Preoperative imaging for early-stage cutaneous melanoma: predictors, usage, and utility at a single institution

A comprehensive analysis of metastatic disease following surgery for clinically localized cutaneous melanoma

BACKGROUND

The National Comprehensive Cancer Network considers "baseline staging" (whole body computed tomography or positron emission tomography scans with or without brain magnetic resonance imaging scans) for all patients with asymptomatic melanoma who had a positive sentinel lymph node biopsy result. The true yield of these workups is unknown.

METHODS

We created cohorts of adult patients with malignant melanoma using the National Cancer Database (2012-2020) to mimic 3 common scenarios: 1) clinically node-negative disease, with positive sentinel lymph node biopsy results; 2) clinically node-negative disease, with negative sentinel lymph node biopsy results; and 3) clinically node-positive disease, with confirmed lymph node metastases. Multivariable regression, supervised decision trees, and nomograms were constructed to assess the risk of metastases based on key features.

RESULTS

In total, 10 371 patients were in scenario 1, 55 172 were in scenario 2, and 4012 were in scenario 3. The proportion of patients with any metastatic disease (brain metastases) were as follows: 1.4% (0.3%) in scenario 1, 0.3% (<0.1%) in scenario 2, and 11.6% (1.6%) in scenario 3. On multivariable regression, Breslow depth greater than 4, ulceration, and lymphovascular invasion were associated with greater risk of metastatic disease. A supervised decision tree for patients in scenarios 1 and 2 found that the only groups with more than 2% risk of metastases were groups with T4 tumors or T2/T3 tumors with ulceration and lymphovascular invasion. Most groups had a negligible risk (<0.1%) of brain metastases.

CONCLUSION

This study is the first large analysis to guide the use of imaging for cutaneous melanoma. Among patients with clinically node negative disease, metastatic disease is uncommon, and brain metastases are exceedingly rare. Further investigation could promote a tailored approach to metastatic workups guided by individual risk factors.

A Preliminary Study for Quantitative Assessment with HFUS (High- Frequency Ultrasound) of Nodular Skin Melanoma Breslow Thickness in Adults Before Surgery: Interdisciplinary Team Experience

Background:

Cutaneous melanoma is one of the most severe skin diseases. Nodular melanoma is the second melanoma subtype in order of frequency. The prognosis of skin melanoma depends on the vertical growth of the tumor (Breslow index). For this measurement, excisional biopsy is strongly recommended. This is, however, an invasive procedure and may cause damage to the lymphatic drainage system. The HFUS system, , can be extremely useful for determining tumor thickness in the preoperative phase, given its high resolution capacity. The aim of this preliminary study is to define the role of HFUS for the nodular skin melanoma Breslow thickness in adults before surgery by making a comparison with histological features.

Methods:

In this study, 14 melanocytic lesions (8 male and 6 female) were evaluated with dermatoscopic clinical features strongly indicative of nodular melanoma. Out of these, excisional biopsy of 7 lesions was requested. The ultrasounds were performed preoperatively. The images were acquired through the first ultrasound scanner with ultra-high frequency probes (range from 50MHz to 70 MHz) available on the market under the EEC mark (Vevo "MD, FUJIFILM Visual Sonics, Amsterdam, the Netherlands) equipped with a linear probe of 50-70 MHz.

Results:

From the ultrasonographic analysis of 14 nodular melanoma thickness was determined for the presence of two hyperechogenic laminae, separated by a hypo / anechoic space. The twelve lesions were in situ while the other two lesions showed ultrasonography for example; the satellite lesions (less than two centimeters from the primary lesion) and in transit (localizable to more than two centimeters from the primary lesion). Four of these lesions were ulcerated. A comparsion was made the 7 lesions on between the thickness calculated with this method, and that obtained on the bioptic piece. The presence of a positive concordance has been evident in all of the cases.

Conclusions:

If further studies are needed to support its widespread clinical use, its is believed that, in expert hands and with an interdisciplinary team, HFUS is already capable to reliably calculate a Breslow index in a large majority of patients with cutaneous 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.

Overuse of Health Care Services in the Management of Cancer: A Systematic Review

BACKGROUND

Overuse, the provision of health services for which harms outweigh the benefits, results in suboptimal patient care and may contribute to the rising costs of cancer care. We performed a systematic review of the evidence on overuse in oncology.

METHODS

We searched Medline, EMBASE, the Cochrane Library, Web of Science, SCOPUS databases, and 2 grey literature sources, for articles published between December 1, 2011 and March 10, 2017. We included publications from December 2011 to evaluate the literature since the inception of the ABIM Foundation's Choosing Wisely initiative in 2012. We included original research articles quantifying overuse of any medical service in patients with a cancer diagnosis when utilizing an acceptable standard to define care appropriateness, excluding studies of cancer screening. One of 4 investigator reviewed titles and abstracts and 2 of 4 reviewed each full-text article and extracted data. Methodology used PRISMA guidelines.

RESULTS

We identified 59 articles measuring overuse of 154 services related to imaging, procedures, and therapeutics in cancer management. The majority of studies addressed adult or geriatric patients (98%) and focused on US populations (76%); the most studied services were diagnostic imaging in low-risk prostate and breast cancer. Few studies evaluated active cancer therapeutics or interventions aimed at reducing overuse. Rates of overuse varied widely among services and among studies of the same service.

CONCLUSIONS

Despite recent attention to overuse in cancer, evidence identifying areas of overuse remains limited. Broader investigation, including assessment of active cancer treatment, is critical for identifying improvement targets to optimize value in cancer care.

