media. Conclusions: This semiautomatic algorithm is capable of performing rapid, accurate, and efficient 3D dosimetry. The proposed method considers tissue and activity heterogeneity using tissue-specific DVKs. Furthermore, this method provides results in <1 min, making it suitable for everyday clinical practice.

The role of interventional radiology in the treatment of patients with pancreatic cancer

Interventional radiology (IR) provides minimally invasive therapeutic and palliative options for the treatment of pancreatic cancer depending on the stage of the disease. IR plays a critical, and also a very effective role, in both pre- and post-operative care of the patients with early stage resectable disease and also in palliative treatment of the patients with locally advanced or metastatic disease. In this article, we aimed to present the capability and the limitations of IR procedures including: local treatment options of primary and metastatic pancreatic cancer, palliation of biliary and intestinal obstructions, minimally invasive treatment of post-operative complications, and pain management.

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.

Chemorefractory liver metastasis from cervical cancer successfully treated with a combination of yttrium-90 and immunotherapy

Liver metastases in cervical cancer is rare and can be difficult-to-treat. The current guidelines established by the Gynecologic Oncology Group recommend platinum-based systemic chemotherapy in combination with an anti-angiogenic agent such as bevacizumab, however, overall survival remains poor following diagnosis and options for patients who fail chemotherapy are limited. Yttrium-90 (Y90) radioembolization (RE) has shown great promise in the treatment of chemo-refractory colorectal liver metastases. We describe a 30-year-old female with a history of stage IB endocervical adenocarcinoma who later developed metastases to the liver, that were unresponsive to multiple chemotherapeutics and chemoembolization, and was successfully treated with Y90 RE with concurrent systemic Pembrolizumab. The Y90 RE treatment resulted in positive clinical and imaging responses with improvement in her quality of life, all of which continue to persist at the time of writing this manuscript about 8-months into her RE treatment.

Surgical and local treatment of hepatic metastasis in pancreatic ductal adenocarcinoma: recent advances and future prospects

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with increasing incidence and mortality. More than half of PDAC patients develop metastases, with the liver being the most common site. Patients with pancreatic ductal adenocarcinoma with liver metastases (PCLM) have a very limited scope for surgery due to aggressive tumor behavior and poor prognosis. However, with the improvements in preoperative systemic therapy and perioperative outcomes, an increasing number of patients are being considered for surgical management. However, the best choice of surgical treatment and criteria for selecting suitable PCLM patients who may benefit from surgical treatment remains controversial. Palliative local treatments, such as ablation, locoregional chemotherapy, and brachytherapy, which are less invasive and have fewer contraindications and complications, are the preferred alternatives to surgery. The present study reviews the advances in the management of PCLM, with focus on resection and local therapies.

Transarterial Radioembolization Treatment of Pancreatic Cancer Patients with Liver-Dominant Metastatic Disease Using Yttrium-90 Glass Microspheres: A Single-Institution Retrospective Study

PURPOSE

To retrospectively evaluate the safety and efficacy of transarterial radioembolization (TARE) with yttrium-90 (⁹⁰Y)-labeled glass microspheres in pancreatic adenocarcinoma patients with liver-dominant metastatic disease.

MATERIALS AND METHODS

This retrospective, single-center study evaluated 26 patients (12 men and 14 women; mean age, 65.5 ± 11.2 years) with liver-dominant metastatic pancreatic cancer who were treated with TARE from April 2010 to September 2017. All patients received systemic chemotherapy before TARE, and 19 received systemic therapy after embolization. Nineteen patients had extrahepatic disease at the time of TARE. Response to treatment was determined by Response Evaluation Criteria in Solid Tumors at 3 months.

RESULTS

Median overall survival (OS) from pancreatic cancer diagnosis was 33.0 months (range, 8.5-87.5 months); median OS from diagnosis of liver metastasis was 21.8 months (range, 2.0-86.2 months); and median OS from TARE treatment was 7.0 months (range, 1.0-84.1 months). Grade 1-2 clinical toxicities were noted in 21 patients (80.8%), and 24 patients (92.3%) had grade 1-2 biochemical toxicities. Four patients (15.4%) had grade 3 clinical toxicities, and 6 patients (23.1%) had grade 3 biochemical toxicities. Imaging was available in 22 patients (84.6%) and demonstrated partial response in 1 patient, stable disease in 9 patients, and progressive disease in 12 patients. Improved hepatic progression-free survival was associated in patients younger than 65 years and in those whose carbohydrate antigen 19-9 level decreased or remained stable after treatment.

CONCLUSIONS

TARE with ⁹⁰Y-labeled glass microspheres is safe and led to promising OS in liver-dominant metastatic pancreatic cancer.

Ablative, Endovascular, and Biliary Interventions for Patients with Pancreatic Cancer

Interventional radiologists have multiple points of involvement in the treatment and management of patients with pancreatic adenocarcinoma. There is increasing interest in cytoreductive treatment of the primary tumor as well as metastatic disease via arterial and ablative techniques. The focus of this article is on the current evidence for pancreatic irreversible electroporation. For patients undergoing curative surgery or terminal palliation, interventional radiology can manage complications and symptoms. In this article, therapeutic and palliative options in this group of patients including postoperative embolization, biliary drainage, and stent placement are reviewed.