Acral malignant melanoma; emphasis on the primary metastasis and the usefulness of preoperative ultrasound for sentinel lymph node metastasis

This study aimed to evaluate the most common primary metastatic location of acral malignant melanoma and to evaluate the usefulness of preoperative ultrasound for sentinel lymph node metastasis. Ninety-eight Korean acral malignant melanoma patients were enrolled. Acral malignant melanoma was present in 76 lower limbs and in 22 upper limbs. The most common origin location was the sole (33.7%). The most common location of primary metastasis was loco-regional recurrence (22/34, 64.7%). The sensitivity, specificity, positive predictive value, and negative predictive value of preoperative sentinel lymph node ultrasound was 29.1%, 94.6%, 63.6%, and 80.5%, respectively. We postulate the unusefulness of preoperative ultrasound for sentinel lymph node metastasis in acral malignant melanoma.

Ultrasound, CT, MRI, or PET-CT for staging and re-staging of adults with cutaneous melanoma

BACKGROUND

Melanoma is one of the most aggressive forms of skin cancer, with the potential to metastasise to other parts of the body via the lymphatic system and the bloodstream. Melanoma accounts for a small percentage of skin cancer cases but is responsible for the majority of skin cancer deaths. Various imaging tests can be used with the aim of detecting metastatic spread of disease following a primary diagnosis of melanoma (primary staging) or on clinical suspicion of disease recurrence (re-staging). Accurate staging is crucial to ensuring that patients are directed to the most appropriate and effective treatment at different points on the clinical pathway. Establishing the comparative accuracy of ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET)-CT imaging for detection of nodal or distant metastases, or both, is critical to understanding if, how, and where on the pathway these tests might be used.

OBJECTIVES

Primary objectivesWe estimated accuracy separately according to the point in the clinical pathway at which imaging tests were used. Our objectives were:• to determine the diagnostic accuracy of ultrasound or PET-CT for detection of nodal metastases before sentinel lymph node biopsy in adults with confirmed cutaneous invasive melanoma; and• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for whole body imaging in adults with cutaneous invasive melanoma:○ for detection of any metastasis in adults with a primary diagnosis of melanoma (i.e. primary staging at presentation); and○ for detection of any metastasis in adults undergoing staging of recurrence of melanoma (i.e. re-staging prompted by findings on routine follow-up).We undertook separate analyses according to whether accuracy data were reported per patient or per lesion.Secondary objectivesWe sought to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for whole body imaging (detection of any metastasis) in mixed or not clearly described populations of adults with cutaneous invasive melanoma.For study participants undergoing primary staging or re-staging (for possible recurrence), and for mixed or unclear populations, our objectives were:• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of nodal metastases;• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of distant metastases; and• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of distant metastases according to metastatic site.

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception up to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We studied reference lists as well as published systematic review articles.

SELECTION CRITERIA

We included studies of any design that evaluated ultrasound (with or without the use of fine needle aspiration cytology (FNAC)), CT, MRI, or PET-CT for staging of cutaneous melanoma in adults, compared with a reference standard of histological confirmation or imaging with clinical follow-up of at least three months' duration. We excluded studies reporting multiple applications of the same test in more than 10% of study participants.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2)). We estimated accuracy using the bivariate hierarchical method to produce summary sensitivities and specificities with 95% confidence and prediction regions. We undertook analysis of studies allowing direct and indirect comparison between tests. We examined heterogeneity between studies by visually inspecting the forest plots of sensitivity and specificity and summary receiver operating characteristic (ROC) plots. Numbers of identified studies were insufficient to allow formal investigation of potential sources of heterogeneity.

