Liver disease induced by radioembolization of liver tumors

Biochemical Safety of Ablative Yttrium-90 Radioembolization for Hepatocellular Carcinoma as a Function of Percent Liver Treated

Purpose

Transarterial radioembolization can serve as an ablative therapy for early-stage hepatocellular carcinoma (HCC). Given the volumetric variability of liver segments, this study aimed to characterize the safety of ablative radioembolization by determining percent liver treated (%LT) thresholds associated with biochemical toxicity.

Patients and Methods

Patients with HCC receiving a single ablative radioembolization treatment using glass microspheres from 2017 through 2020 were reviewed. %LT was calculated as treatment angiosome volume divided by whole liver volume. Biochemical toxicities were defined as increases in Albumin-Bilirubin (ALBI) grade or Child-Pugh (CP) class compared to baseline and albumin or bilirubin adverse events (AEs) per the Common Terminology Criteria for Adverse Events. Receiver operating characteristic curves and multivariate logistic regression analyses were performed to assess the impact of %LT on toxicities.

Results

Of 141 patients analyzed, 53% (n=75) were ALBI 1, 45% (n=64) ALBI 2, 79% (n=111) CP-A, and 21% (n=30) CP-B. A %LT ≥14.5% was associated with grade/class increases in ALBI 2 (p≤0.01) and CP-B patients (p=0.026). In multivariate analysis, a %LT ≥14.5% was an independent predictor of increases in the ALBI 2 and CP-B groups (p<0.01). No significant %LT threshold was found for ALBI 1 and CP-A patients. No grade 3/4 albumin or bilirubin AEs were reported, while grade 2 AEs were related to an initial whole liver volume <1.3 L (p≤0.01).

Conclusion

Patients with ALBI 2 and CP-B liver function are less likely to have an increase in their respective grade/class when treating <14.5% of the liver using glass microspheres. ALBI 1 and CP-A patients showed no definitive %LT threshold for biochemical toxicity within the range of this study.

ALBI Score Is a Strong Predictor of Toxicity Following SIRT for Hepatocellular Carcinoma

Simple Summary

SIRT, also known as radioembolization, is a new treatment for hepatocellular carcinoma. However, the precise role is still not clearly determined. Here, we describe how a new score, ALBI, used to better assess liver functions, can help to select patients for this treatment. We clearly showed that the ALBI grade was associated with toxicity and survival after this treatment.

Abstract

Background: Selective internal radiation therapy (SIRT) is an innovative treatment of hepatocellular carcinoma (HCC). The albumin-bilirubin (ALBI) score was designed to better evaluate liver functions in HCC. Methods: We studied, retrospectively, data from patients treated with SIRT for HCC. The primary endpoint was the occurrence of radioembolization-induced liver disease (REILD). The secondary endpoint was overall survival (OS). Results: 222 patients were studied. The ALBI grade 1 patients had significantly less REILD (3.4%) after the first SIRT than ALBI grade 2 or 3 patients (16.8%, p = 0.002). Of the 207 patients with data, 77 (37.2%) had a worsening of ALBI grade after one SIRT. The baseline ALBI grade was significantly associated with OS (p = 0.001), also in the multivariable analysis. The ALBI grade after the first SIRT was significantly associated with OS (p ≤ 0.001), with median OS of 26.4 months (CI 95% 18.2–34.7) for ALBI grade 1 patients (n = 48) versus 17.3 months (CI 95% 12.9–21.8) for ALBI grade 2 patients (n = 123) and 8.1 months (CI 95% 4.1–12.1) for ALBI grade 3 patients (n = 36). Conclusions: The baseline ALBI grade is a strong predictor of REILD. The baseline ALBI score and variations of ALBI are prognostic after SIRT.

Selective Internal Radiation Therapy in Breast Cancer Liver Metastases: Outcome Assessment Applying a Prognostic Score

Selective internal radiation therapy (SIRT) is a therapy option in patients with breast cancer liver metastasis (BCLM). This analysis aimed at identifying a prognostic score regarding overall survival (OS) after SIRT using routine pretherapeutic parameters. Retrospective analysis of 38 patients (age, 59 (39-84) years) with BCLM and 42 SIRT procedures. Cox regression for OS included clinical factors (age, ECOG and prior treatments), laboratory parameters, hepatic tumor load and dose reduction due to hepatopulmonary shunt. Elevated baseline ALT and/or AST was present if CTCAE grade ≥ 2 was fulfilled (>3 times the upper limit of normal). Median OS after SIRT was 6.4 months. In univariable Cox, ECOG ≥ 1 (hazard ratio (HR), 3.8), presence of elevated baseline ALT/AST (HR, 3.8), prior liver surgery (HR, 10.2), and dose reduction of 40% (HR, 8.1) predicted shorter OS (each p < 0.05). Multivariable Cox confirmed ECOG ≥ 1 (HR, 2.34; p = 0.012) and elevated baseline ALT/AST (HR, 4.16; p < 0.001). Combining both factors, median OS decreased from 19.2 months (0 risk factors; n = 14 procedures) to 5.9 months (1 factor; n = 20) or 2.2 months (2 factors; n = 8; p < 0.001). The proposed score may facilitate pretherapeutic identification of patients with unfavorable OS after SIRT. This may help to balance potential life prolongation with the hazards of invasive treatment and hospitalization.

Long-Term Maintained Response to Selective Internal Radiation Therapy in an Oligometastatic Uveal Melanoma Patient Treated with Concomitant Anti-PD-1 Therapy

Uveal melanoma (UM) is a primary neoplasm of the eye arising from the melanocytes residing in the iris, ciliary body or choroid. It is the most frequent intraocular malignancy and often determines metastases at distant sites, with a peculiar tropism for the liver. Metastatic UM has a poor prognosis, as any treatment affects the natural course of this fatal disease. Herein, we report a case of a UM metastatic to the liver in a 54 year-old female patient, initially treated with nivolumab without success. The patient was then scheduled for selective internal radiation therapy (SIRT) while continuing immunotherapy. This combination led to a complete and durable response and the patient is currently free of disease, two years after the diagnosis of the hepatic metastases. The association between SIRT and immunotherapy (IT) has very promising perspectives for metastatic UM, especially considering the disappointing or contradictory results of classic chemotherapies, IT alone and targeted therapies. Furthermore, this combination has been shown to have a good security profile. However, further studies are needed to confirm the efficacy of associating SIRT and IT and to clarify some unsolved problems, such as the timing of administration of these two therapies.

Imaging side effects and complications of chemotherapy and radiation therapy: a pictorial review from head to toe

Newer biologic drugs and immunomodulatory agents, as well as more tolerated and effective radiation therapy schemes, have reduced treatment toxicity in oncology patients. However, although imaging assessment of tumor response is adapting to atypical responses like tumor flare, expected changes and complications of chemo/radiotherapy are still routinely encountered in post-treatment imaging examinations. Radiologists must be aware of old and newer therapeutic options and related side effects or complications to avoid a misinterpretation of imaging findings. Further, advancements in oncology research have increased life expectancy of patients as well as the frequency of long-term therapy-related side effects that once could not be observed. This pictorial will help radiologists tasked to detect therapy-related complications and to differentiate expected changes of normal tissues from tumor relapse.

