Magnetic resonance screening trial for hepatic metastasis in patients with locally controlled choroidal melanoma

Surveillance for Metastasis in High-Risk Uveal Melanoma Patients: Standard versus Enhanced Protocols

PURPOSE

to evaluate the effectiveness of enhanced surveillance protocols (EP) utilizing high frequency (HF) or enhanced modality (EM) compared to the standard protocol (SP) in detecting metastasis and determining their impact on overall survival (OS) in high-risk uveal melanoma (UM) patients.

METHODS

A total of 87 consecutive patients with Class 2 (high risk) primary UM were enrolled, with negative baseline systemic staging. The patients underwent systemic surveillance with either SP (hepatic ultrasonography [US] every 6 months) or EP (either HF [US every 3 months] or EM [incorporation hepatic computed tomography/magnetic resonance imaging]) following informed discussion. The main outcome measures were largest diameter of largest hepatic metastasis (LDLM), number of hepatic metastatic lesions, time to detection of metastasis (TDM), and OS.

RESULTS

This study revealed significant differences in LDLM between surveillance protocols, with the use of EP detecting smaller metastatic lesions (HF, EM, and SP were 1.5 cm, 1.6 cm, and 6.1 cm, respectively). Patients on the EM protocol had a lower 24-month cumulative incidence of >3 cm metastasis (3.5% EM vs. 39% SP; p = 0.021), while those on the HF protocol had a higher 24-month cumulative incidence of ≤3 cm metastasis compared to SP (31% HF vs. 10% SP; p = 0.017). Hazard of death following metastasis was significantly reduced in the EP (HR: 0.25; 95% CI: 0.07, 0.84), HF (HR: 0.23; 95% CI: 0.06, 0.84), and EM (HR: 0.11; 95% CI: 0.02, 0.5) groups compared to SP. However, TDM and OS did not significantly differ between protocols.

CONCLUSIONS

Enhanced surveillance protocols improved early detection of hepatic metastasis in UM patients but did not translate into a survival advantage in our study cohort. However, early detection of metastasis in patients receiving liver-directed therapies may lead to improved overall survival.

Metastatic uveal melanoma: The final frontier

Treatment of primary intraocular uveal melanoma has developed considerably, its driver genes are largely unraveled, and the ways to assess its risk for metastases are very precise, being based on an international staging system and genetic data. Unfortunately, the risk of distant metastases, which emerge in approximately one half of all patients, is unaltered. Metastases are the leading single cause of death after uveal melanoma is diagnosed, yet no consensus exists regarding surveillance, staging, and treatment of disseminated disease, and survival has not improved until recently. The final frontier in conquering uveal melanoma lies in solving these issues to cure metastatic disease. Most studies on metastatic uveal melanoma are small, uncontrolled, retrospective, and do not report staging. Meta-analyses confirm a median overall survival of 10-13 months, and a cure rate that approaches nil, although survival exceeding 5 years is possible, estimated 2% either with first-line treatment or with best supportive care. Hepatic ultrasonography and magnetic resonance imaging as surveillance methods have a sensitivity of 95-100% and 83-100%, respectively, to detect metastases without radiation hazard according to prevailing evidence, but computed tomography is necessary for staging. No blood-based tests additional to liver function tests are generally accepted. Three validated staging systems predict, each in defined situations, overall survival after metastasis. Their essential components include measures of tumor burden, liver function, and performance status or metastasis free interval. Age and gender may additionally influence survival. Exceptional mutational events in metastases may make them susceptible to checkpoint inhibitors. In a large meta-analysis, surgical treatment was associated with 6 months longer median overall survival as compared to conventional chemotherapy and, recently, tebentafusp as first-line treatment at the first interim analysis of a randomized phase III trial likewise provided a 6 months longer median overall survival compared to investigator's choice, mostly pembrolizumab; these treatments currently apply to selected patients. Promoting dormancy of micrometastases, harmonizing surveillance protocols, promoting staging, identifying predictive factors, initiating controlled clinical trials, and standardizing reporting will be critical steppingstones in reaching the final frontier of curing metastatic uveal melanoma.