MAIN RESULTS

We included a total of 39 publications reporting on 5204 study participants; 34 studies reporting data per patient included 4980 study participants with 1265 cases of metastatic disease, and seven studies reporting data per lesion included 417 study participants with 1846 potentially metastatic lesions, 1061 of which were confirmed metastases. The risk of bias was low or unclear for all domains apart from participant flow. Concerns regarding applicability of the evidence were high or unclear for almost all domains. Participant selection from mixed or not clearly defined populations and poorly described application and interpretation of index tests were particularly problematic.The accuracy of imaging for detection of regional nodal metastases before sentinel lymph node biopsy (SLNB) was evaluated in 18 studies. In 11 studies (2614 participants; 542 cases), the summary sensitivity of ultrasound alone was 35.4% (95% confidence interval (CI) 17.0% to 59.4%) and specificity was 93.9% (95% CI 86.1% to 97.5%). Combining pre-SLNB ultrasound with FNAC revealed summary sensitivity of 18.0% (95% CI 3.58% to 56.5%) and specificity of 99.8% (95% CI 99.1% to 99.9%) (1164 participants; 259 cases). Four studies demonstrated lower sensitivity (10.2%, 95% CI 4.31% to 22.3%) and specificity (96.5%,95% CI 87.1% to 99.1%) for PET-CT before SLNB (170 participants, 49 cases). When these data are translated to a hypothetical cohort of 1000 people eligible for SLNB, 237 of whom have nodal metastases (median prevalence), the combination of ultrasound with FNAC potentially allows 43 people with nodal metastases to be triaged directly to adjuvant therapy rather than having SLNB first, at a cost of two people with false positive results (who are incorrectly managed). Those with a false negative ultrasound will be identified on subsequent SLNB.Limited test accuracy data were available for whole body imaging via PET-CT for primary staging or re-staging for disease recurrence, and none evaluated MRI. Twenty-four studies evaluated whole body imaging. Six of these studies explored primary staging following a confirmed diagnosis of melanoma (492 participants), three evaluated re-staging of disease following some clinical indication of recurrence (589 participants), and 15 included mixed or not clearly described population groups comprising participants at a number of different points on the clinical pathway and at varying stages of disease (1265 participants). Results for whole body imaging could not be translated to a hypothetical cohort of people due to paucity of data.Most of the studies (6/9) of primary disease or re-staging of disease considered PET-CT, two in comparison to CT alone, and three studies examined the use of ultrasound. No eligible evaluations of MRI in these groups were identified. All studies used histological reference standards combined with follow-up, and two included FNAC for some participants. Observed accuracy for detection of any metastases for PET-CT was higher for re-staging of disease (summary sensitivity from two studies: 92.6%, 95% CI 85.3% to 96.4%; specificity: 89.7%, 95% CI 78.8% to 95.3%; 153 participants; 95 cases) compared to primary staging (sensitivities from individual studies ranged from 30% to 47% and specificities from 73% to 88%), and was more sensitive than CT alone in both population groups, but participant numbers were very small.No conclusions can be drawn regarding routine imaging of the brain via MRI or CT.

AUTHORS' CONCLUSIONS

Review authors found a disappointing lack of evidence on the accuracy of imaging in people with a diagnosis of melanoma at different points on the clinical pathway. Studies were small and often reported data according to the number of lesions rather than the number of study participants. Imaging with ultrasound combined with FNAC before SLNB may identify around one-fifth of those with nodal disease, but confidence intervals are wide and further work is needed to establish cost-effectiveness. Much of the evidence for whole body imaging for primary staging or re-staging of disease is focused on PET-CT, and comparative data with CT or MRI are lacking. Future studies should go beyond diagnostic accuracy and consider the effects of different imaging tests on disease management. The increasing availability of adjuvant therapies for people with melanoma at high risk of disease spread at presentation will have a considerable impact on imaging services, yet evidence for the relative diagnostic accuracy of available tests is limited.

Gamma probe and ultrasound guided fine needle aspiration cytology of the sentinel node (GULF) trial - overview of the literature, pilot and study protocol

BACKGROUND

Sentinel node (SN) biopsy (SNB) detects clinically occult metastases of breast cancer and melanoma in 20-30%. Wound infections, seroma and lymph edema occur in up to 10%. Targeted ultrasound (US) of the SN, (with fine needle aspiration cytology (FNAC) if appropriate) has been investigated as a minimally invasive alternative, but reported sensitivity rates are too low to replace SNB. Our hypothesis is that the use of a handheld gamma probe concomitant with US may improve sensitivity. Our aim is to provide an overview of the current literature on preoperative nodal staging of clinical N0 melanoma patients, report on a pilot, and present a study protocol for a minimally invasive alternative to the SNB: Gamma probe and Ultrasound guided Fine needle aspiration cytology of the sentinel node (GULF trial).

METHODS

The GULF trial is a multicenter open single arm observational trial. Newly diagnosed cT1b-4N0M0 cutaneous melanoma or cT1-3N0M0 breast cancer patients, aged >18 years, presenting for SNB are eligible. 120 patients will be included for preoperative targeted gamma probe guided US and FNAC of the SN. Afterwards all patients proceed to surgical SNB. Primary endpoint is the sensitivity of FNAC. Secondary endpoints include SN identification rate and the histopathological compatibility of Core Needle Biopsy and FNAC vs. SNB. Secondary endpoints were investigated in a pilot with 10 FNACs and marker placements, and 10 FNACs combined with Core Needle Biopsy.

RESULTS

A pilot in 20 patients showed that SN identification rate was 90%, supporting the feasibility of this technique.

DISCUSSION

There is broad experience with US (in combination with FNAC) prior to SNB, but sensitivity and specificity are too low to completely abandon SNB. Promising alternative techniques potentially will replace SNB in the future but more evidence is needed in the form of prospective studies. Accurate identification of the SN for US-FNAC has been proven feasible in our pilot. When adequate sensitivity can be reached, US-FNAC provides a minimally invasive alternative for the surgical SNB procedure.

TRIAL REGISTRATION

The GULF trial is registered in the Netherlands Trial Registry (NTR), ID: NRT5193 . May 1st 2015.