Hepatobiliary Scintigraphy and Glass 90Y Radioembolization with Personalized Dosimetry: Dynamic Changes in Treated and Nontreated Liver

Background: The functional changes that occur over time in the liver following ⁹⁰Y-radioembolization (RE) using personalized dosimetry (PD) remain to be investigated. Methods: November 2016–October 2019: we retrospectively included hepatocellular carcinoma (HCC) patients treated by ⁹⁰Y-glass RE using PD, who underwent hepatobiliary scintigraphy (HBS) at baseline and at 15 days, 1, 2, 3, and 6 months after RE. Results: There were 16 patients with unilobar disease (100%) included, and 64 HBS were performed. Whole liver function significantly decreased over time. The loss was maximal at 2 weeks: −32% (p = 0.002) and remained below baseline at 1 (−15%; p = 0.002), 2 (−25%; p < 0.001), and 3 months (−16%; p = 0.027). No radioembolization-induced liver disease was observed. Treated liver function strongly decreased to reach −64% (p < 0.001) at 2 months. Nontreated liver function decreased at 2 weeks (−21%; p = 0.027) and remained below baseline before reaching +20% (p = 0.002) and +59% (p < 0.001) at 3 and 6 months, respectively. Volumetric and functional changes exhibited parallel evolutions in the treated livers (p = 0.01) but independent evolutions in the nontreated livers (p = 0.08). Conclusion: RE using PD induces significant regional changes in liver function over time. As early as 15 days following RE, both the treated and nontreated livers showed a decreased function. Nontreated liver function recovered after 3 months and greatly increased afterwards.

Impact of Pharmaceutical Prophylaxis on Radiation-Induced Liver Disease Following Radioembolization

Simple Summary

Radioembolization has failed to prove survival benefit in randomized trials, and, depending on various factors including tumor biology, response rates may vary considerably. Studies showed positive correlations between survival and absorbed tumor dose. Therefore, increasing currently prescribed tumor doses may be favorable for improving patient outcomes. The dominant limiting factor for increasing RE dose prescriptions is the relatively low tolerance of liver parenchyma to radiation with the possible consequence of a radiation-induced liver disease. Advances in RILD prevention may help increasing tolerable radiation doses to improve patient outcomes. Our study aimed to evaluate the impact of post-therapeutic RILD-prophylaxis in a cohort of intensely pretreated liver metastatic breast cancer patients. The results of this study as well as pathophysiological considerations warrant further investigations of RILD prophylaxis to increase dose prescriptions in radioembolization.

Abstract

Background: Radioembolization (RE) with yttrium-90 (⁹⁰Y) resin microspheres yields heterogeneous response rates in with primary or secondary liver cancer. Radiation-induced liver disease (RILD) is a potentially life-threatening complication with higher prevalence in cirrhotics or patients exposed to previous chemotherapies. Advances in RILD prevention may help increasing tolerable radiation doses to improve patient outcomes. This study aimed to evaluate the impact of post-therapeutic RILD-prophylaxis in a cohort of intensely pretreated liver metastatic breast cancer patients; Methods: Ninety-three patients with liver metastases of breast cancer received RE between 2007 and 2016. All Patients received RILD prophylaxis for 8 weeks post-RE. From January 2014, RILD prophylaxis was changed from ursodeoxycholic acid (UDCA) and prednisolone (standard prophylaxis [SP]; n = 59) to pentoxifylline (PTX), UDCA and low-dose low molecular weight heparin (LMWH) (modified prophylaxis (MP); n = 34). The primary endpoint was toxicity including symptoms of RILD; Results: Dose exposure of normal liver parenchyma was higher in the modified vs. standard prophylaxis group (47.2 Gy (17.8–86.8) vs. 40.2 Gy (12.5–83.5), p = 0.017). All grade RILD events (mild: bilirubin ≥ 21 µmol/L (but <30 μmol/L); severe: (bilirubin ≥ 30 µmol/L and ascites)) were observed more frequently in the SP group than in the MP group, albeit without significance (7/59 vs. 1/34; p = 0.140). Severe RILD occurred in the SP group only (n = 2; p > 0.1). ALBI grade increased in 16.7% patients in the MP and in 27.1% patients in the SP group, respectively (group difference not significant); Conclusions: At established dose levels, mild or severe RILD events proved rare in our cohort. RILD prophylaxis with PTX, UDCA and LMWH appears to have an independent positive impact on OS in patients with metastatic breast cancer and may reduce the frequency and severity of RILD. Results of this study as well as pathophysiological considerations warrant further investigations of RILD prophylaxis presumably targeting combinations of anticoagulation (MP) and antiinflammation (SP) to increase dose prescriptions in radioembolization.

Liver metastases

Liver metastases are commonly detected in a range of malignancies including colorectal cancer (CRC), pancreatic cancer, melanoma, lung cancer and breast cancer, although CRC is the most common primary cancer that metastasizes to the liver. Interactions between tumour cells and the tumour microenvironment play an important part in the engraftment, survival and progression of the metastases. Various cells including liver sinusoidal endothelial cells, Kupffer cells, hepatic stellate cells, parenchymal hepatocytes, dendritic cells, resident natural killer cells as well as other immune cells such as monocytes, macrophages and neutrophils are implicated in promoting and sustaining metastases in the liver. Four key phases (microvascular, pre-angiogenic, angiogenic and growth phases) have been identified in the process of liver metastasis. Imaging modalities such as ultrasonography, CT, MRI and PET scans are typically used for the diagnosis of liver metastases. Surgical resection remains the main potentially curative treatment among patients with resectable liver metastases. The role of liver transplantation in the management of liver metastasis remains controversial. Systemic therapies, newer biologic agents (for example, bevacizumab and cetuximab) and immunotherapeutic agents have revolutionized the treatment options for liver metastases. Moving forward, incorporation of genetic tests can provide more accurate information to guide clinical decision-making and predict prognosis among patients with liver metastases.

Incidence and risk factors for sustained hepatic function toxicity 6 months after radioembolization: analysis of the radiation-emitting sir-spheres in non-resectable liver tumor (RESIN) registry

Background

To quantify rates and risk factors for toxicity after hepatic radioembolization using resin yttrium-90 microspheres.

Methods

Radiation-Emitting SIR-Spheres in Non-resectable liver tumor (RESIN) registry enrollees were reviewed with 614 patients included. Mean patient age was 63.1±12.5 years. The majority of patients were male (n=375, 61%) and white (n=490, 80%). Common tumor types were hepatocellular (n=197, 32%), colorectal (n=187, 30%) and neuroendocrine (n=56, 9%). Hepatotoxicity was measured using the Common Terminology Criteria for Adverse Events (CTCAE v 5). Potential risk factors for hepatotoxicity were tested using the Kruskal-Wallis or Pearson Chi-squared tests, and multivariate linear regressions.

Results

At 6 months, 115 patients (18.7%) died (n=91, 14.8%), entered hospice (n=20, 3.3%) or sought treatment elsewhere (n=4, 4%). Seven (1.1%) deaths were from liver decompensation. Grade 3 toxicity rates were: bilirubin (n=85, 13.8%), albumin (n=28, 4.6%), ALT (n=26, 4.2%) and AST (n=37, 6.0%). For each of these liver function test components, baseline abnormal labs predicted Grade 3 toxicity at follow-up by Kruskal-Wallis test (P<0.001) and linear regression (all P<0.03). Other significant factors predicting toxicity at regression included elevated Body-Mass Index (albumin P=0.0056), whole liver treatment (bilirubin P=0.046), and lower tumor volume (ALT and INR, P<0.035 for both).

Conclusions

Baseline liver function abnormalities prior to radioembolization is the strongest predictor of post-treatment Grade 3 toxicity with rates as high as 13.8%. Toxicity rates for specific lab values are affected by large volume treatments especially with low tumor volumes.

