Radioembolization with yttrium-90 resin microspheres for neuroendocrine tumor liver metastases

Abstract

RESULTSThe mean follow-up was 23.0±19.4 months and the median overall survival was 39 months (95% CI, 12.6-65.4 months), with one-and two-year survival rates of 71% and 45%, respectively. Imaging follow-up using RECIST at three-month intervals demonstrated partial response in 43%, complete remission in 3%, stable disease in 37%, and progressive disease in 17% of patients. Extent of tumor involvement was found to have a statistically significant influence on overall survival (P = 0.03). The existence of extrahepatic disease at the time of radioembolization, radiographic response, age, and primary neuroendocrine tumor site were not significant prognostic factors. CONCLUSIONThe current study demonstrates the effectiveness and safety of radioembolization for the treatment of unresectable NETLMs. We identified that the extent of tumor involvement has a significant effect on overall survival. The use of imaging methods reflecting metabolic activity or cellularity such as scintigraphy or diffusion-weighted MRI would be more appropriate, for the response evaluation of liver metastases after radioembolization. N euroendocrine tumors (NETs) are a heterogenous group of slow-growing and hormon-releasing malignant tumors. Even though primary NETs originate from a number of locations, 40%-70% of all carcinoids arise in the small intestine and appendix (1, 2). The most common site for metastasis is the liver. Neuroendocrine tumor liver metastasis (NETLM) results in hormone-secretion-related symptoms leading to carcinoid syndrome, pressure on structures, or liver replacement (1-4). Patients with liver metastasis have a five-year survival rate of less than 20% (5). Over the years, improvements in local treatments yielded better control of the symptoms and survival rates, yet only 10% of the patients have limited illness and are eligible for surgery (6). Patient symptomatology and survival can be improved by transarterial treatments like embolization and chemoembolization (6). Limitations of these techniques include the short duration of the effects and the controversial approaches regarding the optimal timing and sequence of the procedures due to the variability of tumor progression (7,8). Long-term survival benefit was not achieved with systemic chemotherapy (9-11) and treatment with somatostatin analogues is mostly associated with symptomatic relief; there is no clear knowledge of their effect on survival of patients who have carcinoid tumor and metastasis (12).Selective internal radiation therapy (SIRT) has been used to treat unresectable primary and secondary liver cancers for over a decade.

Single‐institution experience of radioembolization with yttrium‐90 microspheres for unresectable metastatic neuroendocrine liver tumors

“…Of note, all patients in this group had a variety of treatments before 90 Y treatment, including somatostatin analogs, surgical lobectomy, chemotherapy, TAE/TACE, RFA, molecularly targeted drugs, and external irradiation. Some reported disease control rates of different treatments for unresectable liver metastases of NET range from 40.7% to 53% for chemotherapy, from 50% to 100% for TAE/TACE, and from 64.7% to 96.4% for 90 Y therapy . TAE/TACE and 90 Y treatments have a similar disease control rate, both of which were better than that of chemotherapy.…”

“…Many factors were reported to relate the overall survival in patients who had metastatic liver NET, including ECOG performance score, bilirubin, hepatic tumor burden, prior surgery, size of target lesions, baseline chemistry values, Ki‐67 index, presence of extrahepatic disease, and ability to deliver a specified dose . To our knowledge, this study is the first to show that Child–Pugh B class and positive lymph node metastases are associated with reduced overall survival for metastatic NET to liver after radioembolization.…”

S2k-Leitlinie Neuroendokrine Tumore

“…Bei Patienten mit signifikanter extrahepatischer Metastasierung sollte die RE möglichst nicht zur Anwendung kommen, da diese methodenimmanent nur die hepatische Tumorlast behandeln kann [558]. Bei Patienten, bei denen die hepatische Tumorlast jedoch voraussichtlich die weitere Prognose bestimmt und die extrahepatische Tumorlast prognostisch nicht relevant ist ("liverdominant disease"), kann eine RE zur Anwendung kommen und sinnvoll sein [558,659]. Die Studienergebnisse hierzu sind limitiert, allerdings war beispielsweise bei Peker et al eine extrahepatische Metastasierung kein prognostisch ungünstiger Faktor [659].…”

Arterial Therapies of Non-Colorectal Liver Metastases

“…The largest series by Kennedy [ 25 ] showed a PR in 61% of the patients with low toxicities, mainly fatigue (6.5%). A recent study by Peker et al [ 26 ] demonstrated the safety and effectiveness of the treatment of unresectable liver NET, with 1- and 2-year survival rates of 71 and 45%, respectively. A recent meta-analysis by Devcic et al [ 27 ] showed an average objective response of 50% and a weighted average disease control rate of 86%.…”