Hepatic Ultrasonography Compared With Computed Tomography and Magnetic Resonance Imaging at Diagnosis of Metastatic Uveal Melanoma

PURPOSE

To evaluate the consistency of hepatic ultrasonography (US) with staging computed tomography (CT) and magnetic resonance imaging (MRI), to analyze why US was inconsistent with CT/MRI, and to compare CT/MRI.

DESIGN

Reliability analysis.

METHODS

Two hundred fifteen patients whose primary uveal melanoma was managed in the Helsinki University Hospital and who were diagnosed with hepatic metastases by US within 60 days of staging CT/MRI from January 1999 to December 2016 were included. Patients attended a real-life follow-up schedule including hepatic US, liver function tests (LFT), and a confirmatory CT/MRI. We evaluated the consistency of US with staging CT/MRI regarding the presence and number of metastases.

RESULTS

The enrolled patients underwent 215 US, 167 CT, and 69 MRI examinations, and 67% of them had biopsy-confirmed metastases. Screening was regular for 98% of the patients, and 66% were asymptomatic. US was fully consistent with CT/MRI in detecting metastases in 113 (53%) patients, in 63 (29%) CT/MRI showed more metastases, and in 16 (7%) CT/MRI showed fewer metastases than US. CT/MRI was inconsistent with US in 23 (11%) patients. The sensitivity of US in detecting metastases was 96% (95% confidence interval, 92-98). US failed to suggest metastases in 10 patients. LFT were abnormal in 6 of them, and a newly detected hepatic lesion was present by US in 4.

CONCLUSIONS

Hepatic US is a sensitive screening modality in detecting metastases in patients with primary uveal melanoma, if combined with LFT and, in case of any newly detected lesion, a confirmatory MRI.

Melanoma liver metastases with special imaging features on magnetic resonance imaging after microwave ablations: How to evaluate technical efficacy?

Purpose

To evaluate the technical feasibility of microwave ablation (MWA) for melanoma liver metastases with persistent high signal on magnetic resonance imaging (MRI).

Materials and Methods

Seven patients with 22 target melanoma liver metastases who underwent MWA treatment were included. All procedure-related complications were observed and recorded. One month after MWA, the imaging features of treated liver metastases and ablation zones with different MRI sequences were reviewed to evaluate technique efficacy. To verify the correctness of the evaluation, MRI scans during patient follow-up were reviewed and compared with images before MWA to analyze changes in treated liver metastases and ablation zones.

Results

All ablations were performed successfully, and there were no procedure-related major complications. After ablation, according to MRI T1-weighted pre-contrast or contrast sequences, the persistence of high signals from the treated lesions was noted inside the ablation zones of 19 lesions. Among these 19 lesions, 17 were completely covered by the ablation zones and were considered successfully treated, whereas two lesions were not completely covered and were considered unsuccessfully treated. Three lesions could not be detected on any MRI sequence after ablation and were also considered successfully treated. Finally, MRI scans during patient follow-up care verified these evaluations.

Conclusion

MWA is a technically feasible option for melanoma liver metastases with special imaging features on MRI.

Imaging of ocular melanoma metastasis

Ocular melanoma is the most common adult primary intraocular tumour. Although <1% of patients have metastatic disease at the time of initial diagnosis, most will develop metastasis at varying lengths of time. Metastasis surveillance is therefore critical in the follow-up of patients with ocular melanoma. Liver is the most common site of metastasis and prognosis is based on the treatment of liver metastasis. Hence, imaging of liver metastasis is vital. MRI is the most specific modality for imaging liver metastasis and is at least as sensitive as CT. Extrahepatic metastasis such as retroperitoneal nodules and bone metastases are also better evaluated on MRI. Gadolinium-based contrast agents are extremely helpful for detecting liver lesions. In particular, newer hepatobiliary contrast agents which offer an additional hepatobiliary phase of excretion help in the detection of even tiny liver metastases. Diffusion-weighted imaging is helpful when an i.v. contrast cannot be administered. Treated lesions are also better evaluated with MRI. CT is useful for evaluating lung nodules, large liver metastasis or in patients in whom MRI is medically contraindicated. The disadvantage lies in its inability to detect small liver metastasis and the radiation dose involved. The lesions treated with iodized oil as part of chemoembolization procedures can be followed on CT. Ultrasound can be used only for detecting hepatic metastases. However, it is heavily operator dependent, technically challenging and time consuming especially in patients who are large. Extrahepatic metastasis cannot be seen on ultrasound. Its utility is primarily for the biopsy of liver lesions. Positron emission tomography (PET)-CT can detect lung nodules and large liver lesions but is insensitive to small liver lesions. Moreover, the high radiation dose is a major disadvantage.