3D voxel-based dosimetry to predict contralateral hypertrophy and an adequate future liver remnant after lobar radioembolization

INTRODUCTION

Volume changes induced by selective internal radiation therapy (SIRT) may increase the possibility of tumor resection in patients with insufficient future liver remnant (FLR). The aim was to identify dosimetric and clinical parameters associated with contralateral hepatic hypertrophy after lobar/extended lobar SIRT with ⁹⁰Y-resin microspheres.

MATERIALS AND METHODS

Patients underwent ⁹⁰Y PET/CT after lobar or extended lobar (right + segment IV) SIRT. ⁹⁰Y voxel dosimetry was retrospectively performed (PLANET Dose; DOSIsoft SA). Mean absorbed doses to tumoral/non-tumoral-treated volumes (NTL) and dose-volume histograms were extracted. Clinical variables were collected. Patients were stratified by FLR at baseline (T0-FLR): < 30% (would require hypertrophy) and ≥ 30%. Changes in volume of the treated, non-treated liver, and FLR were calculated at < 2 (T1), 2-5 (T2), and 6-12 months (T3) post-SIRT. Univariable and multivariable regression analyses were performed to identify predictors of atrophy, hypertrophy, and increase in FLR. The best cut-off value to predict an increase of FLR to ≥ 40% was defined using ROC analysis.

RESULTS

Fifty-six patients were studied; most had primary liver tumors (71.4%), 40.4% had cirrhosis, and 39.3% had been previously treated with chemotherapy. FLR in patients with T0-FLR < 30% increased progressively (T0: 25.2%; T1: 32.7%; T2: 38.1%; T3: 44.7%). No dosimetric parameter predicted atrophy. Both NTL-Dmean and NTL-V30 (fraction of NTL exposed to ≥ 30 Gy) were predictive of increase in FLR in patients with T0 FLR < 30%, the latter also in the total cohort of patients. Hypertrophy was not significantly associated with tumor dose or tumor size. When ≥ 49% of NTL received ≥ 30 Gy, FLR increased to ≥ 40% (accuracy: 76.4% in all patients and 80.95% in T0-FLR < 30% patients).

CONCLUSION

NTL-Dmean and NTL exposed to ≥ 30 Gy (NTL-V30) were most significantly associated with increase in FLR (particularly among patients with T0-FLR < 30%). When half of NTL received ≥ 30 Gy, FLR increased to ≥ 40%, with higher accuracy among patients with T0-FLR < 30%.

The joint use of 99mTc-MAA-SPECT/CT and cone-beam CT optimizes radioembolization planning

Purpose

To determine which imaging method used during radioembolization (RE) work-up: contrast-enhanced computed tomography (CECT), ^99mTc-MAA-SPECT/CT or cone beam-CT (CBCT), more accurately predicts the final target volume (TgV) as well as the influence that each modality has in the dosimetric calculation.

Methods

TgVs from ^99mTc-MAA-SPECT/CT, CECT and CBCT were consecutively obtained in 24 patients treated with RE and compared with ⁹⁰Y PET/CT TgV. Using the TgVs estimated by each imaging modality and a fictitious activity of 1 GBq, the corresponding absorbed doses by tumor and non-tumoral parenchyma were calculated for each patient. The absorbed doses for each modality were compared with the ones obtained using ⁹⁰Y PET/CT TgV.

Results

^99mTc-MAA-SPECT/CT predicted ⁹⁰Y PET/CT TgV better than CBCT or CECT, even for selective or superselective administrations. Likewise, ^99mTc-MAA-SPECT/CT showed dosimetric values more similar to those obtained with ⁹⁰Y PET/CT. Nevertheless, CBCT provided essential information for RE planning, such as ensuring the total coverage of the tumor and, in cases with more than one feeding artery, splitting the activity according to the volume of tumor perfused by each artery.

Conclusion

The joint use of ^99mTc-MAA-SPECT/CT and CBCT optimizes dosimetric planning for RE procedures, enabling a more accurate personalized approach.

Radioembolization in patients with hepatocellular carcinoma: a series of 53 cases

OBJECTIVE

To contribute our results to increase the scientific evidence about the use of radioembolization in the management of patients with hepatocellular carcinoma.

MATERIAL AND METHODS

This retrospective review included 53 patients with hepatocellular carcinoma treated with radioembolization at our center. Patients were classified according to the BCLC algorithm in detail according to their Child-Pugh functional status. We analyzed survival using the Kaplan-Meier method. We used Cox regression analysis to determine clinically significant parameters, including the doses administered in the parameters studied.

RESULTS

Patients ranged in age from 28 to 86 years (mean, 60 years). A total of 61 procedures were done. The mean activity administered was 2.8 GBq (0.7-6.4 GBq), with a mean dose of 229.9Gy (74-425.9Gy) administered in the tumor. Progression-free survival was 6.7 months and overall survival was 12.8 months. Differences in disease-free survival according to BCLC and Child-Pugh classification were not significant (p=0.848 and p=0.252, respectively). The clinical parameters that were significantly different with respect to overall survival were bilirubin levels (p<0.001), pretreatment transaminase levels (AST) (p=0.022), Child-Pugh subclassification (p=0.003), and dose administered in the tumor (p=0.001). Only one patient had a severe adverse reaction, developing posttreatment liver failure resulting in death.

CONCLUSIONS

Radioembolization is safe and efficacious in the treatment of patients with hepatocellular carcinoma. Liver function and the doses received by the tumor are key parameters for the efficacy of treatment. The increase in the scientific evidence supports the inclusion of this technique in treatment guidelines.

Multi-modal and sequential treatment of liver cancer and its impact on the gastrointestinal tract

Hepatic tumors include hepatocellular cancer (HCC) and cholangiocarcinoma (CC), a small subgroup of tumors (approx. 1%) are classified as combined hepatocellularcholangiocellular carcinomas. Different stage-dependent therapeutic approaches comprise resection, local ablative techniques, locoregional therapies, systemic treatment, liver transplantation in selected cases and possible combination of these treatment modalities. This review summarizes current knowledge on multi-modal treatment strategies for liver cancer focusing on gastrointestinal side effects.

Personalised versus standard dosimetry approach of selective internal radiation therapy in patients with locally advanced hepatocellular carcinoma (DOSISPHERE-01): a randomised, multicentre, open-label phase 2 trial

BACKGROUND

All randomised phase 3 studies of selective internal radiation therapy for advanced hepatocellular carcinoma published to date have reported negative results. However, these studies did not use personalised dosimetry. We aimed to compare the efficacy of a personalised versus standard dosimetry approach of selective internal radiation therapy with yttrium-90-loaded glass microspheres in patients with hepatocellular carcinoma.

METHODS

DOSISPHERE-01 was a randomised, multicentre, open-label phase 2 trial done at four health-care centres in France. Patients were eligible if they were aged 18 years or older and had unresectable locally advanced hepatocellular carcinoma, at least one measurable lesion 7 cm or more in size, a hepatic reserve of at least 30% after selective internal radiation therapy, no extrahepatic spread (other than to the lymph nodes of the hilum, with a lesion <2 cm in size), and no contraindications to selective internal radiation therapy, as assessed by use of a technetium-99m macro-aggregated albumin scan. Patients were randomly assigned (1:1) by use of a permutated block method, with block sizes of four and without stratification, to receive either standard dosimetry (120 ± 20 Gy) targeted to the perfused lobe; standard dosimetry group) or personalised dosimetry (≥205 Gy targeted to the index lesion; personalised dosimetry group). Investigators, patients, and study staff were not masked to treatment. The primary endpoint was the investigator-assessed objective response rate in the index lesion, according to European Association for the Study of the Liver criteria, at 3 months after selective internal radiation therapy in the modified intention-to-treat population. Safety was assessed in all patients who received at least one selective internal radiation therapy injection, and analysed on the basis of the treatment actually received (defined by central dosimetry assessment). The trial is registered with ClinicalTrials.gov, NCT02582034, and has been completed.

