A systematic review of yttrium-90 radioembolization for unresectable liver metastases of melanoma

Intra-Abdominal Malignant Melanoma: Challenging Aspects of Epidemiology, Clinical and Paraclinical Diagnosis and Optimal Treatment—A Literature Review

According to European consensus-based interdisciplinary guidelines for melanoma, cutaneous melanoma (CM) is the most deadly form of dermatological malignancy, accounting for 90% of the deaths of skin cancer patients. In addition to cutaneous melanoma, mucosal melanoma occurs in four major anatomical sites, including the upper respiratory tract, the conjunctiva, the anorectal region, and the urogenital area. As this cancer type metastasizes, a classification used in the current medical literature is the distinction between secondary lesions and primary malignant melanoma of the abdominal cavity. Given that malignant melanoma is the most common cancer that spreads to the gastrointestinal tract, different imaging modalities compete to diagnose the phenomenon correctly and to measure its extension. Treatment is primarily surgery-based, supported by immunotherapy, and prolongs survival, even when performed at stage IV illness. In the end, special forms of malignant melanoma are discussed, such as melanoma of the genito-urinary tract and amelanotic/achromic melanoma. The importance of this present literature review relies on yielding and grouping consistent and relevant, updated information on the many aspects and challenges that a clinician might encounter during the diagnosis and treatment of a patient with intra-abdominal melanoma.

Selective internal radiation therapy for hepatic metastases of uveal melanoma: a systematic review

OBJECTIVE

Uveal melanoma (UM) commonly metastasizes to the liver. Treatment usually consists of liver-directed therapies, such as selective internal radiation therapy (SIRT). This review aimed to assess the effectiveness and safety of SIRT for hepatic metastases from UM.

METHODS

The study protocol is available at OSF (https://osf.io/vhyct/). EMBASE and MEDLINE were searched until July 2020, using terms related to SIRT and hepatic metastases from UM. Studies reporting outcomes of SIRT in patients with UM and at least one hepatic metastasis were included. Data on overall survival (OS), hepatic progression free survival (hPFS) or tumor response were collected. The Newcastle-Ottawa Scale (NOS) was used to assess risk of bias.

RESULTS

11 studies were included, reporting outcomes for 268 patients with hepatic metastases from UM. Most studies (n = 9, 81.8%) were retrospective. Disease control was achieved in 170 patients (67.5%) and the median OS from time of SIRT was 12.3 months. Median hPFS was 5.4 months. Low-grade side-effects were common but serious complications were infrequent. There were two treatment-related deaths. The median NOS score was 6 (moderate risk of bias).

CONCLUSION

SIRT appears to be a safe and effective treatment for patients with unresectable hepatic metastases from UM. The certainty of our results is unclear due to predominantly retrospective data with moderate risk of bias. Further prospective studies are required to explore the role of SIRT in UM.

ADVANCES IN KNOWLEDGE

SIRT appears to be a safe treatment for patients with unresectable hepatic metastases from UM. Further prospective work is required.

Yttrium-90 radioembolization for unresectable hepatic metastases of breast cancer: A systematic review

BACKGROUND

Liver metastases secondary to breast cancer are associated with unfavourable prognosis. Radioembolization with ytrrium-90 is an emerging option for management of liver metastases of breast cancer when other systemic therapies have failed to achieve disease control. However, unlike the case of other liver tumours (colorectal/melanoma metastases/cholangiocarcinoma), its role in the management of breast liver metastases is yet to be elucidated.

AIM

The aims of this systematic review were to (1) assess the effect of radioembolization with yttrium-90 on tumour response; and (2) to estimate patient survival post radioembolization.

METHODS

The review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A systematic literature search was performed using the PubMed and EMBASE databases from January 2007 to December 2018. The initial search yielded 265 reports which were potentially suitable for inclusion in this review. Studies published in English reporting at least one outcome of interest were considered to be suitable for inclusion. Conference abstracts; case reports, animal studies and reports not published in English were excluded from this review. Data was retrieved from each individual report on the name of primary author, year of publication, patient demographics, type of microspheres used, radiation dose delivered to tumour, duration of follow-up, disease control rate (%), tumour response, and overall patient survival.

RESULTS

The final number of studies which met the inclusion criteria was 12 involving 452 patients. There were no randomized controlled trials identified after the literature search. The age of the patients included in this review ranged from 52 to 61 years. The duration of the follow up period post-radioembolization ranged from 6 to 15.7 mo. The total number of patients with breast metastases not confined to the liver was 236 (52.2%). Cumulative analysis revealed that radioembolization with yttrium-90 conferred tumour control rate in 81% of patients. Overall survival post-radioembolization ranged from 3.6 to 20.9 mo with an estimated mean survival of 11.3 mo.

CONCLUSION

Radioembolization with ytrrium-90 appears to confer control of tumour growth rate in most patients, however its effect on patient survival need to be elucidated further. Furthermore, quality evidence in the form of randomized trials is needed in order to assess the effect of radioembolization in more depth.

Multi-modal image analysis for semi-automatic segmentation of the total liver and liver arterial perfusion territories for radioembolization

Purpose

We have developed a multi-modal imaging approach for SIRT, combining ^99mTc-MAA SPECT/CT and/or ⁹⁰Y PET, ¹⁸F-FDG PET/CT, and contrast-enhanced CBCT for voxel-based dosimetry, as a tool for treatment planning and verification. For radiation dose prediction calculations, a segmentation of the total liver volume and of the liver perfusion territories is required.

Method

In this paper, we proposed a procedure for multi-modal image analysis to assist SIRT treatment planning. The pre-treatment ¹⁸F-FDG PET/CT, ^99mTc-MAA SPECT/CT, and contrast-enhanced CBCT images were registered to a common space using an initial rigid, followed by a deformable registration. The registration was scored by an expert using Likert scores. The total liver was segmented semi-automatically based on the PET/CT and SPECT/CT images, and the liver perfusion territories were determined based on the CBCT images. The segmentations of the liver and liver lobes were compared to the manual segmentations by an expert on a CT image.

Result

Our methodology showed that multi-modal image analysis can be used for determination of the liver and perfusion territories using CBCT in SIRT using all pre-treatment studies. The results for image registration showed acceptable alignment with limited impact on dosimetry.

The image registration performs well according to the expert reviewer (scored as perfect or with little misalignment in 94% of the cases). The semi-automatic liver segmentation agreed well with manual liver segmentation (dice coefficient of 0.92 and an average Hausdorff distance of 3.04 mm). The results showed disagreement between lobe segmentation using CBCT images compared to lobe segmentation based on CT images (average Hausdorff distance of 14.18 mm), with a high impact on the dosimetry (differences up to 9 Gy for right and 21 Gy for the left liver lobe).

Conclusion

This methodology can be used for pre-treatment dosimetry and for SIRT planning including the determination of the activity that should be administered to achieve the therapeutical goal. The inclusion of perfusion CBCT enables perfusion-based definition of the liver lobes, which was shown to be markedly different from the anatomical definition in some of the patients.