Prospective study of surveillance testing for metastasis in 100 high-risk uveal melanoma patients

Despite advances in the local treatment of UM, half of patients develop metastases typically to the liver with poor survival. Microscopic complete surgical resection (R0) of liver metastases improves survival in high selected patients. Early identification of high-risk patients might allow detection of asymptomatic metastases, and increase R0 liver surgery rate. From October 2006 to December 2009, we conducted a prospective study to detect early minimal lesions with 6-monthly liver function tests (LFTs) and liver MRI in 100 high-risk patients. High risk was defined by primary tumor clinical or genomic criteria: thickness>8mm or diameter>15 mm, or extra-scleral extension, or monosomy 3 by FISH or aCGH. With a median follow-up of 49 months, the 5-year metastasis-free survival and overall survival were 47 and 33%, respectively. Of the 60 patients who became metastatic, 50 (83%) had exclusive liver metastasis. LFTs screening had no sufficient accurary, but biannual MRI showed high predictive value to detect metastasis and select patients eligible for curative surgery: 25/50 underwent laparotomy and among them, 8/25 (32%) had a R0 surgery. Median survival after metastasis was 14 months, mean survival reached 40 months in the R0 resected population. Six-monthly liver MRI screening is recommended in patients with large tumors or genomic high risk in order to detect early patient candidates to complete resection of liver metastases.

Progress in the management of patients with uveal melanoma. The 2012 Ashton Lecture

Uveal melanomas are diverse in their clinical features and behaviour. More than 90% involve the choroid, the remainder being confined to the ciliary body and iris. Most patients experience visual loss and more than a third require enucleation, in some cases because of pain. Diagnosis is based on slit-lamp biomicroscopy and/or ophthalmoscopy, with ultrasonography, autofluorescence photography, and/or biopsy in selected cases. Conservation of the eye with useful vision has improved with advances in brachytherapy, proton beam radiotherapy, endoresection, exoresection, transpupillary thermotherapy, and photodynamic therapy. Despite ocular treatment, almost 50% of patients develop metastatic disease, which occurs almost exclusively in patients whose tumour shows chromosome 3 loss and/or class 2 gene expression profile. When the tumour shows such lethal genetic changes, the survival time depends on the anatomical stage and the histological grade of malignancy. Prognostication has improved as a result of progress in multivariate analysis including all the major risk factors. Screening for metastases is more sensitive as a consequence of advances in liver scanning with magnetic resonance imaging and other methods. More patients with metastases are living longer, benefiting from therapies such as: partial hepatectomy; radiofrequency ablation; ipilumumab immunotherapy; selective internal radiotherapy; intra-hepatic chemotherapy, possibly with isolated liver perfusion; and systemic chemotherapy. There is scope for improvement in the detection of uveal melanoma so as to maximise any opportunities for conserving the eye and vision, as well as preventing metastatic spread. Patient management has been enhanced by the formation of multidisciplinary teams in specialised ocular oncology centres.

(18)F-fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging in patients with liver metastases from uveal melanoma: results from a pilot study

PURPOSE

(18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and MRI are used for detecting liver metastases from uveal melanoma. The introduction of new treatment options in clinical trials might benefit from early response assessment. Here, we determine the value of FDG-PET/CT with respect to MRI at diagnosis and its potential for monitoring therapy.