FINDINGS

Between Dec 5, 2015, and Jan 4, 2018, 93 patients were assessed for eligibility. Of these patients, 60 were randomly assigned: 31 to the personalised dosimetry group and 29 to the standard dosimetry group (intention-to-treat population). 56 (93%) patients (28 in each group) were treated (modified intention-to-treat population). In the modified intention-to-treat population, 20 (71% [95% CI 51-87]) of 28 patients in the personalised dosimetry group and ten (36% [19-56]) of 28 patients in the standard dosimetry group had an objective response (p=0·0074). In the safety analysis population, a least one serious adverse event was reported in seven (20%) of the 35 patients who received personalised dosimetry, and in seven (33%) of the 21 patients who received standard dosimetry. The most frequent (ie, occurring in >5% of patients) grade 3 or higher adverse events were ascites (one [3%] patient who received personalised dosimetry vs two [10%] patients who received standard dosimetry), hepatic failure (two [6%] vs none), lymphopenia (12 [34%] vs nine [43%]), increased aspartate aminotransferase concentrations (three [9%] vs two [10%]), increased alanine aminotransferase concentrations (three [9%] vs none), anaemia (two [6%] vs one [5%]), gastrointestinal haemorrhage (none vs two [10%]), and icterus (none vs two [10%]). One treatment-related death occurred in each group.

INTERPRETATION

Compared with standard dosimetry, personalised dosimetry significantly improved the objective response rate in patients with locally advanced hepatocellular carcinoma. The results of this study suggest that personalised dosimetry is likely to improve outcomes in clinical practice and should be used in future trials of selective internal radiation therapy.

FUNDING

Biocompatibles UK, a Boston Scientific Group company.

Management of patients with intermediate stage hepatocellular carcinoma

Hepatocellular carcinoma (HCC) causes a significant health burden globally and its impact is expected to increase in the coming years. Intermediate stage HCC, as defined by the Barcelona Clinic Liver Cancer (BCLC) system stage B, represents up to 30% of patients at diagnosis and encompasses a broad spectrum of tumor burden. Several attempts have been made to further subclassify this heterogenous group. The current standard of care recommended by BCLC for intermediate stage HCC patients is transarterial chemoembolization (TACE), with modest outcomes reported. While refinements have been made to TACE technique and patient selection, it remains non-curative. In the real-world setting, only 60% of patients with intermediate stage HCC receive TACE, with the remainder deviating to a range of other therapies that have shown promise in select patient subgroups. These include curative treatments (resection, ablation, and liver transplantation), radiotherapy (stereotactic and radioembolization), systemic therapies, and their combination. In this review, we summarize the classifications and current management for patients with intermediate stage HCC as well as highlight recent key developments in this space.

Liver Resection After Selective Internal Radiation Therapy with Yttrium-90: Safety and Outcomes

Introduction

Selective internal radiotherapy (SIRT) with yttrium-90 (Y-90) is an intra-arterial therapy for hepatic malignancy in patients who are unsuitable for surgical resection. This treatment is considered palliative, although some patients can demonstrate a response that is adequate to facilitate surgical resection with curative intent.

Methods

All patients who underwent liver resection post SIRT were reviewed. Data gathered included patient demographics, tumor type, surgical details, and post-operative outcomes.

Results

Twelve patients underwent SIRT followed by liver resection (7 males and 5 females). Pathologies were hepatocellular carcinoma (n = 5), metastatic colorectal cancer (n = 5), and neuroendocrine tumor (n = 2). Lesional response (size, volume, and RECIST (response evaluation criteria in solid tumors)) was calculated and where appropriate functional liver remnant (FLR) is presented. Mean FLR increase was 264cm³ (range − 123 to 909), and all cases demonstrated a partial response according to RECIST with a mean largest lesion volume reduction of 475cm³ (range 14–1632). No post-SIRT complications were noted. Hepatectomy occurred at a mean of 322 days from SIRT treatment. Ninety-day morbidity was 67% (n = 6), complications post-surgery were analyzed according to the Clavien-Dindo classification scale; a total of 15 events occurred in 6 patients. Ninety-day mortality of 11% (n = 1).

Conclusion

In selected cases, liver resection is possible post SIRT. As this can represent a potentially curative option, it is important to reconsider resection in the follow-up of patients undergoing SIRT. Post-operative complications are noted following major and extended liver resection. Therefore, further studies are needed to improve patient selection.

Chronic Hepatotoxicity in Patients with Metastatic Neuroendocrine Tumor: Transarterial Chemoembolization versus Transarterial Radioembolization

PURPOSE

To compare the manifestations of chronic liver injury following transarterial chemoembolization with those of transarterial radioembolization (TARE) in patients with neuroendocrine tumor (NET).

MATERIALS AND METHODS

This study consisted of an Institutional Review Board-approved single-institution retrospective analysis of NET patients who received transarterial chemoembolization from 2006 to 2016 and TARE from 2005 to 2014 and survived at least 1 year from the initial treatment. Patients receiving only transarterial chemoembolization (n = 63) or TARE (n = 28) were evaluated for the presence or absence of durable hepatic toxicities occurring at least 6 months after initial treatment. The definitions and grades of liver injury were adapted from Common Terminology Criteria for Adverse Events version 4.0 and were characterized by the presence of laboratory or clinical toxicities of Grade 3 or above.

RESULTS

Chronic hepatic toxicity occurred in 14 of 63 transarterial chemoembolization patients (22%) with a total of 26 Grade 3-4 events, in whom elevation of bilirubin was the most common toxicity, compared to 8 of 28 TARE patients (29%) with a total of 16 Grade 3-4 and 2 Grade 5 events, in whom ascites were the most frequent toxicity. There were more laboratory toxicities in the transarterial chemoembolization group (65% vs 38%, P = .11) and fewer Grade 4-5 injuries (6% vs 27% of patients, P = .06). There was also a significantly higher number of patients who experienced intrahepatic progression of disease in the transarterial chemoembolization cohort than in the TARE patients (75% vs 43%, respectively; P = .005).

CONCLUSIONS

Delayed hepatotoxicity from transarterial chemoembolization and TARE occurred in 22% and 29% of patients, respectively, from 6 months to several years following treatment. Transarterial chemoembolization-related toxicities on average were less severe and manifested primarily as laboratory derangements, compared to TARE toxicities which consisted of clinical hepatic decompensation.

The Role of Interventional Radiology for the Treatment of Hepatic Metastases from Neuroendocrine Tumor: An Updated Review

Interventional radiology plays an important role in the management of patients with neuroendocrine tumor liver metastasis (NELM). Transarterial embolization (TAE), transarterial chemoembolization (TACE), and selective internal radiation therapy (SIRT) are intra-arterial therapies available for these patients in order to improve symptoms and overall survival. These treatment options are proposed in patients with NELM not responding to systemic therapies and without extrahepatic progression. Currently, available data suggest that TAE should be preferred to TACE in patients with NELM from extrapancreatic origin because of similar efficacy and better patient tolerance. TACE is more effective in patients with pancreatic NELM and SIRT has shown promising results along with good tolerance. However, large randomized controlled trials are still lacking in this setting. Available literature mainly consists in small sample size and retrospective studies with important technical heterogeneity. The purpose of this review is to provide an updated overview of the currently reported endovascular interventional radiology procedures that are used for the treatment of NELM.