[High frequency ultrasound]

Diagnostic ultrasound has become a standard procedure in clinical dermatology. Devices with intermediate high frequencies of 7.5-15 MHz are used in dermato-oncology for the staging and postoperative care of skin tumor patients and in angiology for improved vessel diagnostics. In contrast, the high frequency ultrasound systems with 20-100 MHz probes offer a much higher resolution, yet with a lower penetration depth of about 1 cm. The main indications are the preoperative measurements of tumor thickness in malignant melanoma and other skin tumors and the assessment of inflammatory and soft tissue diseases, offering information on the course of these dermatoses and allowing therapy monitoring. This article gives an overview on technical principles, devices, mode of examination, influencing factors, interpretation of the images, indications but also limitations of this technique.

Enhanced sonographic imaging to diagnose lymph node metastasis: importance of blood vessel volume and density

Lymph node size is an important variable in ultrasound diagnosis of lymph node metastasis. However, the size criterion often leads to oversight of tumor-positive lymph nodes within the range of "normal" size, such that more accurate diagnostic criteria for lymph node metastasis are required. In this study, we show how diagnosis of lymph node metastasis can be improved by evaluating changes in blood vessel volume and density using a novel contrast-enhanced high-frequency ultrasound (CE-HFUS) system with Sonazoid. An MRL/MpJ-lpr/lpr (MRL/lpr) mouse model of lymph node metastasis was used in which lymph nodes are similar in size to humans. Metastasis via lymphatic vessels to proper axillary lymph nodes (proper ALN) was induced by injection of tumor cells into the subiliac lymph nodes. Within 21 days of injection, significant increases in blood vessel volume and density, but no increases in the size of the proper ALNs, were observed. The increase in blood vessel density was confirmed with immunohistochemical analysis and was positively related to tumor cell proliferation as measured using bioluminescence imaging. Together, our results showed that alterations in blood vessel volume and density precede alterations in lymph node size in the early stages of lymph node metastasis. Detection of these changes by ultrasonography may offer new criteria for early diagnosis of lymph node metastasis.

Role of high-resolution ultrasound and PET/CT imaging for preoperative characterization of sentinel lymph nodes in cutaneous melanoma

The purpose of our study was the comparison of high-resolution ultrasound (HRUS) and positron emission tomography combined with computerised tomography (PET/CT) in the preoperative characterization and identification of subclinical nodal metastases focusing on sentinel lymph nodes (SLN) in melanoma patients. Patients with cutaneous melanoma (CM) who received sentinel lymph node biopsy at the Department of Dermatology and Allergy, University of Bonn, between January 2009 and January 2011 had been evaluated with a retrospective computer-aided search concerning preoperative staging procedures. A combination of PET/CT and HRUS had been performed preoperatively in 20 of 123 patients. A total of 59 SLNs had been removed in those 20 patients followed by histopathologic examination. HRUS correctly identified two of 17 positive SLNs whereas PET/CT imaging identified none. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of HRUS were 11.8 % (95 % confidence interval [CI] = 3.3-34.3), 100 % (95 % CI = 91.6-100.0), 100.0 % (95 % CI = 34.2-100.0), and 73.7 % (95 % CI = 61.0-83.3), respectively. On the basis of this limited study cohort, HRUS had a better value than PET/CT in preoperative identification of positive SLNs, suggesting a possible diagnostic superiority of HRUS in general characterization of peripheral nodal disease in CM.

Influence of sporting activity and smoking on peripheral lymph nodes in patients with melanoma analyzed by high-resolution ultrasound

BACKGROUND

The sonographic examination of peripheral lymph nodes (LNs) plays an important role in the preoperative treatment and in the follow-up of patients with melanoma.

OBJECTIVE

A prospective study including 200 consecutive patients with a history of invasive cutaneous melanoma was performed at the Department of Dermatology and Allergy, University of Bonn, Germany, to examine the influence of sporting activity, physical workload, interferon alfa therapy, smoking habits, and infections of the upper respiratory tract on morphology and number of LNs analyzed by high-resolution ultrasound.

METHODS

Between May 2010 and June 2011, 106 men and 94 women (mean age 51.1 ± 12.8 years) were included in this study. During their follow-up visits for cutaneous melanoma, high-resolution ultrasound examination of cervical, axillary, and inguinal LN regions were performed. LN diameters and volumes were measured and correlated with the above given factors.

RESULTS

Sports-active patients had more LNs in inguinal regions, a higher volume and a larger LN diameter, and a higher maximum width of the hypoechoic LN margin in comparison with the nonactive patients. Patients with a hard physical workload in their occupations had a significantly higher volume of the biggest LN. Compared with nonsmoking patients smokers presented higher values in the total quantity of the LNs, in the greatest volume of LN, and in the greatest diameter of LN in the cervical regions. The other factors had no significant influence on the LN parameters.

LIMITATIONS

Our study population was too small to comment on influencing factors in more detail especially the influences of different sporting activities or smoking habits.

CONCLUSION

Sporting activity, physical workload, and smoking habits as associated cofactors influencing sonomorphologic aspects in patients with cutaneous melanoma should always be considered.