MATERIAL AND METHODS

Ten patients with biopsy-proven liver metastases of uveal melanoma enrolled in a randomized phase III trial (NCT00110123) underwent both FDG-PET coupled with unenhanced CT and gadolinium-diethylene triamine pentaacetic acid-enhanced liver MRI within 4 weeks. FDG-PET and MRI were evaluated blindly and then compared using the ratio of lesion to normal liver parenchyma PET-derived standardized uptake value (SUV). The influence of lesion size and response to chemotherapy were studied.

RESULTS

Overall, 108 liver lesions were seen: 34 (31%) on both modalities (1-18 lesions/patient), four (4%) by PET/CT only, and 70 (65%) by MRI only. SUV correlated with MRI lesion size (r=0.81, P<0.0001). PET/CT detected 26 of 33 (79%) MRI lesions of more than or equal to 1.2 cm, whereas it detected only eight of 71 (11%) lesions of less than 1.2 cm (P<0.0001). MRI lesions without PET correspondence were small (0.6±0.2 vs. 2.1±1.1 cm, P<0.0001). During follow-up (six patients, 30 lesions), the ratio lesion-to-normal-liver SUV diminished in size-stable lesions (1.90±0.64-1.46±0.50, P<0.0001), whereas it increased in enlarging lesions (1.56±0.40-1.99±0.56, P=0.032).

CONCLUSION

MRI outweighs PET/CT for detecting small liver metastases. However, PET/CT detected at least one liver metastasis per patient and changes in FDG uptake not related to size change, suggesting a role in assessing early therapy response.

Surveillance testing for metastasis from primary uveal melanoma and effect on patient survival

PURPOSE

To evaluate the quality of evidence about effectiveness of regular periodic surveillance testing for metastasis in patients with primary uveal melanoma (PUM) following treatment of the primary tumor in prolonging survival.

DESIGN

Literature review and personal perspective of the authors.

METHODS

Identification and analysis of peer-reviewed articles on human PUM published between 1980 and 2009 that reported on "screening," "surveillance," or "systemic follow-up evaluation" for metastasis in patients with PUM following treatment of primary tumor.

RESULTS

Of 4222 identified articles, only 31 were considered satisfactory for inclusion in this study. Satisfactory articles reported levels of specific biomarkers when metastasis was first confirmed (14), percentage of patients with abnormal results on surveillance testing (13), values of diagnostic markers (eg, sensitivity, specificity) associated with evaluated components of a surveillance regimen (7), survival time after first detection of metastasis from primary uveal melanoma (7), total survival time after initial diagnosis or initial treatment of primary uveal melanoma (3), percentage of patients whose metastatic tumors were detected by presymptomatic testing (5), surveillance regimens employed by different groups (1), and relationship with generally accepted clinical and histopathologic prognostic factors for primary uveal melanoma metastasis (1). However, none of these articles reported survival times of comparable subgroups of patients in which regular periodic surveillance for metastasis vs no surveillance was performed.

CONCLUSION

Available evidence from the peer-reviewed literature does not provide any compelling evidence of survival benefit for any regimen or frequency of surveillance for metastasis relative to no such testing. In view of this, advisability of periodic surveillance for metastasis in routine clinical practice must be questioned.

[Hepatic cysts: diagnosis and management]

Cystic lesions of the liver are common and usually benign. The most frequent lesion is simple hepatic cyst: typical imaging findings make their diagnosis easy and they require no treatment. Complicated hepatic cysts (i.e., compression, hemorrhage, infection) have more variable imaging findings making diagnosis more difficult; they may evoke other diagnoses. Asymptomatic hepatic cysts do not require any treatment or follow-up. Symptomatic cysts may benefit from simple follow-up or may be treated by laparoscopic fenestration or alcohol sclerotherapy. The differential diagnosis of complicated hepatic cysts includes cystadenoma, cystadenocarcinoma, hydatid cyst, or cystic metastasis; surgical resection is usually indicated for these lesions.