The safety of hepatectomy after transarterial radioembolization: Single institution experience and review of the literature

BACKGROUND AND OBJECTIVES

The liver is a frequent site of malignancy, both primary and metastatic. The treatment goal of patients with liver cancer may include transarterial radioembolization (TARE). There are limited reports on the safety of hepatectomy following TARE. Our study's purpose is to review patients who have received TARE followed by hepatectomy.

METHODS

A retrospective study was performed on patients diagnosed with any liver cancer from 2013 to 2019 who underwent TARE followed by hepatectomy. Postoperative complications were prospectively collected. Descriptive statistics and the Kaplan-Meier test were used to assess survival outcomes.

RESULTS

Twelve patients were treated with a TARE followed by a hepatectomy (nine with ≥4 segments resected). Diagnoses included: six HCC, four cholangiocarcinoma, one metastatic neuroendocrine tumor, and one metastatic colorectal cancer. There were no 90-day post-hepatectomy mortalities and the overall morbidity was 66% (16% severe ≥MAGS 3). Hepatectomy-specific complications after hepatectomy included two (16%) bile leaks and no post-hepatectomy liver failures. The median recurrence free survival was 26 months. Overall survival at 1-year was 78% and at 3 years was 47%.

CONCLUSIONS

Our results support the safety of hepatectomy in select patients after TARE. Additional comparison to patients who receive hepatectomy as a first-line treatment for liver cancers should be investigated.

The utility of 99mTc-mebrofenin hepatobiliary scintigraphy with SPECT/CT for selective internal radiation therapy in hepatocellular carcinoma

BACKGROUND

Studies assessing the impact of selective internal radiation therapy (SIRT) on the regional liver function in patients with hepatocellular carcinoma (HCC) are sparse. This study assessed the changes in total and regional liver function using hepatobiliary scintigraphy (HBS) and investigated the utility of HBS to predict post-SIRT liver dysfunction.

METHODS

Patients treated with SIRT for HCC between 2011 and 2019, underwent Tc-mebrofenin HBS with single-photon emission computed tomography/computed tomography (SPECT/CT) before and 6 weeks after SIRT. The corrected mebrofenin uptake rate (cMUR) and corresponding volume was measured in the total liver, and in treated and nontreated liver regions. Patients with and without post-SIRT liver dysfunction were compared.

RESULTS

A total of 29 patients, all Child-Pugh-A and mostly intermediate (72%) stage HCC were included in this study. Due to SIRT, the cMURtotal declined from 5.8 to 4.5%/min/m (P < 0.001). Twenty-two patients underwent a lobar SIRT, which induced a decline in cMUR (2.9-1.7%/min/m, P < 0.001) and volume (1228-1101, P = 0.002) of the treated liver region, without a change in cMUR (2.4-2.0%/min/m, P = 0.808) or volume (632-644 mL, P = 0.661) of the contralateral nontreated lobe. There were no significant pre-SIRT differences in total or regional cMUR or volume between patients with and without post-SIRT liver dysfunction.

CONCLUSION

In patients treated with SIRT for HCC, HBS accurately identified changes in total and regional liver function and may have a complementary role to personalize lobar or selective SIRT. In this pilot study, there were no pre-SIRT differences in cMUR or volume to aid in predicting post-SIRT liver dysfunction.

Personalised Dosimetry in Radioembolisation for HCC: Impact on Clinical Outcome and on Trial Design

Selective internal radiation therapy (SIRT) of hepatocellular carcinoma (HCC) has been used for many years, usually without any specific dosimetry endpoint. Despite good clinical results in early phase studies or in cohort studies, three randomized trials in locally advanced HCC available failed to demonstrate any improvement of overall overall survival (OS) in comparison with sorafenib. In recent years, many studies have evaluated the dosimetry of SIRT using either a simulation-based dosimetry (macroaggregated albumin (MAA)-based) or a post-therapy-based one (⁹⁰Y-based). The goal of this review is to present the dosimetry concept, tools available, its limitations, and main clinical results described for HCC patients treated with ⁹⁰Y-loaded resin or glass microspheres. With MAA-based dosimetry, the threshold tumor doses allowing for a response were between 100 and 210 Gy for resin microspheres and between 205 and 257 Gy for glass microspheres. The significant impact of the tumor dose on OS was reported with both devices. The correlation between ⁹⁰Y-based dosimetry and response was also reported. Regarding the safety, preliminary results are available for both products but with a larger range of normal liver doses values correlated with liver toxicities due to numerous confounding factors. Based on those results, international expert group recommendations for personalized dosimetry have been provided for both devices. The clinical impact of personalized dosimetry has been recently confirmed in a multicenter randomized study demonstrating a doubling of the response rate and an OS of 150% while using personalized dosimetry. Even if technical dosimetry improvements are still under investigation, the use of personalized dosimetry has to be generalized for both clinical practice and trial design.

Radioembolization of hepatocarcinoma with 90Y glass microspheres: treatment optimization using the dose-toxicity relationship

AIM

Transarterial radioembolization (TARE) is, by all standards, a radiation therapy. As such, according to Euratom Directive 2013/59, it should be optimized by a thorough treatment plan based on the distinct evaluation of absorbed dose to the lesions and to the non-tumoural liver (two-compartment dosimetry). Since the dosimetric prediction with ^99mTc albumin macro-aggregates (MAA) of non-tumoural liver is much more accurate than the same prediction on lesions, treatment planning should focus on non-tumoural liver rather than on lesion dosimetry. The aim of this study was to determine a safety limit through the analysis of pre-treatment dosimetry with ^99mTc-MAA single photon emission computed tomography (SPECT/CT), in order to deliver the maximum tolerable absorbed dose to non-tumoural liver.

METHODS

Data from intermediate/advanced hepato-cellular carcinoma (HCC) patients treated with ⁹⁰Y glass microspheres were collected in this single-arm retrospective study. Injection was always lobar, even in case of bilobar disease, to avoid treating the whole liver in a single session. A three-level definition of liver decompensation (LD) was introduced, considering toxicity only in cases of liver decompensation requiring medical action (LD type C, LDC). We report LDC rates, receiver operating characteristic (ROC) analysis between LDC and NO LDC absorbed dose distributions, normal tissue complication probability (NTCP) curves and uni- and multivariate analysis of risk factors associated with toxicity.

RESULTS

A 6-month timeline was defined as necessary to capture all treatment-related toxicity events. Previous transarterial chemoembolization (TACE), presence or extension of portal vein tumoural thrombosis (PVTT) and tumour pattern (nodular versus infiltrative) were not associated with tolerance to TARE. On the contrary, at the multivariate analysis, the absorbed dose averaged over the whole non-tumoural liver (including the non-injected lobe) was a prognostic indicator correlated with liver decompensation (odds ratio = 4.24). Basal bilirubin > 1.1 mg/dL was a second even more significant risk factor (odds ratio = 6.35). NTCP analysis stratified with this bilirubin cut-off determined a 15% liver decompensation risk at 50 Gy/90 Gy for bilirubin >/< 1.1 mg/dL. These results are valid for a ⁹⁰Y glass microsphere administration 4 days after the reference time.

CONCLUSION

Given the low predictive accuracy of ^99mTc-MAA on lesion absorbed dose reported by several authors, an optimized TARE with ⁹⁰Y glass microspheres with lobar injection 4 days after reference time should aim at an absorbed dose averaged over the whole non-tumoural liver of 50 Gy/90 Gy for basal bilirubin higher/lower than 1.1 mg/dL, respectively.