Assessment of Cutaneous Melanoma by Use of Very- High-Frequency Ultrasound and Real-Time Elastography

OBJECTIVE

The primary objective of this study was to evaluate the usefulness of very-high-frequency ultrasound as tool for assessment of skin melanoma by investigation of the correlation between the ultrasound measurement of the thickness of a melanoma and the histopathologically measured Breslow index. The secondary objective was to assess the potential role of real-time elastography in the preoperative evaluation of skin melanoma.

SUBJECTS AND METHODS

The study included 42 cutaneous melanoma lesions in 39 adult subjects examined in the division of ultrasound of a department of radiology between September 2011 and January 2015. Gray-scale sonographic features at 40 MHz (thickness, echogenicity, contour) and real-time strain elastographic (qualitative and semiquantitative, strain ratio) characteristics were evaluated and compared with the pathologic results.

RESULTS

The melanoma lesions had a homogeneous hypoechoic appearance with a regular contour and stiff or medium consistency. The mean difference between Breslow index and ultrasound thickness was -0.05 mm (95% CI, -0.24 to 0.13 mm), sustaining the absence of significant differences between these two measurements. A strong relation was identified between real-time elastographic appearance and strain ratio for the relations between lesion and hypodermis and between lesion and neighboring dermis (p < 0.002) or hypodermis.

CONCLUSION

Our study showed that very-high-frequency ultrasound and real-time elastography can be useful examinations for comprehensive preoperative evaluation of cutaneous melanoma.

Yield of Computed Tomography at Baseline Staging of Melanoma

BACKGROUND

Current guidelines call for baseline imaging only for very high-risk (T4b) primary cutaneous melanomas.

OBJECTIVES

To estimate the frequency of computed tomography (CT) at baseline staging of primary cutaneous melanoma and the diagnostic yield of CT; and to describe the types and frequencies of incidentaloma findings.

MATERIAL AND METHODS

Cross-sectional study of cutaneous melanoma cases (tumor classifications Tis to T4bN0M0) attended between 2008 and 2014 in a specialized melanoma unit. Reports of CT scans performed during baseline staging were reviewed to determine the frequency of positive scan results, incidentaloma findings, unit cost for detection of metastasis, and factors associated with the decision to order CT.

RESULTS

CT results were available for 310 of the 419 patients included (73.99%). The tumor classifications were as follows: Tis, 17; T1, 137; T2, 71; T3, 48; and T4, 37. The CT results were negative in 81.61%, and incidentalomas were found in 18.06%. Additional primary tumors were found in 2 patients (0.64%), and metastasis was identified in one patient (0.32%). The cost of finding the case of metastasis was €71,234.90. A T2 tumor classification (odds ratio [OR], 8.73) and age under 70 years (OR, 3.53) were associated with greater likelihood of CT being ordered. Excision of the primary tumor in the melanoma unit (OR, 0.08) was associated with less likelihood of ordering CT.

CONCLUSIONS

The results for this patient series support current recommendations restricting CT at baseline to cases where there is high risk of metastasis (stagesiiC-iii).

Imaging malignant melanoma with (18)F-5-FPN

PURPOSE

Radiolabelled benzamides are attractive candidates for targeting melanoma because they bind to melanin and exhibit high tumour uptake and retention. (18)F-5-Fluoro-N-(2-[diethylamino]ethyl)picolinamide ((18)F-5-FPN), a benzamide analogue, was prepared and its pharmacokinetics and binding affinity evaluated both in vitro and in vivo to assess its clinical potential in the diagnosis and staging of melanoma.

METHODS

(18)F-5-FPN was prepared and purified. Its binding specificity was measured in vitro in two different melanoma cell lines, one pigmented (B16F10 cells) and one nonpigmented (A375m cells), and in vivo in mice xenografted with the same cell lines. Dynamic and static PET images using (18)F-5-FPN were obtained in the tumour-bearing mice, and the static images were also compared with those acquired with (18)F-FDG. PET imaging with (18)F-5-FPN was also performed in B16F10 tumour-bearing mice with lung metastases.

RESULTS

(18)F-5-FPN was successfully prepared with radiochemical yields of 5 - 10 %. Binding of (18)F-5-FPN to B16F10 cells was much higher than to A375m cells. On dynamic PET imaging B16F10 tumours were visible about 1 min after injection of the tracer, and the uptake gradually increased over time. (18)F-5-FPN was rapidly excreted via the kidneys. B16F10 tumours were clearly visible on static images acquired 1 and 2 h after injection, with high uptake values of 24.34 ± 6.32 %ID/g and 16.63 ± 5.41 %ID/g, respectively, in the biodistribution study (five mice). However, there was no visible uptake by A375m tumours. (18)F-5-FPN and (18)F-FDG PET imaging were compared in B16F10 tumour xenografts, and the tumour-to-background ratio of (18)F-5-FPN was ten times higher than that of (18)F-FDG (35.22 ± 7.02 vs. 3.29 ± 0.53, five mice). (18)F-5-FPN PET imaging also detected simulated lung metastases measuring 1 - 2 mm.

CONCLUSION

(18)F-5-FPN specifically targeted melanin in vitro and in vivo with high retention and affinity and favourable pharmacokinetics. (18)F-5-FPN may be an ideal molecular probe for melanoma diagnosis and staging.

Follow-up in patients with low-risk cutaneous melanoma: is it worth it?

Follow-up examinations in melanoma aim to detect recurrences or secondary melanomas in an early phase of development. Follow-up guidelines that have been developed in many European countries, the USA and Australia show varying recommendations and are controversial, especially in patients with melanomas of 1.0 mm tumor thickness or less. This group contains 50-70% of all melanoma patients and the majority is unlikely to develop recurrences. On the other hand, within this entity, subgroups at higher risk for recurrences can be defined who require a more intense follow-up. This article discusses recommendations for the frequency, duration and costs of follow-up in low-risk melanoma patients. Patient preferences are addressed and a risk-adapted follow-up scheme is proposed.