Expected and Unexpected Imaging Findings after 90Y Transarterial Radioembolization for Liver Tumors

Transarterial radioembolization (TARE), also called radioembolization or selective internal radiation therapy, is an interventional radiology technique used to treat primary liver tumors and liver metastases. The aim of this therapy is to deliver tumoricidal doses of radiation to liver tumors while selecting a safe radiation dose limit for nontumoral liver and lung tissue. Hence, correct treatment planning is essential to obtaining good results. However, this treatment invariably results in some degree of irradiation of normal liver parenchyma, inducing different radiologic findings that may affect follow-up image interpretation. When evaluating treatment response, the treated area size, tumor necrosis, devascularization, and changes seen at functional MRI must be taken into account. Unlike with other interventional procedures, with TARE, it can take several months for the tumor response to become evident. Ideally, responding lesions will show reduced size and decreased enhancement 3-6 months after treatment. In addition, during follow-up, there are many imaging findings related to the procedure itself (eg, peritumoral edema, inflammation, ring enhancement, hepatic fibrosis, and capsular retraction) that can make image interpretation and response evaluation difficult. Possible complications, either hepatic or extrahepatic, also can occur and include biliary injuries, hepatic abscess, radioembolization-induced liver disease, and radiation pneumonitis or dermatitis. A complete understanding of these possible posttreatment changes is essential for correct radiologic interpretations during the follow-up of patients who have undergone TARE. ^©RSNA, 2019.

Incidence of Radioembolization-Induced Liver Disease and Liver Toxicity Following Repeat 90Y-Radioembolization: Outcomes at a Large Tertiary Care Center

PURPOSE

The complication profile following repeat Y-radioembolization (RE) is not well understood, and repeat RE is sometimes avoided because of concerns for RE-induced liver disease (REILD) and liver toxicity. The purpose of this study was to examine the incidence of REILD and liver toxicity following repeat Y-RE and to identify potential risk factors.

METHODS

A retrospective analysis of patients undergoing repeat RE to the same hepatic lobe between 2013 and 2018 was performed. Baseline factors were evaluated as predictors of liver toxicity, mortality, and REILD, which was defined as the presence symptomatic ascites or jaundice in the absence of biliary obstruction within 8 weeks following RE. Post-RE complications were graded according to the Common Terminology Criteria for Adverse Events version 5.

RESULTS

A total of 39 patients underwent repeat RE with 14 (35.9%) experiencing Common Terminology Criteria for Adverse Events toxicity of grade 2 or greater, 3 (10.3%) grade 3, and no grade 4 or greater. A Model for End Stage Liver Disease score of 8 or greater was associated with grade 2 toxicity or greater (26.7% vs 75%; P = 0.013). Only 3 patients (7.7%) experienced REILD due to symptomatic ascites without jaundice. Greater than 2 REs were associated with a greater rate of 6-month mortality (12% vs 58.3%, P = 0.003), 12-month mortality (28% vs 75%, P = 0.007), and REILD (0% vs 21.4%, P = 0.016). Age, sex, microsphere type, cirrhosis, Child-Pugh, and Eastern Cooperative Oncology Group status were not significantly associated with complications, REILD, or survival.

CONCLUSIONS

Repeat Y-RE appears to be well tolerated with a low rate of high-grade adverse events and REILD.

Contralateral Liver Hypertrophy and Oncological Outcome Following Radioembolization with 90Y-Microspheres: A Systematic Review

Radioembolization with ⁹⁰Y-microspheres has been reported to induce contralateral liver hypertrophy with simultaneous ipsilateral control of tumor growth. The aim of the present systematic review was to summarize the evidence of contralateral liver hypertrophy and oncological outcome following unilateral treatment with radioembolization. A systematic literature search using the MEDLINE, EMBASE, and Cochrane libraries for studies published between 2008 and 2020 was performed. A total of 16 studies, comprising 602 patients, were included. The median kinetic growth rate per week of the contralateral liver lobe was 0.7% and declined slightly over time. The local tumor control was 84%. Surgical resection after radioembolization was carried out in 109 out of 362 patients (30%). Although the available data suggest that radioembolization prior to major hepatectomy is safe with a promising oncological outcome, the definitive role of radioembolization requires assessment within controlled clinical trials.

Assessment of hepatocellular carcinoma treatment response with LI-RADS: a pictorial review

Computed tomography (CT) and magnetic resonance imaging (MRI) play critical roles for assessing treatment response of hepatocellular carcinoma (HCC) after locoregional therapy. Interpretation is challenging because posttreatment imaging findings depend on the type of treatment, magnitude of treatment response, time interval after treatment, and other factors. To help radiologists interpret and report treatment response in a clear, simple, and standardized manner, the Liver Imaging Reporting and Data System (LI-RADS) has developed a Treatment Response (LR-TR) algorithm. Introduced in 2017, the system provides criteria to categorize response of HCC to locoregional treatment (e.g., chemical ablation, energy-based ablation, transcatheter therapy, and radiation therapy). LR-TR categories include Nonevaluable, Nonviable, Equivocal, and Viable. LR-TR does not apply to patients on systemic therapies. This article reviews the LR-TR algorithm; discusses locoregional therapies for HCC, treatment concepts, and expected posttreatment findings; and illustrates LI-RADS treatment response assessment with CT and MRI.

Impact of combined selective internal radiation therapy and sorafenib on survival in advanced hepatocellular carcinoma

BACKGROUND & AIMS

Sorafenib is the recommended treatment for patients with advanced hepatocellular carcinoma (HCC). We aimed to compare the efficacy and safety of a combination of sorafenib and selective internal radiation therapy (SIRT) - with yttrium-90 (⁹⁰Y) resin microspheres - to sorafenib alone in patients with advanced HCC.

METHODS

SORAMIC is a randomised controlled trial comprising diagnostic, local ablation and palliative cohorts. Based on diagnostic study results, patients were assigned to local ablation or palliative cohorts. In the palliative cohort, patients not eligible for TACE were randomised 11:10 to SIRT plus sorafenib (SIRT + sorafenib) or sorafenib alone. The primary endpoint was overall survival (OS; Kaplan-Meier analysis) in the intention-to-treat (ITT) population.

RESULTS

In the ITT cohort, 216 patients were randomised to SIRT + sorafenib and 208 to sorafenib alone. Median OS was 12.1 months in the SIRT + sorafenib arm, and 11.4 months in the sorafenib arm (hazard ratio [HR] 1.01; 95% CI 0.81-1.25; p = 0.9529). Median OS in the per protocol population was 14.0 months in the SIRT + sorafenib arm (n = 114), and 11.1 months in the sorafenib arm (n = 174; HR 0.86; p = 0.2515). Subgroup analyses of the per protocol population indicated a survival benefit of SIRT + sorafenib for patients without cirrhosis (HR 0.46; 0.25-0.86; p = 0.02); cirrhosis of non-alcoholic aetiology (HR 0.63; p = 0.012); or patients ≤65 years old (HR 0.65; p = 0.05). Adverse events (AEs) of Common Terminology Criteria for AE Grades 3-4 were reported in 103/159 (64.8%) patients who received SIRT + sorafenib, 106/197 (53.8%) patients who received sorafenib alone (p = 0.04), and 8/24 (33.3%) patients who only received SIRT.

CONCLUSION

Addition of SIRT to sorafenib did not result in a significant improvement in OS compared with sorafenib alone. Subgroup analyses led to hypothesis-generating results that will support the design of future studies.

LAY SUMMARY

Sorafenib given orally is the recommended treatment for patients with advanced hepatocellular carcinoma (HCC). In selective internal radiation therapy (SIRT), also known as radioembolisation, microscopic, radioactive resin or glass spheres are introduced into the blood vessels that feed the tumours in the liver. This study found that the addition of SIRT with ⁹⁰yttrium-loaded resin microspheres to sorafenib treatment in people with advanced HCC did not significantly improve overall survival compared with sorafenib treatment alone. However, the results give an indication of how future studies using this combination therapy in people with advanced HCC could be designed.

STUDY REGISTRATION

EudraCT 2009-012576-27, NCT0112 6645.

Secondary technical resectability of colorectal cancer liver metastases after chemotherapy with or without selective internal radiotherapy in the randomized SIRFLOX trial

Background

Secondary resection of initially unresectable colorectal cancer liver metastases (CRLM) can prolong survival. The added value of selective internal radiotherapy (SIRT) to downsize lesions for resection is not known. This study evaluated the change in technical resectability of CRLM with the addition of SIRT to FOLFOX‐based chemotherapy.

Methods

Baseline and follow‐up hepatic imaging of patients who received modified FOLFOX (mFOLFOX6: fluorouracil, leucovorin, oxaliplatin) chemotherapy with or without bevacizumab (control arm) versus mFOLFOX6 (with or without bevacizumab) plus SIRT using yttrium‐90 resin microspheres (SIRT arm) in the phase III SIRFLOX trial were reviewed by three or five (of 14) expert hepatopancreatobiliary surgeons for resectability. Reviewers were blinded to one another, treatment assignment, extrahepatic disease status, and information on clinical and scanning time points. Technical resectability was defined as at least 60 per cent of reviewers (3 of 5, or 2 of 3) assessing a patient's liver metastases as surgically removable.

Results

Some 472 patients were evaluable (SIRT, 244; control, 228). There was no significant baseline difference in the proportion of technically resectable liver metastases between SIRT (29, 11·9 per cent) and control (25, 11·0 per cent) arms (P = 0·775). At follow‐up, significantly more patients in both arms were deemed technically resectable compared with baseline: 159 of 472 (33·7 per cent) versus 54 of 472 (11·4 per cent) respectively (P = 0·001). More patients were resectable in the SIRT than in the control arm: 93 of 244 (38·1 per cent) versus 66 of 228 (28·9 per cent) respectively (P < 0·001).

Conclusion

Adding SIRT to chemotherapy may improve the resectability of unresectable CRLM.

Yttrium-90 Radioembolization After Local Hepatic Therapy: How Prior Treatments Impact Patient Selection, Dosing, and Toxicity

Numerous local treatment strategies now exist for patients with primary and metastatic liver tumors. Increasingly, patients who cannot be adequately treated with a single form of focal therapy, go on to receive a variety of sequential treatments. However, the impact of each prior therapy on subsequent treatments and the cumulative toxicity of these therapies remains uncertain. Yttrium-90 radioembolization is becoming an increasingly common treatment for patients with hepatic malignancies. Though the baseline toxicity of radioembolization is low, greater care must be taken when treating patients who have undergone prior hepatic treatments. While this population can be treated safely, additional measures should be taken to ensure that patients are carefully screened and all effort is made to minimize liver toxicity.

Complications of Stem Cell Transplantation that Affect Infections in Stem Cell Transplant Recipients, with Analogies to Patients with Hematologic Malignancies

This article discusses the complications of hematopoietic stem cell transplantion (HSCT) that affect infections in HSCT recipients, with analogies to patients with hematologic malignancies. Mucositis, with mucosal barrier disruption, is common and increases the risk of gram-positive and anaerobic bacterial, and fungal infections, and can evolve to typhlitis. Engraftment syndrome; graft-versus-host disease, hepatic sinusoidal obstruction syndrome; and posterior reversible encephalopathy syndrome can affect the infectious potential either directly from organ dysfunction or indirectly from specific treatment. Pulmonary infections can predispose to life threatening complications including diffuse alveolar hemorrhage, idiopathic pulmonary syndrome, bronchiolitis obliterans syndrome, and bronchiolitis obliterans with organizing pneumonia.

Yttrium-90 Complications: Prevention and Management

Radioembolization has become a more prevalent treatment for both primary and secondary liver of the liver. Radioembolization is a relatively safe procedure with major complications being rare. Understanding how to identify the potential complications and their treatment can help make the procedure even safer and mitigate the risk of severe life threatening complications. In this article, we will review the most common complications, how to identify them, and how manage them.

Dosimetry of Y-90 Microspheres Utilizing Tc-99m SPECT and Y-90 PET

Dosimetry for yttrium-90 radioembolization continues to generate interest and controversy, as multiple approaches have been used effectively. Traditionally, simple formulas primarily based on patients' body weight or perfused liver volume were used. Over the past several years, dosimetry refinements have led to marked improvements in this therapy from both a safety and efficacy standpoint. Technetium-99m macroaggregated albumin single photon emission computed tomography (SPECT) optimizes pretreatment dosimetry to ensure delivery of a therapeutic radiation dose to the tumor while minimizing nontarget radiation to healthy hepatic tissue. Post-treatment yttrium-90 PET utilizing the inherent internal pair production of yttrium-90 accurately calculates the absorbed dose to tumors and to the normal hepatic parenchyma, which correlates with patient outcomes. As dosimetric calculations become more complex, quantitative imaging with Tc-99m SPECT and Y-90 PET may set the new standard for radioembolization dosimetry.

Holmium-166 Radioembolization in Hepatocellular Carcinoma: Feasibility and Safety of a New Treatment Option in Clinical Practice

PURPOSE

To investigate clinical feasibility, technical success and toxicity of ¹⁶⁶Ho-radioembolization (¹⁶⁶Ho-RE) as new approach for treatment of hepatocellular carcinomas (HCC) and to assess postinterventional calculation of exact dosimetry through quantitative analysis of MR images.

MATERIALS AND METHODS

From March 2017 to April 2018, nine patients suffering from HCC were treated with ¹⁶⁶Ho-RE. To calculate mean doses on healthy liver/tumor tissue, MR was performed within the first day after treatment. For evaluation of hepatotoxicity and to rule out radioembolization-induced liver disease (REILD), the Model for End-Stage Liver Disease (MELD) Score, the Common Terminology Criteria for Adverse Events and specific laboratory parameters were used 1-day pre- and posttreatment and after 60 days. After 6 months, MR/CT follow-up was performed.

RESULTS

In five patients the right liver lobe, in one patient the left liver lobe and in three patients both liver lobes were treated. Median administered activity was 3.7 GBq (range 1.7-5.9 GBq). Median dose on healthy liver tissue was 41 Gy (21-55 Gy) and on tumor tissue 112 Gy (61-172 Gy). Four patients suffered from mild postradioembolization syndrome. No significant differences in median MELD-Score were observed pre-, posttherapeutic and 60 days after ¹⁶⁶Ho-RE. No deterioration of liver function and no indicators of REILD were observed. One patient showed a complete response, four a partial response, three a stable disease and one a progressive disease at the 6 months follow-up.

CONCLUSION

¹⁶⁶Ho-RE seems to be a feasible and safe treatment option with no significant hepatotoxicity for treatment of HCC.

Quantitative comparison of pre-therapy 99mTc-macroaggregated albumin SPECT/CT and post-therapy PET/MR studies of patients who have received intra-arterial radioembolization therapy with 90Y microspheres

OBJECTIVE

The aim of our study was to compare yttrium -90 (⁹⁰Y) dosimetry obtained from pre-therapy ^99mTc-macroaggregated albumin (MAA) SPECT/CT versus post-therapy PET/MRI imaging among patients with primary or metastatic hepatic tumors.

MATERIALS AND METHODS

Prior to ⁹⁰Y radioembolization (RE), 32 patients underwent a scan using MAA mimicking ⁹⁰Y distribution. After RE with ⁹⁰Y microspheres, the patients were imaged on a PET/MRI system. Reconstructed images were transferred to a common platform and used to calculate ⁹⁰Y dosimetry. The Passing-Bablok regression scatter diagram and the Bland and Altman method were used to analyze the difference between dosimetry values.

RESULTS

For MAA and PET/MRI modalities, the mean liver doses for all 32 subjects were 43.0 ± 20.9 Gy and 46.5 ± 22.7 Gy, respectively, with a mean difference of 3.4 ± 6.2 Gy. The repeatibility coefficient was 12.1 (27.0% of the mean). The Spearman rank correlation coefficient was high (ρ = 0.92). Although, there was a substantial difference in the maximum doses to the liver between the modalities, the mean liver doses were relatively close, with a difference of 24.0% or less.

CONCLUSIONS

The two main contributors to the difference between dosimetry calculations using MAA versus ⁹⁰Y PET/MRI can be attributed to the changes in catheter positioning as well as the liver ROIs used for the calculations. In spite of these differences, our results demonstrate that the dosimetry values obtained from pre-therapy MAA SPECT/CT scans and PET/MRI post-therapy ⁹⁰Y studies were not significantly different.

90Y TOF-PET based EUD reunifies patient survival prediction in resin and glass microspheres radioembolization of HCC tumours

Clinical studies reported a twofold ratio between the efficacies per Gy of resin versus glass spheres. Our aim is to investigate whether this difference could result from the different degrees of heterogeneity in sphere distribution between the two medical devices. The ⁹⁰Y TOF-PET based equivalent uniform doses (EUD) was used for this purpose. 58 consecutive HCC radioembolizations were retrospectively analyzed. Absorbed doses D and Jones-Hoban EUD in lesions were computed. Radioembolization efficacy was assessed using Kaplan-Meier survival curves. In order to match together the glass and resin spheres survival curves using a 40 Gy-threshold, an efficacy factor of 0.73 and 0.36 has to be applied on their absorbed dose, respectively. Using EUD, a nice matching between glass and resin survival curves was obtained with a better separation of the responding and not responding survival curves. The results clearly support the fact that the activity heterogeneity observed in ⁹⁰Y TOF-PET post radioembolization does not only result from statistical noise, but also reflects the actual heterogeneity of the spheres distribution. Use of EUD reunifies the efficacy of the two medical devices.

Gastroenteropancreatic Neuroendocrine Tumors

Neuroendocrine tumors (NETs) are heterogeneous malignancies arising from the diffuse neuroendocrine system. They frequently originate in the gastroenteropancreatic (GEP) tract and the bronchopulmonary tree, and their incidence has steadily increased in the last 3 decades. Fundamental biologic and genomic differences underlie the clinical heterogeneity of NETs, and distinct molecular features characterize NETs of different grades and different primary sites. Although surgery remains the cornerstone of treatment for localized tumors, systemic treatment options for patients with metastatic NETs have expanded considerably. Somatostatin analogs have demonstrated both antisecretory and antitumor efficacy. Peptide receptor radionuclide therapy with lutetium-177 dotatate (¹⁷⁷ Lu-DOTATATE) has been approved for advanced GEP-NETs. The antitumor activity of everolimus has been demonstrated across a wide spectrum of NETs, and the antiangiogenic agent sunitinib has been approved for pancreatic NETs (pNETs). Chemotherapy with temozolomide and capecitabine has recently demonstrated an unprecedented prolongation of progression-free survival in a randomized trial of pNETs. Multiple retrospective series have reported the efficacy of liver-directed therapies both for palliating symptoms of hormone excess and for controlling tumor growth. Telotristat, an oral inhibitor of tryptophan hydroxylase, has been shown to reduce diarrhea in patients with carcinoid syndrome. Defining the therapeutic algorithm and identifying biomarkers predictive of response to treatments are among the main priorities for the next decade of research in the NET field.

Long-term radiological and histological outcomes following selective internal radiation therapy to liver metastases from breast cancer

Liver metastasis from breast cancer is associated with poor prognosis and is a major cause of early morbidity and mortality. When liver resection is not feasible, minimally invasive directed therapies are considered to attempt to prolong survival. Selective internal radiation therapy (SIRT) with yttrium-90 microspheres is a liver-directed therapy that can improve local control of liver metastases from colorectal cancer. We present a case of a patient with a ductal breast adenocarcinoma, who developed liver and bone metastasis despite extensive treatment with systemic chemotherapies. Following SIRT to the liver, after an initial response, the patient ultimately progressed in the liver after 7 months. Liver tumor histology obtained 20 months after the SIRT intervention demonstrated the presence of the resin microspheres in situ. This case report demonstrates the long-term control that may be achieved with SIRT to treat liver metastases from breast cancer that is refractory to previous chemotherapies, and the presence of microspheres in situ long-term.

The Role of Liver-Directed Therapy in Metastatic Colorectal Cancer

Purpose of Review

Colorectal cancer liver metastasis is a major clinical problem, and surgical resection is the only potentially curative treatment. We seek to discuss various liver-directed therapy modalities and explore their roles in the evolving realm of treatment strategies for metastatic colorectal cancer.

Recent Findings

Clinical outcomes for patients with colorectal cancer liver metastases have improved as more patients undergo potentially curative resection and as the armamentarium of systemic treatment and liver-directed therapies continues to expand. Liver-directed therapies have been developed as adjuncts to improve resectability, employed in the adjuvant setting to potentially reduce local recurrence rates, and utilized in the palliative setting with the aim to improve overall survival.

Summary

Ongoing research is expected to validate the role of these evolving therapeutic options, and determine how best to sequence and when to apply these therapies.

Comparison of Cone-Beam Tomography and Cross-Sectional Imaging for Volumetric and Dosimetric Calculations in Resin Yttrium-90 Radioembolization

PURPOSE

To compare the use of cone-beam computed tomography versus contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) in the calculation of liver volume and planned dose for yttrium-90 radioembolization.

MATERIALS AND METHODS

The study retrospectively assessed 47 consecutive patients who underwent resin Y-90 radioembolization consecutively over a 2-year period at a single center. Volume calculation software was used to determine perfused lobar liver volumes from cone-beam CT (CBCT) images obtained during mapping angiography. CBCT-derived volumes were compared with perfused lobar volume derived from contrast-enhanced CT and MRI. Nominal activities as determined by the SIR-Spheres Microspheres Activity Calculator were similarly calculated and compared using both CBCT and conventionally acquired volumes.

RESULTS

A total of 82 hepatic lobes were assessed in 47 patients. The mean percentage difference between combined CT-MRI- and CBCT-derived calculated lobar volumes was 25.3% (p = 0.994). The mean percentage difference in calculated dose between the two methods was 21.8 ± 24.6% (p = 0.42). Combined left and right lobar CT-derived dose difference was less than 10% in 22 lobes, between 10 and 25% in 20 lobes, between 25 and 50% in 13 lobes and greater than 50% in 5 lobes. Combined left and right lobar MRI-derived dose difference was less than 10% in 11 lobes, between 10 and 25% in 7 lobes, between 25 and 50% in 2 lobes and greater than 50% in 1 lobe.

CONCLUSIONS

Although volume measurements derived from CT/MRI did not differ significantly from those derived from CBCT, variability between the two methods led to large and unexpected differences in calculated dose.